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<img alt="Erlang logo" src="../../../doc/erlang-logo.png"><br><small><a href="users_guide.html">User's Guide</a><br><a href="index.html">Reference Manual</a><br><a href="release_notes.html">Release Notes</a><br><a href="../pdf/erts-5.9.3.1.pdf">PDF</a><br><a href="../../../doc/index.html">Top</a></small><p><strong>Erlang Run-Time System Application (ERTS)</strong><br><strong>Release Notes</strong><br><small>Version 5.9.3.1</small></p>
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<li title="Erts 5.9.3.1"><a href="notes.html#id61630">Erts 5.9.3.1</a></li>
<li title="Erts 5.9.3"><a href="notes.html#id61669">Erts 5.9.3</a></li>
<li title="Erts 5.9.2"><a href="notes.html#id62535">Erts 5.9.2</a></li>
<li title="Erts 5.9.1.2"><a href="notes.html#id67647">Erts 5.9.1.2</a></li>
<li title="Erts 5.9.1.1"><a href="notes.html#id67681">Erts 5.9.1.1</a></li>
<li title="Erts 5.9.1"><a href="notes.html#id128534">Erts 5.9.1</a></li>
<li title="Erts 5.9.0.1"><a href="notes.html#id128838">Erts 5.9.0.1</a></li>
<li title="Erts 5.9"><a href="notes.html#id128886">Erts 5.9</a></li>
<li title="Erts 5.8.5"><a href="notes.html#id129687">Erts 5.8.5</a></li>
<li title="Erts 5.8.4"><a href="notes.html#id130246">Erts 5.8.4</a></li>
<li title="Erts 5.8.3.2"><a href="notes.html#id130900">Erts 5.8.3.2</a></li>
<li title="Erts 5.8.3.1"><a href="notes.html#id130937">Erts 5.8.3.1</a></li>
<li title="Erts 5.8.3"><a href="notes.html#id130997">Erts 5.8.3</a></li>
<li title="Erts 5.8.2"><a href="notes.html#id131413">Erts 5.8.2</a></li>
<li title="Erts 5.8.1.2"><a href="notes.html#id131898">Erts 5.8.1.2</a></li>
<li title="Erts 5.8.1.1"><a href="notes.html#id99120">Erts 5.8.1.1</a></li>
<li title="Erts 5.8.1"><a href="notes.html#id99152">Erts 5.8.1</a></li>
<li title="Erts 5.8"><a href="notes.html#id100010">Erts 5.8</a></li>
<li title="Erts 5.7.5.2"><a href="notes.html#id101018">Erts 5.7.5.2</a></li>
<li title="Erts 5.7.5.1"><a href="notes.html#id101050">Erts 5.7.5.1</a></li>
<li title="Erts 5.7.5"><a href="notes.html#id101119">Erts 5.7.5</a></li>
<li title="Erts 5.7.4"><a href="notes.html#id102019">Erts 5.7.4</a></li>
<li title="Erts 5.7.3"><a href="notes.html#id102526">Erts 5.7.3</a></li>
<li title="Erts 5.7.2"><a href="notes.html#id103123">Erts 5.7.2</a></li>
<li title="Erts 5.7.1"><a href="notes.html#id103479">Erts 5.7.1</a></li>
<li title="Erts 5.7"><a href="notes.html#id103743">Erts 5.7</a></li>
<li title="Erts 5.6.5.1"><a href="notes.html#id104654">Erts 5.6.5.1</a></li>
<li title="Erts 5.6.5"><a href="notes.html#id104765">Erts 5.6.5</a></li>
<li title="Erts 5.6.4.2"><a href="notes.html#id105135">Erts 5.6.4.2</a></li>
<li title="Erts 5.6.4.1"><a href="notes.html#id105224">Erts 5.6.4.1</a></li>
<li title="Erts 5.6.4"><a href="notes.html#id105287">Erts 5.6.4</a></li>
<li title="Erts 5.6.3.3"><a href="notes.html#id105684">Erts 5.6.3.3</a></li>
<li title="Erts 5.6.3.2"><a href="notes.html#id105794">Erts 5.6.3.2</a></li>
<li title="Erts 5.6.3.1"><a href="notes.html#id105828">Erts 5.6.3.1</a></li>
<li title="Erts 5.6.3"><a href="notes.html#id105859">Erts 5.6.3</a></li>
<li title="Erts 5.6.2"><a href="notes.html#id106272">Erts 5.6.2</a></li>
<li title="Erts 5.6.1.1"><a href="notes.html#id106528">Erts 5.6.1.1</a></li>
<li title="Erts 5.6.1"><a href="notes.html#id106623">Erts 5.6.1</a></li>
<li title="Erts 5.6"><a href="notes.html#id107077">Erts 5.6</a></li>
<li title="Erts 5.5.5.5"><a href="notes.html#id108044">Erts 5.5.5.5</a></li>
<li title="Erts 5.5.5.4"><a href="notes.html#id108075">Erts 5.5.5.4</a></li>
<li title="Erts 5.5.5.3"><a href="notes.html#id108123">Erts 5.5.5.3</a></li>
<li title="Erts 5.5.5.2"><a href="notes.html#id108193">Erts 5.5.5.2</a></li>
<li title="Erts 5.5.5.1"><a href="notes.html#id108224">Erts 5.5.5.1</a></li>
<li title="Erts 5.5.5"><a href="notes.html#id108292">Erts 5.5.5</a></li>
<li title="Erts 5.5.4.3"><a href="notes.html#id108618">Erts 5.5.4.3</a></li>
<li title="Erts 5.5.4.2"><a href="notes.html#id108718">Erts 5.5.4.2</a></li>
<li title="Erts 5.5.4.1"><a href="notes.html#id108799">Erts 5.5.4.1</a></li>
<li title="Erts 5.5.4"><a href="notes.html#id108834">Erts 5.5.4</a></li>
<li title="Erts 5.5.3.1"><a href="notes.html#id109149">Erts 5.5.3.1</a></li>
<li title="Erts 5.5.3"><a href="notes.html#id109470">Erts 5.5.3</a></li>
<li title="Erts 5.5.2.2"><a href="notes.html#id109933">Erts 5.5.2.2</a></li>
<li title="Erts 5.5.2.1"><a href="notes.html#id109967">Erts 5.5.2.1</a></li>
<li title="Erts 5.5.2"><a href="notes.html#id110022">Erts 5.5.2</a></li>
<li title="Erts 5.5.1.1"><a href="notes.html#id110431">Erts 5.5.1.1</a></li>
<li title="Erts 5.5.1"><a href="notes.html#id110465">Erts 5.5.1</a></li>
<li title="ERTS 5.5"><a href="notes.html#id110826">ERTS 5.5</a></li>
<li title="ERTS 5.4.13"><a href="notes.html#id111349">ERTS 5.4.13</a></li>
<li title="ERTS 5.4.12"><a href="notes.html#id111567">ERTS 5.4.12</a></li>
<li title="ERTS 5.4.11"><a href="notes.html#id111679">ERTS 5.4.11</a></li>
<li title="ERTS 5.4.10"><a href="notes.html#id111831">ERTS 5.4.10</a></li>
<li title="ERTS 5.4.9.2"><a href="notes.html#id112028">ERTS 5.4.9.2</a></li>
<li title="ERTS 5.4.9.1"><a href="notes.html#id112073">ERTS 5.4.9.1</a></li>
<li title="ERTS 5.4.9"><a href="notes.html#id112109">ERTS 5.4.9</a></li>
<li title="ERTS 5.4.8"><a href="notes.html#id112276">ERTS 5.4.8</a></li>
<li title="ERTS 5.4.7"><a href="notes.html#id112476">ERTS 5.4.7</a></li>
<li title="ERTS 5.4.6"><a href="notes.html#id112564">ERTS 5.4.6</a></li>
<li title="ERTS 5.4.5"><a href="notes.html#id112724">ERTS 5.4.5</a></li>
<li title="ERTS 5.4.4"><a href="notes.html#id112881">ERTS 5.4.4</a></li>
<li title="ERTS 5.4.3"><a href="notes.html#id113104">ERTS 5.4.3</a></li>
<li title="ERTS 5.4.2.1"><a href="notes.html#id113230">ERTS 5.4.2.1</a></li>
<li title="ERTS 5.4.2"><a href="notes.html#id113266">ERTS 5.4.2</a></li>
<li title="ERTS 5.4.1"><a href="notes.html#id113330">ERTS 5.4.1</a></li>
</ul>
</li></ul>
</div></div>
<div id="content">
<div class="innertube">
<h1>1 ERTS Release Notes</h1>
<p>This document describes the changes made to the ERTS application.</p>
<h3><a name="id61630">1.1
Erts 5.9.3.1</a></h3>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
Create an erl_crash.dump if no heart exists and no
ERL_CRASH_DUMP_SECONDS is set (behaviour changed).</p>
<p>
Don't create an erl_crash.dump if heart do exists and no
ERL_CRASH_DUMP_SECONDS is set (behaviour not changed).</p>
<p>
This changes the behaviour back to the R15B02 default
considering if a beam was running with no heart.</p>
<p>
Own Id: OTP-10602</p>
</li>
</ul>
<h3><a name="id61669">1.2
Erts 5.9.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Fix linking in OpenBSD. (Thanks to Matthew Dempsky)</p>
<p>
Own Id: OTP-10395</p>
</li>
<li>
<p>
Fix bug causing fallback atomics to be used even though
healthy gcc atomics or libatomic_ops was detected.</p>
<p>
Own Id: OTP-10418</p>
</li>
<li>
<p>
Ensure 'erl_crash.dump' when asked for it. This will
change erl_crash.dump behaviour.</p>
<p>
* Not setting ERL_CRASH_DUMP_SECONDS will now terminate
beam immediately on a crash without writing a crash dump
file.</p>
<p>
* Setting ERL_CRASH_DUMP_SECONDS to 0 will also terminate
beam immediately on a crash without writing a crash dump
file, i.e. same as not setting ERL_CRASH_DUMP_SECONDS
environment variable.</p>
<p>
* Setting ERL_CRASH_DUMP_SECONDS to a negative value will
let the beam wait indefinitely on the crash dump file
being written.</p>
<p>
* Setting ERL_CRASH_DUMP_SECONDS to a positive value will
let the beam wait that many seconds on the crash dump
file being written.</p>
<p>
A positive value will set an alarm/timeout for restart
both in beam and in heart if heart is running.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-10422 Aux Id: kunagi-250 [161] </p>
</li>
<li>
<p>
Fix bug where MSVRT100.dll was not included in the
windows installer.</p>
<p>
Own Id: OTP-10481</p>
</li>
<li>
<p>In the expression
<span class="code"><<Bin/binary,...>></span>, if <span class="code">Bin</span> was
a bitstring with a size not a multiple of 8, either no
exception was generated or an incorrect exception was
generated. (Thanks to Adam Rutkowski for reporting this
bug.)</p>
<p>
Own Id: OTP-10524</p>
</li>
<li>
<p>
The runtime system could crash while scheduling a port
task. The port task was scheduled either due to an
external I/O event being triggered, a driver timeout
being triggered, or data being sent over a distribution
channel.</p>
<p>
Own Id: OTP-10556</p>
</li>
<li>
<p>
<span class="code">erlang:memory(ets)</span> erroneously included the size
of each ETS-table main structure twice.</p>
<p>
Own Id: OTP-10558</p>
</li>
<li>
<p>
Fix compile error in generated file hipe_amd64_bifs.S for
Solaris.</p>
<p>
Own Id: OTP-10577</p>
</li>
<li>
<p>
A faulty spec for process_info/2 could cause false
dialyzer warnings. The spec is corrected.</p>
<p>
Own Id: OTP-10584</p>
</li>
<li>
<p>
In very rare cases, the VM could crash if a garbage
collector was called while executing an appending bit
syntax instruction. The symptom was a core when
reallocating memory in the function erts_bs_append. The
garbage collector bug is now corrected.</p>
<p>
Own Id: OTP-10590</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Improve support for building and testing in embedded ppc
environments.</p>
<p>
Own Id: OTP-10265 Aux Id: kunagi-159
[daf97f67-5724-4812-a5b6-7e86990133d2-1] </p>
</li>
<li>
<p>
Due to a race condition on Windows, sometimes when
printing to standard output and then immediately
terminating erlang all data would not be printed. The
emulator now waits for all data to be printed before
exiting.</p>
<p>
Own Id: OTP-10325 Aux Id: kunagi-166
[dd72d0e2-3e76-4a51-8b56-7564e24eecae] </p>
</li>
<li>
<p>
The frequency with which sleeping schedulers are woken
due to outstanding memory deallocation jobs has been
reduced.</p>
<p>
Own Id: OTP-10476 Aux Id: OTP-10162 </p>
</li>
<li>
<p>
Clearer warnings about the dangers of misuse of <span class="bold_code"><a href="erl_nif.html#WARNING">native functions</a></span> and
<span class="bold_code"><a href="erl_driver.html#WARNING">drivers</a></span>
have been added to the documentation.</p>
<p>
Own Id: OTP-10557</p>
</li>
</ul>
<h3><a name="id62535">1.3
Erts 5.9.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Fix erl_prim_loader errors in handling of primary
archive. The following errors have been corrected:</p>
<p>
<ul> <li> If primary archive was named "xxx", then a
file in the same directory named "xxxyyy" would be
interpreted as a file named "yyy" inside the archive.
</li> <li> erl_prim_loader did not correctly create
and normalize absolute paths for primary archive and
files inside it, so unless given with exact same path
files inside the archive would not be found. E.g. if
escript was started as /full/path/to/xxx then
"./xxx/file" would not be found since erl_prim_loader
would try to match /full/path/to/xxx with
/full/path/to/./xxx. Same problem with ../. </li>
<li> Depending on how the primary archive was built,
erl_prim_loader:list_dir/1 would sometimes return an
empty string inside the file list. This was a virtual
element representing the top directory of the archive.
This has been removed. </li> </ul></p>
<p>
Thanks to Tuncer Ayaz and Shunichi Shinohara for
reporting and co-authoring corrections.</p>
<p>
Own Id: OTP-10071</p>
</li>
<li>
<p>Fix: Add port-I/O statistics for active once and true
and not only active false.</p>
<p>
Own Id: OTP-10073</p>
</li>
<li>
<p>
The 64-bit windows installer did not look in the right
directories for 64-bit version of Microsoft Visual C++
2010 Redistibutable Package and hence took the wrong
decision about having to install the redistributable
package if the 32-bit version was installed but not the
64-bit and vice versa. This bug has now been fixed
Furthermore the sub-installer for the redistributable
package is now run in silent mode if the erlang installer
is.</p>
<p>
Own Id: OTP-10096</p>
</li>
<li>
<p>
epmd would fail to start automatically when starting a
distributed erlang node installed in a location with a
whitespace in the path.</p>
<p>
Own Id: OTP-10106</p>
</li>
<li>
<p>
A more or less harmless bug that sometimes caused memory
deallocations to be delayed longer than intended has been
fixed.</p>
<p>
Own Id: OTP-10116</p>
</li>
<li>
<p>
Fix bug causing emulator crash when running HiPE on ARM.
Bug has existed since R15B.</p>
<p>
Own Id: OTP-10137</p>
</li>
<li>
<p> A bug regarding spaces in C function prototypes has
been fixed. (Thanks to Richard O'Keefe.) </p>
<p>
Own Id: OTP-10138</p>
</li>
<li>
<p>
Corrected dtrace pid length in message related probes.
(Thanks to Zheng Siyao)</p>
<p>
Own Id: OTP-10142</p>
</li>
<li>
<p>
Correct formating in exit error messages</p>
<p>
Ensure displayed sizes are not negative. (Thanks to
Michael Santos)</p>
<p>
Own Id: OTP-10148</p>
</li>
<li>
<p>
fix escript/primary archive reloading</p>
<p>
If the mtime of an escript/primary archive file changes
after being added to the code path, correctly reload the
archive and update the cache. (Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-10151</p>
</li>
<li>
<p>
Doc fix: link from erlang:now/0 to os:timestamp/0</p>
<p>
Sometimes os:timestamp/0 is more appropriate than
erlang:now/0. The documentation for the former has a link
to the latter; this patch adds a link in the other
direction to make os:timestamp/0 more visible. Thanks to
Magnus Henoch</p>
<p>
Own Id: OTP-10180</p>
</li>
<li>
<p>
The caret in the werl window (on Windows) could appear at
the wrong place after regaining focus. This is now
corrected.</p>
<p>
Own Id: OTP-10181</p>
</li>
<li>
<p>
Fix bug that in some cases could cause corrupted binaries
in ETS tables with <span class="code">compressed</span> option.</p>
<p>
Own Id: OTP-10182</p>
</li>
<li>
<p>
Fix use of "clever" mktime</p>
<p>
Commit 1eef765 introduced regression (conditional
_always_ evaluates to true) in which
erlang:localtime_to_universaltime/2 stopped working on
systems configured with timezone without DST (i.e. UTC)
on *BSD platforms: 1>
erlang:localtime_to_universaltime({{2012,1,1},{0,0,0}},
true). ** exception error: bad argument Thanks to Piotr
Sikora</p>
<p>
Own Id: OTP-10187</p>
</li>
<li>
<p>
Relocate bodies of DTrace probes to the statically-linked
VM.</p>
<p>
Due to various operating systems (in both the DTrace and
SystemTap worlds) not fully supporting DTrace probes (or
SystemTap-compatibility mode probes) in shared libraries,
we relocate those probes to the statically-linked virtual
machine. This could be seen as pollution of the pristine
VM by a (yet) experimental feature. However:</p>
<p>
1. This code can be eliminated completely by the C
preprocessor. 2. Leaving the probes in the dyntrace NIF
shared library simply does not work correctly on too many
platforms. *Many* thanks to Macneil Shonle at Basho for
assisting when my RSI-injured fingers gave out. (note:
Solaris 10 and FreeBSD 9.0-RELEASE can take a long time
to compile)</p>
<p>
Own Id: OTP-10189</p>
</li>
<li>
<p>
Fix bug in <span class="code">ets:test_ms/2</span> that could cause emulator
crash when using <span class="code">'$_'</span> in match spec.</p>
<p>
Own Id: OTP-10190</p>
</li>
<li>
<p>
Supplying a filename longer than the operating system
MAX_PATH to file:read_link/1 would cause a crash
(Segemntation fault/Critical Error) on all platforms.
This is now corrected.</p>
<p>
Own Id: OTP-10200</p>
</li>
<li>
<p>
If Perl was configured to interpret files as being
encoded in UTF-8, the build would crash in
<span class="code">make_preload</span>. (Thanks to Aaron Harnly for noticing
this issue.)</p>
<p>
Own Id: OTP-10201</p>
</li>
<li>
<p>
Fix the erlc -MP flag</p>
<p>
Because of a copy-and-paste error in erlc.c, the -MP flag
had the same effect as -MG. As a workaround, you had to
pass +makedep_phony to enable the MP option. This patch
makes -MP work as intended.</p>
<p>
Own Id: OTP-10211</p>
</li>
<li>
<p>
Allow mixed IPv4 and IPv6 addresses to sctp_bindx</p>
<p>
Also allow mixed address families to bind, since the
first address on a multihomed sctp socket must be bound
with bind, while the rest are to be bound using
sctp_bindx. At least Linux supports adding address of
mixing families. Make inet_set_faddress function
available also when HAVE_SCTP is not defined, since we
use it to find an address for bind to be able to mix ipv4
and ipv6 addresses. Thanks to Tomas Abrahamsson</p>
<p>
Own Id: OTP-10217</p>
</li>
<li>
<p>
Fix support for leap seconds-aware timezones</p>
<p>
erlang:universaltime_to_localtime is leap seconds-aware
(since 2008), however erlang:localtime_to_universaltime
is not, which gives surprising results on systems
configured with leap seconds-aware timezones: 1>
erlang:universaltime_to_localtime({{2012,1,1},{0,0,0}}).
{{2012,1,1},{0,0,0}} 2>
erlang:localtime_to_universaltime({{2012,1,1},{0,0,0}}).
{{2012,1,1},{0,0,24}} and completely breaks
calendar:local_time_to_universal_time_dst: 3>
calendar:local_time_to_universal_time_dst({{2011,1,1},{0,0,0}}).
[] Thanks to Piotr Sikora</p>
<p>
Own Id: OTP-10227</p>
</li>
<li>
<p>
erlsrv: gracefully stop emulator on Windows shutdown</p>
<p>
Windows will send the SERVICE_CONTROL_SHUTDOWN event to
the service control handler when shutting down the
system. Instead of ignoring the event, erlsrv will now
invoke the stop action. Likewise, the Erlang emulator
(and it's po drivers) must not quit upon reception of the
CTRL_SHUTDOWN_EVENT event in th console control handler.
Thanks to Jan Kloetzke</p>
<p>
Own Id: OTP-10228</p>
</li>
<li>
<p>
Fix dtrace bug in file rename operation.</p>
<p>
Own Id: OTP-10234</p>
</li>
<li>
<p>
Fix bug in memory management of driver port data locks
(PDL). In some cases PDLs could be deallocated before
<span class="code">ready_async</span> or <span class="code">async_free</span> callback was
called.</p>
<p>
Own Id: OTP-10249</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Add port and suspend options to lock-counter
profiling. (Thanks to Rick Reed)</p>
<p>
Own Id: OTP-10051</p>
</li>
<li>
<p>
Latency when using the active_once option in gen_tcp
communication is reduced.</p>
<p>
Own Id: OTP-10055 Aux Id: sto139 </p>
</li>
<li>
<p>Remove bit8 option support from inet</p>
<p>
Own Id: OTP-10056</p>
</li>
<li>
<p>
The OS Pid of a port program is now available by calling
erlang:port_info(Port,os_pid), Thanks to Matthias Lang
for the original patch.</p>
<p>
Own Id: OTP-10057</p>
</li>
<li>
<p>
Fix openpty usage in run_erl. </p>
<p>
Reopening a slave file descriptor which was closed
earlier could lead to a misbehaving connection. This has
now been remedied.</p>
<p>
Own Id: OTP-10076</p>
</li>
<li>
<p>
Remove all code, documentation, options and diagnostic
functions which were related to the experimental hybrid
heap implementation.</p>
<p>
Own Id: OTP-10105</p>
</li>
<li>
<p>
Optimizations of memory deallocations.</p>
<p>
Own Id: OTP-10162 Aux Id: OTP-7775 </p>
</li>
<li>
<p>
Optimization of process locking.</p>
<p>
Own Id: OTP-10163</p>
</li>
<li>
<p>
Added a xcomp example file for powerpc-dso-linux-gnu</p>
<p>
Own Id: OTP-10198</p>
</li>
<li>
<p>
Detect when middle endian doubles are used by a platform
and account for it when decoding floats. (Thanks to Mike
Sperber)</p>
<p>
Own Id: OTP-10209</p>
</li>
</ul>
<h3><a name="id67647">1.4
Erts 5.9.1.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
On Linux systems using heart (erl -heart) and a
HEAR_BEAT_TIMEOUT less than default, heart could fire
even though Erlang was running fine after approx 298 to
497 days (depending on kernel config). This was due to
the behaviour of the times(2) system call. Usage of
times(2) is now replaced with clock_gettime(2) and the
CLOCK_MONOTONIC clock, resulting in a more stable
solution. The Erlang VM itself has used clock_gettime(2)
on linux since before R12B, so this only affects the
heart program.</p>
<p>
Own Id: OTP-10111 Aux Id: seq12075 </p>
</li>
</ul>
<h3><a name="id67681">1.5
Erts 5.9.1.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
If threads support for the runtime system had been
disabled at compile time (<span class="code">--disable-threads</span> had
been passed to <span class="code">configure</span>), and the <span class="code">+A</span>
command line argument of <span class="code">erl</span> was passed when
starting the runtime system, <span class="bold_code"><a href="erl_driver.html#driver_system_info">driver_system_info()</a></span>
erroneously claimed that the runtime system had async
threads even though it had not.</p>
<p>
Due to this bug the file driver did not split tasks into
smaller chunks, but instead completed the whole task at
once, i.e., the scheduler got occupied with I/O for a
longer time than intended.</p>
<p>
Own Id: OTP-10059</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
A proposal for a new scheduler wakeup strategy has been
implemented. For more information see the documentation
of the <span class="bold_code"><a href="erl.html#+sws">+sws</a></span> command
line argument of <span class="code">erl</span>.</p>
<p>
Own Id: OTP-10033 Aux Id: Seq12025 </p>
</li>
<li>
<p>
A switch for configuration of busy wait length for
scheduler threads has been added. For more information
see the documentation of the <span class="bold_code"><a href="erl.html#+sbwt">+sbwt</a></span> command line argument
of <span class="code">erl</span>.</p>
<p>
Own Id: OTP-10044 Aux Id: Seq11976 </p>
</li>
<li>
<p>
The extra memory barriers introduced by bug-fix OTP-9281
were unnecessarily used also on tables without the
<span class="code">write_concurrency</span> option enabled. This could
unnecessarily degrade performance of ETS tables without
<span class="code">write_concurrency</span> on some hardware (e.g. PowerPC)
while not effecting performance at all on other hardware
(e.g. x86/x86_64).</p>
<p>
OTP-9281 (R14B03): ETS tables using the
<span class="code">write_concurrency</span> option could potentially get
into an internally inconsistent state.</p>
<p>
Own Id: OTP-10048 Aux Id: OTP-9281 </p>
</li>
</ul>
<h3><a name="id128534">1.6
Erts 5.9.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p><span class="code">erlang:system_profile</span> errorneous profiled the
profiler process when observing runnable processes. This
has been corrected. </p>
<p>
Own Id: OTP-9849</p>
</li>
<li>
<p>Calling trace_info/2 asking for information about a
function that had native could could crash the run-time
system.</p>
<p>
Own Id: OTP-9886</p>
</li>
<li>
<p>
reduce smp locking time range in erts_garbage_collect
(thanks to Jovi Zhang)</p>
<p>
Own Id: OTP-9912</p>
</li>
<li>
<p>
Fix typo in supervisor behaviour doc (Thanks to Ricardo
Catalinas Jiménez)</p>
<p>
Own Id: OTP-9924</p>
</li>
<li>
<p>
Correct spelling of registered (Thanks to Richard
Carlsson)</p>
<p>
Own Id: OTP-9925</p>
</li>
<li>
<p>
erts: Remove unused variable (Thanks to Jovi Zhang)</p>
<p>
Own Id: OTP-9926</p>
</li>
<li>
<p>
Fix bug in ETS with <span class="code">compressed</span> option and
insertion of term containing large integers (>2G) on
64-bit machines. Seen to cause emulator crash. (Thanks to
Diego Llarrull for excellent bug report)</p>
<p>
Own Id: OTP-9932</p>
</li>
<li>
<p>
Handle Linux OS where /sys/devices/system/node is only
readable by root. Fallback to /sys/devices/system/cpu for
topology info.</p>
<p>
Own Id: OTP-9978</p>
</li>
<li>
<p> When an escript ends now all printout to standard
output and standard error gets out on the terminal. This
bug has been corrected by changing the behaviour of
erlang:halt/0,1, which should fix the same problem for
other escript-like applications, i.e that data stored in
the output port driver buffers got lost when printing on
a TTY and exiting through erlang:halt/0,1. </p>
<p> The BIF:s erlang:halt/0,1 has gotten improved
semantics and there is a new BIF erlang:halt/2 to
accomplish something like the old semantics. See the
documentation. </p>
<p> Now erlang:halt/0 and erlang:halt/1 with an integer
argument will close all ports and allow all pending async
threads operations to finish before exiting the emulator.
Previously erlang:halt/0 and erlang:halt(0) would just
wait for pending async threads operations but not close
ports. And erlang:halt/1 with a non-zero integer argument
would not even wait for pending async threads operations.
</p>
<p> To roughly the old behaviour, to not wait for ports
and async threads operations when you exit the emulator,
you use erlang:halt/2 with an integer first argument and
an option list containing {flush,false} as the second
argument. Note that now is flushing not dependant of the
exit code, and you can not only flush async threads
operations which we deemed as a strange behaviour anyway.
</p>
<p>Also, erlang:halt/1,2 has gotten a new feature: If the
first argument is the atom 'abort' the emulator is
aborted producing a core dump, if the operating system so
allows. </p>
<p>
Own Id: OTP-9985</p>
</li>
<li>
<p>
Added check to inet driver to avoid building on operating
systems that do not yet have IPv6 compatible socket API.
(Thanks to Peer Stritzinger)</p>
<p>
Own Id: OTP-9996</p>
</li>
<li>
<p>
Fix bug when the number of CPUs actually found is lower
than the configured value. (Thanks to Benjamin
Herrenschmidt)</p>
<p>
Own Id: OTP-10004</p>
</li>
<li>
<p>
The runtime system without SMP support and without thread
support erroneously busy waited when no work was present.
This bug first appeared in <span class="code">erts-5.9</span>.</p>
<p>
Own Id: OTP-10019</p>
</li>
<li>
<p>
Various typographical errors corrected in documentation
for common_test, driver, erl_driver and windows
installation instructions. (Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-10037</p>
</li>
<li>
<p>
Fix memory leak caused by race on exiting process</p>
<p>
Own Id: OTP-10041</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Add <span class="code">erlang:statistics(scheduler_wall_time)</span> to
ensure correct determination of scheduler utilization.
Measuring scheduler utilization is strongly preferred
over CPU utilization, since CPU utilization gives very
poor indications of actual scheduler/vm usage.</p>
<p>
Own Id: OTP-9858</p>
</li>
<li>
<p>
ERTS internal API improvements. In some cases the amount
of atomic read operations needed have been reduced due to
this.</p>
<p>
Own Id: OTP-9922</p>
</li>
<li>
<p>
The DTrace source patch from Scott Lystig Fritchie is
integrated in the source tree. Using an emulator with
dtrace probe is still not supported for production use,
but may be a valuable debugging tool. Configure with
--with-dynamic-trace=dtrace (or
--with-dynamic-trace=systemtap) to create a build with
dtrace probes enabled. See runtime_tools for
documentation and examples.</p>
<p>
Own Id: OTP-10017</p>
</li>
</ul>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
enif_make_copy may invalidate enif_inspect_binary.</p>
<p>
Own Id: OTP-9828</p>
</li>
</ul>
<h3><a name="id128838">1.7
Erts 5.9.0.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
A feature test for the <span class="code">lwsync</span> instruction
performed on PowerPC hardware at runtime system startup
got into an eternal loop if the instruction was not
supported. This bug was introduced in erts-5.9/OTP-R15B.</p>
<p>
Own Id: OTP-9843</p>
</li>
<li>
<p>
I/O events could potentially be delayed for ever when
enabling kernel-poll on a non-SMP runtime system
executing on Solaris. When also combined with
async-threads the runtime system hung before completing
the boot phase. This bug was introduced in
erts-5.9/OTP-R15B.</p>
<p>
Own Id: OTP-9844</p>
</li>
</ul>
<h3><a name="id128886">1.8
Erts 5.9</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Honor option <span class="code">packet_size</span> for http packet parsing
by both TCP socket and <span class="code">erlang:decode_packet</span>. This
gives the ability to accept HTTP headers larger than the
default setting, but also avoid DoS attacks by accepting
lines only up to whatever length you wish to allow. For
consistency, packet type <span class="code">line</span> also honor option
<span class="code">packet_size</span>. (Thanks to Steve Vinoski)</p>
<p>
Own Id: OTP-9389</p>
</li>
<li>
<p> A few contracts in the <span class="code">lists</span> module have been
corrected. </p>
<p>
Own Id: OTP-9616</p>
</li>
<li>
<p>
The Unicode noncharacter code points 16#FFFE and 16#FFFE
were not allowed to be encoded or decoded using the
<span class="code">unicode</span> module or bit syntax. That was
inconsistent with the other noncharacters 16#FDD0 to
16#FDEF that could be encoded/decoded. To resolve the
inconsistency, 16#FFFE and 16#FFFE can now be encoded and
decoded. (Thanks to Alisdair Sullivan.)</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9624</p>
</li>
<li>
<p>
Make epp search directory of current file first when
including another file This completes a partial fix in
R11 that only worked for include_lib(). (Thanks to
Richard Carlsson)</p>
<p>
Own Id: OTP-9645</p>
</li>
<li>
<p>
Fixed memory leak in
<span class="code">enif_inspect_io_list_as_binary</span> when applied on a
process independent environment.</p>
<p>
Own Id: OTP-9668</p>
</li>
<li>
<p>The number of beam catches allowed in code are no
longer statically defined and will grow according to its
need.</p>
<p>
Own Id: OTP-9692</p>
</li>
<li>
<p>
Add missing parenthesis in heart doc.</p>
<p>
Add missing spaces in the Reference Manual distributed
section.</p>
<p>
In the HTML version of the doc those spaces are necessary
to separate those words.</p>
<p>
Own Id: OTP-9693</p>
</li>
<li>
<p>
Fixes module erlang doc style: option description (Thanks
to Ricardo Catalinas Jiménez)</p>
<p>
Own Id: OTP-9697</p>
</li>
<li>
<p>
Specifying a scope to binary:match/3 when using multiple
searchstrings resulted in faulty return values. This is
now corrected.</p>
<p>
Own Id: OTP-9701</p>
</li>
<li>
<p>
The runtime system crashed if more than one thread tried
to exit the runtime system at the same time.</p>
<p>
Own Id: OTP-9705</p>
</li>
<li>
<p>
Fix documentation for erlang:process_flag/2</p>
<p>
For the subsection about process_flag(save_calls, N)
there's an unrelated paragraph about process priorities
which was copied from the preceeding subsection regarding
process_flag(priority, Level). (Thanks to Filipe David
Manana)</p>
<p>
Own Id: OTP-9714</p>
</li>
<li>
<p>
Calls to <span class="code">erlang:system_flag(schedulers_online, N)</span>
and/or <span class="code">erlang:system_flag(multi_scheduling,
block|unblock)</span> could cause internal data used by this
functionality to get into an inconsistent state. When
this happened various problems occurred. This bug was
quite hard to trigger, so hopefully no-one has been
effected by it.</p>
<p>
A spinlock used by the run-queue management sometimes got
heavily contended. This code has now been rewritten, and
the spinlock has been removed.</p>
<p>
Own Id: OTP-9727</p>
</li>
<li>
<p>
Use libdlpi to get physical address (Thanks to Trond
Norbye)</p>
<p>
Own Id: OTP-9818</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p> An option list argument can now be passed to
<span class="code">file:read_file_info/2, file:read_link_info/2</span> and
<span class="code">file:write_file_info/3</span> and set time type
information in the call. Valid options are <span class="code">{time,
local}, {time, universal}</span> and <span class="code">{time, posix}</span>.
In the case of <span class="code">posix</span> time no conversions are made
which makes the operation a bit faster. </p>
<p>
Own Id: OTP-7687</p>
</li>
<li>
<p>A number of memory allocation optimizations have been
implemented. Most optimizations reduce contention caused
by synchronization between threads during allocation and
deallocation of memory. Most notably:</p> <ul> <li>
Synchronization of memory management in scheduler
specific allocator instances has been rewritten to use
lock-free synchronization. </li> <li> Synchronization
of memory management in scheduler specific pre-allocators
has been rewritten to use lock-free synchronization.
</li> <li> The 'mseg_alloc' memory segment allocator
now use scheduler specific instances instead of one
instance. Apart from reducing contention this also
ensures that memory allocators always create memory
segments on the local NUMA node on a NUMA system. </li>
</ul>
<p>
Own Id: OTP-7775</p>
</li>
<li>
<p>
The ethread atomic memory operations API used by the
runtime system has been extended and improved.</p>
<p>
The ethread library now also performs runtime tests for
presence of hardware features, such as for example SSE2
instructions, instead of requiring this to be determined
at compile time.</p>
<p>
All uses of the old deprecated atomic API in the runtime
system have been replaced with the use of the new atomic
API. In a lot of places this change imply a relaxation of
memory barriers used.</p>
<p>
Own Id: OTP-9014</p>
</li>
<li>
<p>gen_sctp:open/0-2 may now return
{error,eprotonosupport} if SCTP is not supported</p>
<p>gen_sctp:peeloff/1 has been implemented and creates a
one-to-one socket which also are supported now</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9239</p>
</li>
<li>
<p>
Sendfile has been added to the file module's API.
sendfile/2 is used to read data from a file and send it
to a tcp socket using a zero copying mechanism if
available on that OS.</p>
<p>
Thanks to Tuncer Ayaz and Steve Vinovski for original
implementation</p>
<p>
Own Id: OTP-9240</p>
</li>
<li>
<p>
enif_get_reverse_list function added to nif API. This
function should be used to reverse small lists which are
deep within other structures making it impractical to do
the reverse in Erlang.</p>
<p>
Own Id: OTP-9392</p>
</li>
<li>
<p>
The deprecated concat_binary/1 BIF has been removed. Use
<span class="code">list_to_binary</span> or <span class="code">iolist_to_binary/1</span>
instead.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9421</p>
</li>
<li>
<p>Erlang/OTP can now be built using parallel make if you
limit the number of jobs, for instance using '<span class="code">make
-j6</span>' or '<span class="code">make -j10</span>'. '<span class="code">make -j</span>' does not
work at the moment because of some missing
dependencies.</p>
<p>
Own Id: OTP-9451</p>
</li>
<li>
<p>Line number and filename information are now included
in exception backtraces as a fourth element in the MFA
tuple. The information will be pretty-printed by the
shell and used by <span class="code">common_test</span> to provide better
indication of where a test case.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9468</p>
</li>
<li>
<p>All binary constants used to be handled as heap
binaries (i.e. the entire binary would be copied when
sent to another process). Binary constants larger than 64
bytes are now refc binaries (i.e. the actual data in the
binary will not be copied when sent to another
process).</p>
<p>
Own Id: OTP-9486</p>
</li>
<li>
<p>
If a float and an integer is compared, the integer is
only converted to a float if the float datatype can
contain it. Otherwise the float is converted to an
integer.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9497</p>
</li>
<li>
<p>
Add NIF function enif_is_number</p>
<p>
This function allows for easily determining if a term
represents or not a number (integer, float, small or
big).(Thanks to Filipe David Manana)</p>
<p>
Own Id: OTP-9629</p>
</li>
<li>
<p>
The ERTS internal system block functionality has been
replaced by new functionality for blocking the system.
The old system block functionality had contention issues
and complexity issues. The new functionality piggy-backs
on thread progress tracking functionality needed by newly
introduced lock-free synchronization in the runtime
system. When the functionality for blocking the system
isn't used, there is more or less no overhead at all.
This since the functionality for tracking thread progress
is there and needed anyway.</p>
<p>
Own Id: OTP-9631</p>
</li>
<li>
<p>
An ERTS internal, generic, many to one, lock-free queue
for communication between threads has been introduced.
The many to one scenario is very common in ERTS, so it
can be used in a lot of places in the future. Currently
it is used by scheduling of certain jobs, and the async
thread pool, but more uses are planned for the future.</p>
<p>
Drivers using the driver_async functionality are not
automatically locked to the system anymore, and can be
unloaded as any dynamically linked in driver.</p>
<p>
Scheduling of ready async jobs is now also interleaved in
between other jobs. Previously all ready async jobs were
performed at once.</p>
<p>
Own Id: OTP-9632</p>
</li>
<li>
<p>
Tuple funs (a two-element tuple with a module name and a
function) are now officially deprecated and will be
removed in R16. Use '<span class="code">fun M:F/A</span>' instead. To make
you aware that your system uses tuple funs, the very
first time a tuple fun is applied, a warning will be sent
to the error logger.</p>
<p>
Own Id: OTP-9649</p>
</li>
<li>
<p>
Changed the internal BIF calling convention. Will make
simpler faster code and allow BIFs with an arbitrary
arity.</p>
<p>
Own Id: OTP-9662</p>
</li>
<li>
<p>
Windows native critical sections are now used internally
in the runtime system on Windows as mutex implementation.
This since they perform better under extreme contention
than our own implementation.</p>
<p>
Own Id: OTP-9671</p>
</li>
<li>
<p>
Convert some erl_nif macros into inline functions. Allow
for better compile time type checking. (Thanks to Tuncer
Ayaz)</p>
<p>
Own Id: OTP-9675</p>
</li>
<li>
<p>
The <span class="code">+scl</span> command line flag has been added. It can
be used for disabling compaction of scheduler load. For
more information see the <span class="code">erl(1)</span> documentation.</p>
<p>
Own Id: OTP-9695</p>
</li>
<li>
<p>The build system has been updated so that Erlang/OTP
can be built on Mac OS X Lion systems without a GCC
compiler. The INSTALL guide has been updated with
instructions on how to install a GCC compiler and build
Erlang/OTP with it, in order to get a run-time system
with better performance.</p>
<p>
Own Id: OTP-9712</p>
</li>
<li>
<p>
When loading a module, the system use to run on a single
scheduler during the entire loading process. This has
been changed to only take down the system just before
inserting the loaded code into the system tables,
resulting in a much shorter disruption if a module is
loaded in a busy system. (Suggested by Bob Ippolito.)</p>
<p>
Own Id: OTP-9720</p>
</li>
<li>
<p>
Possible to run HiPE without floating point exceptions
(FPE). Useful on platforms that lack reliable FPE. Slower
float operations compared to HiPE with FPE.</p>
<p>
Own Id: OTP-9724</p>
</li>
<li>
<p>
As of ERTS version 5.9 (OTP-R15B) the runtime system will
by default <strong>not</strong> bind schedulers to logical
processors.</p>
<p>
If the Erlang runtime system is the only operating system
process that binds threads to logical processors, this
improves the performance of the runtime system. However,
if other operating system processes (as for example
another Erlang runtime system) also bind threads to
logical processors, there might be a performance penalty
instead. In some cases this performance penalty might be
severe. Due to this, we change the default so that the
user must make an active decision in order to bind
schedulers.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9726</p>
</li>
<li>
<p>
The use of <span class="code">erlang:system_flag(scheduler_bind_type,
_)</span> and <span class="code">erlang:system_flag(cpu_topology, _)</span>
have been deprecated and scheduled for removal in
erts-5.10/OTP-R16. For more information see the
documentation of <span class="code">erlang:system_flag/2</span>.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9749</p>
</li>
<li>
<p>
An ancient workaround for a Windows bug was removed from
the open_port code, open_port({spawn,...}...) is now
faster. Thanks to Daniel Goertzen.</p>
<p>
Own Id: OTP-9766</p>
</li>
<li>
<p>
The use of deprecated 32bit time_t on 32bit Windows is
removed.</p>
<p>
Own Id: OTP-9767</p>
</li>
<li>
<p>
The NIF <span class="code">reload</span> mechanism is deprecated. Do not use
it as an upgrade method for live production systems. It
might be removed in future releases. It can still serve
as a development feature but a warning message will be
logged each time it is used.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9771</p>
</li>
<li>
<p>The driver interface has been changed to enable 64-bit
aware drivers. Most importantly the return types for
ErlDrvEntry callbacks 'call' and 'control' has ben
enlarged which require drivers to be changed or they will
cause emulator crashes. See <span class="bold_code"><a href="erl_driver.html#rewrites_for_64_bits"> Rewrites for
64-bit driver interface </a></span> in the driver manual.
</p>
<p>Due to this driver <span class="bold_code"><a href="erl_driver.html#version_management">version
management</a></span> is now mandatory. A driver that is
not written with version management or a driver that was
compiled with the wrong major version will be not be
loaded by the emulator.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-9795</p>
</li>
<li>
<p>
Eliminate use of deprecated regexp module</p>
<p>
Own Id: OTP-9810</p>
</li>
</ul>
<h3><a name="id129687">1.9
Erts 5.8.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Several bugs concerning constant binary constructions
such as <<0:4294967295>> have been corrected.
Depending on the actual size of the binary and the type
of run-time system (32-bit, halfword, 64-bit), such
expression could either crash the run-time system or make
the loader refuse loading of the module.</p>
<p>
Own Id: OTP-9284</p>
</li>
<li>
<p>
The Erlsrv utility failed to stop the erlang machine if
no StopAction was defined when the service was stopped.
This is now corrected.</p>
<p>
Own Id: OTP-9344</p>
</li>
<li>
<p>
Due to a bug in glibc the runtime system could abort
while trying to destroy a mutex. A fix for this was
introduced in R14B02. This fix did, however, not solve
the problem. The runtime system will now issue a warning
instead of aborting.</p>
<p>
Own Id: OTP-9373 Aux Id: OTP-9009 </p>
</li>
<li>
<p>
Replace atom in DRV macro in prim_file with string</p>
<p>
An experimental version of Dialyzer discovered that the
atom that replaced the DRV macro in prim_file ends up in
calls to erlang:open_port({spawn, Driver}, Portopts) as
the Driver argument. The documentation states that this
call requires a string there.</p>
<p>
This change is also consistent with the one introduced in
commit 0f03b1e9d2bef3bc830c31a369261af4c5234727 by Kostis
Sagonas.</p>
<p>
Own Id: OTP-9377</p>
</li>
<li>
<p>
Fix typos in the epmd documentation (Thanks to Holger
Weiß )</p>
<p>
Own Id: OTP-9387</p>
</li>
<li>
<p>
Fix faulty integer terms created by NIF API from 64-bit
integers on halfword emulator. (Thanks to Paolo Negri and
Paul Davis)</p>
<p>
Own Id: OTP-9394</p>
</li>
<li>
<p>
Fix <span class="code">epmd</span> crash on vxworks caused by faulty
argument to select() system call.</p>
<p>
Own Id: OTP-9427 Aux Id: seq11855 </p>
</li>
<li>
<p>
The ets:test_ms function could in rare cases truncate the
error messages. This is now corrected.</p>
<p>
Own Id: OTP-9435</p>
</li>
<li>
<p>
Fix bug related to hibernate and HiPE (clear
F_HIBERNATE_SCHED flag)</p>
<p>
F_HIBERNATE_SCHED flag that was introduced in
b7ecdcd1ae9e11b8f75e must be cleared in hipe_mode_switch
as well. Otherwise, processes running HiPE code that
hibernate, wake up and then trap into a BIF will not be
rescheduled.(Thanks to Paul Guyot)</p>
<p>
Own Id: OTP-9452</p>
</li>
<li>
<p>
Fix bug in FreeBSD topology detection code (Thanks to
Paul Guyot)</p>
<p>
Own Id: OTP-9453</p>
</li>
<li>
<p>
Fix use of logical operator && with constant
operand instead of bitwise & (Thanks to Cristian
Greco)</p>
<p>
Own Id: OTP-9454</p>
</li>
<li>
<p>
inet: error if fd does not match socket domain</p>
<p>
If an IPv4 fd is opened as an IPv6 socket, unexpected
behaviour can occur. For example, if an IPv4 UDP socket
is opened and passed into Erlang as an IPv6 socket, the
first 3 bytes (corresponding to 1 byte representing the
protocol family, 2 bytes set to the port) are stripped
from the payload. The cause of the UDP payload truncation
happens in inet_drv.c:packet_inet_input when a call to
inet_get_address fails silently because the family is set
to PF_INET6 but the buffer len is the size of an IPv4
struct sockaddr_in.</p>
<p>
(Thanks to Andrew Tunnell-Jones for finding the bug and
the test case!)</p>
<p>
Own Id: OTP-9455</p>
</li>
<li>
<p>
erts: use a union to avoid strict aliasing issues</p>
<p>
Use a union for pointer type conversion to avoid compiler
warnings about strict-aliasing violations with gcc-4.1.
gcc >= 4.2 does not emit the warning. erts: adapt
matrix_nif to R14 erl_nif API changes (Thanks To Tuncer
Ayaz)</p>
<p>
Own Id: OTP-9487</p>
</li>
<li>
<p>
fix 64-bit issues in the garbage collection (Thanks to
Richard Carlsson)</p>
<p>
Own Id: OTP-9488</p>
</li>
<li>
<p>
epmd: fix compiler warnings</p>
<p>
Suppress compiler warnings about ignored return values.
(Thanks to Michael Santos )</p>
<p>
Own Id: OTP-9500</p>
</li>
<li>
<p>
Fix non-existing function (erlang:disconnect/1) in
distributed reference manual (Thanks to Fabian Król)</p>
<p>
Own Id: OTP-9504</p>
</li>
<li>
<p>
Document fdatasync -lrt requirement (SunOS <= 5.10)
(Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-9512</p>
</li>
<li>
<p>
Let epmd ignore empty ERL_EPMD_ADDRESS</p>
<p>
If the environment variable ERL_EPMD_ADDRESS is set to
the empty string, empd now behaves like it does by
default when ERL_EPMD_ADDRESS is unset. That is, in this
case, epmd now listens on all available interfaces
instead of using only the loopback interface, which
happened because epmd added the loopback address to the
(in this case empty) list of addresses specified via
ERL_EPMD_ADDRESS.</p>
<p>
Also, epmd now ignores ERL_EPMD_ADDRESS if it contains
only separator characters (comma and space).</p>
<p>
The same applies to epmd's -address option.(Thanks to
Holger Weiß)</p>
<p>
Own Id: OTP-9525</p>
</li>
<li>
<p>
Remove dead code in erl_compile (Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-9527</p>
</li>
<li>
<p>
Add erlang:external_size/2 BIF</p>
<p>
This BIF's second parameter is a list of options.
Currently the only allowed option is {minor_version,
Version} where version is either 0 (default) or 1.
(Thanks to Filipe David Manana )</p>
<p>
Own Id: OTP-9528</p>
</li>
<li>
<p>
Fix enif_compare on 64bits machines</p>
<p>
In 64bits machines the Sint type has a size of 8 bytes,
while on 32bits machines it has a 4 bytes size.
enif_compare was ignoring this and therefore returning
incorrect values when the result of the CMP function
(which returns a Sint value) doesn't fit in 4 bytes.
(Thanks to Filipe David Manana)</p>
<p>
Own Id: OTP-9533</p>
</li>
<li>
<p>
Implement or fix -Werror option</p>
<p>
If -Werror is enabled and there are warnings no output
file is written. Also make sure that error/warning
reporting is consistent. (Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-9536</p>
</li>
<li>
<p>In some rare cases we did not have a run queue when
scheduling misc ops. This is now fixed.</p>
<p>
Own Id: OTP-9537</p>
</li>
<li>
<p>Remove misc. compiler warnings</p>
<p>
Own Id: OTP-9542</p>
</li>
<li>
<p>
Two bugs in gen_sctp has been corrected: getopts/setopts
hence also send could only be called from socket owner,
and options 'linger', 'rcvbuf' and 'sndbuf' was read from
wrong protocol layer hence read wrong values by getopts.</p>
<p>
Own Id: OTP-9544</p>
</li>
<li>
<p>
Erlang/OTP can now be built on MacOS X Lion.</p>
<p>
Own Id: OTP-9547</p>
</li>
<li>
<p> XML files have been corrected. </p>
<p>
Own Id: OTP-9550 Aux Id: OTP-9541 </p>
</li>
<li>
<p>
Fix potential errors inspired by running cppcheck(1)
(Thanks to Christian von Roques)</p>
<p>
Own Id: OTP-9557</p>
</li>
<li>
<p>When auxiliary work was enqueued on a scheduler, the
wakeup of the scheduler in order to handle this work
could be lost. Wakeups in order to handle ordinary work
were not effected by this bug. The bug only effected
runtime systems with SMP support as follows:</p> <ul>
<li>Deallocation of some ETS data structures could be
delayed.</li> <li>On Linux systems not using the NPTL
thread library (typically ancient systems with kernel
versions prior to 2.6) and Windows systems, the <span class="code">{Port,
{exit_status, Status}}</span> message from a terminating
port program could be delayed. That is, it only effected
port programs which had been started by passing
<span class="code">exit_status</span> as an option to
<span class="code">open_port/2</span>.</li> </ul>
<p>
Own Id: OTP-9567</p>
</li>
<li>
<p>
Handle rare race in the crypto key server functionality</p>
<p>
Own Id: OTP-9586</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p> Types and specifications have been added. </p>
<p>
Own Id: OTP-9356</p>
</li>
<li>
<p>
New allocator strategy "address order first fit". May
ease the emptying of memory carriers and thereby real
release of memory back to the OS.</p>
<p>
Own Id: OTP-9424</p>
</li>
<li>
<p>
The new <span class="code">erlang:check_old_code/1</span> BIF checks whether
a module has old code.</p>
<p>
Own Id: OTP-9495</p>
</li>
<li>
<p> Update documentation and specifications of some of
the zlib functions. </p>
<p>
Own Id: OTP-9506</p>
</li>
<li>
<p>
Detect the available CPUs on IRIX</p>
<p>
Add support for querying the number of configured and
online processors on SGI systems running IRIX.(Thanks to
Holger Weiß)</p>
<p>
Own Id: OTP-9531</p>
</li>
</ul>
<h3><a name="id130246">1.10
Erts 5.8.4</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Fix binary and iolist overflow problems. Typically
problems arose in length calculation where the result
would exceed (1 bsl 32 - 1).</p>
<p>
Own Id: OTP-9118</p>
</li>
<li>
<p>
Using the old erlang shell (i.e. erl instead on werl) on
windows and doing several init:restart's would eventually
hang the VM. That is no longer the case.</p>
<p>
Own Id: OTP-9139</p>
</li>
<li>
<p>
Removed recursive C code when printing Erlang terms to
buffers, avoiding stack overflows that could cause VM to
crash.</p>
<p>
Own Id: OTP-9140</p>
</li>
<li>
<p>
The send_timeout option in gen_tcp did not work properly
in active mode or with {active,once} options. This is now
corrected.</p>
<p>
Own Id: OTP-9145</p>
</li>
<li>
<p>
Fixed various typos across the documentation (Thanks to
Tuncer Ayaz)</p>
<p>
Own Id: OTP-9154</p>
</li>
<li>
<p>Remove duplicate stack entries which could occur after
calling certain BIFs.</p>
<p>
Own Id: OTP-9163</p>
</li>
<li>
<p>
A race when starting two nodes simultaneously using
run_erl has been removed.</p>
<p>
Own Id: OTP-9164</p>
</li>
<li>
<p>
Add documentation on .erlang processing back again
(Thanks to Gabor Liptak)</p>
<p>
Own Id: OTP-9189</p>
</li>
<li>
<p>
Remove gratuitous paren in driver_entry(Thanks to Tuncer
Ayaz)</p>
<p>
Own Id: OTP-9192</p>
</li>
<li>
<p>
Fix some wrong pointer dereferences (Thanks to Cristian
Greco)</p>
<p>
Own Id: OTP-9194</p>
</li>
<li>
<p>
erts: Remove unused variables (Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-9205</p>
</li>
<li>
<p>
The documentation for <span class="code">init:get_args/0</span> has been
removed. <span class="code">init:get_args/0</span> itself was deprecated in
R9C and removed in R12B. (Thanks to Eric Pailleau.)</p>
<p>
Own Id: OTP-9209</p>
</li>
<li>
<p>
Allow user to specify the IP address epmd binds to</p>
<p>
The IP address(es) epmd binds to can now be specified by
the user, either via epmd's new "-address" option or (if
that's not used) by setting the environment variable
ERL_EPMD_ADDRESS. Multiple addresses may be specified
using a comma-separated list. If the loopback address is
not in this list, it will be added implicitly, so that
the daemon can be queried by an interactive epmd
process.(Thanks to Holger Weiß)</p>
<p>
Own Id: OTP-9213</p>
</li>
<li>
<p>
epmd: include host address in local access check</p>
<p>
In FreeBSD jails, the source and destination address of
connections to localhost are changed to be the IP address
of the jail. Consider connections from the host's IP
address to itself (e.g., the source and destination
address match) to be local for the access control checks.
(Thanks to Michal Santos and Tom at diogunix.com)</p>
<p>
Own Id: OTP-9214</p>
</li>
<li>
<p>
Fix list returned by net_kernel:epmd_module</p>
<p>
Function epmd_module of net_kernel returns a list instead
of an atom, when the epmd_module-flag is used. (Thanks to
Markus Knofe)</p>
<p>
Own Id: OTP-9215</p>
</li>
<li>
<p>
Fix epmd's dbg_perror() output</p>
<p>
The dbg_perror() function now hands the current errno
value over to dbg_gen_printf(). This fixes the problem
that errno had been reset to zero by the time it was used
(to print the corresponding error message) in the
dbg_gen_printf() function. (Thanks to Holger Weiß)</p>
<p>
Own Id: OTP-9223</p>
</li>
<li>
<p>
heart: remove garbage appended to heart command</p>
<p>
heart:get_cmd/0 is documented to return an empty string
if the command is cleared. get_cmd/0 returns 2 extra
bytes: 1 byte for the trailing null, 1 byte from the op
(the op is an unsigned char and 2 bytes are allocated for
it in the returned buffer). (Thanks to Michael Santos)</p>
<p>
Own Id: OTP-9224</p>
</li>
<li>
<p>
file: fix hang reading compressed files</p>
<p>
The gzio driver goes into an infinite loop when reading
past the end of a compressed file. Reported-By: Alex
Morarash (Thanks to Michael Santos)</p>
<p>
Own Id: OTP-9245</p>
</li>
<li>
<p>Eliminate alias warnings from gcc 4.5.2</p>
<p>
Own Id: OTP-9250</p>
</li>
<li>
<p>
Unsigned integer may overflow in error message (Thanks to
Michael Santos)</p>
<p>
Own Id: OTP-9251</p>
</li>
<li>
<p>
Driver names should be strings, not atoms</p>
<p>
Own Id: OTP-9253</p>
</li>
<li>
<p>
driver_entry: Remove gratuitous paren and fix typo
(Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-9254</p>
</li>
<li>
<p>
Fix format specifiers in erl_exit messages</p>
<p>
Fix an error message by using an unsigned integer
specifier as seen in a tweet by @metabrew: #erlang VM
crashed with "no next heap size found: -2090496108,
offset 0", suddenly allocated all available RAM</p>
<p>
Also correct mis-typed string formats in bif.c.(Thanks to
Michael Santos)</p>
<p>
Own Id: OTP-9262</p>
</li>
<li>
<p>
net_drv: remove unused tcp request id inet_drv: remove
gratuitous assignment (Thanks to Tuncer Ayaz)</p>
<p>
Own Id: OTP-9263</p>
</li>
<li>
<p>
Teach run_erl RUN_ERL_DISABLE_FLOWCNTRL for disabling
flow control</p>
<p>
Flow control can cause unwanted behaviour of the beam
process, if accidentally hit Ctrl-S (instead of Ctrl-D to
detach) the entire beam may be blocked.</p>
<p>
Fix this problem by making it possible to turn off flow
control by setting the environment variable
RUN_ERL_DISABLE_FLOWCNTRL. (Thanks to Jonas Faklkevik)</p>
<p>
Own Id: OTP-9270</p>
</li>
<li>
<p>The following bugs due to missing memory barriers have
been fixed:</p> <ul> <li><p> ETS tables using the
<span class="code">write_concurrency</span> option could potentially get
into an internally inconsistent state. </p></li>
<li><p> ETS tables using the <span class="code">ordered_set</span> option
could potentially get into an internally inconsistent
state. </p></li> <li>
<p> A number of memory barriers
have been added when building with the
<span class="code">libatomic_ops</span> API (i.e. when passing
<span class="code">--with-libatomic_ops=PATH</span> to <span class="code">configure</span>) and
the tilera atomics API (i.e. when building for the tilera
chip). Note that these bugs were due to erroneous usage
of the APIs, and not in the implementations of the APIs.
When using these APIs the following bugs where
present:</p> <ul> <li><p> The BIF
<span class="code">erlang:ports/0</span> could return an erroneous result.
</p></li> <li><p> A thread blocking other threads
during code loading, or setup of tracing could
potentially read invalid data. </p></li> <li><p>
Fixation of ETS tables could potentially get into an
internally inconsistent state. </p></li> </ul>
</li> </ul>
<p>
Own Id: OTP-9281</p>
</li>
<li>
<p>
Fix halfword bug for ETS ordered_set when doing
<span class="code">select/match</span> with partly bound key.</p>
<p>
Own Id: OTP-9292</p>
</li>
<li>
<p>
Fix bug in <span class="code">code:is_module_native</span> that caused crash
for deleted modules.</p>
<p>
Own Id: OTP-9298</p>
</li>
<li>
<p>
Calling <span class="code">driver_async_cancel()</span> could cause a
scheduler thread to enter an eternal loop doing no useful
work. (Thanks to Anders Ramsell)</p>
<p>
Own Id: OTP-9302</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
New <span class="code">enif_is_exception function</span> to allow NIFs to
determine whether an <span class="code">ERL_NIF_TERM</span> represents an
exception. (Thanks to Steve Vinoski)</p>
<p>
Own Id: OTP-9150</p>
</li>
<li>
<p>
A process being garbage collected by another process
could be scheduled on another scheduler. This prevented
this scheduler from doing any useful work until the
garbage collection was done. This either occurred due to
a explicit call to the <span class="code">garbage_collect/1</span> BIF, or
due to a garbage collection part of code loading. A
process being garbage collected like this will now not be
scheduled until the garbage collection has completed.</p>
<p>
Own Id: OTP-9211</p>
</li>
<li>
<p>
Remove unnecessary validation copy in
prim_file:drv_command/3 (Thanks to Tony Rogvall)</p>
<p>
Own Id: OTP-9276</p>
</li>
<li>
<p>
Symbolic link handling on windows have been slightly
updated to map error conditions more consequently and
correctly read directory links created outside of the
Erlang environment.</p>
<p>
Own Id: OTP-9279</p>
</li>
<li>
<p>
Due to standard library DLL mismatches between versions
of OpenSSL and Erlang/OTP, OpenSSL is now linked
statically to the crypto driver on Windows. This fixes
problems starting crypto when running Erlang as a service
on all Windows versions.</p>
<p>
Own Id: OTP-9280</p>
</li>
<li>
<p>Halfword emulator memory handling improvements:</p>
<ul> <li>
<p>Much more of internal memory structures
have been made able to use "high" memory and are no
longer restricted to the 4Gb limit that still applies for
all process heap data.</p> </li> <li>
<p>Fixed faulty
values from <span class="code">erlang:memory()</span> caused by 32-bit
counter overflow.</p> </li> <li>
<p>New counter
<span class="code">low</span> in <span class="code">erlang:memory()</span> that sums up all
memory restricted by 4Gb limit.</p> </li> </ul>
<p>
Own Id: OTP-9291 Aux Id: seq11841 </p>
</li>
<li>
<p>
The value set in the undocumented and unsupported
ERL_version_FLAGS (e.g. ERL_R14B03_FLAGS) environment
variable can now be overridden by the command line
(similar to ERL_AFLAGS).</p>
<p>
Own Id: OTP-9297</p>
</li>
</ul>
<h3><a name="id130900">1.11
Erts 5.8.3.2</a></h3>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
Fix halfword emulator bug in <span class="code">ets:select_delete</span> for
<span class="code">ordered_set</span> that caused emulator to crash.</p>
<p>
Own Id: OTP-9258 Aux Id: seq11836 </p>
</li>
</ul>
<h3><a name="id130937">1.12
Erts 5.8.3.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Ets table type ordered_set could order large integer keys
wrongly on pure 64bit platforms. This is now corrected.</p>
<p>
Own Id: OTP-9181</p>
</li>
<li>
<p>
The status of a process was unnecessarily set to waiting
before a process was enqueued in a run queue. This bug
was harmless up until OTP-R14B01. In OTP-R14B02
<span class="code">erlang:hibernate/3</span> was fixed (OTP-9125). After the
introduction of OTP-9125, the previously harmless process
status bug sometimes caused erroneous badarg exceptions
from <span class="code">process_info()</span>.</p>
<p>
OTP-9125 also introduced a thread unsafe access to the
status field of a process which now also have been fixed.</p>
<p>
*** INCOMPATIBILITY with noxs ***</p>
<p>
Own Id: OTP-9197</p>
</li>
</ul>
<h3><a name="id130997">1.13
Erts 5.8.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
The scroll wheel now scrolls the werl window on Windows.</p>
<p>
Own Id: OTP-8985</p>
</li>
<li>
<p>
Some malformed distribution messages could cause VM to
crash, this is now corrected.</p>
<p>
Own Id: OTP-8993</p>
</li>
<li>
<p>
The OS function getifaddrs() can return NULL in some
address fields for e.g PPP and tunnel devices which
caused the emulator to segfault. This bug has now been
corrected.</p>
<p>
Own Id: OTP-8996</p>
</li>
<li>
<p>
The expression <<A:0>> would always produce
an empty binary, even if <span class="code">A</span> was not an integer.
Corrected to cause a <span class="code">badarg</span> exception if the type
of <span class="code">A</span> is invalid. (Thanks to Zvi.)</p>
<p>
Own Id: OTP-8997</p>
</li>
<li>
<p>
A bug that potentially could cause an emulator crash when
deleting an ETS-table has been fixed. A resource leak
when hitting the maximum amount of ETS-tables allowed has
also been fixed.</p>
<p>
Own Id: OTP-8999</p>
</li>
<li>
<p>
A bug in the <span class="code">exit/2</span> BIF could potentially cause an
emulator crash.</p>
<p>
Own Id: OTP-9005</p>
</li>
<li>
<p>
Due to a bug in glibc the runtime system could abort
while trying to destroy a mutex. The runtime system will
now issue a warning instead of aborting.</p>
<p>
Own Id: OTP-9009</p>
</li>
<li>
<p>
A bug in epmd could create strange behaviour when
listen() calls failed. This is now corrected thanks to
Steve Vinoski.</p>
<p>
Own Id: OTP-9024</p>
</li>
<li>
<p>When setting file_info the win32_driver will now
correctly set access and modified time. Previously these
entities were swapped.</p>
<p>
Own Id: OTP-9046</p>
</li>
<li>
<p>
Setting scheduler bind type to <span class="code">unbound</span> failed if
binding of schedulers wasn't supported, or if CPU
topology wasn't present. This even though the
documentation stated that it is possible to set the bind
type to <span class="code">unbound</span>.</p>
<p>
Own Id: OTP-9056 Aux Id: Seq11779 </p>
</li>
<li>
<p>Two problems were fixed in crash dump: The time left
for timers are now shown as unsigned integers and the
contents of ordered_set ETS tables is no longer
included.</p>
<p>
Own Id: OTP-9057</p>
</li>
<li>
<p>
The VM could fail to set IP_TOS and SO_PRIORITY in
certain situations, either because sockets were supplied
as open file descriptors, or because SO_PRIORITY by
default was set higher than the user can explicitly set
it to. Those situations are now handled.</p>
<p>
Own Id: OTP-9069</p>
</li>
<li>
<p>
Wx on MacOS X generated complains on stderr about certain
cocoa functions not beeing called from the "Main thread".
This is now corrected.</p>
<p>
Own Id: OTP-9081</p>
</li>
<li>
<p>
Fix a couple typos in driver_entry(3) (thanks to Tuncer
Ayaz).</p>
<p>
Own Id: OTP-9085</p>
</li>
<li>
<p>
Mention that "-detached" implies "-noinput"</p>
<p>
Clarify that specifying "-noinput" is unnecessary if the
"-detached" flag is given. (thanks to Holger Weiß)</p>
<p>
Own Id: OTP-9086</p>
</li>
<li>
<p>
A potential problem (found by code inspection) when
calling a fun whose code was not loaded has been fixed.</p>
<p>
Own Id: OTP-9095</p>
</li>
<li>
<p>
The emulator could get into a state where it didn't check
for I/O.</p>
<p>
Own Id: OTP-9105 Aux Id: Seq11798 </p>
</li>
<li>
<p>
Attempting to create binaries exceeding 2Gb (using for
example <span class="code">term_to_binary/1</span>) would crash the emulator
with an attempt to allocate huge amounts of memory.
(Thanks to Jon Meredith.)</p>
<p>
Own Id: OTP-9117</p>
</li>
<li>
<p>
Fix erlang:hibernate/3 on HiPE enabled emulator (Thanks
to Paul Guyot)</p>
<p>
Own Id: OTP-9125</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>From this release, the previously experimental
halfword emulator is now official. It can be enabled by
giving the <span class="code">--enable-halfword-emulator</span> option to
the <span class="code">configure</span> script.</p>
<p>The halfword emulator is a 64-bit application, but
uses halfwords (32-bit words) for all data in Erlang
processes, therefore using less memory and being faster
than the standard 64-bit emulator. The total size of all
BEAM code and all process data for all processes is
limited to 4Gb, but ETS tables and off-heap binaries are
only limited by the amount of available memory.</p>
<p>
Own Id: OTP-8941</p>
</li>
<li>
<p>
32-bit atomic memory operations have been introduced
internally in the run time system, and are now used where
appropriate. There were previously only atomic memory
operations of word size available. The 32-bit atomic
memory operations slightly reduce memory consumption, and
slightly improve performance on 64-bit runtime systems.</p>
<p>
Own Id: OTP-8974</p>
</li>
<li>
<p>
Performance enhancements for looking up timer-entries and
removing timers from the wheel.</p>
<p>
Own Id: OTP-8990</p>
</li>
<li>
<p>
Write accesses to ETS tables have been optimized by
reducing the amount of atomic memory operations needed
during a write access.</p>
<p>
Own Id: OTP-9000</p>
</li>
<li>
<p>
Strange C coding in the VM made the -D_FORTIFY_SOURCE
option to gcc-4.5 react badly. The code is now cleaned up
so that it's accepted by gcc-4.5.</p>
<p>
Own Id: OTP-9025</p>
</li>
<li>
<p>
The memory footprint for loaded code has been somewhat
reduced (especially in the 64-bit BEAM machine).</p>
<p>
Own Id: OTP-9030</p>
</li>
<li>
<p>
The maximum number of allowed arguments for an Erlang
function has been lowered from 256 to 255, so that the
number of arguments can now fit in a byte.</p>
<p>
Own Id: OTP-9049</p>
</li>
<li>
<p>
Dependency generation for Makefiles has been added to the
compiler and erlc. See the manual pages for
<span class="code">compile</span> and <span class="code">erlc</span>. (Thanks to Jean-Sebastien
Pedron.)</p>
<p>
Own Id: OTP-9065</p>
</li>
</ul>
<h3><a name="id131413">1.14
Erts 5.8.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p> Fix format_man_pages so it handles all man sections
and remove warnings/errors in various man pages. </p>
<p>
Own Id: OTP-8600</p>
</li>
<li>
<p>
The <span class="code">configure</span> command line argument <span class="bold_code"><a href="javascript:erlhref('../../../doc/../','doc/installation_guide','INSTALL.html#How-to-Build-and-Install-ErlangOTP_A-Closer-Look-at-the-individual-Steps_Configuring');">--enable-ethread-pre-pentium4-compatibility</a></span>
had no effect. This option is now also automatically
enabled if required on the build machine.</p>
<p>
Own Id: OTP-8847</p>
</li>
<li>
<p>
Windows 2003 and Windows XP pre SP3 would sometimes not
start the Erlang R14B VM at all due to a bug in the cpu
topology detection. The bug affects Windows only, no
other platform is even remotely affected. The bug is now
corrected.</p>
<p>
Own Id: OTP-8876</p>
</li>
<li>
<p>
The HiPE run-time in the 64-bit emulator could do a
64-bit write to a 32-bit struct field. It happened to be
harmless on Intel/AMD processors. Corrected. (Thanks to
Mikael Pettersson.)</p>
<p>
Own Id: OTP-8877</p>
</li>
<li>
<p>
A bug in <span class="bold_code"><a href="erl_driver.html#erl_drv_tsd_get">erl_drv_tsd_get()</a></span>
and <span class="bold_code"><a href="erl_nif.html#enif_tsd_get">enif_tsd_get()</a></span>
could cause an emulator crash. These functions are
currently not used in OTP. That is, the crash only occur
on systems with user implemented NIF libraries, or
drivers that use one of these functions.</p>
<p>
Own Id: OTP-8889</p>
</li>
<li>
<p>
Calling <span class="code">erlang:system_info({cpu_topology,
CpuTopologyType})</span> with another <span class="code">CpuTopologyType</span>
element than one of the documented atoms <span class="code">defined</span>,
<span class="code">detected</span>, or <span class="code">used</span> caused an emulator crash.
(Thanks to Paul Guyot)</p>
<p>
Own Id: OTP-8914</p>
</li>
<li>
<p>
The ERTS internal rwlock implementation could get into an
inconsistent state. This bug was very seldom triggered,
but could be during heavy contention. The bug was
introduced in R14B (erts-5.8.1).</p>
<p>
The bug was most likely to be triggered when using the
<span class="code">read_concurrency</span> option on an ETS table that was
frequently accessed from multiple processes doing lots of
writes and reads. That is, in a situation where you
typically don't want to use the <span class="code">read_concurrency</span>
option in the first place.</p>
<p>
Own Id: OTP-8925 Aux Id: OTP-8544 </p>
</li>
<li>
<p>
Tracing to port could cause an emulator crash when
unloading the trace driver.</p>
<p>
Own Id: OTP-8932</p>
</li>
<li>
<p>
Removed use of CancelIoEx on Windows that had been shown
to cause problems with some drivers.</p>
<p>
Own Id: OTP-8937</p>
</li>
<li>
<p>
The fallback implementation used when no native atomic
implementation was found did not compile. (Thanks to
Patrick Baggett, and Tuncer Ayaz)</p>
<p>
Own Id: OTP-8944</p>
</li>
<li>
<p>
Some integer values used during load balancing could
under rare circumstances wrap causing a load unbalance
between schedulers.</p>
<p>
Own Id: OTP-8950</p>
</li>
<li>
<p>
The windows VM now correctly handles appending to large
files (> 4GB).</p>
<p>
Own Id: OTP-8958</p>
</li>
<li>
<p>
Name resolving of IPv6 addresses has been implemented for
Windows versions that support it. The use of ancient
resolver flags (AI_V4MAPPED | AI_ADDRCONFIG) to the
getaddrinfo() function has been removed since e.g FreeBSD
regard mapped IPv4 addresses to be a security problem and
the semantics of the address configured flag is
uncertain.</p>
<p>
Own Id: OTP-8969</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
The help texts produced by the <span class="code">configure</span> scripts
in the top directory and in the erts directory have been
aligned and cleaned up.</p>
<p>
Own Id: OTP-8859</p>
</li>
<li>
<p>
When the runtime system had fewer schedulers than logical
processors, the system could get an unnecessarily large
amount reader groups.</p>
<p>
Own Id: OTP-8861</p>
</li>
<li>
<p>
<span class="code">run_rel</span> has been updated to support Solaris's
/dev/ptmx device and to load the necessary STREAMS
modules so that <span class="code">to_erl</span> can provide terminal echo
of keyboard input. (Thanks to Ryan Tilder.)</p>
<p>
Own Id: OTP-8878</p>
</li>
<li>
<p>
The Erlang VM now supports Unicode filenames. The feature
is turned on by default on systems where Unicode
filenames are mandatory (Windows and MacOSX), but can be
enabled on other systems with the '+fnu' emulator option.
Enabling the Unicode filename feature on systems where it
is not default is however considered experimental and not
to be used for production. Together with the Unicode file
name support, the concept of "raw filenames" is
introduced, which means filenames provided without
implicit unicode encoding translation. Raw filenames are
provided as binaries, not lists. For further information,
see stdlib users guide and the chapter about using
Unicode in Erlang. Also see the file module manual page.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8887</p>
</li>
<li>
<p>Buffer overflows have been prevented in <span class="code">erlc</span>,
<span class="code">dialyzer</span>, <span class="code">typer</span>, <span class="code">run_test</span>,
<span class="code">heart</span>, <span class="code">escript</span>, and <span class="code">erlexec</span>.</p>
(Thanks to Michael Santos.)
<p>
Own Id: OTP-8892</p>
</li>
<li>
<p>
The runtime system is now less eager to suspend processes
sending messages over the distribution. The default value
of the distribution buffer busy limit has also been
increased from 128 KB to 1 MB. This in order to improve
throughput.</p>
<p>
Own Id: OTP-8901</p>
</li>
<li>
<p>
The distribution buffer busy limit can now be configured
at system startup. For more information see the
documentation of the <span class="code">erl</span> <span class="bold_code"><a href="erl.html#+zdbbl">+zdbbl</a></span> command line flag.
(Thanks to Scott Lystig Fritchie)</p>
<p>
Own Id: OTP-8912</p>
</li>
<li>
<p>
The inet driver internal buffer stack implementation has
been rewritten in order to reduce lock contention.</p>
<p>
Own Id: OTP-8916</p>
</li>
<li>
<p>
New ETS option <span class="code">compressed</span>, to enable a more
compact storage format at the expence of heavier table
operations. For test and evaluation, <span class="code">erl +ec</span> can
be used to force compression on all ETS tables.</p>
<p>
Own Id: OTP-8922 Aux Id: seq11658 </p>
</li>
<li>
<p>
There is now a new function inet:getifaddrs/0 modeled
after C library function getifaddrs() on BSD and LInux
that reports existing interfaces and their addresses on
the host. This replaces the undocumented and unsupported
inet:getiflist/0 and inet:ifget/2.</p>
<p>
Own Id: OTP-8926</p>
</li>
<li>
<p>
Support for detection of CPU topology and binding of
schedulers on FreeBSD 8 have been added. (Thanks to Paul
Guyot)</p>
<p>
Own Id: OTP-8939</p>
</li>
<li>
<p>
Several bugs related to hibernate/3 and HiPE have been
corrected. (Thanks to Paul Guyot.)</p>
<p>
Own Id: OTP-8952</p>
</li>
<li>
<p>
Support for soft and hard links on Windows versions and
filesystems that support them is added.</p>
<p>
Own Id: OTP-8955</p>
</li>
<li>
<p>
The win32 virtual machine is now linked large address
aware. his allows the Erlang VM to use up to 3 gigs of
address space on Windows instead of the default of 2
gigs.</p>
<p>
Own Id: OTP-8956</p>
</li>
</ul>
<h3><a name="id131898">1.15
Erts 5.8.1.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p> Fix that the documentation top index generator can
handle an Ericsson internal application group. </p>
<p>
Own Id: OTP-8875</p>
</li>
<li>
<p>In embedded mode, on_load handlers that called
<span class="code">code:priv_dir/1</span> or other functions in <span class="code">code</span>
would hang the system. Since the <span class="code">crypto</span>
application now contains an on_loader handler that calls
<span class="code">code:priv_dir/1</span>, including the <span class="code">crypto</span>
application in the boot file would prevent the system
from starting.</p>
<p>Also extended the <span class="code">-init_debug</span> option to print
information about on_load handlers being run to
facilitate debugging.</p>
<p>
Own Id: OTP-8902 Aux Id: seq11703 </p>
</li>
</ul>
<h3><a name="id99120">1.16
Erts 5.8.1.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Windows 2003 and Windows XP pre SP3 would sometimes not
start the Erlang R14B VM at all due to a bug in the cpu
topology detection. The bug affects Windows only, no
other platform is even remotely affected. The bug is now
corrected.</p>
<p>
Own Id: OTP-8876</p>
</li>
</ul>
<h3><a name="id99152">1.17
Erts 5.8.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Very small floating point numbers generated errors when
converting from list to float in some versions of the VM,
this is now corrected so that i.e.
list_to_float("1.0e-324"). returns 0.0 in all versions of
Erlang.</p>
<p>
Own Id: OTP-7178</p>
</li>
<li>
<p>
Windows Vista and Windows 7 file system virtualization,
which makes "old style" windows programs execute in a
file system sandbox, was previously unintentionally
turned on for the Erlang VM. This is now corrected so
that i.e. writes to C:\Program Files\. without
administrator privileges will fail.</p>
<p>
Own Id: OTP-7405</p>
</li>
<li>
<p>
Fix faulty 64-bit integer term output from drivers. Large
64-bits integers did not generate correct bignums and
could even cause emulator crash. Only affects drivers
using ERL_DRV_INT64 or ERL_DRV_UINT64, introduced in
R13B03.</p>
<p>
Own Id: OTP-8716</p>
</li>
<li>
<p>
Fixed: inet:setopts(S, [{linger,{true,2}}]) returned
{error,einval} for SCTP sockets. The inet_drv had a bug
when checking the option size.</p>
<p>
Own Id: OTP-8726 Aux Id: seq11617 </p>
</li>
<li>
<p>Fix libm linking with --as-needed flag
<p>
When building with "--as-needed" linker flags on Linux
the build will fail. This has now been fixed.</p>
<p>
(Thanks to Christian Faulhammer)</p></p>
<p>
Own Id: OTP-8728</p>
</li>
<li>
<p>
gen_udp:connect/3 was broken for SCTP enabled builds. It
did not detect remote end errors as it should.</p>
<p>
Own Id: OTP-8729</p>
</li>
<li>
<p>Reduce the risk of integer wrapping in bin vheap size
counting.</p> <p>The vheap size series will now use the
golden ratio instead of doubling and fibonacci
sequences.</p>
<p>
Own Id: OTP-8730</p>
</li>
<li>
<p>
ETS ordered_set containing <span class="code">[]</span> as key could cause
strange thing to happen, like an infinite hanging
<span class="code">ets:select</span>.</p>
<p>
Own Id: OTP-8732</p>
</li>
<li>
<p>reference() has been substituted for ref() in the
documentation.</p>
<p>
Own Id: OTP-8733</p>
</li>
<li>
<p>
When a native compiled module called a not loaded
non-native compiled module that had an on_load function,
the export entries were trashed after code loading so on
the next call from the native compiled module to the
non-native compiled the emulator crashed. This bug has
now been fixed.</p>
<p>
Own Id: OTP-8736</p>
</li>
<li>
<p>
HiPE-enabled Erlang VMs running on BSD systems sometimes
generated messages like "Yikes! erts_alloc() returned
misaligned address 0x8016a512c". Fixed. (Thanks to Mikael
Pettersson.)</p>
<p>
Own Id: OTP-8769</p>
</li>
<li>
<p>
A race condition in <span class="code">erts_poll()</span> could cause delay
of poll for I/O.</p>
<p>
Own Id: OTP-8773</p>
</li>
<li>
<p>
Removed some potential vulnerabilities from the Erlang
Port Mapper Daemon (epmd) and straightened up access
control. Also removed hazardous interfaces allowing
anyone on a machine to forcefully unregister other nodes.
This means that the ei_unregister/erl_unregister
interfaces in erl_interface is rendered not only error
prone and mystifying as before, but totally ineffective.
The old behaviour of unchecked node unregistering can be
restored if needed, see epmd documentation for details.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8780</p>
</li>
<li>
<p> Building in a source tree without prebuilt platform
independent build results failed on the SSL examples
when: </p> <ul>
<li> cross building. This has been
solved by not building the SSL examples during a cross
build. </li>
<li> building on Windows. </li>
</ul>
<p>
Own Id: OTP-8791</p>
</li>
<li>
<p>
inet:getsockopt for SCTP sctp_default_send_param had a
bug to not initialize required feilds causing random
answers. It is now corrected.</p>
<p>
Own Id: OTP-8795 Aux Id: seq11655 </p>
</li>
<li>
<p>
The hipe_bifs:get_hrvtime/0 BIF now always returns a real
value even if the "perfctr" Linux kernel extension is not
available. It used to return a dummy value. (Thanks to
Mikael Pettersson.)</p>
<p>
Own Id: OTP-8798</p>
</li>
<li>
<p>
Calling a native-code compiled module with an
<span class="code">on_load</span> function could cause a crash. (Thanks to
Mikael Pettersson.)</p>
<p>
Own Id: OTP-8799</p>
</li>
<li>
<p>The emulator could crash while writing a crash dump if
native-compiled modules had been loaded. (Thanks to Paul
Guyot.)</p>
<p>
Own Id: OTP-8801</p>
</li>
<li>
<p>
The garbage collector could crash if invoked from
native-compiled code after a call to a BIF. (Thanks to
Paul Guyot.)</p>
<p>
Own Id: OTP-8821</p>
</li>
<li>
<p>
A rare memory leak in binary:matches is removed</p>
<p>
Own Id: OTP-8823</p>
</li>
<li>
<p>For a socket in the HTTP packet mode, the return value
from <span class="code">gen_tcp:recv/2,3</span> if there is an error in the
header will be <span class="code">{ok,{http_error,String}}</span> instead of
<span class="code">{error,{http_error,String}}</span> to be consistent with
<span class="code">ssl:recv/2,3</span>.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8831</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
ets:select_reverse/{1,2,3} are now documented.</p>
<p>
Own Id: OTP-7863</p>
</li>
<li>
<p>
External format of integers changed to make full use of
all 32 bits of INTEGER_EXT. This is a compatible change
as old code can read full 32-bit integers but only
produce 28-bit integers as INTEGER_EXT.</p>
<p>
Own Id: OTP-8540 Aux Id: seq11534 </p>
</li>
<li>
<p>
Large parts of the <span class="code">ethread</span> library have been
rewritten. The <span class="code">ethread</span> library is an Erlang
runtime system internal, portable thread library used by
the runtime system itself.</p>
<p>
Most notable improvement is a reader optimized rwlock
implementation which dramatically improve the performance
of read-lock/read-unlock operations on multi processor
systems by avoiding ping-ponging of the rwlock cache
lines. The reader optimized rwlock implementation is used
by miscellaneous rwlocks in the runtime system that are
known to be read-locked frequently, and can be enabled on
ETS tables by passing the <span class="bold_code"><a href="javascript:erlhref('../../../doc/../','stdlib','ets.html#new_2_read_concurrency');">{read_concurrency,
true}</a></span> option upon table creation. See the
documentation of <span class="bold_code"><a href="javascript:erlhref('../../../doc/../','stdlib','ets.html#new-2');">ets:new/2</a></span> for more
information. The reader optimized rwlock implementation
can be fine tuned when starting the runtime system. For
more information, see the documentation of the <span class="bold_code"><a href="javascript:erlhref('../../../doc/../','erts','erl.html#+rg');">+rg</a></span> command line argument
of <span class="code">erl</span>.</p>
<p>
There is also a new implementation of rwlocks that is not
optimized for readers. Both implementations interleaves
readers and writers during contention as opposed to,
e.g., the NPTL (Linux) pthread rwlock implementation
which use either a reader or writer preferred strategy.
The reader/writer preferred strategy is problematic since
it starves threads doing the non-preferred operation.</p>
<p>
The new rwlock implementations in general performs better
in ERTS than common pthread implementations. However, in
some extremely heavily contended cases this is not the
case. Such heavy contention can more or less only appear
on ETS tables. This when multiple processes do very large
amounts of write locked operations simultaneously on the
same table. Such use of ETS is bad regardless of rwlock
implementation, will never scale, and is something we
strongly advise against.</p>
<p>
The new rwlock implementations depend on atomic
operations. If no native atomic implementation is found,
a fallback solution will be used. Using the fallback
implies a performance degradation. That is, it is more
important now than before to build OTP with a native
atomic implementation.</p>
<p>
The <span class="code">ethread</span> library contains native atomic
implementations for, x86 (32 and 64 bit), powerpc (32
bit), sparc V9 (32 and 64 bit), and tilera (32 bit). On
other hardware gcc's builtin support for atomic memory
access will be used if such exists. If no such support is
found, <span class="code">configure</span> will warn about no atomic
implementation available.</p>
<p>
The <span class="code">ethread</span> library can now also use the
<span class="code">libatomic_ops</span> library for atomic memory accesses.
This makes it possible for the Erlang runtime system to
utilize optimized native atomic operations on more
platforms than before. If <span class="code">configure</span> warns about no
atomic implementation available, try using the
<span class="code">libatomic_ops</span> library. Use the <span class="bold_code"><a href="javascript:erlhref('../../../doc/../','doc/installation_guide','INSTALL.html#How-to-Build-and-Install-ErlangOTP_A-Closer-Look-at-the-individual-Steps_Configuring');">--with-libatomic_ops=PATH</a></span>
<span class="code">configure</span> command line argument when specifying
where the <span class="code">libatomic_ops</span> installation is located.
The <span class="code">libatomic_ops</span> library can be downloaded from:
<span class="bold_code"><a href="http://www.hpl.hp.com/research/linux/atomic_ops/">http://www.hpl.hp.com/research/linux/atomic_ops/</a></span></p>
<p>
The changed API of the <span class="code">ethread</span> library has also
caused modifications in the Erlang runtime system.
Preparations for the to come "delayed deallocation"
feature has also been done since it depends on the
<span class="code">ethread</span> library.</p>
<p>
<strong>Note</strong>: When building for x86, the <span class="code">ethread</span>
library will now use instructions that first appeared on
the pentium 4 processor. If you want the runtime system
to be compatible with older processors (back to 486) you
need to pass the <span class="bold_code"><a href="javascript:erlhref('../../../doc/../','doc/installation_guide','INSTALL.html#How-to-Build-and-Install-ErlangOTP_A-Closer-Look-at-the-individual-Steps_Configuring');">--enable-ethread-pre-pentium4-compatibility</a></span>
<span class="code">configure</span> command line argument when configuring
the system.</p>
<p>
Own Id: OTP-8544</p>
</li>
<li>
<p>
erlang:localtime_to_universaltime({{2008, 8, 1}, {0, 0,
0}},true) when TZ=UTC now behaves consistently on all
Unix platforms.</p>
<p>
The problem fixed was originally reported by Paul Guyot
on erlang-bugs mailing list:</p>
<p>
http://www.erlang.org/pipermail/erlang-bugs/2008-November/001077.html</p>
<p>
Own Id: OTP-8580</p>
</li>
<li>
<p>
Optimization reducing memory consumption by two words per
ETS object.</p>
<p>
Own Id: OTP-8737</p>
</li>
<li>
<p>
Fixes for unsupported halfword-emulator</p>
<p>
Own Id: OTP-8745</p>
</li>
<li>
<p>
NIF 64-bit integer support; <span class="code">enif_get_int64</span>,
<span class="code">enif_get_uint64</span>, <span class="code">enif_make_int64</span>,
<span class="code">enif_make_uint64</span>.</p>
<p>
Own Id: OTP-8746</p>
</li>
<li>
<p>
Alignment of trailing data in messages has been adjusted.
This in order to be able to pass data of any type as
trailing data in the future.</p>
<p>
Own Id: OTP-8754</p>
</li>
<li>
<p>
The obsolete/driver.h header file has been removed. It
has been obsolete and deprecated since R8B. Drivers that
still include obsolete/driver.h must be updated to
include erl_driver.h.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8758</p>
</li>
<li>
<p>
Added erlang:system_info(build_type) which makes it
easier to chose drivers, NIF libraries, etc based on
build type of the runtime system.</p>
<p>
The NIF library for crypto can now be built for valgrind
and/or debug as separate NIF libraries that will be
automatically loaded if the runtime system has been built
with a matching build type.</p>
<p>
Own Id: OTP-8760</p>
</li>
<li>
<p>
Further lessened the memory requirements of ETS objects.</p>
<p>
Own Id: OTP-8762</p>
</li>
<li>
<p>The broken elib_malloc alternate memory allocator has
been removed. <span class="code">erlang:system_info(elib_malloc)</span> will
always return <span class="code">false</span>, and in R15,
<span class="code">erlang:system_info(elib_malloc)</span> will fail with a
<span class="code">badarg</span> exception.</p>
<p>
Own Id: OTP-8764</p>
</li>
<li>
<p>
Calling <span class="code">erlang:system_info/1</span> with the new argument
<span class="code">update_cpu_info</span> will make the runtime system
reread and update the internally stored CPU information.
For more information see the documentation of <span class="bold_code"><a href="erlang.html#update_cpu_info">erlang:system_info(update_cpu_info)</a></span>.</p>
<p>
The CPU topology is now automatically detected on Windows
systems with less than 33 logical processors. The runtime
system will now, also on Windows, by default bind
schedulers to logical processors using the
<span class="code">default_bind</span> bind type if the amount of schedulers
is at least equal to the amount of logical processors
configured, binding of schedulers is supported, and a CPU
topology is available at startup.</p>
<p>
Own Id: OTP-8765</p>
</li>
<li>
<p>
The SMP ERTS internal child waiter thread used on Linux
system with NPTL was unintentionally disabled during
cross compilation rewrites (OTP-8323 in R13B03). It has
now been re-enabled. Enabling it again gives a slight
performance improvement.</p>
<p>
Own Id: OTP-8774</p>
</li>
<li>
<p>
<span class="code">epmd</span> used to generate a message to the syslog when
it started up, which could be annoying. This has been
changed to only generate the message if the debug swith
is given. (Thanks to Michael Santos.)</p>
<p>
Own Id: OTP-8775</p>
</li>
<li>
<p>
The scheduler wakeup threshold is now possible to adjust
at system boot. For more information see the <span class="bold_code"><a href="erl.html#+swt">+swt</a></span> command line argument of
<span class="code">erl</span>.</p>
<p>
Own Id: OTP-8811</p>
</li>
<li>
<p>
The undocumented function inet:ifget/2 has been improved
to return interface hardware address (MAC) on platforms
supporting getaddrinfo() (such as BSD unixes). Note it
still does not work on all platforms for example not
Windows nor Solaris, so the function is still
undocumented.</p>
<p>
Buffer overflow and field init bugs for inet:ifget/2 and
inet:getservbyname/2 has also been fixed.</p>
<p>
Thanks to Michael Santos.</p>
<p>
Own Id: OTP-8816</p>
</li>
<li>
<p>
Optimizations for MIPS when using gcc atomics. (Thanks to
Steve Vinoski)</p>
<p>
Own Id: OTP-8834</p>
</li>
<li>
<p>
Lock optimization in timer functionality.</p>
<p>
Own Id: OTP-8835</p>
</li>
</ul>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>Fix epmd and build environment to build on VxWorks</p>
<p>
Own Id: OTP-8838</p>
</li>
</ul>
<h3><a name="id100010">1.18
Erts 5.8</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Driver threads, such as async threads, using <span class="bold_code"><a href="erl_driver.html#ErlDrvPDL">port data locks</a></span>
peeked at the port status field without proper locking
when looking up the driver queue.</p>
<p>
Own Id: OTP-8475</p>
</li>
<li>
<p>
The use of <span class="code">mmap()</span> was unnecessarily disabled when
cross compiling.</p>
<p>
The <span class="code">configure</span> arguments <span class="code">--with-ssl</span>, and
<span class="code">--with-odbc</span> refused to accept libraries outside of
<span class="code">$erl_xcomp_sysroot</span> when cross compiling for no
good reason.</p>
<p>
The <span class="code">configure</span> argument <span class="code">--with-odbc</span> didn't
handle the value <span class="code">yes</span> correct.</p>
<p>
The <span class="code">configure</span> arguments <span class="code">--with-odbc</span>, and
<span class="code">--without-odbc</span> have also been added to the
configure help.</p>
<p>
(Thanks to Steve Vinoski for reporting these issues)</p>
<p>
Own Id: OTP-8484</p>
</li>
<li>
<p>
A call to the BIF <span class="code">unregister(RegName)</span> when a port
had the name <span class="code">RegName</span> registered in the runtime
system without SMP support caused a runtime system crash.
(Thanks to Per Hedeland for the bugfix and test case.)</p>
<p>
Own Id: OTP-8487</p>
</li>
<li>
<p>
The runtime system crashed if fewer logical processors
were found than reported by <span class="code">sysconf(
SC_NPROCESSORS_CONF)</span>.</p>
<p>
Own Id: OTP-8549</p>
</li>
<li>
<p>
Fix memory management bug causing crash of non-SMP
emulator with async threads enabled. The bug did first
appear in R13B03.</p>
<p>
Own Id: OTP-8591 Aux Id: seq11554 </p>
</li>
<li>
<p>
Port locks could be prematurely destroyed.</p>
<p>
Own Id: OTP-8612</p>
</li>
<li>
<p>The <span class="code">empd</span> program could loop and consume 100%
CPU time if an unexpected error ocurred in
<span class="code">listen()</span> or <span class="code">accept()</span>. Now <span class="code">epmd</span> will
terminate if a non-recoverable error occurs. (Thanks to
Michael Santos.)</p>
<p>
Own Id: OTP-8618</p>
</li>
<li>
<p>
When kernel poll has been enabled, a livelock could in
rare circumstances occur. Problem reported by Chetan
Ahuja, fix by Mikael Pettersson.</p>
<p>
Own Id: OTP-8632</p>
</li>
<li>
<p>
Windows: Closing port of program that stalled without
reading all data could deadlock scheduler thread.</p>
<p>
Own Id: OTP-8641</p>
</li>
<li>
<p>
On some combination of Montavista Linux on Cavium Octeon
processors, some socket-related system calls returned
other numbers than -1 for errors. This caused a core dump
in inet_drv.c. Now the code works around this problem.</p>
<p>
Own Id: OTP-8654</p>
</li>
<li>
<p>
Missing memory barriers in <span class="code">erts_poll()</span> could cause
the runtime system to hang indefinitely.</p>
<p>
Own Id: OTP-8658</p>
</li>
<li>
<p>
<span class="code">ethr_rwmutex_tryrlock()</span> acquired and refused to
acquire a lock with inverted logic. The lock was however
never acquired in a thread unsafe manner. (Thanks to JR
Zhang for noting this issue)</p>
<p>
Own Id: OTP-8662</p>
</li>
<li>
<p>
Extreme combinations of register/unregister in a highly
parallell SMP application could crash the VM. The error
is corrected.</p>
<p>
Own Id: OTP-8663</p>
</li>
<li>
<p>
On Windows, files are now opened with FILE_SHARE_DELETE
to get closer to Unix semantics.</p>
<p>
Own Id: OTP-8667</p>
</li>
<li>
<p>
<span class="code">erlang:system_info(multi_scheduling)</span> sometimes
erroneously returned <span class="code">enabled</span> when it should have
returned <span class="code">blocked</span>.</p>
<p>
Own Id: OTP-8675</p>
</li>
<li>
<p>
Fix bug causing <span class="code">erlang:decode_packet</span> and
<span class="code">enif_make_string</span> to generate faulty strings with
negative character values for ascii values larger than
127. (Thanks to Paul Guyot)</p>
<p>
Own Id: OTP-8685</p>
</li>
<li>
<p>
<span class="code">open_port/2</span> with the <span class="code">spawn</span> and
<span class="code">spawn_executable</span> options can include an
<span class="code">{env,Env}</span> option. In some cases unsetting
variables would not work on Unix (typically if more
variables were unset than were actually present in the
environment).</p>
<p>
Own Id: OTP-8701</p>
</li>
<li>
<p>
A user defined CPU topology set via a call to <span class="bold_code"><a href="erlang.html#system_flag_cpu_topology">erlang:system_flag(cpu_topology,
CPUTopology)</a></span> was not properly verified, and
could in worst case cause an emulator crash. The emulator
crash could only occur when a user defined CPU topology
already existed and was redefined.</p>
<p>
Own Id: OTP-8710</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
The grammar for match specifications in ERTS users guide
only described the tracing dialect of match
specifications. An informal grammar for the ETS dialect
is added.</p>
<p>
Own Id: OTP-8086 Aux Id: seq11333 </p>
</li>
<li>
<p>
The module binary from EEP31 (and EEP9) is implemented.</p>
<p>
Own Id: OTP-8217</p>
</li>
<li>
<p>
New NIF API function <span class="code">enif_make_new_binary</span></p>
<p>
Own Id: OTP-8474</p>
</li>
<li>
<p>
The guard BIF <span class="code">is_boolean/1</span> (introduced in R10B)
has now been included in the lists of BIFs allowed in
guards in the Reference Manual.</p>
<p>
Own Id: OTP-8477</p>
</li>
<li>
<p>
Added function <span class="code">zip:foldl/3</span> to iterate over zip
archives.</p>
<p>
Added functions to create and extract escripts. See
<span class="code">escript:create/2</span> and <span class="code">escript:extract/2</span>.</p>
<p>
The undocumented function <span class="code">escript:foldl/3</span> has been
removed. The same functionality can be achieved with the
more flexible functions <span class="code">escript:extract/2</span> and
<span class="code">zip:foldl/3</span>.</p>
<p>
Record fields has been annotated with type info. Source
files as been adapted to fit within 80 chars and trailing
whitespace has been removed.</p>
<p>
Own Id: OTP-8521</p>
</li>
<li>
<p>A regular expression with many levels of parenthesis
could cause a buffer overflow. That has been corrected.
(Thanks to Michael Santos.)</p>
<p>
Own Id: OTP-8539</p>
</li>
<li>
<p>
<span class="code">erlang:decode_packet(httph_bin,..)</span> could return
corrupt header strings or even crash the VM. This has
been fixed. It only happened on 32-bit VM if the header
name was unknown and between 16 and 20 characters long.
Sockets with simular <span class="code">packet</span> option did not suffer
from this bug.</p>
<p>
Own Id: OTP-8548</p>
</li>
<li>
<p>New NIF features:</p> <ul>
<li> Send messages from
a NIF, or from thread created by NIF, to any local
process (<span class="code">enif_send</span>) </li>
<li> Store terms
between NIF calls (<span class="code">enif_alloc_env</span>,
<span class="code">enif_make_copy</span>) </li>
<li> Create binary terms
with user defined memory management
(<span class="code">enif_make_resource_binary</span>) </li>
</ul> <p>And
some incompatible changes made to the API. For more
information see the warning text in <span class="bold_code"><a href="erl_nif.html">erl_nif(3)</a></span>.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8555</p>
</li>
<li>
<p>If the '<span class="code">fop</span>' program (needed for building PDF
files) cannot not be found, it is now possible to build
the HTML and man pages anyway (there will also be dummy
PDF files with no real content created). (Thanks to
Tuncer Ayaz.)</p>
<p>
Own Id: OTP-8559</p>
</li>
<li>
<p>When defining macros the closing right parenthesis
before the dot is now mandatory.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8562</p>
</li>
<li>
<p>Local and imported functions now override the
auto-imported BIFs when the names clash. The pre R14
behaviour was that auto-imported BIFs would override
local functions. To avoid that old programs change
behaviour, the following will generate an error:</p>
<ul>
<li><p>Doing a call without explicit module name
to a local function having a name clashing with the name
of an auto-imported BIF that was present (and
auto-imported) before OTP R14A</p></li>
<li><p>Explicitly importing a function having a name
clashing with the name of an autoimported BIF that was
present (and autoimported) before OTP R14A</p></li>
<li><p>Using any form of the old compiler directive
<span class="code">nowarn_bif_clash</span></p></li> </ul> <p>If the BIF
was added or auto-imported in OTP R14A or later,
overriding it with an import or a local function will
only result in a warning,</p> <p>To resolve clashes, you
can either use the explicit module name <span class="code">erlang</span> to
call the BIF, or you can remove the auto-import of that
specific BIF by using the new compiler directive
<span class="code">-compile({no_auto_import,[F/A]}).</span>, which makes all
calls to the local or imported function without explicit
module name pass without warnings or errors.</p> <p>The
change makes it possible to add auto-imported BIFs
without breaking or silently changing old code in the
future. However some current code ingeniously utilizing
the old behaviour or the <span class="code">nowarn_bif_clash</span> compiler
directive, might need changing to be accepted by the
compiler.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8579</p>
</li>
<li>
<p>
A bug in re that could cause certain regular expression
matches never to terminate is corrected. (Thanks to
Michael Santos and Gordon Guthrie.)</p>
<p>
Own Id: OTP-8589</p>
</li>
<li>
<p>The erlang:open_port spawn and spawn_executable
directives can include an <span class="code">{env,Env}</span> directive to
set up environment variables for the spawned process. A
bug prevented applications from using <span class="code">{env,Env}</span> to
set an environment variable whose value ended with a
'<span class="code">=</span>' (equal sign) character; the trailing equal
sign was mistaken as an indication that an environment
variable was to be cleared from the environment of the
spawned process. (Thanks to Steve Vinoski.)</p>
<p>
Own Id: OTP-8614</p>
</li>
<li>
<p><span class="code">receive</span> statements that can only read out a
newly created reference are now specially optimized so
that it will execute in constant time regardless of the
number of messages in the receive queue for the process.
That optimization will benefit calls to
<span class="code">gen_server:call()</span>. (See <span class="code">gen:do_call/4</span> for
an example of a receive statement that will be
optimized.)</p>
<p>
Own Id: OTP-8623</p>
</li>
<li>
<p>
The functions file:advise/4 and file:datasync/1 have been
added. (Thanks to Filipe David Manana.)</p>
<p>
Own Id: OTP-8637</p>
</li>
<li>
<p>
New NIF API functions: <span class="code">enif_make_atom_len</span>,
<span class="code">enif_make_existing_atom_len</span>,
<span class="code">enif_make_string_len</span>, <span class="code">enif_get_atom_length</span>,
<span class="code">enif_get_list_length</span>, <span class="code">enif_is_list</span>,
<span class="code">enif_is_tuple</span> (by Tuncer Ayaz)</p>
<p>
Own Id: OTP-8640</p>
</li>
<li>
<p>
Support for using gcc's built-in functions for atomic
memory access has been added. This functionallity will be
used if available and no other native atomic
implementation in ERTS is available.</p>
<p>
Own Id: OTP-8659</p>
</li>
<li>
<p>
The number of spinlocks used when implementing atomic
fall-backs when no native atomic implementation is
available has been increased from 16 to 1024.</p>
<p>
Own Id: OTP-8660</p>
</li>
<li>
<p>
Writer preferred pthread read/write locks has been
enabled on Linux.</p>
<p>
Own Id: OTP-8661</p>
</li>
<li>
<p>
The runtime system will by default bind schedulers to
logical processors using the <span class="code">default_bind</span> bind
type if the amount of schedulers are at least equal to
the amount of logical processors configured, binding of
schedulers is supported, and a CPU topology is available
at startup. </p>
<p>
<strong>NOTE:</strong> If the Erlang runtime system is the only
operating system process that binds threads to logical
processors, this improves the performance of the runtime
system. However, if other operating system processes (as
for example another Erlang runtime system) also bind
threads to logical processors, there might be a
performance penalty instead. If this is the case you, are
are advised to unbind the schedulers using the <span class="bold_code"><a href="erl.html#+sbt">+sbtu</a></span> command line argument,
or by invoking <span class="bold_code"><a href="erlang.html#system_flag_scheduler_bind_type">erlang:system_flag(scheduler_bind_type,
unbound)</a></span>.</p>
<p>
Own Id: OTP-8666</p>
</li>
<li>
<p>
The recently added BIFs erlang:min/2, erlang:max/2 and
erlang:port_command/3 are now auto-imported (as they were
originally intended to be). Due to the recent compiler
change (OTP-8579), the only impact on old code defining
it's own min/2, max/2 or port_command/3 functions will be
a warning, the local functions will still be used. The
warning can be removed by using
-compile({no_auto_import,[min/2,max/2,port_command/3]}).
in the source file.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8669 Aux Id: OTP-8579 </p>
</li>
<li>
<p>
There is a new option 'exclusive' to file:open/2 that
uses the OS O_EXCL flag where supported to open the file
in exclusive mode.</p>
<p>
Own Id: OTP-8670</p>
</li>
<li>
<p>
Now, binary_to_term/2 is auto-imported. This will cause a
compile warning if and only if a module has got a local
function with that name.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8671</p>
</li>
<li>
<p>
Alignment of scheduler data and run queues were adjusted.</p>
<p>
Own Id: OTP-8673</p>
</li>
<li>
<p>Call time breakpoint tracing</p> <ul>
<li>Introduce
a <span class="code">call_time</span> option to
<span class="code">erlang:trace_pattern/3</span>.This option enables call
time breakpoint tracing on code that is executed by
processes with call tracing enabled. Call time tracing
stores the number of calls and the time spent of each
function with this trace pattern enabled. The information
can be retrieved with <span class="code">erlang:trace_info/2</span>
</li>
<li>Add a scheduler array for BpData. To solve the
issue of multiple schedulers constantly updating the head
pointer to the bp data wheel, each scheduler now has its
own entrypoint to the wheel. This head pointer can be
updated without a locking being taken.</li>
</ul>
<p>Teach call count tracing to use atomics</p>
<ul>
<li>Call count previously used a global lock for
accessing and writing its counter in the breakpoint. This
is now changed to atomics instead.</li> <li>The
change will let call count tracing and cprof to scale
better when increasing the number of
schedulers.</li>
</ul>
<p>
Own Id: OTP-8677</p>
</li>
<li>
<p><span class="code">eprof</span> has been reimplemented with support in
the Erlang virtual machine and is now both faster (i.e.
slows down the code being measured less) and scales much
better. In measurements we saw speed-ups compared to the
old eprof ranging from 6 times (for sequential code that
only uses one scheduler/core) up to 84 times (for
parallel code that uses 8 cores).</p>
<p>Note: The API for the <span class="code">eprof</span> has been cleaned up
and extended. See the documentation.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8706</p>
</li>
</ul>
<h3><a name="id101018">1.19
Erts 5.7.5.2</a></h3>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
Two bugs in gen_sctp has been corrected: getopts/setopts
hence also send could only be called from socket owner,
and options 'linger', 'rcvbuf' and 'sndbuf' was read from
wrong protocol layer hence read wrong values by getopts.</p>
<p>
Own Id: OTP-9544</p>
</li>
</ul>
<h3><a name="id101050">1.20
Erts 5.7.5.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Driver threads, such as async threads, using <span class="bold_code"><a href="erl_driver.html#ErlDrvPDL">port data locks</a></span>
peeked at the port status field without proper locking
when looking up the driver queue.</p>
<p>
Own Id: OTP-8475</p>
</li>
<li>
<p>
A call to the BIF <span class="code">unregister(RegName)</span> when a port
had the name <span class="code">RegName</span> registered in the runtime
system without SMP support caused a runtime system crash.
(Thanks to Per Hedeland for the bugfix and test case.)</p>
<p>
Own Id: OTP-8487</p>
</li>
<li>
<p>
Fix memory management bug causing crash of non-SMP
emulator with async threads enabled. The bug did first
appear in R13B03.</p>
<p>
Own Id: OTP-8591 Aux Id: seq11554 </p>
</li>
</ul>
<h3><a name="id101119">1.21
Erts 5.7.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Fix <span class="code">binary_to_term</span> crash on compressed term with
corrupt size field.</p>
<p>
Own Id: OTP-8336</p>
</li>
<li>
<p>
Processes and/or ports could get stuck on a blocked
scheduler when <span class="code">erlang:system_flag(multi_scheduling,
block)</span> was used.</p>
<p>
Processes and/or ports could get stuck on an offline
scheduler when schedulers online were reduced using
<span class="code">erlang:system_flag(schedulers_online,
SchedulersOnline)</span>.</p>
<p>
Own Id: OTP-8342</p>
</li>
<li>
<p>Building on Windows will now work if the paths to
<span class="code">mc.exe</span> and <span class="code">rc.exe</span> contain spaces. The
README.win32 file has been updated with some information
about building using Visual Studio 2008. (Thanks to
Andrew Thompson.)</p>
<p>
Own Id: OTP-8345</p>
</li>
<li>
<p>
EPMD now correctly handles the extra data field which can
be given in the ALIVE2_REQ request and retrieved in the
PORT2_RESP response. (Thanks to Klas Johansson.)</p>
<p>
Own Id: OTP-8361</p>
</li>
<li>
<p>
The configure test for reliable floating point exceptions
has been update to work on modern versions of Mac OS X.
(Thanks to Trannie Carter.)</p>
<p>
Own Id: OTP-8368</p>
</li>
<li>
<p>
ERTS makefiles used to detect the use of a gcc C compiler
by checking if CC equaled gcc. That is, the makefiles
failed to detect gcc C compilers with other command line
names than gcc. `configure' now substitute GCC into the
makefiles. If CC is a gcc C compiler, GCC will have the
value yes. (Thanks to Jean-Sébastien Pédron)</p>
<p>
Own Id: OTP-8373</p>
</li>
<li>
<p>
ETS bug causing the <span class="code">memory</span> counter from
<span class="code">ets:info</span> for ordered_set's to sometimes get out of
synch and absurdly high.</p>
<p>
Own Id: OTP-8377 Aux Id: seq11442 </p>
</li>
<li>
<p>
Immediately repeated multi-scheduling block/unblock
cycles using <span class="code">erlang:system_flag(multi_scheduling,
block | unblock)</span> could deadlock the runtime system.</p>
<p>
Own Id: OTP-8386</p>
</li>
<li>
<p>A number of bugs concerning re and unicode are
corrected:</p>
<p>re:compile no longer loses unicode option, which also
fixes bug in re:split.</p>
<p>re:replace now handles unicode charlist replacement
argument</p>
<p>re:replace now handles unicode RE charlist argument
correctly</p>
<p>re:replace now handles binary unicode output correctly
when nothing is replaced.</p>
<p>Most code, testcases and error isolation done by Rory
Byrne.</p>
<p>
Own Id: OTP-8394</p>
</li>
<li>
<p>
The loading of native code was not properly atomic in the
SMP emulator, which could cause crashes. Also a per-MFA
information table for the native code has now been
protected with a lock since it turns that it could be
accessed concurrently in the SMP emulator. (Thanks to
Mikael Pettersson.)</p>
<p>
Own Id: OTP-8397</p>
</li>
<li>
<p>
Fix processes in exiting status that are about to be
scheduled, to not be allowed to garbage collect.</p>
<p>
Own Id: OTP-8420</p>
</li>
<li>
<p>Removed bogus "\011" character sequence in
documentation.</p>
<p>
Own Id: OTP-8422</p>
</li>
<li>
<p>
The resolver routines failed to look up the own node name
as hostname, if the OS native resolver was erroneously
configured, bug reported by Yogish Baliga, now fixed.</p>
<p>
The resolver routines now tries to parse the hostname as
an IP string as most OS resolvers do, unless the native
resolver is used.</p>
<p>
The DNS resolver inet_res and file resolver inet_hosts
now do not read OS configuration files until they are
needed. Since the native resolver is default, in most
cases they are never needed.</p>
<p>
The DNS resolver's automatic updating of OS configuration
file data (/etc/resolv.conf) now uses the 'domain'
keyword as default search domain if there is no 'search'
keyword.</p>
<p>
Own Id: OTP-8426 Aux Id: OTP-8381 </p>
</li>
<li>
<p>
The re module: A regular expression with an option change
at the start of a pattern that had top-level alternatives
could cause overwriting and/or a crash. (Thanks to
Michael Santos.)</p>
<p>
Own Id: OTP-8438</p>
</li>
<li>
<p>
Harmless buffer overflow by one byte in asn1 and
ram_file_drv.</p>
<p>
Own Id: OTP-8451</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Improved GC performance after BIF/NIF call when a lot of
heap fragments was created. This will mainly benefit NIFs
that return large compound terms.</p>
<p>
Own Id: OTP-8240</p>
</li>
<li>
<p>Incompatible changes in the experimental NIF
feature.</p> <ul>
<li> Changed the NIF function
prototypes in order to allow more than 3 function
arguments. </li>
<li> <span class="code">enif_get_data</span> renamed as
<span class="code">enif_priv_data</span>. </li>
<li>
<span class="code">enif_make_string</span> got a third argument for
character encoding. </li>
<li> The return value of
<span class="code">erlang:load_nif/2</span> on error changed. </li>
</ul>
<p>Read more in the documentation of <span class="code">erl_nif</span> and
<span class="code">erlang:load_nif/2</span></p>.
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8304</p>
</li>
<li>
<p>Cross compilation improvements and other build system
improvements.</p>
<p>Most notable:</p> <ul>
<li> Lots of cross
compilation improvements. The old cross compilation
support was more or less non-existing as well as broken.
Please, note that the cross compilation support should
still be considered as experimental. Also note that old
cross compilation configurations cannot be used without
modifications. For more information on cross compiling
Erlang/OTP see the <span class="code">$ERL_TOP/INSTALL-CROSS.md</span> file.
</li>
<li> Support for staged install using <span class="bold_code"><a href="http://www.gnu.org/prep/standards/html_node/DESTDIR.html">DESTDIR</a></span>.
The old broken <span class="code">INSTALL_PREFIX</span> has also been fixed.
For more information see the <span class="code">$ERL_TOP/INSTALL.md</span>
file. </li>
<li> Documentation of the <span class="code">release</span>
target of the top <span class="code">Makefile</span>. For more information
see the <span class="code">$ERL_TOP/INSTALL.md</span> file. </li>
<li>
<span class="code">make install</span> now by default creates relative
symbolic links instead of absolute ones. For more
information see the <span class="code">$ERL_TOP/INSTALL.md</span> file.
</li>
<li> <span class="code">$ERL_TOP/configure --help=recursive</span>
now works and prints help for all applications with
<span class="code">configure</span> scripts. </li>
<li> Doing <span class="code">make
install</span>, or <span class="code">make release</span> directly after
<span class="code">make all</span> no longer triggers miscellaneous
rebuilds. </li>
<li> Existing bootstrap system is now
used when doing <span class="code">make install</span>, or <span class="code">make
release</span> without a preceding <span class="code">make all</span>.
</li>
<li> The <span class="code">crypto</span> and <span class="code">ssl</span>
applications use the same runtime library path when
dynamically linking against <span class="code">libssl.so</span> and
<span class="code">libcrypto.so</span>. The runtime library search path has
also been extended. </li>
<li> The <span class="code">configure</span>
scripts of <span class="code">erl_interface</span> and <span class="code">odbc</span> now
search for thread libraries and thread library quirks the
same way as <span class="code">erts</span> do. </li>
<li> The
<span class="code">configure</span> script of the <span class="code">odbc</span> application
now also looks for odbc libraries in <span class="code">lib64</span> and
<span class="code">lib/64</span> directories when building on a 64-bit
system. </li>
<li> The <span class="code">config.h.in</span> file in the
<span class="code">erl_interface</span> application is now automatically
generated in instead of statically updated which reduces
the risk of <span class="code">configure</span> tests without any effect.
</li>
</ul>
<p>(Thanks to Henrik Riomar for suggestions and
testing)</p>
<p>(Thanks to Winston Smith for the AVR32-Linux cross
configuration and testing)</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-8323</p>
</li>
<li>
<p>NIF improvements:</p> <ul>
<li> Driver API for
multi-threading made available for NIFs. </li>
<li>
Support for mempory managed (garbage collected) resource
objects. A way to pass "pointers" to native data
structures between C and Erlang in a safe way.
</li>
<li> Support for references, floats and term
comparison. </li>
<li> Various new functions, like
<span class="code">enif_inspect_iolist_as_binary</span>,
<span class="code">enif_make_sub_binary</span>, <span class="code">enif_get_string</span>,
<span class="code">enif_get_atom</span>, <span class="code">enif_make_tuple_from_array</span>,
<span class="code">enif_make_list_from_array</span>,
<span class="code">enif_make_existing_atom</span>. </li>
</ul>
<p>
Own Id: OTP-8335</p>
</li>
<li>
<p>
Minor alignment adjustments of scheduler specific data.</p>
<p>
Own Id: OTP-8341</p>
</li>
<li>
<p>The documentation is now possible to build in an open
source environment after a number of bugs are fixed and
some features are added in the documentation build
process. </p>
<p>- The arity calculation is updated.</p>
<p>- The module prefix used in the function names for
bif's are removed in the generated links so the links
will look like
"http://www.erlang.org/doc/man/erlang.html#append_element-2"
instead of
"http://www.erlang.org/doc/man/erlang.html#erlang:append_element-2".</p>
<p>- Enhanced the menu positioning in the html
documentation when a new page is loaded.</p>
<p>- A number of corrections in the generation of man
pages (thanks to Sergei Golovan)</p>
<p>- The legal notice is taken from the xml book file so
OTP's build process can be used for non OTP
applications.</p>
<p>
Own Id: OTP-8343</p>
</li>
<li>
<p>
There is new <span class="code">erlang:binary_to_term/2</span> BIF that
takes an option list. The option <span class="code">safe</span> can be used
to prevent creation of resources that are not garbage
collected (such as atoms). (Thanks to Jayson Vantuyl.)</p>
<p>
Own Id: OTP-8367</p>
</li>
<li>
<p>
The default settings for garbage collection of binaries
has been adjusted to be less aggressive than in R13B03.
It is now also possible configure the settings for binary
GC. See the documentation for <span class="code">spawn_opt/2-5</span>,
<span class="code">erlang:system_info/1</span>, <span class="code">erlang:system_flag/2</span>,
<span class="code">process_flag/2-3</span>, <span class="code">erlang:trace/3</span>, and the
documenation for <span class="code">erl</span> for the new command line
options <span class="code">+hms</span> and <span class="code">+hmbs</span>.</p>
<p>
Own Id: OTP-8370</p>
</li>
<li>
<p>
A bug causing memory corruption in re:run() has been
corrected. (Thanks to Yamashina Hio.)</p>
<p>
Own Id: OTP-8375</p>
</li>
<li>
<p>
The <span class="code">-Werror</span> option for <span class="code">erlc</span> and the
compiler option <span class="code">warnings_as_errors</span> will cause
warnings to be treated as errors. (Thanks to Christopher
Faulet.)</p>
<p>
Own Id: OTP-8382</p>
</li>
<li>
<p>
Explicit top directories in archive files are now
optional.</p>
<p>
For example, if an archive (app-vsn.ez) just contains an
app-vsn/ebin/mod.beam file, the file info for the app-vsn
and app-vsn/ebin directories are faked using the file
info from the archive file as origin. The virtual
direcories can also be listed. For short, the top
directories are virtual if they does not exist.</p>
<p>
Own Id: OTP-8387</p>
</li>
<li>
<p>
An unnecessary lock operation in os:timestamp/0 has been
eliminated, making it slightly more efficient. (Thanks to
Jonas Falkevik and Tuncer Ayaz.)</p>
<p>
Own Id: OTP-8390</p>
</li>
<li>
<p>
There is a new <span class="code">+t</span> emulator option for changing the
maximum number of atoms. (Thanks to Julien Barbot.)</p>
<p>
Own Id: OTP-8405</p>
</li>
<li>
<p>
Fixed numerous compiler warnings generated by gcc 4.4.1
and tile-cc 2.0.1.78377 when compiling the runtime
system.</p>
<p>
Own Id: OTP-8412</p>
</li>
<li>
<p>
<span class="code">configure</span> learned the option
<span class="code">--enable-m32-build</span> to force the building of a
32-bit run-time on systems where the default C compiler
generates 64-bit executables by default.</p>
<p>
Own Id: OTP-8415</p>
</li>
<li>
<p>
HiPE now works in the 64-bit emulator on Mac OS X.
(Thanks to Geoff Cant.)</p>
<p>
Own Id: OTP-8416</p>
</li>
<li>
<p>
Improved handling of symbolic links to escripts</p>
<p>
Own Id: OTP-8417</p>
</li>
<li>
<p>
Add lock profiling tool.</p>
<p>
The Lock profiling tool, lcnt, can make use of the
internal lock statistics when the runtime system is built
with this feature enabled.</p>
<p>
This provides a mechanism to examine potential lock
bottlenecks within the runtime itself.</p>
<p>
- Add erts_debug:lock_counters({copy_save, bool()}). This
option enables or disables statistics saving for
destroyed processes and ets-tables. Enabling this might
consume a lot of memory.</p>
<p>
- Add id-numbering for lock classes which is otherwise
undefined.</p>
<p>
Own Id: OTP-8424</p>
</li>
<li>
<p>
Removed spurious options to the emulator from escript.</p>
<p>
Own Id: OTP-8427</p>
</li>
<li>
<p>
Minor documentation fixes. Mainly anchor adjustments.</p>
<p>
Own Id: OTP-8457</p>
</li>
</ul>
<h3><a name="id102019">1.22
Erts 5.7.4</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
An insufficient stack allocation was made when reading
CPU information on BSD operating systems. (Thanks Michael
Turner and Akira Kitada)</p>
<p>
Own Id: OTP-8207</p>
</li>
<li>
<p>
A bug when supplying an argument without a dash directly
after the program name when starting erlang could prevent
distribution to start. This is now corrected.</p>
<p>
Own Id: OTP-8209</p>
</li>
<li>
<p>
A ticker process could potentially be blocked
indefinitely trying to send a tick to a node not
responding. If this happened, the connection would not be
brought down as it should.</p>
<p>
Own Id: OTP-8218</p>
</li>
<li>
<p>
Using certain firewalls (i.e. MS IAS Client and certain
versions of COMODO) could expose an undocumented
behaviour in the Win32 socket interface causing the name
resolution calls to hang infinitely. This is now worked
around by adding possibilities for port programs under
Windows to use overlapped I/O on their standard
input/output file handles.</p>
<p>
Own Id: OTP-8230</p>
</li>
<li>
<p>
Fixed bug on ETS tables with <span class="code">write_concurrency</span>.
The emulator could crash when doing a <span class="code">select</span> or
<span class="code">match</span> with a bound key without finding any object.</p>
<p>
Own Id: OTP-8242</p>
</li>
<li>
<p>The <span class="code">information-request</span> /
<span class="code">information-response</span>, and
<span class="code">group-leader-change-request</span> /
<span class="code">group-leader-changed-response</span> signal pairs
described below did not always adhere to the signal order
guarantees of Erlang's signal model in the runtime system
with SMP support. These signals could for example
sometimes pass exit signals.</p>
<p>The following BIFs behaviors can be modeled as if an
asynchronous <span class="code">information-request</span> signal is sent to
<span class="code">Pid</span>. If <span class="code">Pid</span> is alive, it responds with an
asynchronous <span class="code">information-response</span> signal;
otherwise, the runtime system responds with a
<span class="code">no-such-process</span> signal. When the response is
received, the caller transforms it into the result of the
BIF.</p> <ul> <li><span class="code">is_process_alive(Pid)</span></li>
<li><span class="code">erlang:process_display(Pid, Type)</span></li>
<li><span class="code">process_info(Pid)</span></li>
<li><span class="code">process_info(Pid, ItemSpec)</span></li> </ul>
<p>When <span class="code">Pid</span> resides on the same node as the caller
of <span class="code">group_leader(GroupLeader, Pid)</span>, the
<span class="code">group_leader/2</span> BIFs behavior can be modeled as if
an asynchronous <span class="code">group-leader-change-request</span> signal
is sent to <span class="code">Pid</span>. If <span class="code">Pid</span> is alive, it
responds with an asynchronous
<span class="code">group-leader-changed-response</span> signal; otherwise,
the runtime system responds with a <span class="code">no-such-process</span>
signal. When the response is received, the caller
transforms it into the result of the BIF. The distributed
case which only consists of an asynchronous
<span class="code">group-leader-change-request</span> signal and no response
is not effected.</p>
<p>
Own Id: OTP-8245</p>
</li>
<li>
<p>
Errors in the <span class="code">system_profile</span> documentation has
been corrected.</p>
<p>
Own Id: OTP-8257</p>
</li>
<li>
<p>
Low watermark socket option modified high watermark
instead of low watermark in the inet_driver. (Thanks to
Feng Yu and Tuncer Ayaz)</p>
<p>
Own Id: OTP-8279</p>
</li>
<li>
<p>
A race condition could cause the runtime system with SMP
support to end up in a completely unresponsive state.</p>
<p>
Own Id: OTP-8297</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
The use of <span class="code">pthread_cond_timedwait()</span> have been
completely removed from the runtime system. This since
its behavior is unpredictable when the system clock is
suddenly changed. The previous use of it was harmless.</p>
<p>
Own Id: OTP-8193</p>
</li>
<li>
<p>
The documentation is now built with open source tools
(xsltproc and fop) that exists on most platforms. One
visible change is that the frames are removed.</p>
<p>
Own Id: OTP-8201</p>
</li>
<li>
<p>
A new garbage collecting strategy for binaries which is
more aggressive than the previous implementation.
Binaries now has a virtual binary heap tied to each
process. When binaries are created or received to a
process it will check if the heap limit has been reached
and if a reclaim should be done. This imitates the
behavior of ordinary Erlang terms. The virtual heaps are
grown and shrunk like ordinary heaps. This will lessen
the memory footprint of binaries in a system.</p>
<p>
Own Id: OTP-8202</p>
</li>
<li>
<p>
The <span class="code">ErlDrvTermData</span> term types used by
<span class="code">driver_output_term()</span> and <span class="code">driver_send_term()</span>
have been extended with the term types
<span class="code">ERL_DRV_INT64</span>, and <span class="code">ERL_DRV_UINT64</span> for
passing 64-bit integers. Also the 64-bit integer data
types <span class="code">ErlDrvSInt64</span> and <span class="code">ErlDrvUInt64</span> have
been introduced.</p>
<p>
For more information see the <span class="bold_code"><a href="erl_driver.html">erl_driver(3)</a></span>
documentation.</p>
<p>
Own Id: OTP-8205</p>
</li>
<li>
<p>
[escript] The restriction that the first line in escripts
must begin with <span class="code">#!</span> has been removed.</p>
<p>
[escript] Some command line options to the escript
executable has now been documented. For example you can
run an escript in the debugger by just adding a command
line option.</p>
<p>
[escript] The documentation of the escript header syntax
has been clarified. For example the header is optional.
This means that it is possible to directly "execute"
<span class="code">.erl</span>, <span class="code">.beam</span> and<span class="code">.zip</span> files.</p>
<p>
Own Id: OTP-8215</p>
</li>
<li>
<p>
The instruction for building OTP on Windows was outdated
and incomplete, the document is updated.</p>
<p>
Also the otp_build script required windows drives to show
up in Cygwin using the /cygdrive prefix. That requirement
is now removed.</p>
<p>
Own Id: OTP-8219</p>
</li>
<li>
<p>
A module can have native implemented functions (NIFs)
that are dynamically loaded by calling
<span class="code">erlang:load_nif/2</span>. This is an experimental feature
that is not yet intended for production systems. It is
released with intention to get some early feedback on the
interfaces before they are carved in stone.</p>
<p>
Own Id: OTP-8220</p>
</li>
<li>
<p>
The <span class="code">float/1</span> BIF would always force a garbage
collection. The BIFs <span class="code">size/1</span>, <span class="code">byte_size/1</span>,
<span class="code">bit_size/1</span>, <span class="code">abs/1</span>, and <span class="code">round/1</span> would
force a garbage-collection if the result was not a
sufficiently small integer.</p>
<p>
Own Id: OTP-8221</p>
</li>
<li>
<p>
The <span class="bold_code"><a href="erlang.html#port_command-3">erlang:port_command/3</a></span>
BIF has been added. <span class="code">erlang:port_command/3</span> is
currently not auto imported, but it is planned to be auto
imported in OTP R14. For more information see the
<span class="bold_code"><a href="erlang.html">erlang(3)</a></span>
documentation.</p>
<p>
Own Id: OTP-8225</p>
</li>
<li>
<p>
'<span class="code">configure --enable-darwin-64bit</span>' would fail if
Snow Leopard had been booted with the 64-bit kernel.
(Thanks to Ryan M. Graham.)</p>
<p>
Own Id: OTP-8236</p>
</li>
</ul>
<h3><a name="id102526">1.23
Erts 5.7.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
On Windows, open_port({spawn,Command},Opts) could not run
executables with spaces in the path or filename,
regardless of quoting efforts. While
open_port({spawn_executable,Exec},Opts) can run any
executable, it was still impossible to use 'spawn' to do
the same thing. This is now corrected.</p>
<p>
Own Id: OTP-8055</p>
</li>
<li>
<p>
The scheduler bind type <span class="code">processor_spread</span> spread
schedulers too much on large NUMA systems.</p>
<p>
The new scheduler bind type <span class="code">spread</span> spreads
schedulers as much as possible, and behaves as
<span class="code">processor_spread</span> previously did. For more
information see the documentation of the <span class="code">+sbt</span>
command line argument in the <span class="code">erl(1)</span> documentation,
and the documentation of
<span class="code">erlang:system_flag(scheduler_bind_type,
SchedulerBindType)</span>.</p>
<p>
Own Id: OTP-8063</p>
</li>
<li>
<p>
Automatically detected CPU topology on Linux system could
erroneously contain logical processors with <span class="code">-1</span> as
identifiers. This happened when
<span class="code">sysconf(_SC_NPROCESSORS_CONF)</span> returned a value
larger than the amount of logical processors found.</p>
<p>
Own Id: OTP-8064</p>
</li>
<li>
<p>
When the minimal term [] (end of list) was sent as the
complete message to a process on another node, and
received there, it could not be decoded. This bug is now
corrected. Fortunately [] is uncommon as the complete
message in real applications but it is a serious bug
anyway.</p>
<p>
Own Id: OTP-8092</p>
</li>
<li>
<p>A bug when the floating point exception pointer was
not initialized has been corrected. It manifested itself
on CentOS 5.1 sometimes when a floating point value was
sent to a remote node. Bug reported and patch suggested
by David Reiss, confirmed by Mikael Pettersson.</p>
<p>Some build problems on IRIX was also corrected.
Problem reported by Patrick Baggett, patch by Mikael
Pettersson.</p>
<p>
Own Id: OTP-8095</p>
</li>
<li>
<p>
A terminating process could erroneously unregister a name
for another process. This could occur under the following
conditions: The name of the terminating process was
unregistered and then registered for another process
simultaneously as the process that first had the name was
terminating.</p>
<p>
Own Id: OTP-8099 Aux Id: seq11344 </p>
</li>
<li>
<p>
Running erlc in a very deep directory (with a path length
of more 256 or more characters) would cause the emulator
to crash in a call to <span class="code">list_to_atom/1</span>. (Thanks to
Chris Newcombe.)</p>
<p>
Own Id: OTP-8124</p>
</li>
<li>
<p>
A deadlock of the runtime system could occur when
unregistering the name of a port.</p>
<p>
Own Id: OTP-8145</p>
</li>
<li>
<p>
<span class="code">Makefile.in</span> has been updated to use the LDFLAGS
environment variable (if set). (Thanks to Davide
Pesavento.)</p>
<p>
Own Id: OTP-8157</p>
</li>
<li>
<p>
The pthread rwlock implemention on Linux could cause
starvation of writers. We, therefore, now use our own
rwlock implementation on Linux.</p>
<p>
Own Id: OTP-8158</p>
</li>
<li>
<p>
Open source Erlang builds are updated to work well on
Snow Leopard (MacOS X 10.6)</p>
<p>
Own Id: OTP-8168</p>
</li>
<li>
<p>
A call to <span class="code">erlang:system_info(schedulers_online)</span>
could end up in an infinite loop. This happened if the
amount of schedulers was larger than one, the amount of
schedulers online was one, and someone was blocking
multi-scheduling.</p>
<p>
Own Id: OTP-8169</p>
</li>
<li>
<p>
An error in erlang:system_profile/2 could cause
timestamped messages to arrive out of order in the SMP
case. This has now been fixed.</p>
<p>
Own Id: OTP-8171</p>
</li>
<li>
<p>
<span class="code">binary_to_atom/2</span> and
<span class="code">binary_to_existing_atom/2</span> would leak memory if the
binary contained unaligned data.</p>
<p>
Own Id: OTP-8192</p>
</li>
<li>
<p>
The async thread pool in the runtime system without SMP
support used a memory allocator that was not thread safe
for async jobs.</p>
<p>
Own Id: OTP-8194</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Processor internal NUMA nodes are now supported in the
ERTS internal CPU topology representation. For more
information see the documentation of the <span class="code">+sct</span>
command line argument in the <span class="code">erl(1)</span> documentation,
and the documentation of
<span class="code">erlang:system_info(cpu_topology)</span>.</p>
<p>
Own Id: OTP-8041</p>
</li>
<li>
<p>
Documentation for ets improved about concurrency.</p>
<p>
Own Id: OTP-8050</p>
</li>
<li>
<p>
Emulator flags in an escript were earlier inherited to
emulators started from from the emulator running the
escript. For example when an escript invoked
<span class="code">os:cmd("erl")</span>, the new emulator were given
erroneous emulator flags. This bug has now been fixed</p>
<p>
Escript filenames may now contain dots.</p>
<p>
Own Id: OTP-8060</p>
</li>
<li>
<p>
Made some BIFs non-recursive (relational operators,hash
and phash) to limit internal stack usage.</p>
<p>
Own Id: OTP-8065</p>
</li>
<li>
<p>
Fixed Windows specific bug in erl_prim_loader. Now it
handles the root directory (e.g. c:/) better. This bug
affected the directory listing in the debugger.</p>
<p>
Own Id: OTP-8080</p>
</li>
<li>
<p>
A TCP socket with option <span class="code">{packet,4}</span> could crash
the emulator if it received a packet header with a very
large size value (>2Gb). The same bug caused
<span class="code">erlang:decode_packet/3</span> to return faulty values.
(Thanks to Georgos Seganos.)</p>
<p>
Own Id: OTP-8102</p>
</li>
<li>
<p>
The maximum size of the export table has been raised from
65536 to 524288 entries.</p>
<p>
Own Id: OTP-8104 Aux Id: seq11345 </p>
</li>
<li>
<p>
The file module has now a read_line/1 function similar to
the io:get_line/2, but with byte oriented semantics. The
function file:read_line/1 works for raw files as well,
but for good performance it is recommended to use it
together with the 'read_ahead' option for raw file
access.</p>
<p>
Own Id: OTP-8108</p>
</li>
<li>
<p>
Fixed bug causing emulator crash when reading a term in
external format containing a corrupt list with a negative
length.</p>
<p>
Own Id: OTP-8117</p>
</li>
<li>
<p>
New emulator flag <span class="code">+sss</span>, to set stack size of
scheduler threads.</p>
<p>
Own Id: OTP-8119</p>
</li>
<li>
<p>
The Windows utility Erlsrv, run in interactive mode now
accepts options for registering internal service name and
description field of Windows registry database.</p>
<p>
Own Id: OTP-8132</p>
</li>
<li>
<p>
<span class="code">erlang:demonitor(Mon, [flush])</span> has been optimized.
Previously it always searched the message queue of the
caller for a <span class="code">'DOWN'</span> message. Current
implementation only search the message queue when
necessary. It is quite common that the search is not
necessary.</p>
<p>
A new option <span class="code">info</span> has been added to
<span class="code">erlang:demonitor/2</span>. For more information see the
<span class="code">erlang(3)</span> documentation.</p>
<p>
Own Id: OTP-8143</p>
</li>
<li>
<p>
I/O tasks could unnecessarily be rescheduled. This was
harmless, but not useful work.</p>
<p>
Own Id: OTP-8148</p>
</li>
<li>
<p>
Minor improvements of <span class="code">erlang:memory/[1,2]</span>.</p>
<p>
Own Id: OTP-8152</p>
</li>
<li>
<p>
New configuration option to enable use of shared zlib.</p>
<p>
Own Id: OTP-8155</p>
</li>
<li>
<p>
Fixed smp bug in ETS that could cause emulator crash when
table with more than 1000 objects accessed by several
processes, including calls to variants of <span class="code">select</span>
or <span class="code">match</span> combined with concurrent object deletion.</p>
<p>
Own Id: OTP-8166 Aux Id: seq11392 </p>
</li>
<li>
<p>
The code path interpretation is now more relaxed. The
flag -code_path_choice now defaults to relaxed instead of
strict. See the documentation of code and init for more
info.</p>
<p>
Own Id: OTP-8170</p>
</li>
<li>
<p>
Load balancing of run queues and check for I/O are
triggered more often than before in situations where
processes are scheduled often but are doing very little
work each time they execute.</p>
<p>
Own Id: OTP-8172</p>
</li>
<li>
<p>
Call tracing binary comprehensions would cause an
emulator crash. (Thanks to Paul Mineiro.)</p>
<p>
Own Id: OTP-8179</p>
</li>
<li>
<p>
<span class="code">binary_to_term/1</span> would crash the emulator instead
of generating a <span class="code">badarg</span> exception when given
certain invalid terms. (Thanks to Scott Lystig Fritchie.)</p>
<p>
Own Id: OTP-8180</p>
</li>
</ul>
<h3><a name="id103123">1.24
Erts 5.7.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Crash dumps should now cause less problems for the
crashdump_viewer application. (For processes where arity
was non-zero, the arguments are now longer printed - they
used to be printed in a format that was not parseable.)</p>
<p>
Own Id: OTP-7472 Aux Id: seq11019, 11292 </p>
</li>
<li>
<p>
Processes could potentially get stuck on an offline
scheduler.</p>
<p>
Own Id: OTP-7990</p>
</li>
<li>
<p>
<span class="code">binary_to_atom/2</span> and
<span class="code">binary_to_existing_atom/2</span> could leak memory if
they caused a <span class="code">badarg</span> exception.</p>
<p>
Own Id: OTP-7997</p>
</li>
<li>
<p>
A process could under very rare circumstances erroneously
be resumed.</p>
<p>
Own Id: OTP-8000</p>
</li>
<li>
<p>
Load balancing between schedulers could under rare
circumstances cause an emulator crash.</p>
<p>
Own Id: OTP-8008</p>
</li>
<li>
<p>
<span class="code">erlang:memory(processes_used)</span> always returned
<span class="code">0</span> instead of the correct value. (Thanks to Geoff
Cant)</p>
<p>
Own Id: OTP-8022</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Major improvements of the Erlang distribution for Erlang
runtime systems with SMP support. Previously distribution
port locks were heavily contended, and all encoding and
decoding for a specific distribution channel had to be
done in sequence. Lock contention due to the distribution
is now negligible and both encoding and decoding of
Erlang messages can be done in parallel.</p>
<p>
The old atom cache protocol used by the Erlang
distribution has been dropped since it effectively
prevented all parallel encoding and decoding of messages
passed over the same distribution channel.</p>
<p>
A new atom cache protocol has been introduced which
isolates atom cache accesses and makes parallel encoding
and decoding of messages passed over the same
distribution channel possible. The new atom cache
protocol also use an atom cache size 8 times larger than
before. The new atom cache protocol is documented in the
ERTS users guide.</p>
<p>
Erlang messages received via the distribution are now
decoded by the receiving Erlang processes without holding
any distribution channel specific locks. Erlang messages
and signals sent over the distribution are as before
encoded by the sending Erlang process, but now without
holding any distribution channel specific locks during
the encoding. That is, both encoding and decoding can be
and are done in parallel regardless of distribution
channel used.</p>
<p>
The part that cannot be parallelized is the atom cache
updates. Atom cache updates are therefore now scheduled
on the distribution port. Since it is only one entity per
distribution channel doing this work there is no lock
contention due to the atom cache updates.</p>
<p>
The new runtime system does not understand the old atom
cache protocol. New and old runtime systems can however
still communicate, but no atom cache will be used.</p>
<p>
Own Id: OTP-7774</p>
</li>
<li>
<p>
Fixed a bug that caused error logging from
<span class="code">driver_select</span> sometimes with additional symptoms
such as failing IP communications or even an emulator
crash.</p>
<p>
Own Id: OTP-7898 Aux Id: seq11304 </p>
</li>
<li>
<p>
Improved SMP concurrency for ETS tables. Several mutating
operations can now be performed truly concurrent on
different records of the same table. To support this, the
table has to be created with option
<span class="code">write_concurrency</span>, as it is achieved at the
expense of some execution and memory overhead.
<span class="code">ets:select</span> and <span class="code">select_count</span> has also been
improved for all tables to not acquire exclusive table
lock during the iteration.</p>
<p>
Own Id: OTP-7922</p>
</li>
<li>
<p>
erl (that is erl.exe and dyn_erl) and erlexec has been
made more dynamic so no hard coded paths needs to added
at installation time to erl (that is erl.ini and erl).
Reltool will make use of this in a future release.</p>
<p>
Own Id: OTP-7952</p>
</li>
<li>
<p>
Added functionality to get higher resolution timestamp
from system. The erlang:now function returns a timestamp
that's not always consistent with the actual operating
system time (due to resilience against large time changes
in the operating system). The function os:timestamp/0 is
added to get a similar timestamp as the one being
returned by erlang:now, but untouched by Erlangs time
correcting and smoothing algorithms. The timestamp
returned by os:timestamp is always consistent with the
operating systems view of time, like the calendar
functions for getting wall clock time, but with higher
resolution. Example of usage can be found in the os
manual page.</p>
<p>
Own Id: OTP-7971</p>
</li>
<li>
<p>
Two new options are added to open_port - spawn_executable
which runs external executables in a controlled way, and
spawn_driver which only opens port to loaded Erlang
drivers. See the erlang manual page for details.</p>
<p>
Own Id: OTP-7995</p>
</li>
<li>
<p>
New functionality in ETS to transfer the ownership of a
table. A table can either change owner be declaring an
"heir", another process that will inherit the table if
the owner terminates. A table can also change owner by
calling a new function <span class="code">ets:give_away</span>.</p>
<p>
Own Id: OTP-8006</p>
</li>
<li>
<p>
Updates to Tilera build environment.</p>
<p>
Own Id: OTP-8009</p>
</li>
<li>
<p>
A stack trace was unnecessarily saved during process
termination.</p>
<p>
Own Id: OTP-8014</p>
</li>
<li>
<p>
User defined CPU topology and scheduler bind type can now
be set from the command line when starting an emulator.
For more information see the documentation of the
<span class="code">+sct</span>, and the <span class="code">+sbt</span> emulator flags in the
<span class="code">erl(1)</span> documentation.</p>
<p>
The CPU topologies returned from
<span class="code">erlang:system_info/1</span> and
<span class="code">erlang:system_flag/2</span> now always contain the
<span class="code">processor</span> level, also when not strictly necessary.</p>
<p>
Own Id: OTP-8030</p>
</li>
<li>
<p>
Various fixes in ETS: <span class="code">ets:first</span> could return a
deleted key in a fixated table. <span class="code">ets:lookup</span> could
return objects out of order if a deleted object was
re-inserted into a fixed bag. <span class="code">ets:delete_object</span>
could fail to delete duplicate objects in a
duplicate_bag.</p>
<p>
Own Id: OTP-8040</p>
</li>
</ul>
<h3><a name="id103479">1.25
Erts 5.7.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Fixed a bug on Windows that could make
<span class="code">gen_tcp:send</span> hang trying to send an iolist of more
than 16 binaries.</p>
<p>
Own Id: OTP-7816</p>
</li>
<li>
<p>
The runtime system could under rare circumstances crash
during load balancing.</p>
<p>
Own Id: OTP-7908 Aux Id: otp-7500 </p>
</li>
<li>
<p>
<span class="code">run_erl</span> uses fallback if Unix98 pseudo-terminal is
not present on host.</p>
<p>
Own Id: OTP-7916 Aux Id: seq11249 </p>
</li>
<li>
<p>
A message buffer memory leak in the runtime system
without smp support has been fixed.</p>
<p>
Own Id: OTP-7941</p>
</li>
<li>
<p>Attempting to append a binary of 16Mb or greater to
another binary using the bit syntax would cause a
<span class="code">system_limit</span> exception. There was also several
cases when constructing binaries when a <span class="code">badarg</span>
exception was generated when it should have been
<span class="code">system_limit</span>.</p>
<p>
Own Id: OTP-7942</p>
</li>
<li>
<p>
The runtime system with SMP support failed to terminate
the caller of <span class="code">link(RemotePid)</span> properly, if
<span class="code">RemotePid</span> was the pid of a process on an
unreachable node. The calling process was in this case
marked as exiting, but never terminated.</p>
<p>
Own Id: OTP-7946</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Rudimentary support for cross compiling is added to the
source release. The support is still in its infancy and
has only been used to cross compile on Linux for a
different cpu architecture and a different Linux version,
but should be extendible to support other platforms as
well. The cross configuration files with examples are
placed in $ERL_TOP/xcomp/. View README.xcomp and run
$ERL_TOP/otp_build -help for further information.</p>
<p>
Own Id: OTP-7854</p>
</li>
<li>
<p>The escape sequence <span class="code">\{</span> which was given a new
interpretation in R13A has retained its old meaning (the
ASCII code for <span class="code">{</span>), which means that codes greater
than 255 have to be stated using hexadecimal characters
(for example, <span class="code">\x{AAA}</span>). The escape sequence
<span class="code">\xH</span> where H is a hexadecimal character followed by
something else but a hexadecimal character is no longer
valid (incompatibility with R13A). Character codes less
than 256 can be stated using two hexadecimal characters
(for example, <span class="code">\x0D</span>).</p>
<p>
Own Id: OTP-7891 Aux Id: OTP-7855 </p>
</li>
<li>
<p>The <span class="code">term_to_binary/1</span> BIF used to be implemented
with recursive C code, which could cause the Erlang
emulator to terminate because of a stack overflow.</p>
<p>Also fixed some minor issues in
<span class="code">term_to_binary/1</span> and <span class="code">binary_to_term/1</span>
pointed out by Matthew Dempsky.</p>
<p>
Own Id: OTP-7894</p>
</li>
<li>
<p>
Several glitches and performance issues in the Unicode
and I/O-system implementation of R13A have been
corrected.</p>
<p>
Own Id: OTP-7896 Aux Id: OTP-7648 OTP-7887 </p>
</li>
<li>
<p>
Minor documentation improvements of the
<span class="code">scheduler_bind_type</span> argument of
<span class="code">erlang:system_flag/2</span>, and the
<span class="code">scheduler_bind_type</span>, and the
<span class="code">scheduler_bindings</span> arguments of
<span class="code">erlang:system_info/1</span>.</p>
<p>
Own Id: OTP-7901 Aux Id: OTP-7777 </p>
</li>
<li>
<p>
There is a new BIF <span class="code">erlang:make_tuple/3</span>.</p>
<p>
Own Id: OTP-7913</p>
</li>
</ul>
<h3><a name="id103743">1.26
Erts 5.7</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p><strong>OpenSource:</strong></p>
<p>FreeBSD leap-seconds are handled according to patch
submitted by OpenSource user Kenji Rikitake. No test case
covers this functionality (unsupported platform).</p>
<p>
Own Id: OTP-7609</p>
</li>
<li>
<p>
A corrected bug in <span class="code">ets</span> for <span class="code">bag</span> and
<span class="code">duplicate_bag</span>. A <span class="code">delete/2</span> or
<span class="code">lookup_element/3</span> could miss objects in a fixed
table if one or more objects with the same key had
already been deleted.</p>
<p>
Own Id: OTP-7665</p>
</li>
<li>
<p>
A new driver call-back <span class="code">stop_select</span> is introduced
to allow drivers to de-select and then close a file
descriptor in a safe way in a SMP emulator. The old way
was not strictly according to posix standard and could in
some rare cases lead to unexpected behavior. A new flag
<span class="code">ERL_DRV_USE</span> can be passed to
<span class="code">driver_select()</span> to tell it that the descriptor
should be closed. <span class="code">stop_select</span> is then called when
it is safe to do so. Old drivers will however still work
as before.</p>
<p>
Own Id: OTP-7670</p>
</li>
<li>
<p>
A bug fixed for TCP sockets with option
<span class="code">{packet,http}</span>. An HTTP request with an absolute
URI was returned with a corrupt path string. This bug did
only exist in R12B-4 and R12B-5.</p>
<p>
Own Id: OTP-7682 Aux Id: OTP-7647 </p>
</li>
<li>
<p>
run_erl did in some cases fail to extract control
sequences from to_erl (like: winsize=X,Y) and did instead
send them to be interpreted by the erlang shell.</p>
<p>
Own Id: OTP-7688</p>
</li>
<li>
<p>
A bug in the installer on Windows not updating file
associations properly is now corrected.</p>
<p>
Own Id: OTP-7746</p>
</li>
<li>
<p>More space than necessary could be allocated in
binaries when appending to a binary (also in a binary
comprehension) and the data appended did not consist of
wholes bytes (e.g. 13 bits).</p>
<p>
Own Id: OTP-7747</p>
</li>
<li>
<p>
The gen_sctp option sctp_peer_addr_params,
#sctp_paddrparams{address={IP,Port} was erroneously
decoded in the inet driver. This bug has now been
corrected.</p>
<p>
Own Id: OTP-7755</p>
</li>
<li>
<p>
Outstanding async driver jobs leaked memory if the
issuing port died before the async jobs completed.</p>
<p>
Own Id: OTP-7784</p>
</li>
<li>
<p>A bug in the dynamic library loading affecting, among
others, OpenSolaris is now corrected. (Thanks to Paul
Fisher.)</p>
<p>
Own Id: OTP-7796</p>
</li>
<li>
<p>
run_erl compile errors fixed for FreeBSD</p>
<p>
Own Id: OTP-7817</p>
</li>
<li>
<p>
A bug in the inet driver for SCTP on Solaris showing for
e.g gen_sctp:abort/1 and gen_sctp:eof/1 has been
corrected. Patch suggestion by Simon Cornish.</p>
<p>
Own Id: OTP-7866</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
The order of objects visited in select for ordered_set is
now documented.</p>
<p>
Own Id: OTP-7339</p>
</li>
<li>
<p>
The runtime system with SMP support now uses multiple,
scheduler specific run queues, instead of one globally
shared run queue.</p>
<p>
The lock protecting the shared run queue was heavily
contended, and the shared run queue also caused Erlang
processes to randomly migrate between schedulers with
negative cache effects as a result.</p>
<p>
With the current scheduler specific run queue solution,
lock contention due to run queue protection has been
reduced, and Erlang processes are only migrated when
needed to balance the load between the schedulers. The
reduced amount of migration also reduce lock contention
on locks protecting the scheduler specific instances of
the erts internal memory allocators.</p>
<p>
The scheduler specific run queues are also a necessity
for a lot of future planned NUMA (Non-Uniform Memory
Access) specific optimizations.</p>
<p>
Own Id: OTP-7500</p>
</li>
<li>
<p>Support for Unicode is implemented as described in
EEP10. Formatting and reading of unicode data both from
terminals and files is supported by the io and io_lib
modules. Files can be opened in modes with automatic
translation to and from different unicode formats. The
module 'unicode' contains functions for conversion
between external and internal unicode formats and the re
module has support for unicode data. There is also
language syntax for specifying string and character data
beyond the ISO-latin-1 range.</p>
<p>The interactive shell will support input and output of
unicode characters when the terminal and operating system
supports it.</p>
<p>Please see the EEP and the io/io_lib manual pages as
well as the stdlib users guide for details.</p>
<p><strong>I/O-protocol incompatibilities:</strong></p>
<p>The io_protocol between io_Server and client is
updated to handle protocol data in unicode formats. The
updated protocol is now documented. The specification
resides in the stdlib <strong>users manual</strong>, which is a
new part of the manual.</p>
<p><strong>io module incompatibilities:</strong></p>
<p>The io:put_chars, io:get_chars and io:get_line all
handle and return unicode data. In the case where
binaries can be provided (as to io:put_chars), they shall
be encoded in UTF-8. When binaries are returned (as by
io:get_line/get_chars when the io_server is set in
<strong>binary mode</strong>) the returned data is also
<strong>always</strong> encoded as UTF-8. The file module however
still returns byte-oriented data, why file:read can be
used instead of io:get_chars to read binary data in
ISO-latin-1.</p>
<p><strong>io_lib module incompatibilities:</strong></p>
<p>io_lib:format can, given new format directives (i.e
"~ts" and "~tc"), return lists containing integers larger
than 255. </p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7648 Aux Id: OTP-7580 OTP-7514 OTP-7494
OTP-7443 OTP-7181 EEP10 EEP11 </p>
</li>
<li>
<p>
The format of the string returned by
<span class="code">erlang:system_info(system_version)</span> (as well as the
first message when Erlang is started) has changed. The
string now contains the both the OTP version number as
well as the erts version number.</p>
<p>
Own Id: OTP-7649</p>
</li>
<li>
<p>
Message passing has been further optimized for parallel
execution. Serial message passing is slightly more
expensive than before, but parallel send to a common
receiver is much cheaper.</p>
<p>
Own Id: OTP-7659</p>
</li>
<li>
<p>
Lock contention on the atom table lock when decoding
Erlang terms on the external format has been drastically
reduced.</p>
<p>
Own Id: OTP-7660</p>
</li>
<li>
<p>
The undocumented, unsupported, and deprecated guard BIF
<span class="code">is_constant/1</span> has been removed.</p>
<p>
*** INCOMPATIBILITY with R12B ***</p>
<p>
Own Id: OTP-7673</p>
</li>
<li>
<p>
The Erlang process lock implementation has been improved
by Mat Hostetter at Tilera Corporation.</p>
<p>
Own Id: OTP-7692</p>
</li>
<li>
<p>
A <span class="code">{nodedown, Node}</span> message passed by the
<span class="code">net_kernel:monitor_nodes/X</span> functionality is now
guaranteed to be sent after <span class="code">Node</span> has been removed
from the result returned by <span class="code">erlang:nodes/Y</span>.</p>
<p>
Own Id: OTP-7725</p>
</li>
<li>
<p>The short-circuit operators <span class="code">andalso</span> and
<span class="code">orelse</span> no longer guarantees that their second
argument is either <span class="code">true</span> or <span class="code">false</span>. As a
consequence, <span class="code">andalso</span>/<span class="code">orelse</span> are now
tail-recursive.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7748</p>
</li>
<li>
<p>
A new BIF, <span class="code">lists:keyfind/3</span>, has been added. It
works like <span class="code">lists:keysearch/3</span> except that it does
not wrap the returned tuple in a <span class="code">value</span> tuple in
case of success. (Thanks to James Hague for suggesting
this function.)</p>
<p>
Own Id: OTP-7752</p>
</li>
<li>
<p>
Optimization for drivers by creating small binaries
direct on process heap.</p>
<p>
Own Id: OTP-7762</p>
</li>
<li>
<p><span class="code">I bsl N</span> could cause the Erlang virtual machine
to run of memory instead generating a <span class="code">system_limit</span>
if N was absurdly huge. (Thanks to Daniel Hedlund.)</p>
<p>There would always be a garbage collection when
evaluating <span class="code">I bsl N</span> or <span class="code">I bsr N</span> if <span class="code">I</span>
was a bignum.</p>
<p>If <span class="code">I</span> is an integer and <span class="code">N</span> a bignum, <span class="code">I
bsl N</span> will now cause the correct <span class="code">system_limit</span>
exception instead of <span class="code">bad_arith</span> as in earlier
releases.</p>
<p>If <span class="code">I</span> is an integer and <span class="code">N</span> a bignum, <span class="code">I
bsr N</span> will return either 0 or -1 depending on the
sign of <span class="code">I</span> instead of causing a <span class="code">bad_arith</span>
exception as in earlier releases.</p>
<p>
Own Id: OTP-7764</p>
</li>
<li>
<p>
Scheduler threads can now be bound to logical processors
on newer Linux and Solaris systems. More systems will be
supported in the future.</p>
<p>
In some cases performance has increased drastically when
binding schedulers. Schedulers are not bound by default,
though. This since it might cause a performance
degradation if multiple programs have bound to
processors, e.g. multiple Erlang runtime systems. For
more information see the documentation of
<span class="code">erlang:system_flag/2</span>.</p>
<p>
In order to bind scheduler threads the CPU topology need
to be known. On some newer Linux and Solaris systems the
runtime system automatically detects the CPU topology. If
the emulator isn't able to automatically detect the CPU
topology, the CPU topology can be defined. For more
information see the documentation of
<span class="code">erlang:system_flag/2</span>.</p>
<p>
Own Id: OTP-7777</p>
</li>
<li>
<p>The compiler will refuse to a compile file where the
module name in the file differs from the output file
name.</p>
<p>When compiling using <span class="code">erlc</span>, the current working
directory will no be included in the code path (unless
explicitly added using "-pa .").</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7793</p>
</li>
<li>
<p>
The BIFs <span class="code">atom_to_binary/2</span>,
<span class="code">binary_to_atom/2</span>, and
<span class="code">binary_to_existing_atom/2</span> have been added.</p>
<p>
Own Id: OTP-7804</p>
</li>
<li>
<p>
The amount of schedulers online can now be changed during
operation. The amount of schedulers online defaults to
the same amount as available logical processors. For more
information see the documentation of
<span class="code">erlang:system_flag/2</span> and <span class="code">erl</span>.</p>
<p>
Own Id: OTP-7811</p>
</li>
<li>
<p>The deprecated functions <span class="code">erlang:fault/1</span>,
<span class="code">erlang:fault/2</span>, and <span class="code">file:rawopen/2</span> have
been removed.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7812</p>
</li>
<li>
<p>
Erts internal dynamically allocated process and port
specific data for rarely used data. This is used to
reduce memory usage of processes and ports that do not
use specific functionality. More functionality will be
moved to process and port specific data in future
releases.</p>
<p>
Own Id: OTP-7818</p>
</li>
<li>
<p>
New packet type <span class="code">http_bin</span> for gen_tcp sockets and
<span class="code">erlang:decode_packet</span>. It works like <span class="code">http</span>
except that strings are returned as binaries instead of
lists.</p>
<p>
Own Id: OTP-7821</p>
</li>
<li>
<p>
The obsolete wd_keeper program for embedded Solaris
systems has been removed.</p>
<p>
Own Id: OTP-7822</p>
</li>
<li>
<p>
Nodes belonging to different independent clusters can now
co-exist on the same host with the help of a new
environment variable setting ERL_EPMD_PORT.</p>
<p>
Own Id: OTP-7826</p>
</li>
<li>
<p>There are new functions <span class="code">erlang:min/2</span> and
<span class="code">erlang:max/2</span> to calculate the minimum and maximum
of two terms, respectively. Note that the functions are
not auto-imported, so they need to be imported explicitly
or the <span class="code">erlang</span> prefix must be used when calling
them.</p>
<p>
Own Id: OTP-7841</p>
</li>
<li>
<p>The copyright notices have been updated.</p>
<p>
Own Id: OTP-7851</p>
</li>
<li>
<p>Enhanced build environment for cross compilation to
Tilera Tile architecture.</p>
<p>Support for native ethread atomics on Tilera
Tile64/TilePro (Thanks to Tilera Corporation).</p>
<p>
Own Id: OTP-7852</p>
</li>
<li>
<p>The escape sequences <span class="code">\x</span> and <span class="code">\{</span> have been
assigned new interpretations (they used to return the
ASCII code for <span class="code">x</span> and <span class="code">{</span> respectively). One
or more octal characters inside curly brackets after a
leading backslash is from now on an alternative to the
existing syntax <span class="code">\NNN</span>, but can also be used for
codes greater than 255. In a similar fashion, one or more
hexadecimal characters can be put inside curly brackets
after a leading <span class="code">\x</span>. Furthermore, the escape
sequences <span class="code">\xH</span> and <span class="code">\xHH</span>, where N is a
hexadecimal character, can be used for codes less than
256.</p>
<p>NOTE: These new escape sequences are still considered
experimental and may be changed in the R13B release.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7855</p>
</li>
<li>
<p>
The PCRE library's exported function names are now
prefixed with erts_ in the erlang emulator to avoid
clashes with dynamically loaded drivers.</p>
<p>
Own Id: OTP-7861</p>
</li>
<li>
<p>
A runtime system with SMP support will now be built by
default on most platforms if a usable posix thread
library or native windows threads are found.</p>
<p>
For more information see the top README file.</p>
<p>
Own Id: OTP-7872</p>
</li>
</ul>
<h3><a name="id104654">1.27
Erts 5.6.5.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
A corrected bug in <span class="code">ets</span> for <span class="code">bag</span> and
<span class="code">duplicate_bag</span>. A <span class="code">delete/2</span> or
<span class="code">lookup_element/3</span> could miss objects in a fixed
table if one or more objects with the same key had
already been deleted.</p>
<p>
Own Id: OTP-7665</p>
</li>
<li>
<p>
A bug fixed for TCP sockets with option
<span class="code">{packet,http}</span>. An HTTP request with an absolute
URI was returned with a corrupt path string. This bug did
only exist in R12B-4 and R12B-5.</p>
<p>
Own Id: OTP-7682 Aux Id: OTP-7647 </p>
</li>
<li>
<p>
Calling <span class="code">gen_tcp:send()</span> from several processes on
socket with option <span class="code">send_timeout</span> could lead to much
longer timeout than specified. The solution is a new
socket option <span class="code">{send_timeout_close,true}</span> that will
do automatic close on timeout. Subsequent calls to send
will then immediately fail due to the closed connection.</p>
<p>
Own Id: OTP-7731 Aux Id: seq11161 </p>
</li>
<li>
<p>
A process being garbage collected via the
<span class="code">garbage_collect/1</span> BIF or the
<span class="code">check_process_code/2</span> BIF didn't handle message
receive and resume correctly during the garbage collect.
When this occurred, the process returned to the state it
had before the garbage collect instead of entering the
new state.</p>
<p>
Own Id: OTP-7738</p>
</li>
</ul>
<h3><a name="id104765">1.28
Erts 5.6.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
A bug in inet_drv concerning gen_tcp:connect has been
corrected. A connect towards a non-open port through open
firewalls could sometimes erroneously be successful. Any
subsequent operation would fail, though.</p>
<p>
Own Id: OTP-6542</p>
</li>
<li>
<p>
Floating point arithmetics in drivers could cause a
runtime system crash and/or unexpected results on runtime
systems with floating point exceptions enabled. Floating
point exceptions are disabled unless explicitly enabled
or if hipe is enabled.</p>
<p>
Own Id: OTP-7237</p>
</li>
<li>
<p>
A bug when many sockets got signalled simultaneously
causing the emulator to panic with the message
"Inconsistent, why isnt io reported?" is now corrected.</p>
<p>
Own Id: OTP-7420</p>
</li>
<li>
<p>
Starting erl with option "-detached" now disconnects
correctly from terminal session on Unix.</p>
<p>
Own Id: OTP-7461</p>
</li>
<li>
<p>
Mended gdb etp-commands for ETS access.</p>
<p>
Own Id: OTP-7538</p>
</li>
<li>
<p>
<span class="code">erlang:decode_packet/3</span> allows white space between
HTTP header tag and colon according to RFC2616.</p>
<p>
Own Id: OTP-7543</p>
</li>
<li>
<p>
An emulator compiled for SCTP now starts even if the
dynamic libraries are not present. The SCTP driver is
then of course not loaded.</p>
<p>
Own Id: OTP-7551</p>
</li>
<li>
<p>To build on Mac OS X, 10.3.0 or later is now required
because of fixes for two problems:</p>
<p>There would be a resource leak when <span class="code">erl_ddl</span>
attempted to unload a driver. This problem has been
corrected by using <span class="code">dlopen()</span> (which works on all
modern Unix-like platforms) instead of the Mac OS X
specific API calls.</p>
<p>Signal handling in the run-time system for HiPE has
been updated to work on later versions of Mac OS X than
10.2.x. Therefore, <span class="code">--enable-hipe</span> now works on Mac
OS X with Intel CPUs.</p>
<p>Thanks to Geoff Cant for the patches.</p>
<p>
Own Id: OTP-7562</p>
</li>
<li>
<p>Corrected some information about the protocol between
EPMD and Erlang nodes. (Thanks to Michael Regen.)</p>
<p>
Own Id: OTP-7594</p>
</li>
<li>
<p>
When using
<span class="code">erlang:system_monitor(Pid,{long_gc,Time})</span>, and the
GC time exceeded 1 second, it sometimes erroneously
showed up as about 4300 seconds. (This bug was corrected
in R9C, but re-introduced in R12B.) (Thanks to Chris
Newcombe.)</p>
<p>
Own Id: OTP-7622 Aux Id: OTP-4903, seq8379 </p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
The driver entry of a dynamically loaded driver is now
copied when loaded which enables some internal
optimizations. Note that drivers that modify the driver
entry during execution will not work anymore. Such a
miss-use of the driver interface is however not
supported.</p>
<p>
Own Id: OTP-6900</p>
</li>
<li>
<p>
The split function is now added to the re library.
Exceptions and errors from both run, replace and split
are made more consistent.</p>
<p>
Own Id: OTP-7514 Aux Id: OTP-7494 </p>
</li>
<li>
<p>
Fixed harmless compiler warnings when building the
emulator and minor build changes in order to avoid
unnecessary rebuilds.</p>
<p>
Own Id: OTP-7530</p>
</li>
<li>
<p>
There is now experimental support for loading of code
from archive files. See the documentation of <span class="code">code</span>,
<span class="code">init</span>, <span class="code">erl_prim_loader </span> and <span class="code">escript</span>
for more info.</p>
<p>
The error handling of <span class="code">escripts</span> has been improved.</p>
<p>
An <span class="code">escript</span> may now set explicit arguments to the
emulator, such as <span class="code">-smp enabled</span>.</p>
<p>
An <span class="code">escript</span> may now contain a precompiled beam
file.</p>
<p>
An <span class="code">escript</span> may now contain an archive file
containing one or more applications (experimental).</p>
<p>
The internal module <span class="code">code_aux</span> has been removed.</p>
<p>
Own Id: OTP-7548 Aux Id: otp-6622 </p>
</li>
<li>
<p>
The reallocation functionality part of the ERTS internal
memory allocators, now consider current block in
combination with surrounding free blocks as an
alternative location for a reallocation.</p>
<p>
Own Id: OTP-7555</p>
</li>
<li>
<p>There could remain false references from a process to
a module that has been called earlier, so that the
process would be killed if the module was reloaded.
(Thanks to Richard Carlsson.)</p>
<p>Also, the fix for this bug also made it possible to
make stack backtraces (as returned from
<span class="code">erlang:get_stacktrace/0</span> and other functions) more
correct in that the immediate caller is always included
in the stack backtrace (it could sometimes be
missing).</p>
<p>
Own Id: OTP-7559</p>
</li>
<li>
<p>
Improved locking in IO-handling for better smp
performance.</p>
<p>
Own Id: OTP-7560</p>
</li>
<li>
<p>
Improved BIF rescheduling functionality.</p>
<p>
Own Id: OTP-7587</p>
</li>
<li>
<p>
Loading a module compiled with Erlang/OTP R9C and calling
<span class="code">module_info/0</span> in the module would crash the
emulator. The emulator now refuses to load any module
compiled with R9C or earlier. (Note: only trivial modules
compiled with R10B or earlier could be loaded anyway.)
(Thanks to Martin Kjellin.)</p>
<p>
Own Id: OTP-7590</p>
</li>
</ul>
<h3><a name="id105135">1.29
Erts 5.6.4.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
A process calling one of the following BIFs could under
very rare conditions deadlock in the runtime system with
SMP support: <span class="code">check_process_code/2</span>,
<span class="code">garbage_collect/1</span>, <span class="code">process_info/[1,2]</span>,
<span class="code">system_flag/2</span>, and
<span class="code">erlang:suspend_process/[1,2]</span>.</p>
<p>
Own Id: OTP-7582</p>
</li>
<li>
<p>
A couple of statistics variables were not managed in a
thread safe manner in the runtime system with SMP
support.</p>
<p>
Own Id: OTP-7583</p>
</li>
<li>
<p>
An extremely rare race condition when terminating a
process could potentially cause a runtime system crash.</p>
<p>
Own Id: OTP-7584</p>
</li>
<li>
<p>
Under certain conditions and when using run_erl/to_erl,
the terminal Erlang driver (ttsl_drv) could crash the
emulator by doing a division by zero due to incorrect
handling of terminals reporting a zero width. For
terminals reporting zero width, the driver now fallbacks
to a default width of 80 and a default height of 24
(vt100), as a fallback behaviour. This fixes the crashes
and also makes output on "dumb" terminals much more
readable.</p>
<p>
Own Id: OTP-7592 Aux Id: seq11073 </p>
</li>
</ul>
<h3><a name="id105224">1.30
Erts 5.6.4.1</a></h3>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
A new <span class="code">erts_alloc</span> parameter
<span class="code">+M<S>rmbcmt</span> (relative multiblock carrier
move threshold) has been added. It determines when to
force a moving realloc in a multiblock carrier when a
block is shrunk. For more information see the
<span class="code">erts_alloc(3)</span> documentation.</p>
<p>
Own Id: OTP-7540</p>
</li>
<li>
<p>The new option <span class="code">+d</span> can be given to <span class="code">erl</span> to
suppress the crash dump generation if an internal error
is detected. As a result, a more useful core dump is
produced.</p>
<p>
Own Id: OTP-7578 Aux Id: seq11052 </p>
</li>
</ul>
<h3><a name="id105287">1.31
Erts 5.6.4</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Double backslashes in format string passed to the erts
internal printf implementation produced erroneous
results. No such format strings were passed to the erts
internal printf implementation, i.e., the bug was
therefore completely harmless. (Thanks to Perry Smith.)</p>
<p>
Own Id: OTP-7408</p>
</li>
<li>
<p>
Large files are now handled on Windows, where the
filesystem supports it.</p>
<p>
Own Id: OTP-7410</p>
</li>
<li>
<p>
Bug fixed for <span class="code">{packet,http}</span> when space follows
http headers.</p>
<p>
Own Id: OTP-7458</p>
</li>
<li>
<p>
The trace option <span class="code">running</span> could cause an emulator
crash if the current function couldn't be determined.</p>
<p>
Own Id: OTP-7484</p>
</li>
<li>
<p>
Using 16#ffffFFFF as a timeout value in receive...after
would often cause a timeout almost at once due to an
32-bit integer overflow. (Thanks to Serge Aleynikov and
Matthias Lang.)</p>
<p>
Own Id: OTP-7493</p>
</li>
<li>
<p>
For the process that an escript runs in, the
<span class="code">trap_exit</span> process flag is now <span class="code">false</span> instead
of <span class="code">true</span> (as in previous releases). Scripts that
depend on the previous (counter-intuitive) behaviour
might not work. (Thanks to Bengt Kleberg.)</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7517</p>
</li>
<li>
<p>
A bug in the <span class="code">string:to_integer/1</span> builtin made the
emulator unstable. This is now corrected. (Thanks to Lev
Walkin.)</p>
<p>
Own Id: OTP-7526</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Performance for ETS intensive applications should now
be better in the SMP emulator. Also, ETS table
identifiers (as returned by <span class="code">ets:new/2</span>) are now
spread out in wider range than before (using 28 bits in a
32-bit emulator) to make sure that the table identifier
for a deleted table will not be quickly re-used.</p>
<p>NOTE: Table identifiers can now be negative integers.
Programs that (incorrectly) assume that table identifiers
can only be positive integers might stop to work. (The
type of a table identifier is intentionally not
documented, and may change in a future release.)</p>
<p>
Own Id: OTP-7348</p>
</li>
<li>
<p>
New BIF <span class="code">erlang:decode_packet/3</span> that extracts a
protocol packet from a binary. Similar to the socket
option <span class="code">{packet, Type}</span>. Also documented the socket
packet type <span class="code">http</span> and made it official.
<strong>NOTE</strong>: The tuple format for <span class="code">http</span> packets
sent from an active socket has been changed in an
incompatible way.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7404</p>
</li>
<li>
<p>
The source code for the documentation for some
applications (erts, kernel, stdlib, and several others)
are now included in the source tar ball. There is
currently no Makefile support for building HTML files
from the source (such support will be included in a
future release).</p>
<p>
Own Id: OTP-7406</p>
</li>
<li>
<p>
A lot of frequently accessed memory counters (erts
internal) have been removed. This since they hurt
performance on the runtime system with SMP support. As a
result <span class="code">erlang:memory/[0,1]</span> will only deliver a
result if all <span class="code">erts_alloc(3)</span> allocators are enabled
(default). The result delivered when all
<span class="code">erts_alloc(3)</span> allocators are enabled are both more
accurate and less accurate than before. More memory than
before are included in the result, but the different
parts that are summed are not gathered atomically. A call
to <span class="code">erlang:memory/[0,1]</span> is much cheaper for the
system than before. This since the information isn't
gathered atomically anymore which was very expensive.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7468</p>
</li>
<li>
<p>
Pre-allocators used for, for example, timers, and
messages have been rewritten to be scheduler specific.
That is, different schedulers will now allocate from
different pools which reduces lock contention.</p>
<p>
Own Id: OTP-7470</p>
</li>
<li>
<p>
On Mac OS X, file:sync/1 now guarantees that all
filesystem buffers are written to the disk by using the
fcntl() with F_FULLFSYNC option. Previously, file:sync/1
called fsync(), which only guaranteed that the data had
been transferred to the disk drive. (Thanks to Jan
Lehnardt.)</p>
<p>
Own Id: OTP-7471</p>
</li>
<li>
<p>
Termination of a process that takes a long time can now
be preempted, i.e., the terminating process will be
rescheduled for later continuation of termination so that
other processes can execute. Termination of a process
that owns many and/or large ets tables typically takes a
long time.</p>
<p>
Own Id: OTP-7477</p>
</li>
<li>
<p>
A new trace option <span class="code">exiting</span> has been added. The
<span class="code">exiting</span> trace is similar to the <span class="code">running</span>
trace, but for exiting processes. For more information
see the erlang(3) documentation.</p>
<p>
The <span class="code">erlang:trace/3</span> bif now doesn't block other
scheduler threads if only one tracee is specified in the
call to <span class="code">erlang:trace/3</span>.</p>
<p>
Own Id: OTP-7481</p>
</li>
<li>
<p>
The re module is extended with repetitive matches (global
option) and replacement function.</p>
<p>
Own Id: OTP-7494 Aux Id: OTP-7181 </p>
</li>
<li>
<p>
In the section about binary construction, the reference
manual now mentions what happens when an integer value
does not fit into an integer segment of size N (namely,
that the N least significant bits will be put into into
the binary and that the most significant bits will be
silently discarded). (Thanks to Edwin Fine.)</p>
<p>
Own Id: OTP-7506</p>
</li>
<li>
<p>
Setting the <span class="code">{active,once}</span> for a socket (using
inets:setopts/2) is now specially optimized (because the
<span class="code">{active,once}</span> option is typically used much more
frequently than other options).</p>
<p>
Own Id: OTP-7520</p>
</li>
</ul>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
Floating point arithmetics in drivers can cause a runtime
system crash and/or unexpected results on runtime systems
with floating point exceptions enabled. Floating point
exceptions are disabled unless explicitly enabled or if
hipe is enabled.</p>
<p>
Own Id: OTP-7237</p>
</li>
</ul>
<h3><a name="id105684">1.32
Erts 5.6.3.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Binary construction with an integer field of size 0 at
the end of the constructed binary (and the size given in
a variable), would cause a write of one byte outside the
memory reserved for the binary, which in turn could cause
an emulator crash.</p>
<p>
Own Id: OTP-7422</p>
</li>
<li>
<p>
A race condition in the dynamic driver implementation
could cause an emulator crash. (Thanks to Paul Fisher)</p>
<p>
Own Id: OTP-7464</p>
</li>
<li>
<p>
Calls to <span class="code">erlang:system_info(allocated_areas)</span> could
cause the runtime system with SMP support to crash.</p>
<p>
Own Id: OTP-7474</p>
</li>
<li>
<p>
The <span class="code">env</span> option to <span class="code">open_port()</span> could cause
the runtime system with SMP support to crash.</p>
<p>
Own Id: OTP-7475</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Operations that needed to block other threads in the
runtime system with SMP support unnecessarily waited for
async threads to block. Most important the
<span class="code">erlang:memory/[0,1]</span> bif, code loading, and the
<span class="code">erlang:trace/3</span> bif.</p>
<p>
Own Id: OTP-7480</p>
</li>
</ul>
<h3><a name="id105794">1.33
Erts 5.6.3.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Calls to <span class="code">erlang:memory/[0,1]</span> could cause the
runtime system with SMP support to crash.</p>
<p>
Own Id: OTP-7415</p>
</li>
</ul>
<h3><a name="id105828">1.34
Erts 5.6.3.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Doing local call trace on bit syntax matching code that
has been optimized with delayed sub-binary creation could
crash the emulator.</p>
<p>
Own Id: OTP-7399 Aux Id: seq10978 </p>
</li>
</ul>
<h3><a name="id105859">1.35
Erts 5.6.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Only one to_erl process at a time is allowed to connect
to the same run_erl pipe. Prevents buggy behaviour when
IO from several to_erl's get interleaved.</p>
<p>
Own Id: OTP-5107</p>
</li>
<li>
<p>
IPv6 name resolving has now been fixed to use
getaddrinfo() patch (thoroughly reworked) courtesy of Love
Hörnquist-Åstrand submitted by Fredrik Thulin. It also
can use gethostname2() patch (also reworked) courtesy of
Mikael Magnusson for debian submitted by Sergei Golovan.</p>
<p>
Own Id: OTP-5382</p>
</li>
<li>
<p>
Improved error handling in run_erl</p>
<p>
Own Id: OTP-7252</p>
</li>
<li>
<p>A permanent fix for the deadlock issue temporarily
fixed by OTP-7260.</p> <dl>
<dt><strong>OTP-7260</strong></dt>
<dd>
The runtime system with SMP support could under rare
circumstances deadlock when a distribution channel was
taken down while multiple simultaneous operations were
performed on it. </dd>
</dl>
<p>
Own Id: OTP-7267 Aux Id: OTP-7260 </p>
</li>
<li>
<p>
./configure has been improved to find 64-bit OpenSSL
libraries.</p>
<p>
Own Id: OTP-7270</p>
</li>
<li>
<p>
A terminating process could under very rare circumstances
trigger a bug which could crash the runtime system with
SMP support.</p>
<p>
Own Id: OTP-7272</p>
</li>
<li>
<p>
SCTP_ADDR_CONFIRMED events are now handled by gen_sctp.</p>
<p>
Own Id: OTP-7276</p>
</li>
<li>
<p>
binary_to_term/1 would crash the emulator if the binary
data contained an external fun with non-atom module
and/or function. Corrected to generate a badarg
exception.</p>
<p>
Own Id: OTP-7281</p>
</li>
<li>
<p>
On Mac OS 10.5 (Leopard), sending to socket which the
other end closes could cause the emulator to consume 100%
CPU time. (Thanks to Matthias Radestock.)</p>
<p>
Own Id: OTP-7289</p>
</li>
<li>
<p>
The vanilla driver used on Windows could crash the
emulator and sometimes produced corrupt files. The
vanilla driver is the driver that is used when one only
pass a filename as first argument to <span class="code">open_port/2</span>.
<strong>NOTE</strong>: This use of <span class="code">open_port/2</span> is
<strong>obsolete</strong>, and the documentation of this use has
previously been removed. The functionality is only
present for backward compatibility reasons and
<strong>will</strong> eventually be removed.</p>
<p>
Own Id: OTP-7301</p>
</li>
<li>
<p>
Faulty matching in binaries larger than 512Mb on 64bit
machines fixed.(On 32bit, the size limit for binaries is
still 512Mb). Thanks to Edwin Fine and Per Gustafsson for
finding fault and fix.</p>
<p>
Own Id: OTP-7309</p>
</li>
<li>
<p>
crypto:start() on Windows caused emulator to hang on
error popup window if openssl DLL was not found. Windows
error popups now suppressed.</p>
<p>
Own Id: OTP-7325</p>
</li>
<li>
<p>
Configuration option <span class="code">without-termcap</span> can be used to
disable the use of termcap libraries for terminal cursor
control in the shell.</p>
<p>
Own Id: OTP-7338</p>
</li>
<li>
<p>
to_erl reports its terminal window size to run_erl in
order to get output formatted accordingly</p>
<p>
Own Id: OTP-7342</p>
</li>
<li>
<p>
On Solaris, the <span class="code">compressed</span> option for file
operations did not work if the file descriptor happened
to be greater than 255 (a problem with fopen() and
friends in Solaris itself).</p>
<p>
Own Id: OTP-7343 Aux Id: seq10949 </p>
</li>
<li>
<p>
A race condition in the runtime system with SMP support
causing an erroneous removal of a newly created ets table
has been fixed.</p>
<p>
The race occurred when a process removed a table during
termination simultaneously as another process removed the
same table via <span class="code">ets:delete/1</span> and a third process
created a table that accidentally got the same internal
table index as the table being removed.</p>
<p>
Own Id: OTP-7349</p>
</li>
<li>
<p>
<span class="code">zlib:inflate</span> failed when the size of the inflated
data was an exact multiple of the internal buffer size
(4000 bytes by default).</p>
<p>
Own Id: OTP-7359</p>
</li>
<li>
<p>
If the total number of allowed atoms is exceeded, there
will now be a controlled termination of the emulator with
a crash dump file. The emulator used to simply crash.
(Thanks Howard Yeh and Thomas Lindgren.)</p>
<p>
Own Id: OTP-7372</p>
</li>
<li>
<p>
The break handler in werl on Windows could cause the
emulator to hang or crash, that is now corrected.</p>
<p>
Own Id: OTP-7394 Aux Id: seq10969 </p>
</li>
<li>
<p>
The configure script now tests for an serious
optimization bug in gcc-4.3.0. If the bug is present, the
configure script will abort (if this happens, the only
way to build Erlang/OTP is to change to another version
of gcc). (Thanks to Mikael Pettersson.)</p>
<p>
Own Id: OTP-7397</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
On Unix, the emulator now notices when the width of the
terminal has changed. (Thanks to Matthew Dempsky and
Patrick Mahoney.)</p>
<p>
Own Id: OTP-7290</p>
</li>
<li>
<p>
There is a new function <span class="code">init:stop/1</span> which can be
used to shutdown the system cleanly AND generate a
non-zero exit status or crash dump. (Thanks to Magnus
Froberg.)</p>
<p>
Own Id: OTP-7308</p>
</li>
<li>
<p>
process_info(Pid, garbage_collection) now returns more
information</p>
<p>
Own Id: OTP-7311</p>
</li>
<li>
<p>
The <span class="code">hide</span> option for <span class="code">open_port/2</span> is now
documented. (Thanks to Richard Carlsson.)</p>
<p>
Own Id: OTP-7358</p>
</li>
</ul>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
Floating point arithmetics in drivers can cause a runtime
system crash on runtime systems with floating point
exceptions enabled. Floating point exceptions are
disabled unless explicitly enabled or if hipe is enabled.</p>
<p>
Own Id: OTP-7237</p>
</li>
</ul>
<h3><a name="id106272">1.36
Erts 5.6.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
The maximum length of an atom of 255 characters is now
strictly enforced. <span class="code">binary_to_term/1</span> will now fail
with a badarg if an encoded term contains an atom longer
than 255 characters. Atoms created by drivers will now be
truncated to 255 characters if necessary. (Thanks to
Matthew Dempsky.)</p>
<p>
Own Id: OTP-7147</p>
</li>
<li>
<p>
A bug in "bignum handling" on some 64bit architectures
could cause rem and div operations on large numbers to
hang indefinitely. Rem operations involving the smallest
negative number representable in 28 bits or 60 bits could
also cause access violation and emulator crash. Both
errors are corrected.</p>
<p>
Own Id: OTP-7177</p>
</li>
<li>
<p>
When doing the initial garbage collection after waking a
hibernated process, a fullsweep garbage collection was
unnecessarily triggered.</p>
<p>
Own Id: OTP-7212</p>
</li>
<li>
<p>The beta testing module <span class="code">gen_sctp</span> now supports
active mode as stated in the documentation. Active mode
is still rather untested, and there are some issues about
what should be the right semantics for
<span class="code">gen_sctp:connect/5</span>. In particular: should it be
blocking or non-blocking or choosable. There is a high
probability it will change semantics in a (near) future
patch.</p> <p>Try it, give comments and send in bug
reports!</p>
<p>
Own Id: OTP-7225</p>
</li>
<li>
<p>
Invalid arguments to <span class="code">ets:update_counter/3</span> were not
handled correctly. A tuple position (<span class="code">Pos</span>) less
than 1 caused the element directly following the key to
be updated (as if no position at all had been specified).
All invalid values for <span class="code">Pos</span> will now fail with
<span class="code">badarg</span>.</p>
<p>
Own Id: OTP-7226</p>
</li>
<li>
<p>
The runtime system with SMP support could under rare
circumstances deadlock when a distribution channel was
taken down while multiple simultaneous operations were
performed on it.</p>
<p>
Own Id: OTP-7260</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
More checksum/hash algorithms from the zlib library are
now available as built in functions (like md5 hashes has
been for a long time).</p>
<p>
Own Id: OTP-7128</p>
</li>
<li>
<p>
Minor improvements in the garbage collector.</p>
<p>
Own Id: OTP-7139 Aux Id: OTP-7132 </p>
</li>
<li>
<p>
The switch "-detached" to the windows werl program now
can create an erlang virtual machine without any main
window and without a temporary console showing.</p>
<p>
Own Id: OTP-7142</p>
</li>
<li>
<p><span class="code">erlang:system_info/1</span> now accepts the
<span class="code">logical_processors</span>, and <span class="code">debug_compiled</span>
arguments. For more info see the, <span class="code">erlang(3)</span>
documentation.</p> <p>The scale factor returned by
<span class="code">test_server:timetrap_scale_factor/0</span> is now also
effected if the emulator uses a larger amount of
scheduler threads than the amount of logical processors
on the system. </p>
<p>
Own Id: OTP-7175</p>
</li>
<li>
<p>
A new BIF ets:update_element/3. To update individual
elements within an ets-tuple, without having to read,
update and write back the entire tuple.</p>
<p>
Own Id: OTP-7200</p>
</li>
<li>
<p>
A process executing the <span class="code">processes/0</span> BIF can now be
preempted by other processes during its execution. This
in order to disturb the rest of the system as little as
possible. The returned result is, of course, still a
consistent snapshot of existing processes at a time
during the call to <span class="code">processes/0</span>.</p>
<p>
The documentation of the <span class="code">processes/0</span> BIF and the
<span class="code">is_process_alive/1</span> BIF have been updated in order
to clarify the difference between an existing process and
a process that is alive.</p>
<p>
Own Id: OTP-7213</p>
</li>
</ul>
<h3><a name="id106528">1.37
Erts 5.6.1.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Not enough parameters were passed when sending an error
report in erl_check_io.c (Thanks to Matthew Dempsky).</p>
<p>
Own Id: OTP-7176</p>
</li>
<li>
<p>
In rare circumstances, complex binary matching code could
cause the emulator to crash or not match when it should.
(Thanks to Rory Byrne.)</p>
<p>
Own Id: OTP-7198</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The <span class="code">{allocator_sizes, Alloc}</span> and
<span class="code">alloc_util_allocators</span> arguments are now accepted
by <span class="code">erlang:system_info/1</span>. For more information see
the <span class="code">erlang(3)</span> documentation.</p>
<p>
Own Id: OTP-7167</p>
</li>
<li>
<p>
The finishing reallocation of the heap block when
hibernating a process is now always moving the heap block
since it drastically reduces memory fragmentation when
hibernating large amounts of processes.</p>
<p>
Own Id: OTP-7187</p>
</li>
</ul>
<h3><a name="id106623">1.38
Erts 5.6.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
The SMP emulator on sparc64 erroneously used the sparc32
atomic and the sparc32 spinlock implementations which
caused it to crash.</p>
<p>
Own Id: OTP-7006</p>
</li>
<li>
<p>
Call tracing the new guard BIFs <span class="code">byte_size</span>,
<span class="code">bit_size</span>, or <span class="code">tuple_size</span> and the loading a
module that uses one of those functions, could cause the
emulator to terminate.</p>
<p>
Own Id: OTP-7008</p>
</li>
<li>
<p>
configuring --enable-darwin-universal or
--enable-darwin-64bit on MacOSX could result in a non
optimized emulator. Top level configure script now
corrected.</p>
<p>
Own Id: OTP-7014</p>
</li>
<li>
<p>
configuring --with-gd did not produce correct include
flags for percept.</p>
<p>
Own Id: OTP-7015</p>
</li>
<li>
<p>
Environment variables weren't handled in thread safe
manner in the runtime system with SMP support on Windows.</p>
<p>
<span class="code">erl_drv_putenv()</span>, and <span class="code">erl_drv_getenv()</span> has
been introduced for use in drivers. Do <strong>not</strong> use
putenv(), or getenv() directly in drivers. For more
information see the <span class="code">erl_driver</span> documentation.</p>
<p>
Own Id: OTP-7035</p>
</li>
<li>
<p>
HIPE: Corrected the choice of interface to the send/3 and
setnode/3 BIFs for native-compiled code. Using the
incorrect interface could, in unusual circumstances, lead
to random runtime errors.</p>
<p>
Own Id: OTP-7067</p>
</li>
<li>
<p>
Garbage collections could become extremely slow when
there were many keys in the process dictionary. (Thanks
to Fredrik Svahn.)</p>
<p>
Own Id: OTP-7068</p>
</li>
<li>
<p>
The duplicate documentation directory in the windows
installation is removed.</p>
<p>
Own Id: OTP-7070</p>
</li>
<li>
<p>Documentation bugfixes and clarifications.</p> (Thanks
to Joern (opendev@gmail.com), Matthias Lang, and Richard
Carlsson.)
<p>
Own Id: OTP-7079</p>
</li>
<li>
<p>
The runtime system with SMP support <strong>not</strong> using
the native atomic integer implementation part of OTP
could deadlock when run on a system with more than one
logical processor. That is, only the runtime system with
SMP support on <strong>other</strong> hardware platforms than
x86, x86_64, sparc32, and powerpc32 were effected by this
bug.</p>
<p>
Own Id: OTP-7080</p>
</li>
<li>
<p>
The break handling code (run when Ctrl-C is hit) could
could potentially deadlock the runtime system with SMP
support.</p>
<p>
Own Id: OTP-7104</p>
</li>
<li>
<p>
The sctp driver has been updated to work against newer
lksctp packages e.g 1.0.7 that uses the API spelling
change adaption -> adaptation. Older lksctp (1.0.6) still
work. The erlang API in gen_sctp.erl and inet_sctp.hrl
now spells 'adaptation' regardless of the underlying C
API.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7120</p>
</li>
<li>
<p>A bug in <span class="code">erlang:phash2/1</span> on 64-bit platforms
has been fixed. (Thanks to Scott Lystig Fritchie.)</p>
<p>
Own Id: OTP-7127</p>
</li>
<li>
<p>
The emulator could under rare circumstances crash while
garbage collecting.</p>
<p>
Own Id: OTP-7132</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The documentation has been updated so as to reflect
the last updates of the Erlang shell as well as the minor
modifications of the control sequence <span class="code">p</span> of the
<span class="code">io_lib</span> module.</p> <p>Superfluous empty lines have
been removed from code examples and from Erlang shell
examples.</p>
<p>
Own Id: OTP-6944 Aux Id: OTP-6554, OTP-6911 </p>
</li>
<li>
<p>
Bit syntax construction with a small integer in a
non-byte aligned field wider than the CPU's word size
could cause garbage bits in the beginning of the field.</p>
<p>
Own Id: OTP-7085</p>
</li>
<li>
<p>
All Windows versions older than Windows 2000 are now
<strong>not supported</strong> by the Erlang runtime system. This
since there was a need for usage of features introduced
in Windows 2000.</p>
<p>
Own Id: OTP-7086</p>
</li>
<li>
<p>Memory management improvements especially for the
runtime system with SMP support:</p> <ul> <li> The
runtime system with SMP support can now use multiple,
thread specific instances of most memory allocators. This
improves performance since it reduces lock contention in
the memory allocators. It may however increase memory
usage for some applications. The runtime system with SMP
support will by default enable this feature on most
allocators. The amount of instances used can be
configured. </li> <li> <span class="code">driver_alloc()</span>,
<span class="code">driver_realloc()</span>, and <span class="code">driver_free()</span> now use
their own erts specific memory allocator instead of the
default <span class="code">malloc()</span> implementation on the system.
</li> <li> The default configuration of some
allocators have been changed to fit applications that use
much memory better. </li> <li> Some new
<span class="code">erts_alloc</span> configuration parameters have been
added. </li> <li> <span class="code">erts_alloc_config</span> has been
modified to be able to create configurations suitable for
multiple instances of allocators. </li> <li> The
returned value from <span class="code">erlang:system_info({allocator,
Alloc})</span> has been changed. This since an allocator may
now run in multiple instances. </li> </ul> <p>If you
for some reason want the memory allocators to be
configured as before, you can pass the <span class="code">+Mea r11b</span>
command-line argument to <span class="code">erl</span>.</p> <p>For more
information see the <span class="code">erts_alloc(3)</span>, the
<span class="code">erts_alloc_config(3)</span>, and the <span class="code">erlang(3)</span>
documentation.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7100</p>
</li>
<li>
<p>
On Unix, denormalized floating point numbers could not be
created using <span class="code">list_to_float/1</span> or
<span class="code">binary_to_term/1</span>. (Thanks to Matthew Dempsky.)</p>
<p>
Own Id: OTP-7122</p>
</li>
<li>
<p>
Native atomic integers and spin-locks are now also
available for the runtime system with SMP support on
sparc64.</p>
<p>
Own Id: OTP-7130</p>
</li>
<li>
<p>
FP exceptions support for sparc64 userspace on Linux has
been added. Note that FP exception support is now turned
off by default, so to actually enable it you need to do
'<span class="code">./configure --enable-fp-exceptions</span>'.</p>
<p>
Own Id: OTP-7131</p>
</li>
</ul>
<h3><a name="id107077">1.39
Erts 5.6</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
A bug for raw files when reading 0 bytes returning 'eof'
instead of empty data has been corrected.</p>
<p>
Own Id: OTP-6291 Aux Id: OTP-6967 </p>
</li>
<li>
<p>
All exported functions in gzio.c have now been renamed to
avoid conflict with drivers that are indirectly linked
with an external zlib library.</p>
<p>
Own Id: OTP-6816 Aux Id: OTP-6591 </p>
</li>
<li>
<p>
On the 64-bit Erlang emulator, bit syntax construction
with integers containing more than 60 bits ("big
numbers") into fields with more than 60 bits could
produce incorrect results.</p>
<p>
Own Id: OTP-6833</p>
</li>
<li>
<p>
When the runtime system failed to allocate memory for
binaries, it could dead lock while writing the
<span class="code">erl_crash.dump</span>.</p>
<p>
Own Id: OTP-6848</p>
</li>
<li>
<p>
The runtime system with SMP support could deadlock if a
process called the <span class="code">erlang:suspend_process(Pid)</span> BIF
or the <span class="code">erlang:garbage_collect(Pid)</span> BIF while the
process identified by <span class="code">Pid</span> was currently running
and the process calling the BIFs was terminated during
the call to the BIFs.</p>
<p>
Processes suspending each other via the
<span class="code">erlang:suspend_process/1</span> BIF or garbage collecting
each other via the <span class="code">erlang:garbage_collect/1</span> BIF
could deadlock each other when the runtime system with
SMP support was used.</p>
<p>
Own Id: OTP-6920</p>
</li>
<li>
<p>
<span class="code">dbg</span> could leave traced processes in a suspended
state if the tracer process was killed with exit reason
<span class="code">kill</span>.</p>
<p>
<span class="code">erlang:suspend_process/2</span> has been introduced which
accepts an option list as second argument. For more
information see the <span class="code">erlang(3)</span> documentation.</p>
<p>
Processes suspended via
<span class="code">erlang:suspend_process/[1,2]</span> will now be
automatically resumed if the process that called
<span class="code">erlang:suspend_process/[1,2]</span> terminates.</p>
<p>
Processes could previously be suspended by one process
and resumed by another unless someone was tracing the
suspendee. This is <strong>not</strong> possible anymore. The
process resuming a process <strong>has</strong> to be the one
that suspended it.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6946</p>
</li>
<li>
<p>file:write_file/3, file:write/2 and file:read/2 could
crash (contrary to documentation) for odd enough file
system problems, e.g write to full file system. This bug
has now been corrected.</p> <p>In this process the file
module has been rewritten to produce better error codes.
Posix error codes now originate from the OS file system
calls or are generated only for very similar causes (for
example 'enomem' is generated if a memory allocation
fails, and 'einval' is generated if the file handle in
Erlang is a file handle but currently invalid).</p>
<p>More Erlang-ish error codes are now generated. For
example <span class="code">{error,badarg}</span> is now returned from
<span class="code">file:close/1</span> if the argument is not of a file
handle type. See file(3).</p> <p>The possibility to write
a single byte using <span class="code">file:write/2</span> instead of a list
or binary of one byte, contradictory to the
documentation, has been removed.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6967 Aux Id: OTP-6597 OTP-6291 </p>
</li>
<li>
<p>
Monitor messages produced by the system monitor
functionality, and garbage collect trace messages could
contain erroneous heap and/or stack sizes when the actual
heaps and/or stacks were huge.</p>
<p>
As of erts version 5.6 the <span class="code">large_heap</span> option to
<span class="code">erlang:system_monitor/[1,2]</span> has been modified. The
monitor message is sent if the sum of the sizes of all
memory blocks allocated for all heap generations is equal
to or larger than the specified size. Previously the
monitor message was sent if the memory block allocated
for the youngest generation was equal to or larger than
the specified size.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6974 Aux Id: seq10796 </p>
</li>
<li>
<p>
<span class="code">inet:getopts/2</span> returned random values on Windows
Vista.</p>
<p>
Own Id: OTP-7003</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
The emulator internal process lock implementation has
been rewritten and optimized. A slight risk of starvation
existed in the previous implementation. This risk has
also been eliminated in the new implementation.</p>
<p>
Own Id: OTP-6500</p>
</li>
<li>
<p>
Bitstrings (bit-level) binaries and binary comprehensions
are now part of the language. See the Reference Manual.</p>
<p>
Own Id: OTP-6558</p>
</li>
<li>
<p>
The windows version of erlang now has SMP support. The
SMP emulator is run by default on machines which shows
more than one virtual or physical processor.</p>
<p>
Own Id: OTP-6560 Aux Id: OTP-6925 </p>
</li>
<li>
<p>
The details of the compressed term format has been
documented in erl_ext_dist.txt. (Thanks to Daniel
Goertzen.)</p>
<p>
Own Id: OTP-6755</p>
</li>
<li>
<p>
The runtime system with SMP support is now started by
default if more than one logical processor are detected.
For more information, see the <span class="code">erl(3)</span>
documentation.</p>
<p>
Own Id: OTP-6756</p>
</li>
<li>
<p>
The external format for Erlang terms and the distribution
protocol are now documented in ERTS User's Guide.</p>
<p>
Own Id: OTP-6779</p>
</li>
<li>
<p>
New BIF's erlang:system_profile/1 and
erlang:system_profile/2. These BIF's controls concurrency
profiling options for processes, ports and schedulers.</p>
<p>
Own Id: OTP-6783 Aux Id: OTP-6285 </p>
</li>
<li>
<p>
The <span class="code">ErlDrvTermData</span> term types used by
<span class="code">driver_output_term()</span> and <span class="code">driver_send_term()</span>
have been extended with the term types
<span class="code">ERL_DRV_BUF2BINARY</span>, <span class="code">ERL_DRV_EXT2TERM</span>, and
<span class="code">ERL_DRV_UINT</span>. <span class="code">ERL_DRV_BUF2BINARY</span> is used
for passing and creating a binary,
<span class="code">ERL_DRV_EXT2TERM</span> is used for passing terms encoded
with the external term format, and <span class="code">ERL_DRV_UINT</span> is
used for passing unsigned integers.</p>
<p>
Also the data types <span class="code">ErlDrvUInt</span> and
<span class="code">ErlDrvSInt</span> have been added which makes it more
obvious how arguments to term types are interpreted with
regards to width and signedness.</p>
<p>
The incorrect data types <span class="code">ErlDriverTerm</span>,
<span class="code">ErlDriverBinary</span>, and <span class="code">ErlDriverPort</span> in the
<span class="code">erl_driver(3)</span> documentation have been replaced
with the correct data types <span class="code">ErlDrvTermData</span>,
<span class="code">ErlDrvBinary</span>, and <span class="code">ErlDrvPort</span>.</p>
<p>
For more information see the <span class="code">erl_driver(3)</span>
documentation.</p>
<p>
Own Id: OTP-6823</p>
</li>
<li>
<p>
Miscellaneous improvements of the erts internal thread
library.</p>
<p>
It now support optimized atomic operations and spin-locks
on windows.</p>
<p>
Fall-backs based on mutexes and/or spin-locks for missing
optimized atomic operations, spin-locks, or rwlocks has
been implemented. This makes it possible to compile the
runtime system with SMP support on a lot more platforms.</p>
<p>
Default stack size on OpenBSD has been increased to 256
kilo-words.</p>
<p>
Own Id: OTP-6831 Aux Id: OTP-6560 </p>
</li>
<li>
<p>Many bit syntax operations, both construction and
matching, are faster. For further information, see the
Efficiency Guide.</p>
<p>
Own Id: OTP-6838</p>
</li>
<li>
<p>Literal lists, tuples, and binaries are no longer
constructed at run-time as they used to be, but are
stored in a per-module constant pool. Literals that are
used more than once are stored only once.</p>
<p>This is not a change to the language, only in the
details of its implementation. Therefore, the
implications of this change is described in the
Efficiency Guide.</p>
<p>Example 1: In the expression <span class="code">element(BitNum-1,
{1,2,4,8,16,32,64,128})</span>, the tuple used to be
constructed every time the expression was executed, which
could be detrimental to performance in two ways if the
expression was executed in a loop: the time to build the
tuple itself and the time spent in garbage collections
because the heap filled up with garbage faster.</p>
<p>Example 2: Literal strings, such as <span class="code">"abc"</span>, used
to be stored in the compiled code compactly as a byte
string and expanded to a list at run-time. Now all
strings will be stored expanded to lists (such as
<span class="code">[$a,$b,$c]</span>) in the constant pool. That means that
the string will be faster to use at run-time, but that it
will require more space even when not used. If space is
an issue, you might want to use binary literals (that is,
<span class="code"><<"abc">></span>) instead of string literals for
infrequently used long strings (such as error
messages).</p>
<p>
Own Id: OTP-6850</p>
</li>
<li>
<p>The Erlang driver API has been extended with a
portable POSIX thread like API for multi-threading. The
Erlang driver thread API provides:</p> <ul>
<li>Threads</li> <li>Mutexes</li> <li>Condition
variables</li> <li>Read/Write locks</li>
<li>Thread specific data</li> </ul> <p>For more
information see the <span class="code">erl_driver(3)</span>
documentation.</p>
<p>
Own Id: OTP-6857</p>
</li>
<li>
<p>
Recursive calls now usually consume less stack than in
R11B. See the Efficiency Guide.</p>
<p>
Own Id: OTP-6862 Aux Id: seq10746 </p>
</li>
<li>
<p>
The deprecated BIFs <span class="code">erlang:old_binary_to_term/1</span>
and <span class="code">erlang:info/1</span> have been removed.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6876</p>
</li>
<li>
<p>
Calls to driver call-backs triggered by external events
are now scheduled and interleaved with execution of
Erlang processes also on the runtime system without SMP
support.</p>
<p>
Own Id: OTP-6878</p>
</li>
<li>
<p>
Faster arithmetic of integers of more than 27 bits signed
(or 60 bits signed on an 64-bit CPU), and also faster
integer multiplication. (Thanks to Tony Rogvall.)</p>
<p>
Own Id: OTP-6891</p>
</li>
<li>
<p>Significant improvements of the <span class="code">process_info</span>
BIFs:</p> <ul> <li> <span class="code">process_info/2</span> can now be
called with a list of items as second argument in order
to atomically retrieve information about multiple items.
</li> <li> <span class="code">process_info/[1,2]</span> has been
optimized in the runtime system with SMP support. The
whole scheduler could previously be blocked for a
significant period of time in <span class="code">process_info/[1,2]</span>
waiting for a lock on the process being inspected. The
Erlang process calling <span class="code">process_info/[1,2]</span> can
still be blocked for a significant period of time waiting
for the lock, but the scheduler will now be able to run
other processes while the process calling
<span class="code">process_info/[1,2]</span> waits for the lock. </li>
<li> <span class="code">process_info/2</span> now accept a few more items
than before. </li> <li> The documentation of
<span class="code">process_info/[1,2]</span> has been improved. </li>
</ul> <p>For more information see the <span class="code">erlang(3)</span>
documentation.</p>
<p>
Own Id: OTP-6899</p>
</li>
<li>
<p>
<span class="code">open_port({}, [])</span> could crash the emulator.
(Thanks to Matthew Dempsky.)</p>
<p>
Own Id: OTP-6901</p>
</li>
<li>
<p>Two new guard BIFs have been introduced as a
recommended replacement for <span class="code">size/1</span>. (The
<span class="code">size/1</span> BIF will be removed no earlier than in
R14B.) The BIFs are <span class="code">tuple_size/1</span> to calculate the
size of a tuple and <span class="code">byte_size/1</span> to calculate the
number of bytes needed for the contents of the binary or
bitstring (rounded up to the nearest number of bytes if
necessary).</p>
<p>There is also a new <span class="code">bit_size/1</span> BIF that returns
the exact number of bits that a binary or bitstring
contains.</p>
<p>
Own Id: OTP-6902</p>
</li>
<li>
<p>The <span class="code">ets:fixtable/2</span> function, which has been
deprecated for several releases, has been removed.</p>
<p>The <span class="code">ets:info/1</span> function has been reimplemented
as a BIF, which guarantees that information returned is
consistent.</p>
<p>The <span class="code">ets:info/2</span> function now fails with reason
<span class="code">badarg</span> if the second argument is invalid.
(Dialyzer can be used to find buggy code where the second
argument is misspelled.)</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6906</p>
</li>
<li>
<p>
As the linux kernel may generate a minor fault when
tracing with CPU timestamps, and there exists no patch to
the Linux kernel that fixes the problem, cpu timestamps
are disabled on Linux for now.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6922</p>
</li>
<li>
<p>The functions io:columns/0, io:columns/1, io:rows/0
and io:rows/1 are added to allow the user to get
information about the terminal geometry. The shell takes
some advantage of this when formatting output. For
regular files and other io-devices where height and width
are not applicable, the functions return
{error,enotsup}.</p>
<p>Potential incompatibility: If one has written a custom
io-handler, the handler has to either return an error or
take care of io-requests regarding terminal height and
width. Usually that is no problem as io-handlers, as a
rule of thumb, should give an error reply when receiving
unknown io-requests, instead of crashing.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-6933</p>
</li>
<li>
<p>
<span class="code">driver_caller()</span> can now also be used from the
<span class="code">start</span> callback of a driver.</p>
<p>
Own Id: OTP-6951</p>
</li>
<li>
<p>
The emulator can now be compiled for 64bit intel, as well
as a 32bit universal binary on darwin/MacOSX 10.4 and
10.5.</p>
<p>
Own Id: OTP-6961</p>
</li>
<li>
<p>
If <span class="code">open_port</span> fails because all available ports are
already in use, it will now throw a <span class="code">system_limit</span>
exception instead of an <span class="code">enfile</span> exception.
(<span class="code">enfile</span> might still be thrown if the operating
system would return ENFILE.)</p>
<p>
Own Id: OTP-6968</p>
</li>
<li>
<p>
The <span class="code">spawn_monitor/1</span> and <span class="code">spawn_monitor/3</span> BIFs
are now auto-imported (i.e. they no longer need an
<span class="code">erlang:</span> prefix).</p>
<p>
Own Id: OTP-6975</p>
</li>
<li>
<p>
On Windows, the werl window now handles resize, so that
the whole window can be utilized. Text selection is also
updated to be line oriented instead of rectangle oriented
as in earlier versions.</p>
<p>
Own Id: OTP-6994 Aux Id: OTP-6933 </p>
</li>
<li>
<p>
Kqueue support (kernel-poll) has been enabled on FreeBSD.
The problem with kqueue not detecting writes on a pipe on
FreeBSD was actually not a kqueue issue, but a writev on
pipes issue. Neither poll(), nor select() detected the
write when the bug hit. NetBSD and DragonFlyBSD probably
have or have had the same bug. This bug should have been
fixed in FreeBSD 6.3 and FreeBSD 7.0 thanks to
Jean-Sebastien Pedron.</p>
<p>
Own Id: OTP-7001</p>
</li>
</ul>
<h3><a name="id108044">1.40
Erts 5.5.5.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Hanging writes on temporarily unavailable NFS
filesystems could cause the execution of (not file
related) erlang code to get blocked even though I/O
threads were used. This is now corrected.</p>
<p>
Own Id: OTP-6907 Aux Id: seq10771 </p>
</li>
</ul>
<h3><a name="id108075">1.41
Erts 5.5.5.4</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
Data passed to a driver via <span class="code">erlang:port_call</span> could
be corrupted when the runtime system with SMP support was
used. (Thanks to YAMASHINA Hio.)</p>
<p>
Own Id: OTP-6879</p>
</li>
<li>
<p>
In the SMP emulator, if several processes called
ets:update_counter/3 (even for different tables) when the
counter values exceeded 27 bits, the counter values could
be corrupted or the emulator could crash.</p>
<p>
Own Id: OTP-6880 Aux Id: seq10760 </p>
</li>
</ul>
<h3><a name="id108123">1.42
Erts 5.5.5.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Creating a named table using <span class="code">ets:new/2</span> or
renaming a named table using <span class="code">ets:rename/2</span> could in
rare circumstances succeed, meaning that there would be
two or more tables with the same name. Now such call will
fail with a <span class="code">badarg</span> exception as it is supposed to
do.</p>
<p><span class="code">ets:delete/1</span> used on a named table now removes
the name immediately so that a new table with the same
name can be created.</p>
<p>Turning on call trace on the internal BIF that
implements <span class="code">ets:delete/1</span> would crash the
emulator.</p>
<p>SMP emulator only: Using <span class="code">ets:rename/2</span> on a
table that <span class="code">ets:safe_fixtable/2</span> has been used on
could cause an emulator crash or undefined behaviour
because of a missing lock.</p>
<p>
Own Id: OTP-6872 Aux Id: seq10756, seq10757 </p>
</li>
</ul>
<h3><a name="id108193">1.43
Erts 5.5.5.2</a></h3>
<h4>Known Bugs and Problems</h4>
<ul>
<li>
<p>
ets:select/3 on ordered_set and with a chunksize a
multiple of 1000 gave all elements instead of just 1000.
Also ets:slot/2 on ordered set could give unexpected
results on SMP emulator. Both problems are corrected.</p>
<p>
Own Id: OTP-6842</p>
</li>
</ul>
<h3><a name="id108224">1.44
Erts 5.5.5.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>
All exported functions in gzio.c have now been renamed to
avoid conflict with drivers that are indirectly linked
with an external zlib library.</p>
<p>
Own Id: OTP-6816 Aux Id: OTP-6591 </p>
</li>
<li>
<p>
Calling binary_to_term/1 with certain invalid binaries
would crash the emulator.</p>
<p>
Own Id: OTP-6817</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>
Restored speed of bit-syntax matching of 32 bits
integers.</p>
<p>
Own Id: OTP-6789 Aux Id: seq10688 </p>
</li>
</ul>
<h3><a name="id108292">1.45
Erts 5.5.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>The functions in gzio.c have been renamed to avoid
conflict with drivers that indirectly linked with an
external zlib library.</p>
<p>Own Id: OTP-6591</p>
</li>
<li>
<p>The emulator without SMP support dumped core if an
async-thread finished a job after the emulator had begun
writing an <span class="code">erl_crash.dump</span>. </p>
<p>Own Id: OTP-6685</p>
</li>
<li>
<p>In bit syntax matching, integer fields with greater
size than 16Mb would fail to match. (Thanks to Bertil
Karlsson and Francesco Pierfederici.)</p>
<p>Matching out a 32-bit integer not aligned on a byte
boundary from a binary could cause an heap overflow (and
subsequent termination of the emulator).</p>
<p>A module that contained bit syntax construction with a
literal field size greater than 16Mb would fail to
load.</p>
<p>Several other similar bugs having to do with huge
field sizes were eliminated.</p>
<p>Attempting to construct a binary longer than 536870911
bytes will now fail with a <span class="code">system_limit</span> exception
(rather than fail in mysterious ways or construct an
binary with incorrect contents). Similarily, attempting
to match a binary longer than 536870911 bytes will now
fail (instead of producing an incorrect result). This
limitation has been documented in the Efficiency Guide.
(The limit is in the 32-bit emulator; use the 64-bit
emulator if you need to handle larger binaries than
536870911.)</p>
<p>Own Id: OTP-6686</p>
</li>
<li>
<p>Bugs in rem and div of very large numbers are corrected.</p>
<p>Own Id: OTP-6692</p>
</li>
<li>
<p><span class="code">erlang:system_info({allocator, Alloc})</span> didn't
allocate enough heap when a bignum was part of the result
which could cause an emulator crash.</p>
<p>Own Id: OTP-6693</p>
</li>
<li>
<p>It was previously not possible to pass
<span class="code">erts_alloc</span> the same configuration via the
command-line, as used by default. </p>
<p>A <span class="code">+M*</span> command-line argument that configure a
size of some sort can now be passed a value that equals
the size of the address space. The value used, in this
case, will be <span class="code">"the size of the address space" - 1</span>.</p>
<p>Own Id: OTP-6699</p>
</li>
<li>
<p><span class="code">SysIOVec* driver_peekq(ErlDrvPort port, int *vlen)</span> did not update <span class="code">*vlen</span> if <span class="code">port</span> was
invalid. <span class="code">*vlen</span> is now set to <span class="code">-1</span> if the
<span class="code">port</span> is invalid.</p>
<p>The <span class="code">efile</span> driver
expects <span class="code">*vlen</span> to be updated also when the
<span class="code">port</span> is invalid. This situation occurs seldom, but
when the runtime system has async-threads enabled and
ports are killed it can. When it occurred the runtime
system crashed.</p>
<p>Own Id: OTP-6729</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>For scripts written using <span class="code">escript</span>, there is a new
function <span class="code">escript:script_name/0</span>, which can be used
to retrieve the pathame of the script. The documentation
has been clarified regarding pre-defined macros such as
?MODULE and the module name.</p>
<p>Own Id: OTP-6593</p>
</li>
<li>
<p>The section Guards in the chapter The Abstract Format
of the ERTS User's Guide has been updated.</p>
<p>Own Id: OTP-6600</p>
</li>
<li>
<p>Corrected protocol layer flue for socket options
SO_LINGER, SO_SNDBUF and SO_RCVBUF, for SCTP.</p>
<p>Own Id: OTP-6625 Aux Id: OTP-6336 </p>
</li>
<li>
<p>The behaviour of the inet option {active,once} on peer
close is improved and documented.</p>
<p>Own Id: OTP-6681</p>
</li>
<li>
<p>The inet option send_timeout for connection oriented
sockets is added to allow for timeouts in communicating
send requests to the underlying TCP stack.</p>
<p>Own Id: OTP-6684 Aux Id: seq10637 OTP-6681 </p>
</li>
<li>
<p>The command line flag <span class="code">-args_file FileName</span>, and
the environment variables <span class="code">ERL_AFLAGS</span>, and
<span class="code">ERL_ZFLAGS</span> for the <span class="code">erl</span> command have been
added. For more information see the <span class="code">erl(1)</span>
documentation.</p>
<p>Own Id: OTP-6697</p>
</li>
<li>
<p>The <span class="code">is_constant/1</span> type test has been deprecated.
<span class="code">is_constant/1</span> is improperly named and almost
entirely undocumented.</p>
<p>Own Id: OTP-6731</p>
</li>
</ul>
<h3><a name="id108618">1.46
Erts 5.5.4.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p><span class="code">process_flag(trap_exit, Bad)</span> where <span class="code">Bad</span>
was a term not equal to <span class="code">true</span> or <span class="code">false</span>,
didn't fail with <span class="code">badarg</span> as it should; instead, the
failure was silently ignored. This bug was introduced in
<span class="code">erts-5.5.2</span>.</p>
<p>Own Id: OTP-6627 Aux Id: OTP-6160 </p>
</li>
<li>
<p>The minimum and default stack size for async-threads has
been increased to 16 kilowords. This since the previous
minimum and default stack size of 8 kilowords proved to
be too small (introduced in <span class="code">erts-5.5.4.2</span>).</p>
<p>Own Id: OTP-6628 Aux Id: OTP-6580, Seq10633 </p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>process_flag/2 accepts the new flag <span class="code">sensitive</span>.</p>
<p>Own Id: OTP-6592 Aux Id: seq10555 </p>
</li>
</ul>
<h3><a name="id108718">1.47
Erts 5.5.4.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>When a port steals control over a file descriptor from
another port, the stealing port tests if the other port
is alive. This in order to be able to give an accurate
error message. In the runtime system with SMP support,
this test was done without appropriate locks held. This
could in worst case lead to an erroneous error message;
therefore, this bug is to be considered harmless.</p>
<p>Own Id: OTP-6602</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The default stack size for threads in the async-thread
pool has been shrunk to 8 kilowords, i.e., 32 KB on
32-bit architectures. This small default size has been
chosen since the amount of async-threads might be quite
large. The default stack size is enough for drivers
delivered with Erlang/OTP, but might not be sufficiently
large for other dynamically linked in drivers that use
the <span class="code">driver_async()</span> functionality. A suggested
stack size for threads in the async-thread pool can be
configured via the <span class="code">+a</span> command line argument of
<span class="code">erl(1)</span>.</p>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-6580</p>
</li>
</ul>
<h3><a name="id108799">1.48
Erts 5.5.4.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Setting the time on the system while using heart on a
linux machine where the emulator was built with
clock_gettime support (default from Linux 2.6/erts-5.5.4
and upwards), could make the heart command fire. This was
due to bug in the heart executable which is now
corrected.</p>
<p>Own Id: OTP-6598 Aux Id: seq10614 </p>
</li>
</ul>
<h3><a name="id108834">1.49
Erts 5.5.4</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Corrected misspelling of '<span class="code">-pz</span>' in the help text
for <span class="code">erlc</span>. (Thanks to Ulf Wiger.)</p>
<p>Own Id: OTP-6433</p>
</li>
<li>
<p>The MD5 calculation of a BEAM file done by
<span class="code">code:module_md5/1</span>, <span class="code">beam_lib:md5/1</span>, and by
the compiler for the default value of the <span class="code">vsn</span>
attribute have all been changed so that its result will
be the same on all platforms; modules containing funs
could get different MD5s on different platforms.</p>
<p>Own Id: OTP-6459</p>
</li>
<li>
<p>The emulator could dump core while writing an
<span class="code">erl_crash.dump</span> file if there were funs with a
large terms in its environment. Since there is no way to
inspect a fun's environment in the crashdump_viewer
application anyway, a variables in the environment are
now set to [] before dumping the fun. (Thanks to
Jean-Sebastien Pedron.)</p>
<p>Own Id: OTP-6504</p>
</li>
<li>
<p><span class="code">{Port, {exit_status, S}}</span> messages from ports
opened with the <span class="code">exit_status</span> option could under
rare circumstances be delayed. This bug was present on
Erlang runtime systems without SMP support on all unix
operating systems other than SunOS.</p>
<p>Own Id: OTP-6528</p>
</li>
<li>
<p>A bug in linuxthreads could cause the emulator to dump
core when dlerror() was called before the first call to
dlopen(). As a workaround the emulator always makes a
call to dlopen() on initialization when linuxthreads is
used as thread library.</p>
<p>Own Id: OTP-6530</p>
</li>
<li>
<p>file:sync/1 did not do anything on Windows. Now it calls
the system function for flushing buffers
(FlushFileBuffers()). (Thanks to Matthew Sackman.)</p>
<p>Own Id: OTP-6531</p>
</li>
<li>
<p><span class="code">open_port/2</span> could on the runtime system with SMP
support fail with the wrong exit reason when a port
couldn't be created. When this happened the exit reason
was typically <span class="code">eintr</span>, or <span class="code">ebusy</span> instead of
<span class="code">eagain</span>.</p>
<p>Own Id: OTP-6536</p>
</li>
<li>
<p>The file driver (efile_drv) did not flush data written
using the option 'delayed_write' after the set timeout
time, rather at the next file operation. This bug has now
been corrected.</p>
<p>Own Id: OTP-6538</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>An interface towards the SCTP Socket API Extensions
has been implemented.It is an Open Source patch courtesy
of Serge Aleynikov and Leonid Timochouk. The Erlang code
parts has been adapted by the OTP team, changing the
Erlang API somewhat.</p>
<p>The Erlang interface consists of the module
<span class="code">gen_sctp</span> and an include file
<span class="code">-include_lib("kernel/include/inet_sctp.hrl").</span> for
option record definitions. The <span class="code">gen_sctp</span> module is
documented.</p>
<p>The delivered Open Source patch, before the OTP team
rewrites, was written according to
http://tools.ietf.org/html/draft-ietf-tsvwg-sctpsocket-13
and was claimed to work fine, tested on Linux Fedora Core
5.0 (kernel 2.6.15-2054 or later) and on Solaris 10 and
11. The OTP team rewrites used the same standard document
but might have accidentally broken some functionality. If
so it will soon be patched to working state. The tricky
parts in C and the general design has essentially not
changed. During the rewrites the code was hand tested on
SuSE Linux Enterprise Server 10, and briefly on Solaris
10. Feedbach on code and docs is very much
appreciated.</p>
<p>The SCTP interface is in beta state. It has only been
hand tested and has no automatic test suites in OPT
meaning everything is most certainly not tested. Socket
active mode is broken. IPv6 is not tested. The
documentation has been reworked due to the API changes,
but has not been proofread after this.</p>
<p>Thank you from the OTP team to Serge Aleynikov and
Leonid Timochouk for a valuable contribution. We hope we
have not messed it up too much.</p>
<p>Own Id: OTP-6336</p>
</li>
<li>
<p>A <span class="code">{minor_version,Version}</span> option is now recognized
by <span class="code">term_to_binary/2</span>. {minor_version,1} will cause
floats to be encoded in an exact and more space-efficient
way compared to the previous encoding.</p>
<p>Own Id: OTP-6434</p>
</li>
<li>
<p>There is a new <span class="code">escript</span> program that can be used
for writing scripts in Erlang. Erlang scripts don't need
to be compiled and any arguments can be passed to them
without risk that they are interpreted by the Erlang
system.</p>
<p>Own Id: OTP-6505</p>
</li>
<li>
<p>Setting and getting socket options in a "raw" fashion is
now allowed. Using this feature will inevitably produce
non portable code, but will allow setting ang getting
arbitrary uncommon options on TCP stacks that do have
them.</p>
<p>Own Id: OTP-6519</p>
</li>
<li>
<p>Miscellaneous signal handling improvements on the Erlang
runtime system with SMP support.</p>
<p>The fallback implementation of spin locks and atomic
operations are now implemented using pthread spin locks
when pthread spin locks are found on the system.</p>
<p>The Erlang runtime system with SMP support can now run on
Linux systems that has Linuxthreads instead of NPTL
(Native POSIX Thread Library). Note that the SMP support
hasn't been as thoroughly tested with Linuxthreads as
with NPTL. A runtime system with SMP support will
therefore not be built by default on Linux when NPTL
isn't found. In order to force a build of the runtime
system with SMP support, pass <span class="code">--enable-smp-support</span>
to <span class="code">configure</span> when building OTP.</p>
<p>Own Id: OTP-6525</p>
</li>
</ul>
<h3><a name="id109149">1.50
Erts 5.5.3.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p><span class="code">erlang:system_flag(multi_scheduling, block)</span> could
cause the emulator with SMP support to deadlock.</p>
<p>Own Id: OTP-6431 Aux Id: OTP-6403 </p>
</li>
<li>
<p>The runtime system with SMP support failed to call the
driver timeout callback of ports in state closing. This
could cause ports to fail flushing their I/O queues.</p>
<p>Own Id: OTP-6432</p>
</li>
<li>
<p>The <span class="code">{Port, closed}</span> message from a closed port
could arrive at the port owner before <span class="code">Port</span> had
been removed from the result of <span class="code">erlang:ports/0</span> in
the runtime system with SMP support.</p>
<p>Own Id: OTP-6437</p>
</li>
<li>
<p>The async id of async jobs created via
<span class="code">driver_async</span> wasn't created in a thread safe
manner in the runtime system with SMP support. This could
in worst case cause <span class="code">driver_async_cancel()</span> to
cancel another async job than intended.</p>
<p>Own Id: OTP-6438</p>
</li>
<li>
<p>Under rare circumstances a terminating connection between
two nodes could cause an instantaneous reconnect between
the two nodes to fail on the runtime system with SMP
support.</p>
<p>Own Id: OTP-6447</p>
</li>
<li>
<p>In the documentation of the driver entry field
<span class="code">extended_marker</span> of erts version 5.5.3
(<span class="code">driver_entry(3)</span>), the following is stated: "The
following fields are ignored if this field is equal to
<span class="code">0</span>". This is a documentation bug and has been
changed to: "If this field is equal to <span class="code">0</span>, all the
fields following this field also <strong>have</strong> to be
<span class="code">0</span>, or <span class="code">NULL</span> in case it is a pointer field".</p>
<p>The runtime check for detection of old incompatible
drivers made when loading drivers has been improved. The
emulator can, however, not make sure that a driver that
doesn't use the extended driver interface isn't
incompatible. Therefore, when loading a driver that
doesn't use the extended driver interface, there is a
risk that it will be loaded also when the driver is
incompatible. When the driver use the extended driver
interface, the emulator can verify that it isn't of an
incompatible driver version. You are therefore advised to
use the extended driver interface.</p>
<p>For more information see the <span class="code">erl_driver(3)</span> and
<span class="code">driver_entry(3)</span> documentation.</p>
<p>Own Id: OTP-6452 Aux Id: OTP-6330 </p>
</li>
<li>
<p>When terminating ports on the runtime system with SMP
support, removal of links to processes was done without
locking the link lock on processes. This could cause an
emulator crash.</p>
<p>Own Id: OTP-6475</p>
</li>
<li>
<p>The emulator with SMP support could crash when a port
flushed its I/O queue by calling <span class="code">driver_async()</span>
from the timeout driver callback.</p>
<p>Own Id: OTP-6479</p>
</li>
<li>
<p>Large exit reasons could under rare circumstances cause
the runtime system with SMP support to crash.</p>
<p>Own Id: OTP-6521</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Faster system calls for keeping the time accurate are
used on newer Linux kernels, which can result in a
significant speed-up of the emulator on those systems.</p>
<p>Own Id: OTP-6430</p>
</li>
<li>
<p>Added number of async threads and number of scheduler
threads to the system information that can be retrieved
via <span class="code">driver_system_info()</span>. For more information see
the <span class="code">erl_driver(3)</span> documentation.</p>
<p>Own Id: OTP-6440</p>
</li>
<li>
<p>When <span class="code">SIGUSR1</span> is received by the runtime system
with SMP support, the <span class="code">erl_crash.dump</span> is now
written by a special thread, instead of as before
directly from the signal handler.</p>
<p>Own Id: OTP-6465</p>
</li>
<li>
<p>term_to_binary/2 with compression is now faster.</p>
<p></p>
<p>term_to_binary/2 now accepts the option
'<span class="code">{compressed,Level}</span>' for specifying the
compression level. <span class="code">Level</span> must be in the range 0
(no compression) through 9 (highest compression level).
Default is 6.</p>
<p>Future compatibility bugfix: binary_to_term/1 did not
handle the <span class="code">Uniq</span> and <span class="code">Index</span> fields
correctly.</p>
<p>Own Id: OTP-6494</p>
</li>
<li>
<p>Removed unnecessary reallocation when initializing
kernel-poll set.</p>
<p>Own Id: OTP-6516</p>
</li>
</ul>
<h3><a name="id109470">1.51
Erts 5.5.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Node and fun table entries could under rare circumstances
be deallocated multiple times on the emulator with SMP
support.</p>
<p>Own Id: OTP-6369</p>
</li>
<li>
<p>epoll_wait() can repeat entries for the same file
descriptor in the result array. This could cause the
ready_input, ready_output, or event callbacks of a driver
to unintentionally be called multiple times. We have only
noted repeated entries when an error condition has
occurred on the file descriptor. In this case, the
repeated entries should normally not be a problem for the
driver since it should detect the error and de-select the
file descriptor. Therefore this bug should be considered
harmless. The emulator now coalesce repeated entries into
one.</p>
<p>You are only affected by this bug if you are using
erts-5.5.2.* and the kernel-poll feature on linux.</p>
<p>Own Id: OTP-6376 Aux Id: OTP-6222 </p>
</li>
<li>
<p>If a process that was waiting in gen_tcp:accept/1 was
killed, calling gen_tcp:accept/1 again on the same listen
socket would fail with '<span class="code">{error,einval}</span>'.</p>
<p>Own Id: OTP-6381 Aux Id: seq10535 </p>
</li>
<li>
<p>The emulator failed to start on Solaris 10 when
kernel-poll support was enabled and the maximum number of
filedescriptors configured was less than or equal to 256.</p>
<p>Own Id: OTP-6384 Aux Id: OTP-6222 </p>
</li>
<li>
<p>The R10B compiler could generate unsafe
<span class="code">bs_save/bs_restore</span> instructions that could cause
memory corruption. (The R11B compiler does not have that
problem.) The erlang emulator will now refuse to load
R10B-compiled modules that contain such unsafe
<span class="code">bs_save/bs_restore</span> instructions. In addition, the
beam_validator module in the compiler will also reject
such instructions (in case it is used to validate R10B
code). (Thanks to Matthew Reilly.)</p>
<p>Own Id: OTP-6386</p>
</li>
<li>
<p>Process and port timers could fail to work properly on
the runtime system with SMP support. Many thanks to
Dmitriy Kargapolov and Serge Aleynikov who tracked down
this bug.</p>
<p>Own Id: OTP-6387</p>
</li>
<li>
<p>Bit syntax code compiled by an R10B compiler that matched
out a floating point number would not properly check that
the floating point number was valid; if the float was,
for instance, NaN the emulator could crash.</p>
<p>Own Id: OTP-6395</p>
</li>
<li>
<p>statistics(runtime) on Windows used to return the elapsed
system time for the process, instead of the user time.
Corrected. (Thanks to Robert Virding.)</p>
<p>Own Id: OTP-6407</p>
</li>
<li>
<p>A loadable driver (loaded by erl_ddll) which used
driver_async() would cause the emulator to crash. (Thanks
to Dmitriy Kargapolov.)</p>
<p>Own Id: OTP-6410</p>
</li>
<li>
<p>Under rare circumstances the emulator on unix platforms
could fail to terminate the Erlang port corresponding to
a port program opened with the <span class="code">exit_status</span> option.</p>
<p>Own Id: OTP-6411</p>
</li>
<li>
<p>A link removed via <span class="code">unlink/1</span> could under rare
circumstances transfer exit signals for a short period of
time after the call to <span class="code">unlink/1</span> had returned when
the runtime system with SMP support was used.</p>
<p>Own Id: OTP-6425 Aux Id: OTP-6160 </p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>In the runtime system with SMP support, ports are now
being scheduled on the scheduler threads interleaved with
processes instead of being run in a separate I/O thread.</p>
<p>Own Id: OTP-6262</p>
</li>
<li>
<p>More interfaces are added in erl_ddll, to support
different usage scenarios.</p>
<p>Own Id: OTP-6307 Aux Id: OTP-6234 </p>
</li>
<li>
<p>In the runtime system with SMP support, the global
I/O lock has been replaced with a more fine grained port
locking scheme. Port locking is either done on driver
level, i.e., all ports executing the same driver share a
lock, or on port level, i.e., each port has its own lock.
Currently the inet driver, the efile driver, and the
spawn driver use port level locking and all other
statically linked in drivers use driver level locking. By
default dynamically linked in drivers will use locking on
driver level. For more information on how to enable port
level locking see the <span class="code">erl_driver(3)</span> and the
<span class="code">driver_entry(3)</span> man pages. </p>
<p>As of erts
version 5.5.3 the driver interface has been extended. The
extended interface introduce version management, the
possibility to pass capability flags to the runtime
system at driver initialization, and some new driver API
functions. For example, the <span class="code">driver_system_info()</span>
function which can be used to determine if the driver is
run in a runtime system with SMP support or not. The
extended interface doesn't have to be used, <strong>but</strong>
dynamically linked in driver <strong>have</strong> to be
recompiled. For information see the <span class="code">erl_driver(3)</span>
and the <span class="code">driver_entry(3)</span> man pages. </p>
<p><strong>NOTE:</strong> Dynamically linked in drivers
<strong>have</strong> to be recompiled. </p>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-6330 Aux Id: OTP-6262 </p>
</li>
<li>
<p>A test and debug feature which modifies the timing of the
runtime system has been added. For more information, see
documentation of the <span class="code">+T<Level></span> command line
argument of <span class="code">erl(1)</span>.</p>
<p>Own Id: OTP-6382</p>
</li>
<li>
<p>The version of zlib (http://zlib.net) linked into
run-time system has been updated to version 1.2.3.</p>
<p>Own Id: OTP-6394</p>
</li>
<li>
<p>The <span class="code">erlc</span> program now passes on the <span class="code">-smp</span>
and <span class="code">-hybrid</span> options to the Erlang emulator it
starts. This is mainly useful for compiling native code,
because native code must be compiled with same type of
run-time system as in which it will be run.</p>
<p>If the <span class="code">-s</span> option is given, <span class="code">erlc</span> now
prints a warning that it is deprecated and that it will
be removed in R12B.</p>
<p>Own Id: OTP-6398</p>
</li>
<li>
<p>The <span class="code">schedulers</span> option of
<span class="code">erlang:system_flag/2</span> has been removed, i.e., the
number of scheduler threads cannot be changed after
emulator boot time any more.</p>
<p>A <span class="code">multi_scheduling</span> option has been added to
<span class="code">erlang:system_flag/2</span>. This option can be used for
blocking and unblocking multi-scheduling. For more
information see the <span class="code">erlang(3)</span> documentation.</p>
<p>Own Id: OTP-6403</p>
</li>
<li>
<p>A port program that had been started with the
<span class="code">exit_status</span> option and closed one of the pipes
used for communication with the emulator caused the
emulator to continuously poll for termination of the port
program. This only became a problem when the emulator
didn't have other things to do and the port program
closed a pipe much earlier than it terminated. When the
emulator had other things to do, such as running Erlang
processes, the emulator polled for termination in between
scheduling of processes.</p>
<p>Now the emulator doesn't poll for termination of the port
program at all; instead, it waits for the child signal
from the terminated port program to arrive and then
schedules the Erlang port for termination.</p>
<p>The termination of any port programs have also been
optimized. Previously the termination of any port program
did always cause a scan of a table of the size equal to
maximum number of file descriptors. If the maximum number
of file descriptors was large, this scan could be quite
expensive. Now the search have been reduced to the set of
ports started with the <span class="code">exit_status</span> option.</p>
<p>Note, all of the above only applies to Erlang emulators
on Unix platforms.</p>
<p>Own Id: OTP-6412 Aux Id: seq10194 </p>
</li>
<li>
<p>* BEAM: added support for floating-point exceptions on
FreeBSD (32-bit x86)</p>
<p>* SMP: made locking procedures work even when native
lock operations aren't implemented</p>
<p>* SMP: improved timing accuracy in the timer thread
(if enabled)</p>
<p>Own Id: OTP-6424</p>
</li>
</ul>
<h3><a name="id109933">1.52
Erts 5.5.2.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>A bug in the kernel poll implementation could cause the
emulator to omit polling for events on file descriptors.
The bug was only present when using the kernel poll
implementation based on epoll or kqueue. This bug was
introduced in erts-5.5.2.</p>
<p>Own Id: OTP-6344 Aux Id: OTP-6222 </p>
</li>
</ul>
<h3><a name="id109967">1.53
Erts 5.5.2.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>The run_erl program now acquires its pseudo-ttys using
openpty(3), so that it will work on newer Linux
distributions that don't have the traditional pseudo-tty
devices in the file system. On platforms that don't have
openpty(3), run_erl will still search for pseudo-tty
devices in the file system.</p>
<p>The run_erl program will now wait using waitpid(3) to
prevent the program it spawned to become defunct. run_erl
will also terminate after a delay of 5 seconds (to allow
any pending output to be written to the log file) if the
spawned program terminates even if some child of it still
holds stdin and/or stdout open.</p>
<p>Own Id: OTP-6225 Aux Id: seq10500 </p>
</li>
<li>
<p>A bug in ordered_set ETS datatyp caused ets:select (and
match) to return faulty results when the table contained
process id's from another node.</p>
<p>Own Id: OTP-6338</p>
</li>
</ul>
<h3><a name="id110022">1.54
Erts 5.5.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>erlc: A typo in the help text for '-pa path' was
corrected.</p>
<p>Own Id: OTP-6218</p>
</li>
<li>
<p>Failure in port command/control driver callbacks could
crash the non-SMP emulator. This bug was introduced in
the 5.5 version of erts.</p>
<p>Own Id: OTP-6224</p>
</li>
<li>
<p>Erroneous "<span class="code">Input driver gone away without deselecting!</span>" error reports could sometimes occur
when a driver instance terminated in the ready_output()
callback of the driver. This bug was only present in
emulators that used poll(). Note, that this bug was
harmless, the only effect it had was the erroneous error
report.</p>
<p>Own Id: OTP-6229 Aux Id: OTP-3993, Seq5266, Seq7247,
OTP-4307 </p>
</li>
<li>
<p>The emulator could cause a type assertion failure while
writing an erl_crash.dump, causing the erl_crash.dump to
be terminated and a core dump generated.</p>
<p>Own Id: OTP-6235 Aux Id: seq10444 </p>
</li>
<li>
<p>The registered name of a process is now the last
observable resource removed before links and monitors are
triggered when a process terminates.</p>
<p>Previously ets tables were removed after the registered
name. This could cause problems on the runtime system
with SMP support for code that expected that ets tables
owned by a specific process had been removed if the name
of the process had been removed.</p>
<p>Own Id: OTP-6237</p>
</li>
<li>
<p>Failure to fork() a new (os) process could cause the
emulator to deadlock. This bug affect all emulators with
SMP support, and emulators with async thread support on
SunOS.</p>
<p>Own Id: OTP-6241 Aux Id: OTP-3906 </p>
</li>
<li>
<p>Fprof traces could become truncated for the SMP emulator.
This bug has now been corrected.</p>
<p>Own Id: OTP-6246</p>
</li>
<li>
<p>The undocumented functions inet:getiflist/0,1
inet:ifget/2,3 and inet:getif/1 were completely broken on
Windows. That has been fixed.</p>
<p>Own Id: OTP-6255</p>
</li>
<li>
<p>Behavior in case of disappeared nodes when using the
dist_auto_connect once got changed in R11B-1. The
timeouts regarding normal distributed operations is now
reverted to the old (pre R11B-1).</p>
<p>Own Id: OTP-6258 Aux Id: OTP-6200, seq10449 </p>
</li>
<li>
<p>The bsl and bsr operators could cause the emulator to
crash if given invalid arguments. (Thanks to datacompboy
and Per Gustafsson.)</p>
<p>Own Id: OTP-6259</p>
</li>
<li>
<p>driver_cancel_timer() could under certain circumstances
fail to cancel the timer on the runtime system with SMP
support.</p>
<p>Own Id: OTP-6261</p>
</li>
<li>
<p>A call to erlang:system_info(info) could deadlock the
runtime system with SMP support.</p>
<p>Own Id: OTP-6268</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Exit signals are now truly asynchronous in the runtime
system with SMP support. This simplifies locking in bifs
a lot, and makes process termination cheaper.</p>
<p>Own Id: OTP-6160</p>
</li>
<li>
<p>When tracing on the runtime system with SMP support it
can be difficult to know when a trace has been delivered
to the tracer. A new built in function
<span class="code">erlang:trace_delivered/1</span> has been introduced in
order to make it easier to know when the trace has been
delivered. See the erlang(3) man page for more
information.</p>
<p>Own Id: OTP-6205 Aux Id: OTP-6269 </p>
</li>
<li>
<p>Kernel poll support can now be combined with SMP support.
Currently the following kernel poll versions exist:
<span class="code">/dev/poll</span>, <span class="code">epoll</span>, and <span class="code">kqueue</span>. Linux
<span class="code">kpoll</span> has been replaced with <span class="code">epoll</span>. Some
time in the future there will also be a kernel poll
version using Solaris event ports.</p>
<p>The "check io" implementation for unix has been
completely rewritten. The current kernel poll
implementation reduce the amount of system calls needed
compared to the old kernel poll implementation.</p>
<p>When <span class="code">epoll</span> or <span class="code">kqueue</span> is used either
<span class="code">poll</span> or <span class="code">select</span> is used as fallback.
Previously only <span class="code">poll</span> could be used as fallback.
Since <span class="code">select</span> now can be used as fallback, kernel
poll support is now also available on newer MacOSX. Note
however, when <span class="code">select</span> is used as fallback, the
maximum number of file descriptors is limited to
<span class="code">FD_SETSIZE</span>. </p>
<p>Kernel poll support is now enabled by default if
<span class="code">/dev/poll</span>, <span class="code">epoll</span>, or <span class="code">kqueue</span> is found
when building OTP, i.e. you do not have to pass the
<span class="code">--enable-kernel-poll</span> argument to <span class="code">configure</span>.
As before, kernel poll is disabled by default in the
runtime system. In order to enable it, pass the
<span class="code">+Ktrue</span> command line argument to <span class="code">erl</span>.</p>
<p>Note: <span class="code">configure</span> will refuse to enable kernel poll
support on FreeBSD since <span class="code">kqueue</span> have problems with
(at least) pipes on all version of FreeBSD that we have
tested.</p>
<p>Own Id: OTP-6222 Aux Id: seq10380 </p>
</li>
<li>
<p>The <span class="code">erl_ddll</span> module and the code in the emulator
have been completely rewritten; several bugs were fixed.</p>
<p>Own Id: OTP-6234</p>
</li>
<li>
<p>The SMP emulator now avoids locking for the following
operations (thus making them as fast as in the UP
emulator): <span class="code">atom_to_list/1</span>, atom comparison, atom
hashing, <span class="code">erlang:apply/3</span>.</p>
<p>Own Id: OTP-6252</p>
</li>
<li>
<p>There are new BIFs <span class="code">erlang:spawn_monitor/1,3</span>,
and the new option <span class="code">monitor</span> for
<span class="code">spawn_opt/2,3,4,5</span>.</p>
<p>The <span class="code">observer_backend</span> module has been updated to
handle the new BIFs.</p>
<p>Own Id: OTP-6281</p>
</li>
</ul>
<h3><a name="id110431">1.55
Erts 5.5.1.1</a></h3>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>There is now an option read_packets for UDP sockets that
sets the maximum number of UDP packets that will be read
for each invocation of the socket driver.</p>
<p>Own Id: OTP-6249 Aux Id: seq10452 </p>
</li>
</ul>
<h3><a name="id110465">1.56
Erts 5.5.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Complex pattern matching of strings would fail in the 64
bits emulator because of a bug in the loader. (Thanks to
Igor Goryachev.)</p>
<p>Own Id: OTP-6142</p>
</li>
<li>
<p><span class="code">-134217728 div 134217728</span> and <span class="code">-134217728 rem 134217728</span> would be calculated incorrectly.
<span class="code">abs(-2147483648)</span> could in unlucky circumstances
cause a heap overflow, as could size(Binary) when size of
the binary was larger than 128Mb.</p>
<p>Own Id: OTP-6154</p>
</li>
<li>
<p>erlang:display/1 displayed erroneous values for negative
integers.</p>
<p>Big integers (both positive and negative) were previously
displayed in hexadecimal form while small integers were
displayed in decimal form. All integers are now displayed
in decimal form.</p>
<p>NOTE: erlang:display/1 should only be used for debugging.</p>
<p>Own Id: OTP-6156</p>
</li>
<li>
<p>A call to erlang:trace/3 with erroneous flags caused the
SMP emulator to deadlock instead of exiting the calling
process with badarg.</p>
<p>Own Id: OTP-6175</p>
</li>
<li>
<p>A bug causing the emulator to hang when exiting a process
that is exception traced has been fixed.</p>
<p>Own Id: OTP-6180</p>
</li>
<li>
<p>ets:rename/1 could deadlock, or crash the SMP emulator
when the table wasn't a named table.</p>
<p>ets:next/2, and ets:prev/2 could return erroneous results
on the SMP emulator.</p>
<p>Own Id: OTP-6198 Aux Id: seq10392, seq10415 </p>
</li>
<li>
<p>A memory allocation bug could cause the SMP emulator to
crash when a process had executed a <span class="code">receive after</span>
with a larger timeout than 10 minutes.</p>
<p>Own Id: OTP-6199</p>
</li>
<li>
<p>The runtime system with SMP support did not slowly adjust
its view of time when the system time suddenly changed.</p>
<p>Timeouts could sometimes timeout too early on the runtime
system with SMP support.</p>
<p>Own Id: OTP-6202</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The smp runtime system now automatically detects the
number of logical processors on MacOSX (darwin) and
OpenBSD.</p>
<p>The smp runtime system is now built by default on MacOSX
(darwin) on x86.</p>
<p>Own Id: OTP-6119</p>
</li>
<li>
<p>The <span class="code">-smp</span> command line argument now take the
following options: <span class="code">enable</span>, <span class="code">auto</span>, or
<span class="code">disable</span>.</p>
<p>Especially the <span class="code">-smpauto</span> argument is useful since
it starts the Erlang runtime system with SMP support if
it is available and more than one logical processor are
detected; otherwise, it starts the Erlang runtime system
without SMP support. For more information see the
<span class="code">erl(1)</span> man page.</p>
<p>Own Id: OTP-6126</p>
</li>
<li>
<p>Increased the reduction cost for sending messages in the
SMP emulator so it behaves more like the non-SMP
emulator.</p>
<p>Own Id: OTP-6196</p>
</li>
<li>
<p>A port running a dynamically linked-in driver that exits
due to the driver being unloaded now exits with exit
reason <span class="code">driver_unloaded</span>. Previously the port exited
with exit reason <span class="code">-1</span>.</p>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-6204</p>
</li>
<li>
<p>Changed name of the <span class="code">erlang:system_info/1</span> argument
<span class="code">scheduler</span> to <span class="code">scheduler_id</span>. This since the
<span class="code">scheduler</span> argument so easily could be mixed up
with the <span class="code">schedulers</span> argument (both returning
integers).</p>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-6208</p>
</li>
<li>
<p>The changes below were made by Mikael Pettersson, HiPE.</p>
<p>HiPE runtime system:</p>
<p>Reduce overheads in the HiPE runtime system's BIF glue
code.</p>
<p>Fix bug when exceptions are thrown from BEAM to HiPE.</p>
<p>Support SPARC on Linux.</p>
<p>Support x86 on FreeBSD.</p>
<p>Floating-point exceptions:</p>
<p>Reduce overheads in checking results of floating-point
operations.</p>
<p>Minor bug fix in SSE2 floating-point exception
handling.</p>
<p>Support SSE2 floating-point exceptions on 32-bit x86
machines.</p>
<p>Make FP exceptions work in the SMP runtime system on
FreeBSD/x86.</p>
<p>Support floating-point exceptions on SPARCs running
Linux.</p>
<p>Runtime system:</p>
<p>Minor scheduler optimisation in the non-SMP runtime
system.</p>
<p>Substantial reduction of I/O thread overheads in the
SMP runtime system if the separate timer thread is used.
(In R11B-1, the separate timer thread is not used.)</p>
<p>Own Id: OTP-6211</p>
</li>
</ul>
<h3><a name="id110826">1.57
ERTS 5.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Previously <span class="code">unlink/1</span> and <span class="code">erlang:demonitor/2</span>
behaved completely asynchronous. This had one undesirable
effect, though. You could never know when you were
guaranteed <strong>not</strong> to be affected by a link that you
had unlinked or a monitor that you had demonitored.</p>
<p>The new behavior of <span class="code">unlink/1</span> and
<span class="code">erlang:demonitor/2</span> can be viewed as two operations
performed atomically. Asynchronously send an unlink
signal or a demonitor signal, and ignore any future
results of the link or monitor.</p>
<p><strong>NOTE</strong>: This change can cause some obscure code
to fail which previously did not. For example, the
following code might hang:</p>
<div class="example"><pre>
Mon = erlang:monitor(process, Pid),
%% ...
exit(Pid, bang),
erlang:demonitor(Mon),
receive
{'DOWN', Mon , process, Pid, _} -> ok
%% We were previously guaranteed to get a down message
%% (since we exited the process ourself), so we could
%% in this case leave out:
%% after 0 -> ok
end,
</pre></div>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-5772</p>
</li>
<li>
<p>Two bugs fixed: If the environment variable <span class="code">ERL_FLAGS</span>
was set, its contents would be appended to the end of the
command line even if the command line had an <span class="code">-extra</span>
options. Changed to place the options from <span class="code">ERL_FLAGS</span>
just before <span class="code">-extra</span>. Also, the <span class="code">-smp</span> and
<span class="code">-hybrid</span> flags no longer have any effect if placed
after <span class="code">-extra</span>.</p>
<p>Own Id: OTP-6054</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The documentation for writing drivers in the ERTS User's
Guide has been expanded and updated.</p>
<p>Own Id: OTP-5192</p>
</li>
<li>
<p>The <span class="code">andalso</span> and <span class="code">orelse</span> operators are
now allowed to be used in guards. That also applies to
match specifications.</p>
<p>Own Id: OTP-5894 Aux Id: OTP-5149 </p>
</li>
<li>
<p>There is a new trace match spec function
<span class="code">{exception_trace}</span> and a corresponding trace
message <span class="code">exception_from</span> that can be used to trace
on any exit from a function, both normal function return
and exception return. See the documentation for
details.</p>
<p>The <span class="code">return_to</span> trace message is now also
generated when the execution returns to a function due to
catching an exception.</p>
<p>Own Id: OTP-5956</p>
</li>
<li>
<p>Erlang runtime system with SMP (symmetric multi processing)
support.</p>
<p>The runtime system with SMP support is in this release
focused on stability and there are a number of steps
with optimizations to follow before it will take
full advantage of multi processor systems.
The released system is however truly multi threaded
and you will notice increased performance
for many applications already.
We recommend that you evaluate your application on
the SMP version of the runtime system and wait for some
more optimizations before you use it in a real product.
You will then discover if there are any problems in
your application that needs to be fixed in order for
it to work properly in a multi threaded environment.
More optimized versions of the runtime system
with SMP support will be included in the R11B
maintenance releases.</p>
<p>The SMP enabled runtime system will be started if
the <span class="code">-smp</span> command line argument is passed to
the <span class="code">erl</span> command. In order to make use of more than
one processor core, multiple scheduler threads are used. By
default, the number of scheduler threads will equal
the number of processor cores. The number of scheduler
threads can be set with the <span class="code">+S</span> command line argument.
For more information see the <span class="code">erl(1)</span> man page.</p>
<p>A runtime system with SMP support is by default built on
the following platforms if posix threads, and a gcc
compiler of at least version 2.95 is found:</p>
<ul>
<li>
<p>Linux with at least kernel version 2.6 and the Native
POSIX Thread Library on x86, x86_64, and 32-bits
PowerPC.</p>
</li>
<li>
<p>Solaris of at least version 8 on 32-bits SPARC-V9.</p>
</li>
<li>
<p>MacOSX of at least version 10.4 (Darwin 8.0) on
32-bits PowerPC.</p>
</li>
</ul>
<p>The runtime system with SMP support is known <strong>not</strong>
to build on:</p>
<ul>
<li>
<p>Windows.</p>
</li>
<li>
<p>Linux with kernel versions less than 2.4, or without
the Native POSIX Thread Library.</p>
</li>
<li>
<p>Other hardware platforms than x86, x86_64, 32-bits
SPARC-V9 and 32-bits PowerPC.</p>
</li>
</ul>
<p>Windows will be supported in a future release.</p>
<p>The runtime system with SMP support might build on other
operating systems in combination with supported hardware.
In order to force a build of a runtime system with SMP
support, pass the <span class="code">--enable-smp-support</span> command line
argument to configure. Note, however, that it is not enough
that it builds. The underlying thread library and operating
system has to provide SMP support as well. If the thread
library does not distribute scheduler threads over multiple
processor cores then the runtime system will only seemingly
provide SMP support. If the runtime system is not built by
default on a specific platform, we have <strong>not</strong> tested
it on that platform.</p>
<p><strong>NOTE</strong>: The design of SMP support for drivers is
ongoing. There will probably be incompatible driver
changes (only affecting drivers run on the runtime system
with SMP support) released as patches for R11B.</p>
<p><strong>Potential incompatibility</strong>: Previously, specific
driver call-backs were always called from the same thread.
This is <strong>not</strong> true in the runtime system with SMP
support. Calls to call-backs will be made from different
threads, e.g., two consecutive calls to exactly the same
call-back can be made from two different threads. This
will in <strong>most</strong> cases not be a problem. All calls
to call-backs are synchronized, i.e., only one call-back
will be called at a time.</p>
<p>In the future the default behavior will <strong>probably</strong>
be the following: Calls to call-backs will, as now, be
made from different threads. Calls to call-backs in the
same driver <strong>instance</strong> will be synchronized. It
will probably be possible to configure so that all calls
to call-backs in all driver instances of a specific
driver type will be synchronized. It may be possible to
configure so that all calls to call-backs of a driver
instance or a of a specific driver type will be made from
the same thread.</p>
<p>Parallelism in the Erlang code executed is a necessity
for the Erlang runtime system to be able to take
advantage of multi-core or multi-processor hardware.
There need to be at least as many Erlang processes
runnable as processor cores for the Erlang runtime system
to be able to take advantage of all processor cores.</p>
<p>An Erlang runtime system with SMP support with only one
Erlang process runnable all the time will almost always be
slower than the same Erlang runtime system without SMP
support. This is due to thread synchronization overhead.</p>
<p>Known major bottleneck in the Erlang runtime system:</p>
<ul>
<li>
<p>Currently the I/O system uses one "big lock", i.e. only
one thread can do I/O at a time (with the exception of
async threads and threads created by users own linked-in
drivers). This is high on the list of things to
optimize. Note, code that does not do I/O can be executed
at the same time as one thread does I/O.</p>
</li>
</ul>
<p>Some pitfalls which might cause Erlang programs that work on
the non-SMP runtime system to fail on the SMP runtime
system:</p>
<ul>
<li>
<p>A newly spawned process will often begin executing
immediately. Code that expects that the parent process
will be able to execute for a while before the child
process begins executing is likely to fail.</p>
</li>
<li>
<p>High priority processes could previously provide
mutual exclusion (bad programming style) by preventing
normal and low priority processes from being run. High
priority processes cannot be used this way to provide
mutual exclusion.</p>
</li>
<li>
<p><span class="code">erlang:yield()</span> could be used to provide some
kind of temporary mutual exclusion (also bad programming
style). <span class="code">erlang:yield()</span> cannot be used to provide
any kind of mutual exclusion.</p>
</li>
<li>
<p>Obscure pitfall, only if a process being traced also
sends normal messages to the tracer:<br>
The order between trace messages and normal
messages is undefined. I.e. the order between normal
messages sent from a tracee to a tracer and the trace
messages generated from the same tracee to the same
tracer is undefined. The internal order of normal
messages and the internal order of trace messages will,
of course, be preserved as before.</p>
</li>
</ul>
<p>The kernel poll feature is currently not supported by
the runtime system with SMP support. It will probably be
supported in a future release.</p>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-6006 Aux Id: OTP-6095 </p>
</li>
<li>
<p>Linked-in driver modifications.</p>
<ul>
<li>
<p>Linked-in drivers must be recompiled.</p>
</li>
<li>
<p>The <span class="code">refc</span> field in the <span class="code">ErlDrvBinary</span> type
has been removed. The reference count can be accessed
via API functions. For more information see
the <span class="code">erl_driver(1)</span> man page.</p>
</li>
</ul>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-6095 Aux Id: OTP-6006 </p>
</li>
</ul>
<h3><a name="id111349">1.58
ERTS 5.4.13</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Large files (more than 2 GBytes) are now handled on
Solaris 8.</p>
<p>Own Id: OTP-5849 Aux Id: seq10157 </p>
</li>
<li>
<p>A failing bit syntax construction could fail with the
PREVIOUS exception reason that had occurred in the process
(instead of with <span class="code">badarg</span>).</p>
<p>Own Id: OTP-5911</p>
</li>
<li>
<p>When building OTP, the Kernel application was built in
both the primary and secondary bootstrap steps, which
would cause problems if OTP including its bootstrap is
checked into a version control system (such as CVS).
(Thanks to Sebastian Strollo.)</p>
<p>Own Id: OTP-5921</p>
</li>
<li>
<p><span class="code">binary_to_term(<<131,109,255,255,255,255)</span> and
similar expressions used to crash the emulator instead of
causing a <span class="code">badarg</span> exception. (Thanks to Matthias
Lang.)</p>
<p>Own Id: OTP-5933</p>
</li>
<li>
<p><span class="code">erlang:hibernate/3</span> could sometimes crash the emulator
when no heap was needed.</p>
<p>Own Id: OTP-5940</p>
</li>
<li>
<p>Execution of match specs could under rare circumstances
cause the emulator to dump core.</p>
<p>Execution of match specs could cause memory leaks in the
hybrid emulator.</p>
<p>Own Id: OTP-5955</p>
</li>
<li>
<p>A bug in <span class="code">erlang:trace_info/2</span> when getting info for a
function in a deleted module resulting in an emulator
crash, has been corrected.</p>
<p>Own Id: OTP-5957</p>
</li>
<li>
<p>Different (and old) <span class="code">config.guess</span> files in the
ERTS and Erl_Interface applications would cause build
problems on the new Intel-based iMacs.
(Thanks to Sebastion Strollo.)</p>
<p>Own Id: OTP-5967</p>
</li>
<li>
<p>pthread header and library mismatch on Linux systems (at
least some SuSE and Debian) with both NPTL and
Linuxthreads libraries installed.</p>
<p>Own Id: OTP-5981</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The driver_set_timer did not change the previous timeout
if called a second time. Now it works as specified,
changing the timeout.</p>
<p>Own Id: OTP-5942</p>
</li>
<li>
<p>The undocumented <span class="code">{packet,http}</span> option (for the
<span class="code">gen_tcp</span> module) did not not work correctly when
there were multiple continuation lines. (Thanks to Per
Hedeland.)</p>
<p>Own Id: OTP-5945</p>
</li>
<li>
<p>The setuid_socket_wrap program was corrected to work for
C compilers that treat the <span class="code">char</span> type as unsigned.
(Thanks to Magnus Henoch.)</p>
<p>Own Id: OTP-5946</p>
</li>
</ul>
<h3><a name="id111567">1.59
ERTS 5.4.12</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Fixed a minor build problem on Windows.</p>
<p>Own Id: OTP-5819 Aux Id: OTP-5382 OTP-5540 OTP-5577 </p>
</li>
<li>
<p>The <span class="code">delay_send</span> option for <span class="code">gen_tcp</span> was
broken on Windows.</p>
<p>Own Id: OTP-5822</p>
</li>
<li>
<p>If there were user-defined variables in the boot
script, and their values were not provided using the
<span class="code">-boot_var</span> option, the emulator would refuse to
start with a confusing error message. Corrected to show a
clear, understandable message.</p>
<p>The <span class="code">prim_file</span> module was modified to not depend
on the <span class="code">lists</span> module, to make it possible to start
the emulator using a user-defined loader. (Thanks to
Martin Bjorklund.)</p>
<p>Own Id: OTP-5828 Aux Id: seq10151 </p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The HiPE compiler identifies more leaf functions,
giving slightly faster code.</p>
<p>Corrected problems in HiPE's coalescing register
allocating that would cause it to fail when compiling
very large functions (e.g. some of parse modules in the
Megaco application).</p>
<p>Own Id: OTP-5853</p>
</li>
</ul>
<h3><a name="id111679">1.60
ERTS 5.4.11</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Timers could sometimes timeout too early. This bug has
now been fixed.</p>
<p>Automatic cancellation of timers created by
<span class="code">erlang:send_after(Time,pid(),Msg)</span> and
<span class="code">erlang:start_timer(Time,pid(),Msg)</span> has been
introduced. Timers created with the receiver specified by a
pid, will automatically be cancelled when the receiver
exits. For more information see the <span class="code">erlang(3)</span> man
page.</p>
<p>In order to be able to maintain a larger amount of timers
without increasing the maintenance cost, the internal
timer wheel and bif timer table have been enlarged.</p>
<p>Also a number of minor bif timer optimizations have been
implemented.</p>
<p>Own Id: OTP-5795 Aux Id: OTP-5090, seq8913, seq10139,
OTP-5782 </p>
</li>
<li>
<p><span class="code">erlang:monitor(process,Pid)</span> hanged if <span class="code">Pid</span>
referred to a process on a non-existing node with the same
nodename as the nodename of node on which the call was made.
This bug has now been fixed.</p>
<p>Own Id: OTP-5827</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>By setting Unix environment variables, the priority for
the emulator can be lowered when it is writing crash
dumps and the time allowed for finishing writing a crash
dump can be set to a certain number of seconds. See the
documentation for <span class="code">erl</span> in the ERTS application.
(Also, a few other previously undocumented environment
variables are now documented.)</p>
<p>Own Id: OTP-5818</p>
</li>
<li>
<p>Documentation improvements:</p>
<p>- documentation for <span class="code">erlang:link/1</span> corrected</p>
<p>- command line flag <span class="code">-code_path_cache</span> added</p>
<p>- <span class="code">erl</span> command line flags clarifications</p>
<p>- <span class="code">net_kernel(3)</span> clarifications</p>
<p>Own Id: OTP-5847</p>
</li>
</ul>
<h3><a name="id111831">1.61
ERTS 5.4.10</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>-D_GNU_SOURCE is now always passed on the compile command
line on linux. This in order to ensure that all included
system headers see _GNU_SOURCE defined.</p>
<p>_GNU_SOURCE is now also defined on linux in configure
when looking for features.</p>
<p>Some minor (harmless) configure bugs were also fixed.</p>
<p>Own Id: OTP-5749</p>
</li>
<li>
<p>Some compiler warnings and Dialyzer warnings were
eliminated in the Tools application.</p>
<p>When tracing to a port (which <span class="code">fprof</span> does),
there could be fake schedule out/schedule in messages
sent for a process that had exited.</p>
<p>Own Id: OTP-5757</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The BIFs <span class="code">iolist_size/1</span> and <span class="code">iolist_to_binary/1</span>
has been added.</p>
<p>The BIF <span class="code">list_to_existing_atom/1</span> has been added.</p>
<p>Minor bug fix: The exception reason could be changed
to <span class="code">error</span> inside nested try/catch constructs if the
<span class="code">erlang:raise/3</span> BIF was called with an empty
stacktrace. (Calling <span class="code">erlang:raise/3</span> with an empty
stacktrace is NOT recommended.)</p>
<p>Minor bugfix: On Windows, <span class="code">file:open/2</span> will now
return the documented error reason <span class="code">{error,eisdir}</span>
if the filename refers to a directory (it used to return
<span class="code">{error,eacces}</span>).</p>
<p>The message in the documentation for
<span class="code">erlang:system_monitor/2</span>, description of
<span class="code">busy_dist_port</span>, was corrected.</p>
<p>Own Id: OTP-5709 Aux Id: seq10100 </p>
</li>
<li>
<p>The previously undocumented and UNSUPPORTED <span class="code">zlib</span>
module has been updated in an incompatible way and many
bugs have been corrected. It is now also documented.</p>
<p>*** POTENTIAL INCOMPATIBILITY ***</p>
<p>Own Id: OTP-5715</p>
</li>
<li>
<p>New socket options <span class="code">priority</span> and <span class="code">tos</span> for
platforms that support them (currently only Linux).</p>
<p>Own Id: OTP-5756</p>
</li>
<li>
<p>Only the emulator is now linked with termcap library in
order to decrease library dependencies for other otp
programs.</p>
<p>Own Id: OTP-5758</p>
</li>
</ul>
<h3><a name="id112028">1.62
ERTS 5.4.9.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>The native resolver has gotten an control API for
extended debugging and soft restart. It is:
<span class="code">inet_gethost_native:control(Control)</span><br><span class="code">Control = {debug_level,Level} | soft_restart</span><br><span class="code">Level = integer() in the range 0-4</span>.</p>
<p>Own Id: OTP-5751 Aux Id: EABln25013 </p>
</li>
</ul>
<h3><a name="id112073">1.63
ERTS 5.4.9.1</a></h3>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>On VxWorks, epmd did not handle file descriptors with
higher numbers than 63. Also, if epmd should get a file
descriptor with a number >= FD_SETSIZE, it will close a
the file descriptor and write a message to the log
(instead of mysteriously fail); the Erlang node that
tried to register will fail with a duplicate_name error
(unfortunately, epmd has no way to indicate to the Erlang
node why the register attempt failed).</p>
<p>Own Id: OTP-5716 Aux Id: seq10070 </p>
</li>
</ul>
<h3><a name="id112109">1.64
ERTS 5.4.9</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Timezone data is now initialized better. (was a problem
at least on NetBSD 2.0.2) Thanks to Rich Neswold.</p>
<p>Own Id: OTP-5621</p>
</li>
<li>
<p>The hybrid-heap emulator ('erl -hybrid') is much more
stable. We have corrected all known bugs that caused it
to dump core while running our test suites.</p>
<p>Own Id: OTP-5634</p>
</li>
<li>
<p>Fixed rare memory leaks in <span class="code">erlang:demonitor/1</span> when
distributed monitors were removed.</p>
<p>Own Id: OTP-5692</p>
</li>
<li>
<p>Processes were sometimes unnecessarily garbage collected
when terminating. These unnecessary garbage collections
have now been eliminated.</p>
<p>Own Id: OTP-5693</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The <span class="code">c:i/0</span> function will now run in a paged mode if
there are more than 100 processes in the system. (Thanks
to Ulf Wiger.)</p>
<p><span class="code">erlang:system_info(process_count)</span> has
been optimized and does now return exactly the same value
as <span class="code">length(processes())</span>. Previously
<span class="code">erlang:system_info(process_count)</span> did not include
exiting processes which are included in
<span class="code">length(processes())</span>.</p>
<p>The <span class="code">+P</span> flag for <span class="code">erl</span>, which sets the maximum
number of processes allowed to exist at the same, no longer
accepts values higher than 134217727. (You will still
probably run out of memory before you'll be able to reach
that limit.)</p>
<p>Own Id: OTP-5645 Aux Id: seq9984 </p>
</li>
<li>
<p>The term-building driver functions
<span class="code">driver_output_term()</span> and <span class="code">driver_send_term()</span>
have been updated:</p>
<p>The ERL_DRV_FLOAT type has been added.</p>
<p>For the ERL_DRV_BINARY type, the length and offset are
now validated against the length of the driver binary.</p>
<p>The ERL_DRV_PID type is now implemented (it was
documented, but not implemented).</p>
<p>Own Id: OTP-5674</p>
</li>
</ul>
<h3><a name="id112276">1.65
ERTS 5.4.8</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p><span class="code">ets:delete/1</span> now allows other Erlang process to run
when a large table is being deleted.</p>
<p>Own Id: OTP-5572</p>
</li>
<li>
<p>A bug regarding tcp sockets which results in hanging
<span class="code">gen_tcp:send/2</span> has been corrected. To encounter
this bug you needed one process that read from a socket,
one that wrote more date than the reader read out so the
sender got suspended, and then the reader closed the
socket. (Reported and diagnosed by Alexey Shchepin.)</p>
<p>Corrected a bug in the (undocumented and unsupported)
option <span class="code">{packet,http}</span> for <span class="code">gen_tcp.</span>
(Thanks to Claes Wikstrom and Luke Gorrie.)</p>
<p>Updated the documentation regarding the second argument to
<span class="code">gen_tcp:recv/2</span>, the <span class="code">Length</span> to receive.</p>
<p>Own Id: OTP-5582 Aux Id: seq9839 </p>
</li>
<li>
<p>Erlang/OTP will now build on Mac OS X 10.4 "Tiger" (the
problem was that 10.4 has a partially implemented poll()
function that can't handle devices). Also, on Mac OS X
10.3 "Panther", Erlang/OTP will now use select() instead
of poll() (because poll() on Mac OS X 10.3 is implemented
using select()).</p>
<p>Own Id: OTP-5595</p>
</li>
<li>
<p>A bug in the file driver when opening a file in
compressed mode, and the returned allocated pointer from
the compressing library was in very high memory (>= 2GB),
causing e.g. <span class="code">file:read/2</span> to return
<span class="code">{error,ebadf}</span>, has been corrected.</p>
<p>Own Id: OTP-5618</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The new fun <span class="code">M:F/A</span> construct creates a fun that
refers to the latest version of <span class="code">M:F/A.</span> This syntax is
meant to replace tuple funs <span class="code">{M,F}</span> which have many
problems.</p>
<p>The new type test <span class="code">is_function(Fun,A)</span> (which may be
used in guards) test whether <span class="code">Fun</span> is a fun that can be
applied with <span class="code">A</span> arguments. (Currently, <span class="code">Fun</span>
can also be a tuple fun.)</p>
<p>Own Id: OTP-5584</p>
</li>
<li>
<p>In the HiPE application, there's a new experimental
register allocator (optimistic coalescing), and the
linear scan register allocator is now also available on
ppc. Plus lots of cleanups.</p>
<p>Minor hybrid heap corrections.</p>
<p>The maximum size of a heap used to be artificially
limited so that the size of a heap would fit in 28 bits;
that limitation could cause the emulator to terminate in
a garbage collection even if there still was available
memory. Now the largest heap size for a 32 bit CPU is
1,699,221,830 bytes. (Thanks to Jesper Wilhelmsson.)</p>
<p>Also removed the undocumented <span class="code">+H</span> emulator option.</p>
<p>Own Id: OTP-5596</p>
</li>
</ul>
<h3><a name="id112476">1.66
ERTS 5.4.7</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p><span class="code">to_erl</span> could close unexpectedly on Linux systems.
Also, output from the emulator could be lost. Corrected.</p>
<p>Own Id: OTP-5561</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The <span class="code">cpu_timestamp</span> option for <span class="code">erlang:trace/3</span>
is now also supported on Linux.</p>
<p>Own Id: OTP-5532 Aux Id: seq9813 </p>
</li>
<li>
<p>The last known <span class="code">werl</span> window size/position is now saved
correctly when <span class="code">werl</span> is stopped with the window
minimized. A problem with the placement not being saved if
the emulator is halted or stopped from the JCL menu has also
been fixed.</p>
<p>Own Id: OTP-5544 Aux Id: OTP-5522 </p>
</li>
</ul>
<h3><a name="id112564">1.67
ERTS 5.4.6</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Some math libraries do not always throw floating-point
exceptions on errors. In order to be able to use these
libraries, floating-point errors are now more thoroughly
checked.</p>
<p>Misc floating-point fixes for Linux and MacOSX.</p>
<p>Own Id: OTP-5467</p>
</li>
<li>
<p>An internal buffer was sometimes not cleared which caused
garbage to appear in error messages sent to the error
logger.</p>
<p><span class="code">errno</span> was sometimes clobbered which caused erroneous
error reports about <span class="code">poll()</span> errors.</p>
<p>Only emulators on unix platforms were affected by these
bugs.</p>
<p>Own Id: OTP-5492</p>
</li>
<li>
<p>The ethread library now works on OpenBSD.</p>
<p>Own Id: OTP-5515</p>
</li>
<li>
<p>Corrected a bug in the (undocumented and unsupported)
option <span class="code">{packet,http}</span> for <span class="code">gen_tcp</span>.
(Thanks to Claes Wikstrom and Luke Gorrie.)</p>
<p>Own Id: OTP-5519</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p><span class="code">binary_to_term/1</span> could cause the emulator to crash
when given invalid pids or funs.</p>
<p>Own Id: OTP-5484 Aux Id: seq9801 </p>
</li>
<li>
<p>Some more stability problems were fixed in the
hybrid-heap emulator.</p>
<p>Own Id: OTP-5489</p>
</li>
<li>
<p>After <span class="code">werl</span> was closed with the window minimized, it
was not possible to restart <span class="code">werl</span> with an open
window. A temporary solution has so far been implemented
that restores the initial window settings every time
<span class="code">werl</span> is started.</p>
<p>Own Id: OTP-5522</p>
</li>
</ul>
<h3><a name="id112724">1.68
ERTS 5.4.5</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>If a process had node links (created by
<span class="code">monitor_node/2</span>), executing
<span class="code">process_info(Pid,memory)</span> for that process would
crash the emulator.</p>
<p>Own Id: OTP-5420</p>
</li>
<li>
<p>Minor corrections to the help text printed by <span class="code">erlc -help</span>. The documentation for <span class="code">erlc</span> was also
slightly updated.</p>
<p>Own Id: OTP-5428</p>
</li>
<li>
<p>32-bit words were used for offsets in the garbage
collector. This caused the emulator to crash on 64-bit
machines when heaps were moved more than 4 GB during
garbage collection.</p>
<p>Own Id: OTP-5430</p>
</li>
<li>
<p><span class="code">is_boolean(42.5)</span> failed to load if optimization was
explicitly turned off.</p>
<p>Own Id: OTP-5448</p>
</li>
<li>
<p>If there was a call to <span class="code">Module:foo/X</span> from any loaded
module, the returned by <span class="code">M:module_info(exports)</span> would
always include <span class="code">{foo,X}</span> (even though
<span class="code">Module:foo/X</span> if was not defined).</p>
<p>Own Id: OTP-5450 Aux Id: seq9722 </p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The <span class="code">c</span> option for the <span class="code">+B</span> flag has been
introduced which makes it possible to use Ctrl-C
(Ctrl-Break on Windows) to interrupt the shell process
rather than to invoke the emulator break handler. All new
<span class="code">+B</span> options are also supported on Windows
(<span class="code">werl</span>) as of now. Furthermore, Ctrl-C on Windows has
now been reserved for copying text (what Ctrl-Ins was used
for previously). Ctrl-Break should be used for break
handling. Lastly, the documentation of the system flags has
been updated.</p>
<p>Own Id: OTP-5388</p>
</li>
</ul>
<h3><a name="id112881">1.69
ERTS 5.4.4</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>The function <span class="code">erlang:float/1</span> can now be used in
match specifications and is recognized by
<span class="code">dbg:fun2ms/1</span> and <span class="code">ets:fun2ms/1</span>. This
addition is part of the work to "harmonize" match
specification guards with Erlang guards.</p>
<p>Own Id: OTP-5297 Aux Id: OTP-4927 </p>
</li>
<li>
<p>The <span class="code">register/2</span> BIF would return <span class="code">true</span> even if
the second argument was not a pid for living process.
Corrected to cause an exception.</p>
<p>Own Id: OTP-5324 Aux Id: seq9698 </p>
</li>
<li>
<p>In the 'bag' type of ets tables, elements having the same
key were supposed to be order in insertion order. The
would be wrong if a rehash occurred.</p>
<p>Own Id: OTP-5340 Aux Id: seq9704 </p>
</li>
<li>
<p>Linked in drivers in the Crypto and Asn1 applications
are now compiled with the <span class="code">-D_THREAD_SAFE</span> and
<span class="code">-D_REENTRANT</span> switches on unix when the emulator has
thread support enabled.</p>
<p>Linked in drivers on MacOSX are not compiled with the
undocumented <span class="code">-lbundle1.o</span> switch anymore. Thanks to
Sean Hinde who sent us a patch.</p>
<p>Linked in driver in Crypto, and port programs in SSL, now
compiles on OSF1.</p>
<p>Minor makefile improvements in Runtime_Tools.</p>
<p>Own Id: OTP-5346</p>
</li>
<li>
<p>Fixed a bug in the hybrid heap in distributed send
operations.</p>
<p>Own Id: OTP-5361</p>
</li>
<li>
<p>A BIF <span class="code">erlang:raise/3</span> has been added. See the manual
for details. It is intended for internal system programming
only, advanced error handling.</p>
<p>Own Id: OTP-5376 Aux Id: OTP-5257 </p>
</li>
<li>
<p>Mikael Pettersson (HiPE) corrected a few bugs in the
emulator that caused problems when compiled with the
experimental gcc-4.0.0.</p>
<p>Own Id: OTP-5386</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Minor update of the internal documentation of
the <span class="code">epmd</span> protocol.</p>
<p>The listen port of <span class="code">epmd</span> has now been registered at
IANA:
<span class="bold_code"><a href="http://www.iana.org/assignments/port-numbers">http://www.iana.org/assignments/port-numbers</a></span>.</p>
<p>Own Id: OTP-5234</p>
</li>
<li>
<p><span class="code">run_erl.c</span> now works on Mac OS X and FreeBSD.</p>
<p>Own Id: OTP-5384</p>
</li>
<li>
<p>A few bugs were corrected in the HiPE application.</p>
<p>Own Id: OTP-5385</p>
</li>
</ul>
<h3><a name="id113104">1.70
ERTS 5.4.3</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>Font and color preferences for <span class="code">werl.exe</span> now can be
saved even after the first time you run <span class="code">werl.exe</span>.
The window position and size is also saved. Patch from
James Hague who did all the hard work.</p>
<p>Own Id: OTP-5250</p>
</li>
<li>
<p>OTP archive libraries, e.g. the <span class="code">erl_interface</span>
library, on MacOSX could not be used without first
rerunning <span class="code">ranlib</span> on them. This bug has now been
fixed.</p>
<p>Own Id: OTP-5274</p>
</li>
<li>
<p>Bugs in <span class="code">erlang:hash/2</span> and <span class="code">erlang:phash/2</span> on
64-bit platforms have been fixed.</p>
<p>Own Id: OTP-5292</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>Corrected a crash in the 64-bits emulator.</p>
<p>Corrected a problem in the hybrid heap emulator.</p>
<p>In the chapter about the abstract format in the ERTS User's
Guide, updated the last section about how the abstract
format is stored in BEAM files.</p>
<p>Own Id: OTP-5262</p>
</li>
<li>
<p>The maximum number of concurrent threads in the internal
ethread thread package has been limited to 2048.</p>
<p>Own Id: OTP-5280</p>
</li>
</ul>
<h3><a name="id113230">1.71
ERTS 5.4.2.1</a></h3>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>If Erlang/OTP was installed in a short directory name,
such as <span class="code">C:\Program\erl5.4.2</span>, the emulator would not
start.</p>
<p>Own Id: OTP-5254</p>
</li>
</ul>
<h3><a name="id113266">1.72
ERTS 5.4.2</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>If one used <span class="code">select/3</span> and <span class="code">select/1</span> on a
non-fixed ETS table and deleted objects simultaneously,
the emulator could crash. Note that the result of such
simultaneous operations on tables that are not in a fixed
state is still undefined, but the emulator crash is,
needless to say, fixed.</p>
<p>Own Id: OTP-5209 Aux Id: seq9198 </p>
</li>
<li>
<p>Arithmetic with big numbers could crash the emulator.</p>
<p>The HiPE native code compiler and run-time code in the
emulator has been updated. (Note: Native code is still
not supported.)</p>
<p>Eliminated a few bugs that could crash the hybrid emulator
(which is not supported).</p>
<p>Own Id: OTP-5233 Aux Id: seq9587 </p>
</li>
</ul>
<h3><a name="id113330">1.73
ERTS 5.4.1</a></h3>
<h4>Fixed Bugs and Malfunctions</h4>
<ul>
<li>
<p>The ethread library was unnecessarily rebuilt multiple
times during the build process, also a debug version of
the library was build during the install phase. These
unnecessary builds have now been removed. Note, the
content of the installed Erlang/OTP system is not
effected at all by this change.</p>
<p>Own Id: OTP-5203</p>
</li>
<li>
<p>The emulator could fail to clear the memory segment
cache. This could potentially cause memory allocation to
unnecessarily fail when memory usage was close to its
maximum. This bug has now been fixed.</p>
<p>Own Id: OTP-5211</p>
</li>
<li>
<p>std_alloc (std short for standard) was sometimes called
def_alloc (def short for default). std_alloc is now
everywhere referred to as std_alloc.</p>
<p>Own Id: OTP-5216</p>
</li>
<li>
<p>A documentation bug has been corrected in
the <span class="code">erts_alloc(3)</span> documentation. It was stated that
some of the memory allocators present were by default
disabled. This is true for Erlang/OTP R9C, but is not true
for Erlang/OTP R10B. In R10B all memory allocators present
are enabled by default.</p>
<p>Own Id: OTP-5217</p>
</li>
</ul>
<h4>Improvements and New Features</h4>
<ul>
<li>
<p>The emulator now close all open files and sockets
immediately after receiving an USR1 signal. This causes
the emulator to unregister at <span class="code">epmd</span> as early as
possible.</p>
<p>Own Id: OTP-5221 Aux Id: OTP-4985, seq9514 </p>
</li>
<li>
<p>Try/catch support in the emulator slightly updated.</p>
<p>Own Id: OTP-5229</p>
</li>
</ul>
</div>
<div class="footer">
<hr>
<p>Copyright © 1997-2012 Ericsson AB. All Rights Reserved.</p>
</div>
</div>
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