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<h1>Module type <a href="type_File_descr_watcher_intf.S.html">File_descr_watcher_intf.S</a></h1>
<pre><span class="keyword">module type</span> S = <code class="code">sig</code> <a href="File_descr_watcher_intf.S.html">..</a> <code class="code">end</code></pre><hr width="100%">
<pre><span id="TYPEt"><span class="keyword">type</span> <code class="type"></code>t</span> </pre>
<div class="info ">
A file-descr-watcher is essentially a map from <code class="code">File_descr.t</code> to <code class="code">bool
Read_write.t</code>, which defines the set of file descriptors being watched, and for each
file descriptor, whether it is being watched for read, write, or both. If a file
descriptor is not being watched for neither, it is not in the map.<br>
</div>
<pre><span class="keyword">include</span> Invariant.S</pre>
<pre><span id="VALbackend"><span class="keyword">val</span> backend</span> : <code class="type">Import.Config.File_descr_watcher.t</code></pre>
<pre><span id="VALcreate"><span class="keyword">val</span> create</span> : <code class="type">num_file_descrs:int -> <a href="File_descr_watcher_intf.S.html#TYPEt">t</a></code></pre><div class="info ">
<code class="code">create ~num_file_descrs</code> creates a new file-descr-watcher that is able to watch
file descriptors in <pre class="codepre"><code class="code"> [0, num_file_descrs) </code></pre>.<br>
</div>
<pre><span id="VALset"><span class="keyword">val</span> set</span> : <code class="type"><a href="File_descr_watcher_intf.S.html#TYPEt">t</a> -><br> Import.File_descr.t -> bool <a href="Read_write.html#TYPEt">Read_write.t</a> -> unit</code></pre><div class="info ">
<code class="code">set</code> alters the map of file descriptors being watched. It will take effect on the
next call to <code class="code">thread_safe_check</code>. Calling <code class="code">set fd</code> with <code class="code">{ read = false, write =
false }</code> removes <code class="code">fd</code> from the map.<br>
</div>
<pre><span id="VALiter"><span class="keyword">val</span> iter</span> : <code class="type"><a href="File_descr_watcher_intf.S.html#TYPEt">t</a> -><br> f:(Import.File_descr.t -> <a href="Read_write.Key.html#TYPEt">Read_write.Key.t</a> -> unit) -> unit</code></pre><div class="info ">
<code class="code">iter t ~f</code> iterates over every file descriptor in the map, apply <code class="code">f</code> to it once
for each of {`Read,`Write} that it is being watched for.<br>
</div>
<pre><span class="keyword">module</span> <a href="File_descr_watcher_intf.S.Pre.html">Pre</a>: <code class="code">sig</code> <a href="File_descr_watcher_intf.S.Pre.html">..</a> <code class="code">end</code></pre><div class="info">
<code class="code">pre_check t</code> does whatever non-thread-safe work is necessary to prepare for the
system call that checks file descriptors being ready for read or write.
</div>
<pre><span id="VALpre_check"><span class="keyword">val</span> pre_check</span> : <code class="type"><a href="File_descr_watcher_intf.S.html#TYPEt">t</a> -> <a href="File_descr_watcher_intf.S.Pre.html#TYPEt">Pre.t</a></code></pre>
<pre><span class="keyword">module</span> <a href="File_descr_watcher_intf.S.Check_result.html">Check_result</a>: <code class="code">sig</code> <a href="File_descr_watcher_intf.S.Check_result.html">..</a> <code class="code">end</code></pre><div class="info">
<code class="code">thread_safe_check t pre ~timeout</code> checks the file descriptors for their status and
returns when at least one is available, or the <code class="code">timeout</code> passes.
</div>
<pre><span id="VALthread_safe_check"><span class="keyword">val</span> thread_safe_check</span> : <code class="type"><a href="File_descr_watcher_intf.S.html#TYPEt">t</a> -><br> <a href="File_descr_watcher_intf.S.Pre.html#TYPEt">Pre.t</a> -><br> timeout:<a href="File_descr_watcher_intf.Timeout.html#TYPEt">File_descr_watcher_intf.Timeout.t</a> -><br> <a href="File_descr_watcher_intf.S.Check_result.html#TYPEt">Check_result.t</a></code></pre>
<pre><span id="VALpost_check"><span class="keyword">val</span> post_check</span> : <code class="type"><a href="File_descr_watcher_intf.S.html#TYPEt">t</a> -><br> <a href="File_descr_watcher_intf.S.Check_result.html#TYPEt">Check_result.t</a> -><br> [ `Ok of <a href="File_descr_watcher_intf.Post.html#TYPEt">File_descr_watcher_intf.Post.t</a> <a href="Read_write.html#TYPEt">Read_write.t</a><br> | `Syscall_interrupted<br> | `Timeout ]</code></pre><div class="info ">
<code class="code">post_check t check_result</code> returns the file descriptors available for read and
write. Any file descriptor appearing in <code class="code">post</code> for read must have been watched
for read, as per <code class="code">set</code>. Similarly for write.<br>
</div>
<pre><span id="VALsexp_of_t"><span class="keyword">val</span> sexp_of_t</span> : <code class="type"><a href="File_descr_watcher_intf.S.html#TYPEt">t</a> -> Sexplib.Sexp.t</code></pre><br>
<code class="code">create ~num_file_descrs</code> creates a new file-descr-watcher that is able to watch
file descriptors in <pre class="codepre"><code class="code"> [0, num_file_descrs) </code></pre>.<br>
<br>
<code class="code">set</code> alters the map of file descriptors being watched. It will take effect on the
next call to <code class="code">thread_safe_check</code>. Calling <code class="code">set fd</code> with <code class="code">{ read = false, write =
false }</code> removes <code class="code">fd</code> from the map.<br>
<br>
<code class="code">iter t ~f</code> iterates over every file descriptor in the map, apply <code class="code">f</code> to it once
for each of {`Read,`Write} that it is being watched for.<br>
<br>
<code class="code">pre_check t</code> does whatever non-thread-safe work is necessary to prepare for the
system call that checks file descriptors being ready for read or write. <code class="code">pre_check</code>
does not side effect <code class="code">t</code>.<br>
<br>
<code class="code">thread_safe_check t pre ~timeout</code> checks the file descriptors for their status and
returns when at least one is available, or the <code class="code">timeout</code> passes.
<code class="code">thread_safe_check</code> does not side effect <code class="code">t</code>. Unlike the rest of the functions in
this module, <code class="code">thread_safe_check</code> is thread safe.<br>
<br>
<code class="code">post_check t check_result</code> returns the file descriptors available for read and
write. Any file descriptor appearing in <code class="code">post</code> for read must have been watched
for read, as per <code class="code">set</code>. Similarly for write.<br>
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