<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>The EventBase class</title>
</head>
<body><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="event.timer.html">Event::timer</a></div>
<div class="next" style="text-align: right; float: right;"><a href="eventbase.construct.html">EventBase::__construct</a></div>
<div class="up"><a href="book.event.html">Event</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="class.eventbase" class="reference">
<h1 class="title">The EventBase class</h1>
<div class="partintro"><p class="verinfo">(PECL event >= 1.2.6-beta)</p>
<div class="section" id="eventbase.intro">
<h2 class="title">Introduction</h2>
<p class="para">
<strong class="classname">EventBase</strong>
class represents libevent's event base structure. It holds a set of events
and can poll to determine which events are active.
</p>
<p class="para">
Each event base has a
<em class="emphasis">method</em>
, or a
<em class="emphasis">backend</em>
that it uses to determine which events are ready. The recognized methods
are:
<em>select</em>
,
<em>poll</em>
,
<em>epoll</em>
,
<em>kqueue</em>
,
<em>devpoll</em>
,
<em>evport</em>
and
<em>win32</em>
.
</p>
<p class="para">
To configure event base to use, or avoid specific backend
<a href="class.eventconfig.html" class="classname">EventConfig</a>
class can be used.
</p>
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">
Do
<em class="emphasis">NOT</em>
destroy the
<strong class="classname">EventBase</strong>
object as long as resources of the associated
<em>Event</em>
objects are not released. Otherwise, it will lead to unpredictable
results!
</p>
</div>
</div>
<div class="section" id="eventbase.synopsis">
<h2 class="title">Class synopsis</h2>
<div class="classsynopsis">
<div class="ooclass">
</div>
<div class="classsynopsisinfo">
<span class="ooclass">
<span class="modifier">final</span>
<strong class="classname">EventBase</strong>
</span>
{</div>
<div class="classsynopsisinfo classsynopsisinfo_comment">/* Constants */</div>
<div class="fieldsynopsis">
<span class="modifier">const</span>
<span class="type">integer</span>
<var class="fieldsynopsis_varname"><a href="class.eventbase.html#eventbase.constants.loop-once"><var class="varname">LOOP_ONCE</var></a></var>
<span class="initializer"> = 1</span>
;</div>
<div class="fieldsynopsis">
<span class="modifier">const</span>
<span class="type">integer</span>
<var class="fieldsynopsis_varname"><a href="class.eventbase.html#eventbase.constants.loop-nonblock"><var class="varname">LOOP_NONBLOCK</var></a></var>
<span class="initializer"> = 2</span>
;</div>
<div class="fieldsynopsis">
<span class="modifier">const</span>
<span class="type">integer</span>
<var class="fieldsynopsis_varname"><a href="class.eventbase.html#eventbase.constants.nolock"><var class="varname">NOLOCK</var></a></var>
<span class="initializer"> = 1</span>
;</div>
<div class="fieldsynopsis">
<span class="modifier">const</span>
<span class="type">integer</span>
<var class="fieldsynopsis_varname"><a href="class.eventbase.html#eventbase.constants.startup-iocp"><var class="varname">STARTUP_IOCP</var></a></var>
<span class="initializer"> = 4</span>
;</div>
<div class="fieldsynopsis">
<span class="modifier">const</span>
<span class="type">integer</span>
<var class="fieldsynopsis_varname"><a href="class.eventbase.html#eventbase.constants.no-cache-time"><var class="varname">NO_CACHE_TIME</var></a></var>
<span class="initializer"> = 8</span>
;</div>
<div class="fieldsynopsis">
<span class="modifier">const</span>
<span class="type">integer</span>
<var class="fieldsynopsis_varname"><a href="class.eventbase.html#eventbase.constants.epoll-use-changelist"><var class="varname">EPOLL_USE_CHANGELIST</var></a></var>
<span class="initializer"> = 16</span>
;</div>
<div class="classsynopsisinfo classsynopsisinfo_comment">/* Methods */</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="methodname"><a href="eventbase.construct.html" class="methodname">__construct</a></span>
([ <span class="methodparam">
<span class="type"><a href="class.eventconfig.html" class="type EventConfig">EventConfig</a></span>
<code class="parameter">$cfg</code>
</span>
] )</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">void</span>
<span class="methodname"><a href="eventbase.dispatch.html" class="methodname">dispatch</a></span>
( <span class="methodparam">void</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">void</span>
<span class="methodname"><a href="eventbase.exit.html" class="methodname">exit</a></span>
([ <span class="methodparam">
<span class="type">double</span>
<code class="parameter">$timeout</code>
</span>
] )</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">int</span>
<span class="methodname"><a href="eventbase.getfeatures.html" class="methodname">getFeatures</a></span>
( <span class="methodparam">void</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">string</span>
<span class="methodname"><a href="eventbase.getmethod.html" class="methodname">getMethod</a></span>
([ <span class="methodparam">
<span class="type"><a href="class.eventconfig.html" class="type EventConfig">EventConfig</a></span>
<code class="parameter">$cfg</code>
</span>
] )</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">double</span>
<span class="methodname"><a href="eventbase.gettimeofdaycached.html" class="methodname">getTimeOfDayCached</a></span>
( <span class="methodparam">void</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">void</span>
<span class="methodname"><a href="eventbase.gotexit.html" class="methodname">gotExit</a></span>
( <span class="methodparam">void</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">void</span>
<span class="methodname"><a href="eventbase.gotstop.html" class="methodname">gotStop</a></span>
( <span class="methodparam">void</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">bool</span>
<span class="methodname"><a href="eventbase.loop.html" class="methodname">loop</a></span>
([ <span class="methodparam">
<span class="type">int</span>
<code class="parameter">$flags</code>
</span>
] )</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">bool</span>
<span class="methodname"><a href="eventbase.priorityinit.html" class="methodname">priorityInit</a></span>
( <span class="methodparam">
<span class="type">string</span>
<code class="parameter">$n_priorities</code>
</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">void</span>
<span class="methodname"><a href="eventbase.reinit.html" class="methodname">reInit</a></span>
( <span class="methodparam">
<span class="type">string</span>
<code class="parameter">$base</code>
</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">bool</span>
<span class="methodname"><a href="eventbase.stop.html" class="methodname">stop</a></span>
( <span class="methodparam">void</span>
)</div>
}</div>
</div>
<div class="section" id="eventbase.constants">
<h2 class="title">Predefined Constants</h2>
<dl>
<dt id="eventbase.constants.loop-once">
<span class="term">
<strong><code>EventBase::LOOP_ONCE</code></strong>
</span>
<dd>
<p class="para">
Flag used with
<span class="methodname"><a href="eventbase.loop.html" class="methodname">EventBase::loop()</a></span>
method which means: "block until libevent has an active event, then
exit once all active events have had their callbacks run".
</p>
</dd>
</dt>
<dt id="eventbase.constants.loop-nonblock">
<span class="term">
<strong><code>EventBase::LOOP_NONBLOCK</code></strong>
</span>
<dd>
<p class="para">
Flag used with
<span class="methodname"><a href="eventbase.loop.html" class="methodname">EventBase::loop()</a></span>
method which means: "do not block: see which events are ready now, run
the callbacks of the highest-priority ones, then exit".
</p>
</dd>
</dt>
<dt id="eventbase.constants.nolock">
<span class="term">
<strong><code>EventBase::NOLOCK</code></strong>
</span>
<dd>
<p class="para">
Configuration flag. Do not allocate a lock for the event base, even if
we have locking set up".
</p>
</dd>
</dt>
<dt id="eventbase.constants.startup-iocp">
<span class="term">
<strong><code>EventBase::STARTUP_IOCP</code></strong>
</span>
<dd>
<p class="para">
Windows-only configuration flag. Enables the IOCP dispatcher at
startup.
</p>
</dd>
</dt>
<dt id="eventbase.constants.no-cache-time">
<span class="term">
<strong><code>EventBase::NO_CACHE_TIME</code></strong>
</span>
<dd>
<p class="para">
Configuration flag. Instead of checking the current time every time the
event loop is ready to run timeout callbacks, check after each timeout
callback.
</p>
</dd>
</dt>
<dt id="eventbase.constants.epoll-use-changelist">
<span class="term">
<strong><code>EventBase::EPOLL_USE_CHANGELIST</code></strong>
</span>
<dd>
<p class="para">
If we are using the
<em>epoll</em>
backend, this flag says that it is safe to use Libevent's internal
change-list code to batch up adds and deletes in order to try to do as
few syscalls as possible.
</p>
<p class="para">
Setting this flag can make code run faster, but it may trigger a Linux
bug: it is not safe to use this flag if one has any fds cloned by
dup(), or its variants. Doing so will produce strange and
hard-to-diagnose bugs.
</p>
<p class="para">
This flag can also be activated by settnig the
<em>EVENT_EPOLL_USE_CHANGELIST</em>
environment variable.
</p>
<p class="para">
This flag has no effect if one winds up using a backend other than
<em>epoll</em>
.
</p>
</dd>
</dt>
</dl>
</div>
</div>
<h2>Table of Contents</h2><ul class="chunklist chunklist_reference"><li><a href="eventbase.construct.html">EventBase::__construct</a> — Constructs EventBase object</li><li><a href="eventbase.dispatch.html">EventBase::dispatch</a> — Dispatch pending events</li><li><a href="eventbase.exit.html">EventBase::exit</a> — Stop dispatching events</li><li><a href="eventbase.getfeatures.html">EventBase::getFeatures</a> — Returns bitmask of features supported</li><li><a href="eventbase.getmethod.html">EventBase::getMethod</a> — Returns event method in use</li><li><a href="eventbase.gettimeofdaycached.html">EventBase::getTimeOfDayCached</a> — Returns the current event base time</li><li><a href="eventbase.gotexit.html">EventBase::gotExit</a> — Checks if the event loop was told to exit</li><li><a href="eventbase.gotstop.html">EventBase::gotStop</a> — Checks if the event loop was told to exit</li><li><a href="eventbase.loop.html">EventBase::loop</a> — Dispatch pending events</li><li><a href="eventbase.priorityinit.html">EventBase::priorityInit</a> — Sets number of priorities per event base</li><li><a href="eventbase.reinit.html">EventBase::reInit</a> — Re-initialize event base(after a fork).</li><li><a href="eventbase.stop.html">EventBase::stop</a> — Tells event_base to stop dispatching events</li></ul>
</div>
<hr /><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="event.timer.html">Event::timer</a></div>
<div class="next" style="text-align: right; float: right;"><a href="eventbase.construct.html">EventBase::__construct</a></div>
<div class="up"><a href="book.event.html">Event</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
