php-doc-en/reference/ev/watcher-callbacks.xml
Ruslan Osmanov 27d57bc40b Add: ev extension docs
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@328897 c90b9560-bf6c-de11-be94-00142212c4b1
2012-12-26 19:46:06 +00:00

86 lines
2.8 KiB
XML

<?xml version="1.0" encoding="utf-8"?>
<chapter xml:id="ev.watcher-callbacks" xmlns:phpdoc="http://php.net/ns/phpdoc" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<title>Watcher callbacks</title>
<para>
All watchers can be active(waiting for events) or inactive(paused). Only
active watchers will have their callbacks invoked. All callbacks will be
called with at least two arguments: <parameter>watcher</parameter> - the
watcher, and <parameter>revents</parameter> a bitmask of received
events.
</para>
<para>
Watcher callbacks are passed to the watcher contructors(the classes derived
from <classname>EvWatcher</classname> -
<methodname>EvCheck::__construct</methodname>,
<methodname>EvChild::__construct</methodname> etc.). A watcher callback
should match the following prototype:
</para>
<methodsynopsis>
<type>void</type><methodname>callback</methodname>
<methodparam
choice="opt"><type>object</type><parameter>watcher</parameter><initializer>NULL</initializer></methodparam>
<methodparam
choice="opt"><type>int</type><parameter>revents</parameter><initializer>NULL</initializer></methodparam>
</methodsynopsis>
<para>
<variablelist>
<varlistentry>
<term><parameter>watcher</parameter></term>
<listitem>
<para>
The watcher instance(of a class extending
<classname>EvWatcher</classname>).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>revents</parameter></term>
<listitem>
<para>
<link linkend="ev.constants.watcher-revents">Watcher received events</link>.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
Each watcher type has its associated bit in <parameter>revents</parameter>,
so you can use the same callback for multiple watchers. The event mask is
named after the type, i.e. <classname>EvChild</classname>(or
<methodname>EvLoop::child</methodname>) sets <constant>EV::CHILD</constant>,
<classname>EvPrepare</classname>(or <methodname>EvLoop::prepare</methodname>)
sets <constant>Ev::PREPARE</constant>, <classname>EvPeriodic</classname>(or
<methodname>EvLoop::periodic</methodname>) sets
<constant>Ev::PERIODIC</constant> and so on, with the exception of I/O events
(which can set both <constant>Ev::READ</constant> and
<constant>Ev::WRITE</constant> bits).
</para>
</chapter>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->