construct.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="evchild.construct" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
 <refnamediv>
  <refname>EvChild::__construct</refname>
  <refpurpose>Constructs the EvChild watcher object</refpurpose>
 </refnamediv>
 <refsect1 role="description">
  &reftitle.description;
  <constructorsynopsis>
   <modifier>public</modifier>
   <methodname>EvChild::__construct</methodname>
   <methodparam>
    <type>int</type>
    <parameter>pid</parameter>
   </methodparam>
   <methodparam>
    <type>bool</type>
    <parameter>trace</parameter>
   </methodparam>
   <methodparam>
    <type>callable</type>
    <parameter>callback</parameter>
   </methodparam>
   <methodparam
   choice="opt">
    <type>mixed</type>
    <parameter>data</parameter>
    <initializer>&null;</initializer>
   </methodparam>
   <methodparam
   choice="opt">
    <type>int</type>
    <parameter>priority</parameter>
    <initializer>0</initializer>
   </methodparam>
  </constructorsynopsis>
  <para>
   Constructs the
   <classname>EvChild</classname>
   watcher object.
  </para>
  <para>
   Call the callback when a status change for process ID
   <parameter>pid</parameter>
   (or any
   <emphasis>PID</emphasis>
   if
   <parameter>pid</parameter>
   is
   <literal>0</literal>)
   has been received(a status change happens when the process terminates or
   is killed, or, when
   <parameter>trace</parameter>
   is &true;, additionally when it is stopped or continued). In other words,
   when the process receives a
   <constant>SIGCHLD</constant>,
   <emphasis>Ev</emphasis>
   will fetch the outstanding exit/wait status for all changed/zombie children
   and call the callback.
  </para>
  <para>
   It is valid to install a child watcher after an
   <classname>EvChild</classname>
   has exited but before the event loop has started its next iteration. For
   example, first one calls
   <literal>fork</literal>,
   then the new child process might exit, and only then an
   <classname>EvChild</classname>
   watcher is installed in the parent for the new
   <emphasis>PID</emphasis>.
  </para>
  <para>
   You can access both exit/tracing status and
   <parameter>pid</parameter>
   by using the
   <varname>rstatus</varname>
   and
   <varname>rpid</varname>
   properties of the watcher object.
  </para>
  <para>
   The number of
   <emphasis>PID</emphasis>
   watchers per
   <emphasis>PID</emphasis>
   is unlimited. All of them will be called.
  </para>
  <para>
   The
   <methodname>EvChild::createStopped</methodname>
   method doesn&apos;t start(activate) the newly created watcher.
  </para>
 </refsect1>
 <refsect1 role="parameters">
  &reftitle.parameters;
  <variablelist>
   <varlistentry>
    <term>
     <parameter>pid</parameter>
    </term>
    <listitem>
     <para>
      Wait for status changes of process PID(or any process if PID is
      specified as
      <literal>0</literal>
      ).
     </para>
    </listitem>
   </varlistentry>
   <varlistentry>
    <term>
     <parameter>trace</parameter>
    </term>
    <listitem>
     <para>
      If &false;, only activate the watcher when the process terminates.
      Otherwise(&true;) additionally activate the watcher when the process is
      stopped or continued.
     </para>
    </listitem>
   </varlistentry>
   <varlistentry>
    <term>
     <parameter>callback</parameter>
    </term>
    <listitem>
     <para>
      See
      <link linkend="ev.watcher-callbacks">Watcher callbacks</link>.
     </para>
    </listitem>
   </varlistentry>
   <varlistentry>
    <term>
     <parameter>data</parameter>
    </term>
    <listitem>
     <para>
      Custom data associated with the watcher.
     </para>
    </listitem>
   </varlistentry>
   <varlistentry>
    <term>
     <parameter>priority</parameter>
    </term>
    <listitem>
     <para>
      <link linkend="ev.constants.watcher-pri">Watcher priority</link>
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 role="seealso">
  &reftitle.seealso;
  <simplelist>
   <member>
    <methodname>EvLoop::child</methodname>
   </member>
  </simplelist>
 </refsect1>
</refentry>
<!-- 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
-->