php-doc-en/reference/parallel/parallel.future.xml
Joe Watkins a31156c3d8 more parallel docs
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@347391 c90b9560-bf6c-de11-be94-00142212c4b1
2019-05-07 12:50:54 +00:00

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XML

<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<phpdoc:classref xml:id="class.parallel-future" xmlns:phpdoc="http://php.net/ns/phpdoc" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xi="http://www.w3.org/2001/XInclude">
<title>The parallel\Future class</title>
<titleabbrev>parallel\Future</titleabbrev>
<partintro>
<section>
<title>Futures</title>
<para>
A Future represents the return value or uncaught exception from a task, and exposes an API for cancellation.
</para>
<example>
<title>Example showing Future as return value</title>
<programlisting role="php">
<![CDATA[
<?php
$runtime = new \parallel\Runtime;
$future = $runtime->run(function(){
return "World";
});
printf("Hello %s\n", $future->value());
?>
]]>
</programlisting>
&example.outputs.similar;
<screen>
<![CDATA[
Hello World
]]>
</screen>
</example>
<para>
The behaviour of a future also allows it to be used as a simple synchronization point even where the task does not return a value explicitly.
</para>
<example>
<title>Example showing Future as synchronization point</title>
<programlisting role="php">
<![CDATA[
<?php
$runtime = new \parallel\Runtime;
$future = $runtime->run(function(){
echo "in child ";
for ($i = 0; $i < 500; $i++) {
if ($i % 10 == 0) {
echo ".";
}
}
echo " leaving child";
});
$future->value();
echo "\nparent continues\n";
?>
]]>
</programlisting>
&example.outputs.similar;
<screen>
<![CDATA[
in child .................................................. leaving child
parent continues
]]>
</screen>
</example>
</section>
<section xml:id="parallel-future.synopsis">
&reftitle.classsynopsis;
<!-- {{{ Synopsis -->
<classsynopsis>
<ooclass><classname>parallel\Future</classname></ooclass>
<!-- {{{ Class synopsis -->
<classsynopsisinfo>
<ooclass>
<modifier>final</modifier>
<classname>parallel\Future</classname>
</ooclass>
</classsynopsisinfo>
<!-- }}} -->
<classsynopsisinfo role="comment">Resolution</classsynopsisinfo>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('class.parallel-future')/db:refentry/db:refsect1[@audience='resolution']/descendant::db:methodsynopsis[not(@role='procedural')])">
<xi:fallback />
</xi:include>
<classsynopsisinfo role="comment">State</classsynopsisinfo>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('class.parallel-future')/db:refentry/db:refsect1[@audience='state']/descendant::db:methodsynopsis[not(@role='procedural')])">
<xi:fallback />
</xi:include>
<classsynopsisinfo role="comment">Cancellation</classsynopsisinfo>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('class.parallel-future')/db:refentry/db:refsect1[@audience='cancellation']/descendant::db:methodsynopsis[not(@role='procedural')])">
<xi:fallback />
</xi:include>
</classsynopsis>
<!-- }}} -->
</section>
</partintro>
&reference.parallel.parallel.entities.future;
</phpdoc:classref>
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