133 lines
5.0 KiB
HTML
133 lines
5.0 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 2006-2016 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
||
|
|
any later version published by the Free Software Foundation; with the
|
||
|
|
Invariant Sections being "Funding Free Software", the Front-Cover
|
||
|
|
texts being (a) (see below), and with the Back-Cover Texts being (b)
|
||
|
|
(see below). A copy of the license is included in the section entitled
|
||
|
|
"GNU Free Documentation License".
|
||
|
|
|
||
|
|
(a) The FSF's Front-Cover Text is:
|
||
|
|
|
||
|
|
A GNU Manual
|
||
|
|
|
||
|
|
(b) The FSF's Back-Cover Text is:
|
||
|
|
|
||
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
||
|
|
software. Copies published by the Free Software Foundation raise
|
||
|
|
funds for GNU development. -->
|
||
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>GNU libgomp: Implementing PARALLEL construct</title>
|
||
|
|
|
||
|
|
<meta name="description" content="GNU libgomp: Implementing PARALLEL construct">
|
||
|
|
<meta name="keywords" content="GNU libgomp: Implementing PARALLEL construct">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="Library-Index.html#Library-Index" rel="index" title="Library Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="The-libgomp-ABI.html#The-libgomp-ABI" rel="up" title="The libgomp ABI">
|
||
|
|
<link href="Implementing-FOR-construct.html#Implementing-FOR-construct" rel="next" title="Implementing FOR construct">
|
||
|
|
<link href="Implementing-REDUCTION-clause.html#Implementing-REDUCTION-clause" rel="prev" title="Implementing REDUCTION clause">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.indentedblock {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style:oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nocodebreak {white-space:nowrap}
|
||
|
|
span.nolinebreak {white-space:nowrap}
|
||
|
|
span.roman {font-family:serif; font-weight:normal}
|
||
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
||
|
|
<a name="Implementing-PARALLEL-construct"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Implementing-FOR-construct.html#Implementing-FOR-construct" accesskey="n" rel="next">Implementing FOR construct</a>, Previous: <a href="Implementing-REDUCTION-clause.html#Implementing-REDUCTION-clause" accesskey="p" rel="prev">Implementing REDUCTION clause</a>, Up: <a href="The-libgomp-ABI.html#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Library-Index.html#Library-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="Implementing-PARALLEL-construct-1"></a>
|
||
|
|
<h3 class="section">9.10 Implementing PARALLEL construct</h3>
|
||
|
|
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> #pragma omp parallel
|
||
|
|
{
|
||
|
|
body;
|
||
|
|
}
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>becomes
|
||
|
|
</p>
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> void subfunction (void *data)
|
||
|
|
{
|
||
|
|
use data;
|
||
|
|
body;
|
||
|
|
}
|
||
|
|
|
||
|
|
setup data;
|
||
|
|
GOMP_parallel_start (subfunction, &data, num_threads);
|
||
|
|
subfunction (&data);
|
||
|
|
GOMP_parallel_end ();
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> void GOMP_parallel_start (void (*fn)(void *), void *data, unsigned num_threads)
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>The <var>FN</var> argument is the subfunction to be run in parallel.
|
||
|
|
</p>
|
||
|
|
<p>The <var>DATA</var> argument is a pointer to a structure used to
|
||
|
|
communicate data in and out of the subfunction, as discussed
|
||
|
|
above with respect to FIRSTPRIVATE et al.
|
||
|
|
</p>
|
||
|
|
<p>The <var>NUM_THREADS</var> argument is 1 if an IF clause is present
|
||
|
|
and false, or the value of the NUM_THREADS clause, if
|
||
|
|
present, or 0.
|
||
|
|
</p>
|
||
|
|
<p>The function needs to create the appropriate number of
|
||
|
|
threads and/or launch them from the dock. It needs to
|
||
|
|
create the team structure and assign team ids.
|
||
|
|
</p>
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> void GOMP_parallel_end (void)
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>Tears down the team and returns us to the previous <code>omp_in_parallel()</code> state.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|