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| author | rpj <rpj> | 2005-05-05 14:18:27 +0000 |
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| committer | rpj <rpj> | 2005-05-05 14:18:27 +0000 |
| commit | 41f88a82b33cdb357c83b582381232733ed2d039 (patch) | |
| tree | b3690e999b4d934fce7aab79b2693ab086a4ad46 /manual/pthread_once.html | |
| parent | b75686484d99c90317b64184ce5080093ee7d2a9 (diff) | |
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diff --git a/manual/pthread_once.html b/manual/pthread_once.html new file mode 100644 index 0000000..2607d38 --- /dev/null +++ b/manual/pthread_once.html @@ -0,0 +1,85 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<HTML> +<HEAD> + <META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=utf-8"> + <TITLE>PTHREAD_ONCE(3) manual page</TITLE> + <META NAME="GENERATOR" CONTENT="OpenOffice.org 1.1.3 (Linux)"> + <META NAME="CREATED" CONTENT="20050505;322600"> + <META NAME="CHANGED" CONTENT="20050505;21140800"> + <!-- manual page source format generated by PolyglotMan v3.2, --> + <!-- available at http://polyglotman.sourceforge.net/ --> +</HEAD> +<BODY LANG="en-GB" BGCOLOR="#ffffff" DIR="LTR"> +<P><A HREF="#toc">Table of Contents</A></P> +<H2><A HREF="#toc0" NAME="sect0">Name</A></H2> +<P>pthread_once - once-only initialization +</P> +<H2><A HREF="#toc1" NAME="sect1">Synopsis</A></H2> +<P><B>#include <pthread.h></B> +</P> +<P><B>pthread_once_t </B><I>once_control</I> <B>= PTHREAD_ONCE_INIT;</B> +</P> +<P><B>int pthread_once(pthread_once_t *</B><I>once_control</I><B>, +void (*</B><I>init_routine</I><B>) (void));</B> +</P> +<H2><A HREF="#toc2" NAME="sect2">Description</A></H2> +<P>The purpose of <B>pthread_once</B> is to ensure that a piece of +initialization code is executed at most once. The <I>once_control</I> +argument points to a static or extern variable statically initialized +to <B>PTHREAD_ONCE_INIT</B>. +</P> +<P>The first time <B>pthread_once</B> is called with a given +<I>once_control</I> argument, it calls <I>init_routine</I> with no +argument and changes the value of the <I>once_control</I> variable to +record that initialization has been performed. Subsequent calls to +<B>pthread_once</B> with the same <B>once_control</B> argument do +nothing. +</P> +<H2><A HREF="#toc3" NAME="sect3">Cancellation</A></H2> +<P>While <B>pthread_once</B> is not a cancellation point, +<I>init_routine</I> can be. The required effect on <I>once_control</I> +of a cancellation inside the <I>init_routine</I> is to leave it as if +<B>pthread_once</B> had not been called.</P> +<P><B>Pthreads-w32</B> handles <I>init_routine</I> cancellation by +making any threads, that may be waiting on <I>once_control</I>, +re-compete along with any newly arriving threads in the re-running of +<I>init_routine</I>.</P> +<H2><A HREF="#toc4" NAME="sect4">Return Value</A></H2> +<P STYLE="text-decoration: none"><FONT COLOR="#000000"><B>pthread_once</B> +returns 0 on success, or an error code on failure.</FONT></P> +<H2><A HREF="#toc5" NAME="sect5">Errors</A></H2> +<P>The <B>pthread_once</B> function returns the following error code +on error: +</P> +<DL> + <DL> + <DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EINVAL</B> + </DT></DL> +</DL> +<P STYLE="margin-left: 2cm"> +The once_control or init_routine parameter is NULL.</P> +<H2><A HREF="#toc6" NAME="sect6">Author</A></H2> +<P>Xavier Leroy <Xavier.Leroy@inria.fr> +</P> +<P>Modified by Ross Johnson for use with <A HREF="http://sources.redhat.com/pthreads-win32">Pthreads-w32</A>.</P> +<HR> +<P><A NAME="toc"></A><B>Table of Contents</B></P> +<UL> + <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect0" NAME="toc0">Name</A> + </P> + <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect1" NAME="toc1">Synopsis</A> + </P> + <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect2" NAME="toc2">Description</A> + </P> + <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect3" NAME="toc3">Cancellation</A> + </P> + <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect4" NAME="toc4">Return + Value</A> + </P> + <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect5" NAME="toc5">Errors</A> + </P> + <LI><P><A HREF="#sect6" NAME="toc6">Author</A> + </P> +</UL> +</BODY> +</HTML>
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