<!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_JOIN(3) manual page</TITLE> <META NAME="GENERATOR" CONTENT="OpenOffice.org 1.1.3 (Linux)"> <META NAME="CREATED" CONTENT="20050504;18232700"> <META NAME="CHANGED" CONTENT="20050504;18421400"> <!-- manual page source format generated by PolyglotMan v3.2, --> <!-- available at http://polyglotman.sourceforge.net/ --> </HEAD> <BODY LANG="en-GB" BGCOLOR="#ffffff" DIR="LTR"> <H4>POSIX Threads for Windows – REFERENCE - <A HREF="http://sources.redhat.com/pthreads-win32">Pthreads-w32</A></H4> <P><A HREF="index.html">Reference Index</A></P> <P><A HREF="#toc">Table of Contents</A></P> <H2><A HREF="#toc0" NAME="sect0">Name</A></H2> <P>pthread_join - wait for termination of another thread </P> <H2><A HREF="#toc1" NAME="sect1">Synopsis</A></H2> <P><B>#include <pthread.h></B> </P> <P><B>int pthread_join(pthread_t </B><I>th</I><B>, void **</B><I>thread_return</I><B>);</B> </P> <H2><A HREF="#toc2" NAME="sect2">Description</A></H2> <P><B>pthread_join</B> suspends the execution of the calling thread until the thread identified by <I>th</I> terminates, either by calling <A HREF="pthread_exit.html"><B>pthread_exit</B>(3)</A> or by being cancelled. </P> <P>If <I>thread_return</I> is not <B>NULL</B>, the return value of <I>th</I> is stored in the location pointed to by <I>thread_return</I>. The return value of <I>th</I> is either the argument it gave to <A HREF="pthread_exit.html"><B>pthread_exit</B>(3)</A> , or <B>PTHREAD_CANCELED</B> if <I>th</I> was cancelled. </P> <P>The joined thread <B>th</B> must be in the joinable state: it must not have been detached using <A HREF="pthread_detach.html"><B>pthread_detach</B>(3)</A> or the <B>PTHREAD_CREATE_DETACHED</B> attribute to <A HREF="pthread_create.html"><B>pthread_create</B>(3)</A> . </P> <P>When a joinable thread terminates, its memory resources (thread descriptor and stack) are not deallocated until another thread performs <B>pthread_join</B> on it. Therefore, <B>pthread_join</B> must be called once for each joinable thread created to avoid memory leaks. </P> <P>At most one thread can wait for the termination of a given thread. Calling <B>pthread_join</B> on a thread <I>th</I> on which another thread is already waiting for termination returns an error. </P> <H2><A HREF="#toc3" NAME="sect3">Cancellation</A></H2> <P><B>pthread_join</B> is a cancellation point. If a thread is cancelled while suspended in <B>pthread_join</B>, the thread execution resumes immediately and the cancellation is executed without waiting for the <I>th</I> thread to terminate. If cancellation occurs during <B>pthread_join</B>, the <I>th</I> thread remains not joined. </P> <H2><A HREF="#toc4" NAME="sect4">Return Value</A></H2> <P>On success, the return value of <I>th</I> is stored in the location pointed to by <I>thread_return</I>, and 0 is returned. On error, a non-zero error code is returned. </P> <H2><A HREF="#toc5" NAME="sect5">Errors</A></H2> <DL> <DT><B>ESRCH</B> </DT><DD> No thread could be found corresponding to that specified by <I>th</I>. </DD><DT> <B>EINVAL</B> </DT><DD> The <I>th</I> thread has been detached. </DD><DT> <B>EINVAL</B> </DT><DD> Another thread is already waiting on termination of <I>th</I>. </DD><DT> <B>EDEADLK</B> </DT><DD STYLE="margin-bottom: 0.5cm"> The <I>th</I> argument refers to the calling thread. </DD></DL> <H2> <A HREF="#toc6" NAME="sect6">Author</A></H2> <P>Xavier Leroy <Xavier.Leroy@inria.fr> </P> <H2><A HREF="#toc7" NAME="sect7">See Also</A></H2> <P><A HREF="pthread_exit.html"><B>pthread_exit</B>(3)</A> , <A HREF="pthread_detach.html"><B>pthread_detach</B>(3)</A> , <A HREF="pthread_create.html"><B>pthread_create</B>(3)</A> , <A HREF="pthread_attr_setdetachstate.html"><B>pthread_attr_setdetachstate</B>(3)</A> , <A HREF="pthread_cleanup_push.html"><B>pthread_cleanup_push</B>(3)</A> , <A HREF="pthread_key_create.html"><B>pthread_key_create</B>(3)</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 STYLE="margin-bottom: 0cm"><A HREF="#sect6" NAME="toc6">Author</A> </P> <LI><P><A HREF="#sect7" NAME="toc7">See Also</A> </P> </UL> </BODY> </HTML>