<!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_BARRIERATTR_GETPSHARED"(P) manual page</TITLE> <META NAME="GENERATOR" CONTENT="OpenOffice.org 1.1.3 (Linux)"> <META NAME="CREATED" CONTENT="20050504;11552100"> <META NAME="CHANGED" CONTENT="20050505;18080400"> <!-- 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_barrierattr_getpshared, pthread_barrierattr_setpshared - get and set the process-shared attribute of the barrier attributes object (<B>ADVANCED REALTIME THREADS</B>) </P> <H2><A HREF="#toc1" NAME="sect1">Synopsis</A></H2> <P><B>#include <pthread.h> </B> </P> <P><B>int pthread_barrierattr_getpshared(const pthread_barrierattr_t * restrict</B> <I>attr</I><B>, int *restrict</B> <I>pshared</I><B>); <BR>int pthread_barrierattr_setpshared(pthread_barrierattr_t *</B><I>attr</I><B>, int</B> <I>pshared</I><B>); </B> </P> <H2><A HREF="#toc2" NAME="sect2">Description</A></H2> <P>The <B>pthread_barrierattr_getpshared</B> function shall obtain the value of the <I>process-shared</I> attribute from the attributes object referenced by <I>attr</I>. The <B>pthread_barrierattr_setpshared</B> function shall set the <I>process-shared</I> attribute in an initialized attributes object referenced by <I>attr</I>. </P> <P>The <I>process-shared</I> attribute is set to PTHREAD_PROCESS_SHARED to permit a barrier to be operated upon by any thread that has access to the memory where the barrier is allocated. If the <I>process-shared</I> attribute is PTHREAD_PROCESS_PRIVATE, the barrier shall only be operated upon by threads created within the same process as the thread that initialized the barrier; if threads of different processes attempt to operate on such a barrier, the behavior is undefined. The default value of the attribute shall be PTHREAD_PROCESS_PRIVATE. Both constants PTHREAD_PROCESS_SHARED and PTHREAD_PROCESS_PRIVATE are defined in <I><pthread.h></I>. </P> <P><B>Pthreads-w32</B> defines _<B>POSIX_THREAD_PROCESS_SHARED</B> in pthread.h as -1 to indicate that these routines are implemented but that the process shared attribute is not supported.</P> <P>Additional attributes, their default values, and the names of the associated functions to get and set those attribute values are implementation-defined. </P> <H2><A HREF="#toc3" NAME="sect3">Return Value</A></H2> <P>If successful, the <B>pthread_barrierattr_getpshared</B> function shall return zero and store the value of the <I>process-shared</I> attribute of <I>attr</I> into the object referenced by the <I>pshared</I> parameter. Otherwise, an error number shall be returned to indicate the error. </P> <P>If successful, the <B>pthread_barrierattr_setpshared</B> function shall return zero; otherwise, an error number shall be returned to indicate the error. </P> <H2><A HREF="#toc4" NAME="sect4">Errors</A></H2> <P>These functions may fail if: </P> <DL> <DT><B>EINVAL</B> </DT><DD STYLE="margin-bottom: 0.5cm"> The value specified by <I>attr</I> is invalid. </DD><DT> The <B>pthread_barrierattr_setpshared</B> function may fail if: </DT><DT> <B>EINVAL</B> </DT><DD STYLE="margin-bottom: 0.5cm"> The new value specified for the <I>process-shared</I> attribute is not one of the legal values <B>PTHREAD_PROCESS_SHARED</B> or <B>PTHREAD_PROCESS_PRIVATE</B>. </DD><DT> <B>ENOSYS</B> </DT><DD STYLE="margin-bottom: 0.5cm"> The value specified by <I>attr</I> was <B>PTHREAD_PROCESS_SHARED</B> (Pthreads-w32).</DD></DL> <P> These functions shall not return an error code of [EINTR]. </P> <P><I>The following sections are informative.</I> </P> <H2><A HREF="#toc5" NAME="sect5">Examples</A></H2> <P>None. </P> <H2><A HREF="#toc6" NAME="sect6">Application Usage</A></H2> <P>The <B>pthread_barrierattr_getpshared</B> and <B>pthread_barrierattr_setpshared</B> functions are part of the Barriers option and need not be provided on all implementations. </P> <P><B>Pthreads-w32</B> defines <B>_POSIX_BARRIERS</B> and <B>_POSIX_THREAD_PROCESS_SHARED</B> in pthread.h as -1 to indicate that these routines are implemented and may be used, but do not support the process shared option.</P> <H2><A HREF="#toc7" NAME="sect7">Rationale</A></H2> <P>None. </P> <H2><A HREF="#toc8" NAME="sect8">Future Directions</A></H2> <P>None. </P> <H2><A HREF="#toc9" NAME="sect9">See Also</A></H2> <P><A HREF="pthread_barrier_init.html"><B>pthread_barrier_destroy</B>(3)</A> <B>,</B> <A HREF="pthread_barrierattr_init.html"><B>pthread_barrierattr_destroy</B>(3)</A> <B>,</B> <A HREF="pthread_barrierattr_init.html"><B>pthread_barrierattr_init</B>(3)</A> <B>,</B> the Base Definitions volume of IEEE Std 1003.1-2001, <I><pthread.h></I> </P> <H2><A HREF="#toc10" NAME="sect10">Copyright</A></H2> <P>Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at <A HREF="http://www.opengroup.org/unix/online.html">http://www.opengroup.org/unix/online.html</A> . </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">Return Value</A> </P> <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect4" NAME="toc4">Errors</A> </P> <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect5" NAME="toc5">Examples</A> </P> <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect6" NAME="toc6">Application Usage</A> </P> <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect7" NAME="toc7">Rationale</A> </P> <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect8" NAME="toc8">Future Directions</A> </P> <LI><P STYLE="margin-bottom: 0cm"><A HREF="#sect9" NAME="toc9">See Also</A> </P> <LI><P><A HREF="#sect10" NAME="toc10">Copyright</A> </P> </UL> </BODY> </HTML>