yolobs-studio/deps/w32-pthreads/manual/pthread_condattr_setpshared.html

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<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_condattr_getpshared, pthread_condattr_setpshared - get and
set the process-shared condition variable attributes
</P>
<H2><A HREF="#toc1" NAME="sect1">Synopsis</A></H2>
<P><B>#include &lt;pthread.h&gt; </B>
</P>
<P><B>int pthread_condattr_getpshared(const pthread_condattr_t
*restrict</B> <I>attr</I><B>, int *restrict</B> <I>pshared</I><B>);
<BR>int pthread_condattr_setpshared(pthread_condattr_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_condattr_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_condattr_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
<B>PTHREAD_PROCESS_SHARED</B> to permit a condition variable to be
operated upon by any thread that has access to the memory where the
condition variable is allocated, even if the condition variable is
allocated in memory that is shared by multiple processes. If the
<I>process-shared</I> attribute is <B>PTHREAD_PROCESS_PRIVATE</B>,
the condition variable shall only be operated upon by threads created
within the same process as the thread that initialized the condition
variable; if threads of differing processes attempt to operate on
such a condition variable, the behavior is undefined. The default
value of the attribute is <B>PTHREAD_PROCESS_PRIVATE</B>.
</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>
<H2><A HREF="#toc3" NAME="sect3">Return Value</A></H2>
<P>If successful, the <B>pthread_condattr_setpshared</B> function
shall return zero; otherwise, an error number shall be returned to
indicate the error.
</P>
<P>If successful, the <B>pthread_condattr_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>
<H2><A HREF="#toc4" NAME="sect4">Errors</A></H2>
<P>The <B>pthread_condattr_getpshared</B> and
<B>pthread_condattr_setpshared</B> 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></DL>
<P>
The <B>pthread_condattr_setpshared</B> function may fail if:
</P>
<DL>
<DT><B>EINVAL</B>
</DT><DD STYLE="margin-bottom: 0.5cm">
The new value specified for the attribute is outside the range of
legal values for that attribute.
</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><B>Pthreads-w32</B> defines <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_create.html"><B>pthread_create</B>(3)</A> <B>,</B>
<A HREF="pthread_cond_init.html"><B>pthread_cond_destroy</B>(3)</A> <B>,</B>
<A HREF="pthread_condattr_init.html"><B>pthread_condattr_destroy</B>(3)</A>
<B>,</B> <A HREF="pthread_mutex_init.html"><B>pthread_mutex_destroy</B>(3)</A>
<B>,</B> the Base Definitions volume of IEEE&nbsp;Std&nbsp;1003.1-2001,
<I>&lt;pthread.h&gt;</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>
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