📄 pthread_mutexattr_getpshared.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy, see www.w3.org"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 --><!-- Copyright (c) 2001-2003 The Open Group, All Rights Reserved --><title>pthread_mutexattr_getpshared</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="pthread_mutexattr_getpshared"></a> <a name="tag_03_547"></a><!-- pthread_mutexattr_getpshared --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2003 Edition<br>Copyright © 2001-2003 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_03_547_01"></a>NAME</h4><blockquote>pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get and set the process-shared attribute</blockquote><h4><a name="tag_03_547_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('THR TSH')">THR TSH</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> #include <<a href="../basedefs/pthread.h.html">pthread.h</a>><br><br> int pthread_mutexattr_getpshared(const pthread_mutexattr_t *<br> restrict</tt> <i>attr</i><tt>, int *restrict</tt> <i>pshared</i><tt>);<br> int pthread_mutexattr_setpshared(pthread_mutexattr_t *</tt><i>attr</i><tt>,<br> int</tt> <i>pshared</i><tt>); <img src="../images/opt-end.gif" alt="[Option End]" border="0"></tt></code></div><tt><br></tt></blockquote><h4><a name="tag_03_547_03"></a>DESCRIPTION</h4><blockquote><p>The <i>pthread_mutexattr_getpshared</i>() function shall obtain the value of the <i>process-shared</i> attribute from theattributes object referenced by <i>attr</i>. The <i>pthread_mutexattr_setpshared</i>() 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 mutex to be operated upon by any thread thathas access to the memory where the mutex is allocated, even if the mutex is allocated in memory that is shared by multipleprocesses. If the <i>process-shared</i> attribute is PTHREAD_PROCESS_PRIVATE, the mutex shall only be operated upon by threadscreated within the same process as the thread that initialized the mutex; if threads of differing processes attempt to operate onsuch a mutex, the behavior is undefined. The default value of the attribute shall be PTHREAD_PROCESS_PRIVATE.</p></blockquote><h4><a name="tag_03_547_04"></a>RETURN VALUE</h4><blockquote><p>Upon successful completion, <i>pthread_mutexattr_setpshared</i>() shall return zero; otherwise, an error number shall bereturned to indicate the error.</p><p>Upon successful completion, <i>pthread_mutexattr_getpshared</i>() 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 errornumber shall be returned to indicate the error.</p></blockquote><h4><a name="tag_03_547_05"></a>ERRORS</h4><blockquote><p>The <i>pthread_mutexattr_getpshared</i>() and <i>pthread_mutexattr_setpshared</i>() functions may fail if:</p><dl compact><dt>[EINVAL]</dt><dd>The value specified by <i>attr</i> is invalid.</dd></dl><p>The <i>pthread_mutexattr_setpshared</i>() function may fail if:</p><dl compact><dt>[EINVAL]</dt><dd>The new value specified for the attribute is outside the range of legal values for that attribute.</dd></dl><p>These functions shall not return an error code of [EINTR].</p></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_547_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_547_07"></a>APPLICATION USAGE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_547_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_547_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_547_10"></a>SEE ALSO</h4><blockquote><p><a href="pthread_cond_destroy.html"><i>pthread_cond_destroy</i>()</a> , <a href="pthread_create.html"><i>pthread_create</i>()</a> , <a href="pthread_mutex_destroy.html"><i>pthread_mutex_destroy</i>()</a> , <ahref="pthread_mutexattr_destroy.html"><i>pthread_mutexattr_destroy</i>()</a> , the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/pthread.h.html"><i><pthread.h></i></a></p></blockquote><h4><a name="tag_03_547_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 5. Included for alignment with the POSIX Threads Extension.</p></blockquote><h4><a name="tag_03_547_12"></a>Issue 6</h4><blockquote><p>The <i>pthread_mutexattr_getpshared</i>() and <i>pthread_mutexattr_setpshared</i>() functions are marked as part of the Threadsand Thread Process-Shared Synchronization options.</p><p>The <b>restrict</b> keyword is added to the <i>pthread_mutexattr_getpshared</i>() prototype for alignment with theISO/IEC 9899:1999 standard.</p></blockquote><div class="box"><em>End of informative text.</em></div><hr><hr size="2" noshade><center><font size="2"><!--footer start-->UNIX ® is a registered Trademark of The Open Group.<br>POSIX ® is a registered Trademark of The IEEE.<br>[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href="../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>]</font></center><!--footer end--><hr size="2" noshade></body></html>⌨️ 快捷键说明
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