📄 pthread_barrier_init.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_barrier_destroy</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="pthread_barrier_destroy"></a> <a name="tag_03_507"></a><!-- pthread_barrier_destroy --> <!--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_507_01"></a>NAME</h4><blockquote>pthread_barrier_destroy, pthread_barrier_init - destroy and initialize a barrier object (<b>ADVANCED REALTIMETHREADS</b>)</blockquote><h4><a name="tag_03_507_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('THR BAR')">THR BAR</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_barrier_destroy(pthread_barrier_t *</tt><i>barrier</i><tt>);<br> int pthread_barrier_init(pthread_barrier_t *restrict</tt> <i>barrier</i><tt>,<br> const pthread_barrierattr_t *restrict</tt> <i>attr</i><tt>, unsigned</tt> <i>count</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_507_03"></a>DESCRIPTION</h4><blockquote><p>The <i>pthread_barrier_destroy</i>() function shall destroy the barrier referenced by <i>barrier</i> and release any resourcesused by the barrier. The effect of subsequent use of the barrier is undefined until the barrier is reinitialized by another call to<i>pthread_barrier_init</i>(). An implementation may use this function to set <i>barrier</i> to an invalid value. The results areundefined if <i>pthread_barrier_destroy</i>() is called when any thread is blocked on the barrier, or if this function is calledwith an uninitialized barrier.</p><p>The <i>pthread_barrier_init</i>() function shall allocate any resources required to use the barrier referenced by <i>barrier</i>and shall initialize the barrier with attributes referenced by <i>attr</i>. If <i>attr</i> is NULL, the default barrier attributesshall be used; the effect is the same as passing the address of a default barrier attributes object. The results are undefined if<i>pthread_barrier_init</i>() is called when any thread is blocked on the barrier (that is, has not returned from the <a href="../functions/pthread_barrier_wait.html"><i>pthread_barrier_wait</i>()</a> call). The results are undefined if a barrier is usedwithout first being initialized. The results are undefined if <i>pthread_barrier_init</i>() is called specifying an alreadyinitialized barrier.</p><p>The <i>count</i> argument specifies the number of threads that must call <a href="../functions/pthread_barrier_wait.html"><i>pthread_barrier_wait</i>()</a> before any of them successfully return from the call.The value specified by <i>count</i> must be greater than zero.</p><p>If the <i>pthread_barrier_init</i>() function fails, the barrier shall not be initialized and the contents of <i>barrier</i> areundefined.</p><p>Only the object referenced by <i>barrier</i> may be used for performing synchronization. The result of referring to copies ofthat object in calls to <i>pthread_barrier_destroy</i>() or <a href="../functions/pthread_barrier_wait.html"><i>pthread_barrier_wait</i>()</a> is undefined.</p></blockquote><h4><a name="tag_03_507_04"></a>RETURN VALUE</h4><blockquote><p>Upon successful completion, these functions shall return zero; otherwise, an error number shall be returned to indicate theerror.</p></blockquote><h4><a name="tag_03_507_05"></a>ERRORS</h4><blockquote><p>The <i>pthread_barrier_destroy</i>() function may fail if:</p><dl compact><dt>[EBUSY]</dt><dd>The implementation has detected an attempt to destroy a barrier while it is in use (for example, while being used in a <a href="../functions/pthread_barrier_wait.html"><i>pthread_barrier_wait</i>()</a> call) by another thread.</dd><dt>[EINVAL]</dt><dd>The value specified by <i>barrier</i> is invalid.</dd></dl><p>The <i>pthread_barrier_init</i>() function shall fail if:</p><dl compact><dt>[EAGAIN]</dt><dd>The system lacks the necessary resources to initialize another barrier.</dd><dt>[EINVAL]</dt><dd>The value specified by <i>count</i> is equal to zero.</dd><dt>[ENOMEM]</dt><dd>Insufficient memory exists to initialize the barrier.</dd></dl><p>The <i>pthread_barrier_init</i>() function may fail if:</p><dl compact><dt>[EBUSY]</dt><dd>The implementation has detected an attempt to reinitialize a barrier while it is in use (for example, while being used in a <ahref="../functions/pthread_barrier_wait.html"><i>pthread_barrier_wait</i>()</a> call) by another thread.</dd><dt>[EINVAL]</dt><dd>The value specified by <i>attr</i> is invalid.</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_507_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_507_07"></a>APPLICATION USAGE</h4><blockquote><p>The <i>pthread_barrier_destroy</i>() and <i>pthread_barrier_init</i>() functions are part of the Barriers option and need not beprovided on all implementations.</p></blockquote><h4><a name="tag_03_507_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_507_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_507_10"></a>SEE ALSO</h4><blockquote><p><a href="pthread_barrier_wait.html"><i>pthread_barrier_wait</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_507_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 6. Derived from IEEE Std 1003.1j-2000.</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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