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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_condattr_destroy</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="pthread_condattr_destroy"></a> <a name="tag_03_519"></a><!-- pthread_condattr_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_519_01"></a>NAME</h4><blockquote>pthread_condattr_destroy, pthread_condattr_init - destroy and initialize the condition variable attributesobject</blockquote><h4><a name="tag_03_519_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('THR')">THR</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_condattr_destroy(pthread_condattr_t *</tt><i>attr</i><tt>);<br> int pthread_condattr_init(pthread_condattr_t *</tt><i>attr</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_519_03"></a>DESCRIPTION</h4><blockquote><p>The <i>pthread_condattr_destroy</i>() function shall destroy a condition variable attributes object; the object becomes, ineffect, uninitialized. An implementation may cause <i>pthread_condattr_destroy</i>() to set the object referenced by <i>attr</i> toan invalid value. A destroyed <i>attr</i> attributes object can be reinitialized using <i>pthread_condattr_init</i>(); the resultsof otherwise referencing the object after it has been destroyed are undefined.</p><p>The <i>pthread_condattr_init</i>() function shall initialize a condition variable attributes object <i>attr</i> with the defaultvalue for all of the attributes defined by the implementation.</p><p>Results are undefined if <i>pthread_condattr_init</i>() is called specifying an already initialized <i>attr</i> attributesobject.</p><p>After a condition variable attributes object has been used to initialize one or more condition variables, any function affectingthe attributes object (including destruction) shall not affect any previously initialized condition variables.</p><p>This volume of IEEE Std 1003.1-2001 requires two attributes, the <i>clock</i> attribute and the <i>process-shared</i>attribute.</p><p>Additional attributes, their default values, and the names of the associated functions to get and set those attribute values areimplementation-defined.</p></blockquote><h4><a name="tag_03_519_04"></a>RETURN VALUE</h4><blockquote><p>If successful, the <i>pthread_condattr_destroy</i>() and <i>pthread_condattr_init</i>() functions shall return zero; otherwise,an error number shall be returned to indicate the error.</p></blockquote><h4><a name="tag_03_519_05"></a>ERRORS</h4><blockquote><p>The <i>pthread_condattr_destroy</i>() function 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_condattr_init</i>() function shall fail if:</p><dl compact><dt>[ENOMEM]</dt><dd>Insufficient memory exists to initialize the condition variable attributes object.</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_519_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_519_07"></a>APPLICATION USAGE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_519_08"></a>RATIONALE</h4><blockquote><p>See <a href="pthread_attr_init.html"><i>pthread_attr_init</i>()</a> and <a href="pthread_mutex_init.html"><i>pthread_mutex_init</i>()</a> .</p><p>A <i>process-shared</i> attribute has been defined for condition variables for the same reason it has been defined formutexes.</p></blockquote><h4><a name="tag_03_519_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_519_10"></a>SEE ALSO</h4><blockquote><p><a href="pthread_attr_destroy.html"><i>pthread_attr_destroy</i>()</a> , <a href="pthread_cond_destroy.html"><i>pthread_cond_destroy</i>()</a> , <a href="pthread_condattr_getpshared.html"><i>pthread_condattr_getpshared</i>()</a> , <a href="pthread_create.html"><i>pthread_create</i>()</a> , <a href="pthread_mutex_destroy.html"><i>pthread_mutex_destroy</i>()</a> , theBase Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/pthread.h.html"><i><pthread.h></i></a></p></blockquote><h4><a name="tag_03_519_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_519_12"></a>Issue 6</h4><blockquote><p>The <i>pthread_condattr_destroy</i>() and <i>pthread_condattr_init</i>() functions are marked as part of the Threads option.</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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