📄 pthread_rwlock_timedwrlock.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_rwlock_timedwrlock</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="pthread_rwlock_timedwrlock"></a> <a name="tag_03_558"></a><!-- pthread_rwlock_timedwrlock --> <!--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_558_01"></a>NAME</h4><blockquote>pthread_rwlock_timedwrlock - lock a read-write lock for writing</blockquote><h4><a name="tag_03_558_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('THR TMO')">THR TMO</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> #include <<a href="../basedefs/pthread.h.html">pthread.h</a>><br> #include <<a href="../basedefs/time.h.html">time.h</a>><br><br> int pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict</tt> <i>rwlock</i><tt>,<br> const struct timespec *restrict</tt> <i>abs_timeout</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_558_03"></a>DESCRIPTION</h4><blockquote><p>The <i>pthread_rwlock_timedwrlock</i>() function shall apply a write lock to the read-write lock referenced by <i>rwlock</i> asin the <a href="../functions/pthread_rwlock_wrlock.html"><i>pthread_rwlock_wrlock</i>()</a> function. However, if the lock cannotbe acquired without waiting for other threads to unlock the lock, this wait shall be terminated when the specified timeout expires.The timeout shall expire when the absolute time specified by <i>abs_timeout</i> passes, as measured by the clock on which timeoutsare based (that is, when the value of that clock equals or exceeds <i>abs_timeout</i>), or if the absolute time specified by<i>abs_timeout</i> has already been passed at the time of the call.</p><p><sup>[<a href="javascript:open_code('TMR')">TMR</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0">If the Timers option is supported, the timeout shall be based on the CLOCK_REALTIME clock. <img src="../images/opt-end.gif" alt="[Option End]" border="0"> If the Timers option is not supported, the timeout shall be based on the system clock as returned by the<a href="../functions/time.html"><i>time</i>()</a> function. The resolution of the timeout shall be the resolution of the clock onwhich it is based. The <b>timespec</b> data type is defined in the <a href="../basedefs/time.h.html"><i><time.h></i></a>header. Under no circumstances shall the function fail with a timeout if the lock can be acquired immediately. The validity of the<i>abs_timeout</i> parameter need not be checked if the lock can be immediately acquired.</p><p>If a signal that causes a signal handler to be executed is delivered to a thread blocked on a read-write lock via a call to<i>pthread_rwlock_timedwrlock</i>(), upon return from the signal handler the thread shall resume waiting for the lock as if it wasnot interrupted.</p><p>The calling thread may deadlock if at the time the call is made it holds the read-write lock. The results are undefined if thisfunction is called with an uninitialized read-write lock.</p></blockquote><h4><a name="tag_03_558_04"></a>RETURN VALUE</h4><blockquote><p>The <i>pthread_rwlock_timedwrlock</i>() function shall return zero if the lock for writing on the read-write lock objectreferenced by <i>rwlock</i> is acquired. Otherwise, an error number shall be returned to indicate the error.</p></blockquote><h4><a name="tag_03_558_05"></a>ERRORS</h4><blockquote><p>The <i>pthread_rwlock_timedwrlock</i>() function shall fail if:</p><dl compact><dt>[ETIMEDOUT]</dt><dd>The lock could not be acquired before the specified timeout expired.</dd></dl><p>The <i>pthread_rwlock_timedwrlock</i>() function may fail if:</p><dl compact><dt>[EDEADLK]</dt><dd>The calling thread already holds the <i>rwlock</i>.</dd><dt>[EINVAL]</dt><dd>The value specified by rwlock does not refer to an initialized read-write lock object, or the <i>abs_timeout</i> nanosecondvalue is less than zero or greater than or equal to 1000 million.</dd></dl><p>This function 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_558_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_558_07"></a>APPLICATION USAGE</h4><blockquote><p>Applications using this function may be subject to priority inversion, as discussed in the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/xbd_chap03.html#tag_03_285">Section 3.285, Priority Inversion</a>.</p><p>The <i>pthread_rwlock_timedwrlock</i>() function is part of the Threads and Timeouts options and need not be provided on allimplementations.</p></blockquote><h4><a name="tag_03_558_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_558_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_558_10"></a>SEE ALSO</h4><blockquote><p><a href="pthread_rwlock_destroy.html"><i>pthread_rwlock_destroy</i>()</a> , <a href="pthread_rwlock_rdlock.html"><i>pthread_rwlock_rdlock</i>()</a> , <a href="pthread_rwlock_timedrdlock.html"><i>pthread_rwlock_timedrdlock</i>()</a> , <a href="pthread_rwlock_tryrdlock.html"><i>pthread_rwlock_tryrdlock</i>()</a> , <a href="pthread_rwlock_trywrlock.html"><i>pthread_rwlock_trywrlock</i>()</a> , <a href="pthread_rwlock_unlock.html"><i>pthread_rwlock_unlock</i>()</a> , <a href="pthread_rwlock_wrlock.html"><i>pthread_rwlock_wrlock</i>()</a> , the Base Definitions volume of IEEE Std 1003.1-2001, <ahref="../basedefs/pthread.h.html"><i><pthread.h></i></a>, <a href="../basedefs/time.h.html"><i><time.h></i></a></p></blockquote><h4><a name="tag_03_558_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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