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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) 2001-2004 IEEE and The Open Group, All Rights Reserved --><title>pthread_spin_lock</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="pthread_spin_lock"></a> <a name="tag_03_575"></a><!-- pthread_spin_lock --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2004 Edition<br>Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_03_575_01"></a>NAME</h4><blockquote>pthread_spin_lock, pthread_spin_trylock - lock a spin lock object (<b>ADVANCED REALTIME THREADS</b>)</blockquote><h4><a name="tag_03_575_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('THR SPI')">THR SPI</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_spin_lock(pthread_spinlock_t *</tt><i>lock</i><tt>);<br> int pthread_spin_trylock(pthread_spinlock_t *</tt><i>lock</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_575_03"></a>DESCRIPTION</h4><blockquote><p>The <i>pthread_spin_lock</i>() function shall lock the spin lock referenced by <i>lock</i>. The calling thread shall acquire thelock if it is not held by another thread. Otherwise, the thread shall spin (that is, shall not return from the<i>pthread_spin_lock</i>() call) until the lock becomes available. The results are undefined if the calling thread holds the lockat the time the call is made. The <i>pthread_spin_trylock</i>() function shall lock the spin lock referenced by <i>lock</i> if itis not held by any thread. Otherwise, the function shall fail.</p><p>The results are undefined if any of these functions is called with an uninitialized spin lock.</p></blockquote><h4><a name="tag_03_575_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_575_05"></a>ERRORS</h4><blockquote><p>These functions may fail if:</p><dl compact><dt>[EINVAL]</dt><dd>The value specified by <i>lock</i> does not refer to an initialized spin lock object.</dd></dl><p>The <i>pthread_spin_lock</i>() function may fail if:</p><dl compact><dt>[EDEADLK]</dt><dd>A deadlock condition was detected or the calling thread already holds the lock.</dd></dl><p>The <i>pthread_spin_trylock</i>() function shall fail if:</p><dl compact><dt>[EBUSY]</dt><dd>A thread currently holds the lock.</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_575_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_575_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_spin_lock</i>() and <i>pthread_spin_trylock</i>() functions are part of the Spin Locks option and need not beprovided on all implementations.</p></blockquote><h4><a name="tag_03_575_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_575_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_575_10"></a>SEE ALSO</h4><blockquote><p><a href="pthread_spin_destroy.html"><i>pthread_spin_destroy</i>()</a>, <a href="pthread_spin_unlock.html"><i>pthread_spin_unlock</i>()</a>, the Base Definitions volume of IEEE Std 1003.1-2001, <ahref="../basedefs/pthread.h.html"><i><pthread.h></i></a></p></blockquote><h4><a name="tag_03_575_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 6. Derived from IEEE Std 1003.1j-2000.</p><p>In the SYNOPSIS, the inclusion of <a href="../basedefs/sys/types.h.html"><i><sys/types.h></i></a> is no longerrequired.</p><p>IEEE Std 1003.1-2001/Cor 2-2004, item XSH/TC2/D6/107 is applied, updating the ERRORS section so that the[EDEADLK] error includes detection of a deadlock condition.</p></blockquote><div class="box"><em>End of informative text.</em></div><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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