55 lines
2.1 KiB
HTML
55 lines
2.1 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
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<title>Read/write locks are recursive</title>
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<!-- Begin Header Records ========================================== -->
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!--File Edited November 2001 -->
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<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
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</head>
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<body>
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<script language="Javascript" src="../rzahg/synch.js" type="text/javascript">
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</script>
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<h2>Read/write locks are recursive</h2>
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<p>The i5/OS implementation of read/write locks provides a recursive behavior
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not only for shared read locks (as the thread standard specifies), but for
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exclusive write locks as well. The following statements apply to read/write
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locks on i5/OS:</p>
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<ul>
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<li>A thread can acquire any number of shared read locks on a read/write lock.
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Each successful shared read lock that is acquired must be released by a call to
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<strong>pthread_rwlock_unlock()</strong>.</li>
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<li>A thread can acquire any number of exclusive write locks on a read/write
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lock. Each successful exclusive write lock that is acquired must be released by
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a call to <strong>pthread_rwlock_unlock()</strong>.</li>
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</ul>
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<hr>
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<center>
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<table cellpadding="2" cellspacing="2">
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<tr align="center">
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<td valign="middle" align="center">
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<a href="rzah4mst.htm">Pthread APIs</a> |
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<a href="aplist.htm">APIs by category</a></td>
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</tr>
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</table>
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</center>
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</body>
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</html>
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