1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3 4<head> 5<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 6<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 7.0.1.0 for Windows"> 7<META http-equiv="Content-Style-Type" content="text/css"> 8<title>OS_UnlockMutex[R|W|RW]</title> 9<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css"> 10</head> 11 12<body> 13 14<h1 align="left">OS_UnlockMutex[R|W|RW] <IMG src="../../image/NTR.gif" align="middle"><IMG src="../../image/TWL.gif" align="middle"></h1> 15<h2>Syntax</h2> 16 17<dl> 18 <dd> 19<CODE>#include <nitro/os.h></CODE><BR> <BR> <CODE>void OS_UnlockMutexR( OSMutex* mutex );</CODE><BR> <BR> <CODE>void OS_UnlockMutexW( OSMutex* mutex );</CODE><BR> <BR> <CODE>void OS_UnlockMutexRW( OSMutex* mutex );</CODE></dd> 20</dl> 21 22<h2>Arguments</h2> 23<TABLE border="1" width="100%"> 24 <TBODY> 25 <TR> 26 <TD width="13%"><CODE>mutex</CODE></TD> 27 <TD width="87%">Pointer to the <CODE>OSMutex</CODE> structure</TD> 28 </TR> 29 </TBODY> 30</TABLE> 31 32<h2>Return Values</h2> 33<p>None.</p> 34 35<H2>Description</H2> 36<P>The thread calling this function unlocks the <CODE>mutex</CODE>.<BR></P> 37<P>The <CODE>OS_UnlockMutexR</CODE> function unlocks a <CODE>read lock</CODE>. When unlocking a <CODE>read lock</CODE>, it does not matter if the calling thread is not the owner of <CODE>mutex</CODE>. Note that if <CODE>mutex</CODE> has been locked <I>n</I> times, only the <I>nth</I> <CODE>OS_UnlockMutexR</CODE> function call actually releases the lock.</P> 38<P>The <CODE>OS_UnlockMutexW</CODE> function unlocks a <CODE>write lock</CODE>. To unlock a <CODE>write lock</CODE>, the calling thread must be the owner of <CODE>mutex</CODE>. Note that if <CODE>mutex</CODE> has been locked <I>n</I> times by the calling thread, it is only released by the <I>nth</I> call to the <CODE>OS_UnlockMutexW</CODE> function.</P> 39<P>The <CODE>OS_UnlockMutexRW</CODE> function can unlock both a <CODE>read lock</CODE> and a <CODE>write lock</CODE>. It has the characteristics of both the <CODE>OS_UnlockMutexR</CODE> and <CODE>OS_UnlockMutexW</CODE> functions noted above. It can also unlock a mutex locked with the <CODE><A href="OS_LockMutex.html">OS_LockMutex</A></CODE> function.</P> 40<H3><BR>Lock and Unlock Correlation</H3> 41<P>If <CODE><A href="OS_LockMutexRW.html">mutex</A></CODE> has been locked by the <CODE><A href="OS_LockMutexRW.html">OS_LockMutexR</A></CODE> function, unlock it using the <CODE><A href="OS_LockMutexRW.html">OS_UnlockMutexR</A></CODE> or <CODE><A href="OS_LockMutexRW.html">OS_UnlockMutexRW</A></CODE> function. If you try to unlock using the <CODE>OS_UnlockMutexW</CODE> function the process will stop with the <CODE><A href="../debug/OS_Panic.html">OS_Panic</A></CODE> function.</P> 42<P>If <CODE><A href="OS_LockMutexRW.html">mutex</A></CODE> has been locked by the <CODE><A href="OS_LockMutexRW.html">OS_LockMutexW</A></CODE> function, unlock it using the <CODE><A href="OS_LockMutexRW.html">OS_UnlockMutexW</A></CODE> or <CODE><A href="OS_LockMutexRW.html">OS_UnlockMutexRW</A></CODE> function. If you try to unlock using the <CODE>OS_UnlockMutexR</CODE> function, the process will stop with the <CODE><A href="../debug/OS_Panic.html">OS_Panic</A></CODE> function.</P> 43<P>The process will also stop with the <CODE><A href="../debug/OS_Panic.html">OS_Panic</A></CODE> function if you try using the <CODE>OS_UnlockMutexR</CODE>, <CODE>OS_UnlockMutexW</CODE> or <CODE>OS_UnlockMutexRW</CODE> function to unlock a <CODE>mutex</CODE> that is not locked.</P> 44<P>If the process stops with the <CODE><A href="../debug/OS_Panic.html">OS_Panic</A></CODE> function, check the correlation of lock and unlock functions in the application.</P> 45<H3><BR>Exiting the Thread</H3> 46<P>When the thread that is locking <CODE>mutex</CODE> is terminated with the <A href="../thread/OS_ExitThread.html"><CODE>OS_ExitThread</CODE></A> function, <CODE>mutex</CODE> is automatically unlocked.</P> 47<h2>See Also</h2> 48<p><CODE><A href="OS_InitMutex.html">OS_InitMutex</A><BR> <A href="OS_LockMutex.html">OS_LockMutex</A><BR> <A href="OS_TryLockMutex.html">OS_TryLockMutex</A><BR> <A href="../thread/OS_ExitThread.html">OS_ExitThread</A><br> <A href="OS_LockMutexRW.html">OS_LockMutexR</A><BR> <A href="OS_LockMutexRW.html">OS_LockMutexW</A><BR> <A href="OS_TryLockMutexRW.html">OS_TryLockMutexR</A><BR> <A href="OS_TryLockMutexRW.html">OS_TryLockMutexW</A><BR> <A href="OS_LockMutexFromToRW.html">OS_LockMutexFromRToW</A><BR> <A href="OS_LockMutexFromToRW.html">OS_LockMutexFromWToR</A><BR> <A href="OS_TryLockMutexFromToRW.html">OS_TryLockMutexFromRToW</A><BR> <A href="OS_TryLockMutexFromToRW.html">OS_TryLockMutexFromWToR</A></CODE></p> 49<H2>Revision History</H2> 50<P>2008/12/16 Initial version.</P> 51<hr><p>CONFIDENTIAL</p></body> 52</html> 53
