1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

     3 <!-- This component and the accompanying materials are made available under the terms of the License 

     4 "Eclipse Public License v1.0" which accompanies this distribution, 

     5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

     9 -->

    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept xml:lang="en" id="GUID-BA89F4DF-E2F6-5E0B-BF20-F8898FC5D5F8"><title>Mutexes Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody><section><title>Purpose</title> <p>Synchronises exclusive access to shared resources within and between processes.</p> </section> <section><title>Description</title> <p>Mutexes are typically used to serialise access to a section of re-entrant code that cannot be executed concurrently by more than one thread. A mutex object only allows one thread into a controlled section, forcing other threads which attempt to gain access to that section to wait until the first thread has exited from that section.</p> <p>A mutex can be used by threads across any number of processes. If a resource is only shared between the threads within the same process, it can be more efficient to use a critical section.</p> <p>Mutexes are Kernel objects and, as such, are managed by the Kernel, and accessed by user programs through handles. </p> <p>The mutex handle is provided by <xref href="GUID-C0FEA3A0-7DD3-3B87-A919-CB973BC05766.dita"><apiname>RMutex</apiname></xref>.</p> <p><xref href="GUID-A907C7B1-BD90-3E8F-AEA8-5A634BC98D0D.dita"><apiname>TFindMutex</apiname></xref> is used for finding a mutex created by another process.</p> </section> </conbody></concept>