mutex.h

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00001 /*
00002  * mutex.h
00003  *
00004  * Mutual exclusion thread synchonisation class.
00005  *
00006  * Portable Windows Library
00007  *
00008  * Copyright (c) 1993-1998 Equivalence Pty. Ltd.
00009  *
00010  * The contents of this file are subject to the Mozilla Public License
00011  * Version 1.0 (the "License"); you may not use this file except in
00012  * compliance with the License. You may obtain a copy of the License at
00013  * http://www.mozilla.org/MPL/
00014  *
00015  * Software distributed under the License is distributed on an "AS IS"
00016  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
00017  * the License for the specific language governing rights and limitations
00018  * under the License.
00019  *
00020  * The Original Code is Portable Windows Library.
00021  *
00022  * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
00023  *
00024  * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
00025  * All Rights Reserved.
00026  *
00027  * Contributor(s): ______________________________________.
00028  *
00029  * $Log: mutex.h,v $
00030  * Revision 1.14  2005/11/25 00:06:12  csoutheren
00031  * Applied patch #1364593 from Hannes Friederich
00032  * Also changed so PTimesMutex is no longer descended from PSemaphore on
00033  * non-Windows platforms
00034  *
00035  * Revision 1.13  2005/11/08 22:31:00  csoutheren
00036  * Moved declaration of PMutex
00037  *
00038  * Revision 1.12  2005/11/08 22:18:31  csoutheren
00039  * Changed PMutex to use PTimedMutex on non-Windows platforms because
00040  * sem_wait is not recursive. Very sad.
00041  * Thanks to Frederic Heem for finding this problem
00042  *
00043  * Revision 1.11  2005/11/04 06:34:20  csoutheren
00044  * Added new class PSync as abstract base class for all mutex/sempahore classes
00045  * Changed PCriticalSection to use Wait/Signal rather than Enter/Leave
00046  * Changed Wait/Signal to be const member functions
00047  * Renamed PMutex to PTimedMutex and made PMutex synonym for PCriticalSection.
00048  * This allows use of very efficient mutex primitives in 99% of cases where timed waits
00049  * are not needed
00050  *
00051  * Revision 1.10  2003/09/17 05:41:58  csoutheren
00052  * Removed recursive includes
00053  *
00054  * Revision 1.9  2003/09/17 01:18:02  csoutheren
00055  * Removed recursive include file system and removed all references
00056  * to deprecated coooperative threading support
00057  *
00058  * Revision 1.8  2002/09/16 01:08:59  robertj
00059  * Added #define so can select if #pragma interface/implementation is used on
00060  *   platform basis (eg MacOS) rather than compiler, thanks Robert Monaghan.
00061  *
00062  * Revision 1.7  2002/01/23 04:26:36  craigs
00063  * Added copy constructors for PSemaphore, PMutex and PSyncPoint to allow
00064  * use of default copy constructors for objects containing instances of
00065  * these classes
00066  *
00067  * Revision 1.6  2001/05/22 12:49:32  robertj
00068  * Did some seriously wierd rewrite of platform headers to eliminate the
00069  *   stupid GNU compiler warning about braces not matching.
00070  *
00071  * Revision 1.5  1999/03/09 02:59:50  robertj
00072  * Changed comments to doc++ compatible documentation.
00073  *
00074  * Revision 1.4  1999/02/16 08:12:22  robertj
00075  * MSVC 6.0 compatibility changes.
00076  *
00077  * Revision 1.3  1998/11/30 02:50:59  robertj
00078  * New directory structure
00079  *
00080  * Revision 1.2  1998/09/23 06:20:55  robertj
00081  * Added open source copyright license.
00082  *
00083  * Revision 1.1  1998/03/23 02:41:31  robertj
00084  * Initial revision
00085  *
00086  */
00087 
00088 #ifndef _PMUTEX
00089 #define _PMUTEX
00090 
00091 #ifdef P_USE_PRAGMA
00092 #pragma interface
00093 #endif
00094 
00095 #include <ptlib/critsec.h>
00096 #include <ptlib/semaphor.h>
00097 
00119 /*
00120  * On Windows, It is convenient for PTimedMutex to be an ancestor of PSemaphore
00121  * But that is the only platform where it is - every other platform (i.e. Unix)
00122  * uses different constructs for these objects, so there is no need for a PTimedMute
00123  * to carry around all of the PSemaphore members
00124  */
00125 
00126 #ifdef _WIN32
00127 class PTimedMutex : public PSemaphore
00128 {
00129   PCLASSINFO(PTimedMutex, PSemaphore);
00130 #else
00131 class PTimedMutex : public PSync
00132 {
00133   PCLASSINFO(PTimedMutex, PSync)
00134 #endif
00135 
00136   public:
00137     /* Create a new mutex.
00138        Initially the mutex will not be "set", so the first call to Wait() will
00139        never wait.
00140      */
00141     PTimedMutex();
00142     PTimedMutex(const PTimedMutex & mutex);
00143 
00144 // Include platform dependent part of class
00145 #ifdef _WIN32
00146 #include "msos/ptlib/mutex.h"
00147 #else
00148 #include "unix/ptlib/mutex.h"
00149 #endif
00150 };
00151 
00152 // On Windows, critical sections are recursive and so we can use them for mutexes
00153 // The only Posix mutex that is recursive is pthread_mutex, so we have to use that
00154 #ifdef _WIN32
00155 typedef PCriticalSection PMutex;
00156 #else
00157 typedef PTimedMutex PMutex;
00158 #endif
00159 
00160 #endif
00161 
00162 // End Of File ///////////////////////////////////////////////////////////////

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