sl@0: /*
sl@0: ******************************************************************************
sl@0: *
sl@0: *   Copyright (C) 1997-2003, International Business Machines
sl@0: *   Corporation and others.  All Rights Reserved.
sl@0: *
sl@0: ******************************************************************************
sl@0: */
sl@0: //----------------------------------------------------------------------------
sl@0: // File:     mutex.h
sl@0: //
sl@0: // Lightweight C++ wrapper for umtx_ C mutex functions
sl@0: //
sl@0: // Author:   Alan Liu  1/31/97
sl@0: // History:
sl@0: // 06/04/97   helena         Updated setImplementation as per feedback from 5/21 drop.
sl@0: // 04/07/1999  srl               refocused as a thin wrapper
sl@0: //
sl@0: //----------------------------------------------------------------------------
sl@0: #ifndef MUTEX_H
sl@0: #define MUTEX_H
sl@0: 
sl@0: #include "unicode/utypes.h"
sl@0: #include "unicode/uobject.h"
sl@0: #include "umutex.h"
sl@0: 
sl@0: U_NAMESPACE_BEGIN
sl@0: 
sl@0: //----------------------------------------------------------------------------
sl@0: // Code within that accesses shared static or global data should
sl@0: // should instantiate a Mutex object while doing so. You should make your own 
sl@0: // private mutex where possible.
sl@0: 
sl@0: // For example:
sl@0: // 
sl@0: // UMTX myMutex;
sl@0: // 
sl@0: // int InitializeMyMutex()
sl@0: // {
sl@0: //    umtx_init( &myMutex );
sl@0: //    return 0;
sl@0: // }
sl@0: // 
sl@0: // static int initializeMyMutex = InitializeMyMutex();
sl@0: //
sl@0: // void Function(int arg1, int arg2)
sl@0: // {
sl@0: //    static Object* foo;     // Shared read-write object
sl@0: //    Mutex mutex(&myMutex);  // or no args for the global lock
sl@0: //    foo->Method();
sl@0: //    // When 'mutex' goes out of scope and gets destroyed here, the lock is released
sl@0: // }
sl@0: //
sl@0: // Note:  Do NOT use the form 'Mutex mutex();' as that merely forward-declares a function
sl@0: //        returning a Mutex. This is a common mistake which silently slips through the
sl@0: //        compiler!!
sl@0: //
sl@0: 
sl@0: class U_COMMON_API Mutex : public UMemory {
sl@0: public:
sl@0:   inline Mutex(UMTX *mutex = NULL);
sl@0:   inline ~Mutex();
sl@0: 
sl@0: private:
sl@0:   UMTX   *fMutex;
sl@0: 
sl@0:   Mutex(const Mutex &other); // forbid copying of this class
sl@0:   Mutex &operator=(const Mutex &other); // forbid copying of this class
sl@0: };
sl@0: 
sl@0: inline Mutex::Mutex(UMTX *mutex)
sl@0:   : fMutex(mutex)
sl@0: {
sl@0:   umtx_lock(fMutex);
sl@0: }
sl@0: 
sl@0: inline Mutex::~Mutex()
sl@0: {
sl@0:   umtx_unlock(fMutex);
sl@0: }
sl@0: 
sl@0: U_NAMESPACE_END
sl@0: 
sl@0: #endif //_MUTEX_
sl@0: //eof