michael@0: /*
michael@0: ******************************************************************************
michael@0: *
michael@0: *   Copyright (C) 1997-2013, International Business Machines
michael@0: *   Corporation and others.  All Rights Reserved.
michael@0: *
michael@0: ******************************************************************************
michael@0: */
michael@0: //----------------------------------------------------------------------------
michael@0: // File:     mutex.h
michael@0: //
michael@0: // Lightweight C++ wrapper for umtx_ C mutex functions
michael@0: //
michael@0: // Author:   Alan Liu  1/31/97
michael@0: // History:
michael@0: // 06/04/97   helena         Updated setImplementation as per feedback from 5/21 drop.
michael@0: // 04/07/1999  srl               refocused as a thin wrapper
michael@0: //
michael@0: //----------------------------------------------------------------------------
michael@0: #ifndef MUTEX_H
michael@0: #define MUTEX_H
michael@0: 
michael@0: #include "unicode/utypes.h"
michael@0: #include "unicode/uobject.h"
michael@0: #include "umutex.h"
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: //----------------------------------------------------------------------------
michael@0: // Code within that accesses shared static or global data should
michael@0: // should instantiate a Mutex object while doing so. You should make your own 
michael@0: // private mutex where possible.
michael@0: 
michael@0: // For example:
michael@0: // 
michael@0: // UMutex myMutex;
michael@0: // 
michael@0: // void Function(int arg1, int arg2)
michael@0: // {
michael@0: //    static Object* foo;     // Shared read-write object
michael@0: //    Mutex mutex(&myMutex);  // or no args for the global lock
michael@0: //    foo->Method();
michael@0: //    // When 'mutex' goes out of scope and gets destroyed here, the lock is released
michael@0: // }
michael@0: //
michael@0: // Note:  Do NOT use the form 'Mutex mutex();' as that merely forward-declares a function
michael@0: //        returning a Mutex. This is a common mistake which silently slips through the
michael@0: //        compiler!!
michael@0: //
michael@0: 
michael@0: class U_COMMON_API Mutex : public UMemory {
michael@0: public:
michael@0:   inline Mutex(UMutex *mutex = NULL);
michael@0:   inline ~Mutex();
michael@0: 
michael@0: private:
michael@0:   UMutex   *fMutex;
michael@0: 
michael@0:   Mutex(const Mutex &other); // forbid copying of this class
michael@0:   Mutex &operator=(const Mutex &other); // forbid copying of this class
michael@0: };
michael@0: 
michael@0: inline Mutex::Mutex(UMutex *mutex)
michael@0:   : fMutex(mutex)
michael@0: {
michael@0:   umtx_lock(fMutex);
michael@0: }
michael@0: 
michael@0: inline Mutex::~Mutex()
michael@0: {
michael@0:   umtx_unlock(fMutex);
michael@0: }
michael@0: 
michael@0: U_NAMESPACE_END
michael@0: 
michael@0: #endif //_MUTEX_
michael@0: //eof