icuSources/common/mutex.h

   1 /*
   2 ******************************************************************************
   3 *
   4 *   Copyright (C) 1997-2013, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 ******************************************************************************
   8 */
   9 //----------------------------------------------------------------------------
  10 // File:     mutex.h
  11 //
  12 // Lightweight C++ wrapper for umtx_ C mutex functions
  13 //
  14 // Author:   Alan Liu  1/31/97
  15 // History:
  16 // 06/04/97   helena         Updated setImplementation as per feedback from 5/21 drop.
  17 // 04/07/1999  srl               refocused as a thin wrapper
  18 //
  19 //----------------------------------------------------------------------------
  20 #ifndef MUTEX_H
  21 #define MUTEX_H
  22
  23 #include "unicode/utypes.h"
  24 #include "unicode/uobject.h"
  25 #include "umutex.h"
  26
  27 U_NAMESPACE_BEGIN
  28
  29 //----------------------------------------------------------------------------
  30 // Code within that accesses shared static or global data should
  31 // should instantiate a Mutex object while doing so. You should make your own
  32 // private mutex where possible.
  33
  34 // For example:
  35 //
  36 // UMutex myMutex;
  37 //
  38 // void Function(int arg1, int arg2)
  39 // {
  40 //    static Object* foo;     // Shared read-write object
  41 //    Mutex mutex(&myMutex);  // or no args for the global lock
  42 //    foo->Method();
  43 //    // When 'mutex' goes out of scope and gets destroyed here, the lock is released
  44 // }
  45 //
  46 // Note:  Do NOT use the form 'Mutex mutex();' as that merely forward-declares a function
  47 //        returning a Mutex. This is a common mistake which silently slips through the
  48 //        compiler!!
  49 //
  50
  51 class U_COMMON_API Mutex : public UMemory {
  52 public:
  53   inline Mutex(UMutex *mutex = NULL);
  54   inline ~Mutex();
  55
  56 private:
  57   UMutex   *fMutex;
  58
  59   Mutex(const Mutex &other); // forbid copying of this class
  60   Mutex &operator=(const Mutex &other); // forbid copying of this class
  61 };
  62
  63 inline Mutex::Mutex(UMutex *mutex)
  64   : fMutex(mutex)
  65 {
  66   umtx_lock(fMutex);
  67 }
  68
  69 inline Mutex::~Mutex()
  70 {
  71   umtx_unlock(fMutex);
  72 }
  73
  74 U_NAMESPACE_END
  75
  76 #endif //_MUTEX_
  77 //eof