src/external/3rd/library/platform/utils/Base/linux/Mutex.h

   1 ////////////////////////////////////////
   2 //  Mutex.h
   3 //
   4 //  Purpose:
   5 //          1. Declair the CMutex class that encapsulates the functionality of a
   6 //          mutually-exclusive device.
   7 //
   8 //  Revisions:
   9 //          07/10/2001  Created
  10 //
  11
  12 #ifndef BASE_LINUX_MUTEX_H
  13 #define BASE_LINUX_MUTEX_H
  14
  15 #if !defined(_REENTRANT)
  16 #   pragma message( "Excluding Base::CMutex - requires multi-threaded compile. (_REENTRANT)" )
  17 #else
  18
  19
  20 #include "Platform.h"
  21
  22 #ifdef EXTERNAL_DISTRO
  23 namespace NAMESPACE
  24 {
  25
  26 #endif
  27 namespace Base
  28 {
  29
  30     ////////////////////////////////////////
  31     //  Class:
  32     //      CMutex
  33     //
  34     //  Purpose:
  35     //      Encapsulates the functionality of a mutually-exclusive device.
  36     //      This class is valuable for protecting against race conditions
  37     //      within threaded applications.  The CMutex class can be used to
  38     //      only allow a single thread to run within a specified code
  39     //      segment at a time.
  40     //
  41     //  Public Methods:
  42     //      Lock() : Locks the mutex.  If the mutex is already locked, the
  43     //          operating system will block the calling thread until another
  44     //          thread has unlocked the mutex.
  45     //      Unlock() : Unlocks the mutex.
  46     //
  47     class CMutex
  48         {
  49             public:
  50             CMutex();
  51             ~CMutex();
  52
  53             void Lock();
  54                     void Unlock();
  55             private:
  56                     pthread_mutex_t mMutex;
  57             bool            mInitialized;
  58         };
  59
  60     inline void CMutex::Lock(void)
  61     {
  62             if (mInitialized)
  63             pthread_mutex_lock(&mMutex);
  64     }
  65
  66     inline void CMutex::Unlock(void)
  67     {
  68         if (mInitialized)
  69             pthread_mutex_unlock(&mMutex);
  70     }
  71
  72 }
  73 #ifdef EXTERNAL_DISTRO
  74 };
  75 #endif
  76 #endif  //  #if defined(_MT)
  77
  78 #endif  // BASE_LINUX_MUTEX_H
  79