src/external/3rd/library/soePlatform/CSAssist/utils/Base/solaris/Event.h

   1 ////////////////////////////////////////
   2 //  Event.h
   3 //
   4 //  Purpose:
   5 //          1. Declair the CEvent class that encapsulates the functionality of a
   6 //          single-locking semaphore.
   7 //
   8 //  Revisions:
   9 //          07/10/2001  Created
  10 //
  11
  12 #ifndef BASE_SOLARIS_EVENT_H
  13 #define BASE_SOLARIS_EVENT_H
  14
  15 #if !defined(_REENTRANT)
  16 #   pragma message( "Excluding Base::CEvent - requires multi-threaded compile. (_REENTRANT)" )
  17 #else
  18
  19
  20 #include "Platform.h"
  21
  22 namespace Base
  23 {
  24
  25     ////////////////////////////////////////
  26     //  Class:
  27     //      CEvent
  28     //
  29     //  Purpose:
  30     //      Encapsulates the functionality of a singal-locking semaphore.
  31     //      This class is valuable for thread syncronization when a thead's
  32     //      execution needs to be dependent upon another thread.
  33     //
  34     //  Public Methods:
  35     //      Signal() : Signals a thread that has called Wait() so that it can
  36     //          continue execution.  This function returns true if the waiting
  37     //          thread was signalled successfully, otherwise false is returned.
  38     //      Wait() : Halts the calling thread's execution indefinately until
  39     //          a Singal() call is made by an external thread.  If the thread is
  40     //          successfully signalled, the function returns eWAIT_SIGNAL.  If
  41     //          timeout period expires without a signal, eWAIT_TIMEOUT is returned.
  42     //          If the function fails, eWAIT_ERROR is returned.
  43     //
  44     class CEvent
  45     {
  46         public:
  47                 CEvent();
  48                 virtual ~CEvent();
  49
  50             bool    Signal();
  51             int32   Wait(uint32 timeout = 0);
  52         public:
  53             enum    { eWAIT_ERROR, eWAIT_SIGNAL, eWAIT_TIMEOUT };
  54         private:
  55             pthread_mutex_t mMutex;
  56             pthread_cond_t  mCond;
  57             bool            mInitialized;
  58             bool            mSignaled;
  59             int32           mWaiting;
  60     };
  61
  62     inline bool CEvent::Signal()
  63     {
  64         if (!mInitialized)
  65             return false;
  66         pthread_mutex_lock(&mMutex);
  67         if(mWaiting > 0)
  68         {
  69             pthread_cond_signal(&mCond);
  70         }
  71         else
  72         {
  73             mWaiting = true;
  74         }
  75         pthread_mutex_unlock(&mMutex);
  76         return true;
  77     }
  78
  79 }
  80
  81 #endif  //  #if defined(_MT)
  82
  83 #endif  //  BASE_SOLARIS_EVENT_H