Time.hxx

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#if !defined(RESIP_TIME_HXX)
#define RESIP_TIME_HXX

#include "rutil/Mutex.hxx"
#include <limits.h>
#include <cassert>

namespace resip
{

class ResipClock
{
   public:
      ResipClock(void);
      ~ResipClock(void);

      static UInt64 getTimeMicroSec()
      {
         return getSystemTime();
      }


      static UInt64 getTimeMs()
      {
         return getSystemTime()/1000LL;
      }

      static UInt64 getTimeSecs()
      {
         return getSystemTime()/1000000LL;
      }

      static UInt64 getRandomFutureTimeMs( UInt64 futureMs );
      static UInt64 getForever();

      static unsigned getMaxSystemTimeWaitMs(void)
      {
         return mMaxSystemTimeWaitMs;
      }     

      static void queryTimerInfo(unsigned &minRes, unsigned &maxRes, unsigned &actualRes, bool &isMonotonic);

   private:
      static UInt64 getSystemTime();

      static unsigned mMaxSystemTimeWaitMs;

#ifdef WIN32
   private:
      class WinMonoClock
      {
         public:
            WinMonoClock();        

            static UInt64 GetClock64(void)
            {
               return mGTC64();
            }                     

         private:

            static void Initialize(void);
            typedef UInt64 (*PGTC64)(void);

            class GTCInterlocked
            {
               public:

                  static UInt64 GTC64(void);

                  static UInt32 GetMaxWaitMs(void)
                  {
                     //Since the base time isn't updated on every call, need to ensure that it's updated once every 49.7 days.
                     //The base time will lag behind the current tick count, which means the lag time must be used
                     //to determine the max wait.
                     //Also need to add a cushion to this calculaton because ::timeGetTime may not be accurate to 1ms.
                     __int64 maxWait = (__int64)UINT_MAX - mBaseTimeUpdateInterval - mBaseTimeCushion;
                     if (maxWait <= 0)
                     {
                        assert(0);
                        const_cast<UInt32 &>(mBaseTimeUpdateInterval) = 60000;
                        const_cast<UInt32 &>(mBaseTimeCushion) = 120000;
                        return UINT_MAX - mBaseTimeUpdateInterval - mBaseTimeCushion;
                     }
                     return static_cast<UInt32>(maxWait);
                  }

               private:
                  static _declspec(align(128)) volatile UInt64 mBaseTime;
                  static const UInt32 mBaseTimeUpdateInterval = 60000;
                  static const UInt32 mBaseTimeCushion = 120000; 
            };

            class GTCLockDuringRange
            {
               public:

                  static UInt64 GTC64(void);

                  static UInt32 GetMaxWaitMs(void)
                  {
                     return 120000;
                  }

               private:
                  static UInt32 mWrapCounter;

                  static DWORD mPrevTick;

                  static Mutex mWrapCounterMutex;

            };

            class GTCLock
            {
               public:
                  static UInt64 GTC64(void);

               private:
                  static ULARGE_INTEGER mBaseTime;

                  static Mutex mMutex;
            };

            static PGTC64 mGTC64;
      };
#endif
};


}//namespace resip

#endif
/* ====================================================================
 * The Vovida Software License, Version 1.0
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 *
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 * vi: set shiftwidth=3 expandtab:
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