Actual source code: nt_time.c

  1: /*$Id: nt_time.c,v 1.25 2001/04/05 21:06:51 balay Exp $*/

  3: #include <petsc.h>
  4: #if defined (PARCH_win32_gnu) || defined (PARCH_win32)
  5: #include <Windows.h>
  6: #define FACTOR   4294967296.0 /* pow(2,32) */

 10: PetscLogDouble nt_time(void)
 11: {
 12:   static PetscTruth     flag = PETSC_TRUE;
 13:   int                   ierr;

 15:   static LARGE_INTEGER  StartTime,PerfFreq,CurTime;
 16:   static PetscLogDouble SecInTick=0.0;
 17: 
 18:   DWORD                 dwStartHigh,dwCurHigh;
 19:   PetscLogDouble        dTime,dHigh;
 20:   PetscLogDouble        ptime;
 21: 
 22: 
 24:   if (flag) {
 25:     QueryPerformanceCounter(&StartTime);CHKERRQ(!ierr);
 26:     QueryPerformanceFrequency(&PerfFreq);CHKERRQ(!ierr);
 27:     /* Explicitly convert the higher 32 bits, and add the lower 32 bits from the counter */
 28:     /* works on non-pentium CPUs ? */
 29:     SecInTick = 1.0/((double)PerfFreq.HighPart*FACTOR+(double)PerfFreq.LowPart);
 30:     flag = PETSC_FALSE;
 31:   }
 32: 
 33:   QueryPerformanceCounter(&CurTime);CHKERRQ(!ierr);
 34:   dwCurHigh   = (DWORD)CurTime.HighPart;
 35:   dwStartHigh = (DWORD)StartTime.HighPart;
 36:   dHigh       = (signed)(dwCurHigh - dwStartHigh);

 38:   dTime = dHigh*(double)FACTOR + (double)CurTime.LowPart - (double)StartTime.LowPart;
 39:   /* Use the following with older versions of the Borland compiler
 40:   dTime = dHigh*(double)FACTOR + (double)CurTime.u.LowPart - (double)StartTime.u.LowPart;
 41:   */
 42:   ptime = (double)SecInTick*dTime;

 44:   PetscFunctionReturn(ptime);
 45: }
 46: #endif