SecurityTests/cspxutils/cputimeCal/cputimeCal.cpp

   1 /* compare CPUTimeRead() vs CFAbsoluteTimeGetCurrent() */
   2
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include "cputime.h"
   6 #include <CoreFoundation/CoreFoundation.h>
   7
   8 #define WAIT_TIME_SEC   1.0
   9
  10 int main()
  11 {
  12         CPUTime cputimeStart, cputimeEnd;
  13         CFAbsoluteTime start;
  14
  15         printf("Resolution on this machine: %f nanoseconds\n",
  16                 CPUTimeDeltaUs(0ULL, 1ULL) * 1000.0);
  17
  18         start = CFAbsoluteTimeGetCurrent();
  19         cputimeStart = CPUTimeRead();
  20         while((CFAbsoluteTimeGetCurrent() - start) < WAIT_TIME_SEC) {
  21                 ;
  22         }
  23         cputimeEnd = CPUTimeRead();
  24
  25         printf("Waited %f sec; elapsed CPUTime %f s\n",
  26                 WAIT_TIME_SEC, CPUTimeDeltaSec(cputimeStart, cputimeEnd));
  27         printf("cputimeStart %08X:%08X   cputimeEnd %08X:%08X\n",
  28                 (unsigned)(cputimeStart >> 32),
  29                 (unsigned)(cputimeStart & 0xffffffffULL),
  30                 (unsigned)(cputimeEnd >> 32),
  31                 (unsigned)(cputimeEnd & 0xffffffffULL));
  32         printf("cputime raw delta %lu\n",
  33                 (unsigned long)(cputimeEnd - cputimeStart));
  34
  35         return 0;
  36 }