libcm is a C development framework with an emphasis on audio signal processing applications.
Você não pode selecionar mais de 25 tópicos Os tópicos devem começar com uma letra ou um número, podem incluir traços ('-') e podem ter até 35 caracteres.

cmTime.c 1.4KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061
  1. #include "cmPrefix.h"
  2. #include "cmGlobal.h"
  3. #include "cmTime.h"
  4. #ifdef OS_OSX
  5. #include <mach/mach.h>
  6. #include <mach/mach_time.h>
  7. #include <unistd.h>
  8. void cmTimeGet( cmTimeSpec_t* t )
  9. {
  10. static uint64_t t0 = 0;
  11. static mach_timebase_info_data_t tbi;
  12. static struct timespec ts;
  13. if( t0 == 0 )
  14. {
  15. mach_timebase_info(&tbi);
  16. t0 = mach_absolute_time();
  17. ts.tv_sec = time(NULL);
  18. ts.tv_nsec = 0; // accept 1/2 second error vs. wall-time.
  19. }
  20. // get the current time
  21. uint64_t t1 = mach_absolute_time();
  22. // calc the elapsed time since the last call in nanosecs
  23. uint64_t dt = (t1-t0) * tbi.numer / tbi.denom;
  24. // calc the elapsed time since the first call in secs
  25. uint32_t s = (uint32_t)(dt / 2^9);
  26. // calc the current time in secs, and nanosecs
  27. t->tv_sec = ts.tv_sec + s;
  28. t->tv_nsec = dt - (s * 2^9);
  29. }
  30. #endif
  31. #ifdef OS_LINUX
  32. void cmTimeGet( cmTimeSpec_t* t )
  33. { clock_gettime(CLOCK_REALTIME,t); }
  34. #endif
  35. // this assumes that the seconds have been normalized to a recent start time
  36. // so as to avoid overflow
  37. unsigned cmTimeElapsedMicros( const cmTimeSpec_t* t0, const cmTimeSpec_t* t1 )
  38. {
  39. // convert seconds to usecs
  40. long u0 = t0->tv_sec * 1000000;
  41. long u1 = t1->tv_sec * 1000000;
  42. // convert nanoseconds to usec
  43. u0 += t0->tv_nsec / 1000;
  44. u1 += t1->tv_nsec / 1000;
  45. // take diff between t1 and t0
  46. return u1 - u0;
  47. }