关于tbb计时的问题

[茶禅如水]

#include "tbb/tick_count.h"

tick_count start = tick_count::now();
..........

tick_count stop = tick_count::now();
printf("Time to compute room assignments is %f seconds.\n",
(stop - start).seconds());

tbb中提供了这样一个计时的类，应该对线程安全的，可移植性好，在多线程程序计时可以用到。

大家用的什么计时？

[wuganhao]

I think tick_count has nothing to do with thread safty, but only a high performance counter.

[denghui0815]

// 计时函数
__int64 XGetTickCount()
{
__int64 nTick = 0;
#ifdef WIN32
static __int64 nFrequency = 0;
if(nFrequency || QueryPerformanceFrequency((LARGE_INTEGER *)&nFrequency))
{
QueryPerformanceCounter((LARGE_INTEGER *)&nTick);
nTick = nTick * 1000000 / nFrequency;
}
#else
struct timeval tmVal;
struct timezone tmZone;
gettimeofday( &tmVal, &tmZone );
nTick = (__int64)tmVal.tv_sec * 1000000 + tmVal.tv_usec;
#endif
return nTick;
}

[OpenHero]

// 32 位
DWORD StartTime,ElapsedTime;
_asm {
RDTSC
mov StartTime, eax
}
//<.. you code.......>
_asm {
TDRSC
sub eax, StartTime
mov ElapsedTime, eax
}
printf("Time in CPU clocks %d", ElapsedTime);

// 64 位
__int64 StartTime, EndTime;
_asm {
RDTSC
mov DWORD PTR StartTime, eax
mov DWORD PTR StartTime+4, edx
}

// you code
_asm {
RDTSC
mov DWORD PTR EndTime, eax
mov DWORD PTR EndTime+4, eax;
}
printf("Time in CPU clocks %I64d", EndTime - StartTime);