static uint64 calcStampsPerSecond()
{
static bool firstTime = true;
if (firstTime)
{
firstTime = false;
}
#ifdef KBE_USE_RDTSC
return calcStampsPerSecond_rdtsc();
#else
if (g_timingMethod == RDTSC_TIMING_METHOD)
return calcStampsPerSecond_rdtsc();
else if (g_timingMethod == GET_TIME_OF_DAY_TIMING_METHOD)
return calcStampsPerSecond_gettimeofday();
else if (g_timingMethod == GET_TIME_TIMING_METHOD)
return calcStampsPerSecond_gettime();
else
{
char * timingMethod = getenv("KBE_TIMING_METHOD");
if (!timingMethod)
{
g_timingMethod = DEFAULT_TIMING_METHOD;
}
else if (strcmp(timingMethod, "rdtsc") == 0)
{
g_timingMethod = RDTSC_TIMING_METHOD;
}
else if (strcmp(timingMethod, "gettimeofday") == 0)
{
g_timingMethod = GET_TIME_OF_DAY_TIMING_METHOD;
}
else if (strcmp(timingMethod, "gettime") == 0)
{
g_timingMethod = GET_TIME_TIMING_METHOD;
}
else
{
WARNING_MSG(fmt::format("calcStampsPerSecond: "
"Unknown timing method '%s', using clock_gettime.\n",
timingMethod));
g_timingMethod = DEFAULT_TIMING_METHOD;
}
return calcStampsPerSecond();
}
#endif
}
/**
* 每秒cpu所耗时间
*/
uint64 stampsPerSecond()
{
static uint64 _stampsPerSecondCache = calcStampsPerSecond();
return _stampsPerSecondCache;
}