if(!::clock_gettime(CLOCK_MONOTONIC, &t_usec))
timestamp_usec = (t_usec.tv_nsec / 1000ll) + (t_usec.tv_sec* 1000000ll);
return timestamp_usec;
if(!::clock_gettime(CLOCK_MONOTONIC, &t_usec))
timestamp_usec = (t_usec.tv_nsec / 1000ll) + (t_usec.tv_sec* 1000000ll);
return timestamp_usec;