get a clock measuring thread CPU time
pthread_getcpuclockid() function allows the calling
thread to get a clockid_t value that measures the time
spent by CPUs running in user or kernel mode on behalf of the thread specified
pthread_getcpuclockid() will return zero.
Otherwise an error number will be returned to indicate the error.
pthread_getcpuclockid() will fail if:
- thread is an invalid thread ID.
pthread_getcpuclockid() function conforms to
IEEE Std 1003.1-2008 (“POSIX.1”).
pthread_getcpuclockid() function first appeared in
IEEE Std 1003.1d-1999 (“POSIX.1d”) and has been available since