Use the pthread_condattr_setclock(3C) function to set the clock attribute in an initialized attributes object referenced by attr. If pthread_condattr_setclock() is called with a clock_id argument that refers to a CPU-time clock, the call fails. The clock attribute is the clock ID of the clock that is used to measure the timeout service of pthread_cond_timedwait(). The default value of the clock attribute refers to the system clock, CLOCK_REALTIME. At this time, the only other possible value for the clock attribute is CLOCK_MONOTONIC.
int pthread_condattr_setclock(pthread_condattr_t attr, clockid_t clock_id);
#include <pthread.h> pthread_condattr_t attr clockid_t clock_id int ret ret = pthread_condattr_setclock(&attr &clock_id
pthread_condattr_setclock() returns zero after completing successfully. Any other return value indicates that an error occurred. When the following condition occurs, the function fails and returns the corresponding value.
EINVAL
Description:The value specified by clock_id does not refer to a known clock, or is a CPU-time clock.