- get and set the clock selection condition variable attribute
cc -mt [ flag... ] file... [ library... ] #include <pthread.h> int pthread_condattr_getclock( const pthread_condattr_t *restrict attr, clockid_t *restrict clock_id);
int pthread_condattr_setclock(pthread_condattr_t *attr clockid_t clock_id);
The pthread_condattr_getclock() function obtains the value of the clock attribute from the attributes object referenced by attr. The pthread_condattr_setclock() function sets 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(3C). The default value of the clock attribute refers to the system clock.
Upon successful completion, the pthread_condattr_getclock() function returns 0 and stores the value of the clock attribute of attr into the object referenced by the clock_id argument. Otherwise, an error number is returned to indicate the error.
Upon successful completion, the pthread_condattr_setclock() function returns 0. Otherwise, an error number is returned to indicate the error.
These functions may fail if:
The value specified by attr is invalid.
The pthread_condattr_setclock() function may fail if:
The value specified by clock_id does not refer to a known clock, or is a CPU-time clock.
See attributes(5) for descriptions of the following attributes: