The functions pthread_attr_setschedpolicy() and pthread_attr_getschedpolicy(), respectively, set and get the schedpolicy attribute in the attr argument.

The supported values of policy include SCHED_FIFO, SCHED_RR and SCHED_OTHER, which are defined by the header <sched.h>. When threads executing with the scheduling policy SCHED_FIFO or SCHED_RR are waiting on a mutex, they acquire the mutex in priority order when the mutex is unlocked.

If successful, the pthread_attr_setschedpolicy() and pthread_attr_getschedpolicy() functions return 0. Otherwise, an error number is returned to indicate the error.

The pthread_attr_setschedpolicy() or pthread_attr_getschedpolicy() function may fail if:

EINVAL

attr or policy is invalid.

After these attributes have been set, a thread can be created with the specified attributes using pthread_create(). Using these routines does not affect the current running thread.

See attributes(5) for descriptions of the following attributes:

pthread_attr_init(3THR), pthread_attr_setscope(3THR), pthread_attr_setinheritsched(3THR), pthread_attr_setschedparam(3THR), pthread_create(3THR), pthread_setschedparam(3THR), attributes(5), standards(5)