NAME

pthread_attr_setschedpolicy, pthread_attr_getschedpolicy - set and get schedpolicy attribute (REALTIME THREADS)

SYNOPSIS

#include <pthread.h>

int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);
int pthread_attr_getschedpolicy(const pthread_attr_t *attr, 
    int *policy);

DESCRIPTION

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.

RETURN VALUE

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

ERRORS

The pthread_attr_setschedpolicy() and pthread_attr_getschedpolicy() functions will fail if:

[ENOSYS]

The option _POSIX_THREAD_PRIORITY_SCHEDULING is not defined and the implementation does not support the function.

The pthread_attr_setschedpolicy() function may fail if:

[EINVAL]

The value of the attribute being set is not valid.

[ENOTSUP]

An attempt was made to set the attribute to an unsupported value.

EXAMPLES

None.

APPLICATION USAGE

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.

FUTURE DIRECTIONS

None.

SEE ALSO

pthread_attr_init(), pthread_attr_setscope(), pthread_attr_setinheritsched(), pthread_attr_setschedparam(), pthread_create(), <pthread.h>, pthread_setschedparam(), <sched.h>.