pthread_setschedparam(3THR)

Use pthread_setschedparam(3THR) to modify the priority of an existing thread. This function has no effect on scheduling policy.

Prototype:
int	 pthread_setschedparam(pthread_t tid, int policy,
    const struct sched_param *param);

#include <pthread.h>

pthread_t tid;
int ret;
struct sched_param param;
int priority;

/* sched_priority will be the priority of the thread */
sched_param.sched_priority = priority;

/* only supported policy, others will result in ENOTSUP */
policy = SCHED_OTHER;

/* scheduling parameters of target thread */
ret = pthread_setschedparam(tid, policy, &param); 

Return Values

pthread_setschedparam() returns zero after completing successfully. Any other return value indicates that an error occurred. When either of the following conditions occurs, the pthread_setschedparam() function fails and returns the corresponding value.

EINVAL

The value of the attribute being set is not valid.

ENOTSUP

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