Multithreaded Programming Guide

Set the Thread Priority

In Solaris threads, if a thread is to be created with a priority other than that of its parent's, it is created in SUSPEND mode. While suspended, the threads priority is modified using the thr_setprio(3THR) function call; then it is continued.

A higher priority thread will receive precedence by libthread over lower priority threads with respect to synchronization object contention.


thr_setprio(3THR) changes the priority of the thread, specified by tid, within the current process to the priority specified by newprio. (For POSIX threads, see pthread_setschedparam(3THR).)

#include <thread.h>

int thr_setprio(thread_t tid, int newprio)

By default, threads are scheduled based on fixed priorities that range from zero, the least significant, to 127 the most significant.

thread_t tid;
int ret;
int newprio = 20;

/* suspended thread creation */
ret = thr_create(NULL, NULL, func, arg, THR_SUSPENDED, &tid);

/* set the new priority of suspended child thread */
ret = thr_setprio(tid, newprio);

/* suspended child thread starts executing with new priority */
ret = thr_continue(tid);