#include <stdlib.h>#include <pthread.h>#include <stdio.h>#include <sched.h>pthread_cond_t  cond;pthread_mutex_t mp; void *consumer1(void *p) {         pthread_mutex_lock(&mp);                printf("wait>>>(1)\n");                 pthread_cond_wait(&cond, &mp);          pthread_mutex_unlock(&mp);         printf("wake <<<(1)\n");                return NULL; } void *consumer2(void *p) {        pthread_mutex_lock(&mp);                printf("wait>>>(2)\n");                pthread_cond_wait(&cond, &mp);        pthread_mutex_unlock(&mp);        printf("wake <<<(2)\n");                return NULL;}void *consumer3(void *p) {                pthread_mutex_lock(&mp);                 printf("wait>>>(3)\n");                 pthread_cond_wait(&cond, &mp);        pthread_mutex_unlock(&mp);         printf("wake <<<(3)\n");                 return NULL; } int main(int argc, char *argv[]) {               pthread_t  t1, t2, t3;         int ret;        struct sched_param sched;         sched.__sched_priority = 10;                   pthread_cond_init(&cond, NULL);         pthread_mutex_init(&mp, NULL);                 ret = pthread_create(&t1, NULL, consumer1, NULL);        ret = pthread_create(&t2, NULL, consumer2, NULL);        ret = pthread_create(&t3, NULL, consumer3, NULL);         sleep(1);         pthread_setschedparam(t2, SCHED_FIFO, &sched);         sleep(1);         pthread_cond_broadcast(&cond);         sleep(6);         printf("main returned\n");      return 0;}