linux条件变量例程

#include
#include
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
void *thread1(void *);
void *thread2(void *);
int i=1;
main(void)
{
pthread_t t_a;
pthread_t t_b;
pthread_create(&t_a,NULL,thread1,(void *)NULL);
pthread_create(&t_b,NULL,thread2),(void *)NULL);
pthread_join(t_b, NULL);
pthread_mutex_destroy(&mutex);
pthread_cond_destroy(&cond);
exit(0);
}
void *thread1(void *junk)
{
for(i=1;i<=9;i++)
{
pthread_mutex_lock(&mutex);
if(i%3==0)
pthread_cond_signal(&cond);
else
printf("thead1:%d\n",i);
pthread_mutex_unlock(&mutex);
printf("Up Unlock Mutex\n");
usleep(50);
}
}
void *thread2(void *junk)
{
while(i<9)
{
pthread_mutex_lock(&mutex);
if(i%3!=0)
pthread_cond_wait(&cond,&mutex);
printf("thread2:%d\n",i);
pthread_mutex_unlock(&mutex);
printf("Down Ulock Mutex\n");
usleep(50);
}