Linux C 线程的互斥锁和条件变量

这里简单的做了一个生产消费的案例，方便记忆

#include<stdio.h>
#include<stdlib.h>
#include<pthread.h>

#define NUM 10

static int s = 0;
static pthread_cond_t cond_add,cond_sub;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void* add(void* params){
        int i = 0;
        for(i = 0 ; i < NUM ; i++){
                pthread_mutex_lock(&mutex);
                while(s > 0){
                        pthread_cond_wait(&cond_add, &mutex);
                }
                s++;
                printf("生产一个\n");
                pthread_cond_signal(&cond_sub);
                pthread_mutex_unlock(&mutex);
        }
        pthread_mutex_lock(&mutex);
        while(s > 0){
                pthread_cond_wait(&cond_add, &mutex);
        }
        s = -1;
        pthread_cond_signal(&cond_sub);
        pthread_mutex_unlock(&mutex);
        printf("生产线程结束\n");
        pthread_exit(0);
}
void* sub(void* params){
        while(s >= 0){
                pthread_mutex_lock(&mutex);
                while(s == 0){
                        pthread_cond_wait(&cond_sub, &mutex);
                }
                if(s < 0){
                        pthread_mutex_unlock(&mutex);
                        break;
                }
                s--;
                printf("消费一个\n");
                pthread_cond_signal(&cond_add);
                pthread_mutex_unlock(&mutex);
        }
        printf("消费线程结束\n");
        pthread_exit(0);
}

int main(){
        pthread_t p1,p2;
        void * res;

        //初始化条件变量
        pthread_cond_init(&cond_add, NULL);
        pthread_cond_init(&cond_sub, NULL);

        //创建线程
        pthread_create(&p1,NULL,add,NULL);
        pthread_create(&p2,NULL,sub,NULL);

        //等待线程结束
        pthread_join(p1, &res);
        pthread_join(p2, &res);

        //释放资源
        pthread_cond_destroy(&cond_add);
        pthread_cond_destroy(&cond_sub);
        pthread_mutex_destroy(&mutex);

        exit(0);
}