POSIX线程

单线程

#include 
#include 
#include 
#include 
void* thr_fun(void* arg){
    char* no = (char*)arg;
    int i = 0;
    for(; i < 10; i++){
        printf("%s thread, i:%d\n",no,i);
        if(i==5){
            //线程退出（自杀）
            pthread_exit(2);
            //他杀pthread_cancel          
        }
    }   
    return 1;
}

void main(){
    printf("main thread\n");
    //线程id
    pthread_t tid;
    //线程的属性，NULL默认属性
    //thr_fun，线程创建之后执行的函数
    pthread_create(&tid,NULL,thr_fun,"1");
    void* rval;
    //等待tid线程结束
    //thr_fun与退出时传入的参数，都作为第二个参数的内容
    pthread_join(tid,&rval);
    printf("rval:%d\n",(int)rval);
}

线程安全

#include                                                          
#include 
#include 
#include 

int i = 0;
//互斥锁
pthread_mutex_t mutex;

void* thr_fun(void* arg){
    //加锁
    pthread_mutex_lock(&mutex);
    char* no = (char*)arg;
    for(;i < 5; i++){
        printf("%s thread, i:%d\n",no,i);
        sleep(1);
    }
    i=0;
    //解锁
    pthread_mutex_unlock(&mutex);
}

void main(){
    pthread_t tid1, tid2;
    //初始化互斥锁
    pthread_mutex_init(&mutex,NULL);

    pthread_create(&tid1,NULL,thr_fun,"No1");
    pthread_create(&tid2,NULL,thr_fun,"No2");

    pthread_join(tid1,NULL);
    pthread_join(tid2,NULL);

    //销毁互斥锁
    pthread_mutex_destroy(&mutex);
}

生产者消费者模式 条件变量

#include                                                       
#include 
#include 
#include 

//消费者数量
#define CONSUMER_NUM 2
//生产者数量
#define PRODUCER_NUM 1

pthread_t pids[CONSUMER_NUM+PRODUCER_NUM];

//产品队列
int ready = 0;

//互斥锁
pthread_mutex_t mutex;
//条件变量
pthread_cond_t has_product;

//生产
void* producer(void* arg){
    int no = (int)arg;
    //条件变量
    for(;;){
        pthread_mutex_lock(&mutex);
        //往队列中添加产品
        ready++;
        printf("producer %d, produce product\n",no);
        //fflush(NULL);
        //通知消费者，有新的产品可以消费了
        //会阻塞输出
        pthread_cond_signal(&has_product);
        printf("producer %d, singal\n",no);
        pthread_mutex_unlock(&mutex);
        sleep(1);
    }
}

//消费者
void* consumer(void* arg){
    int num = (int)arg;
    for(;;){
        pthread_mutex_lock(&mutex);
        //while?
        //superious wake ‘惊群效应’
        while(ready==0){
            //没有产品，继续等待
            //1.阻塞等待has_product被唤醒
            //2.释放互斥锁，pthread_mutex_unlock
            //3.被唤醒时，解除阻塞，重新申请获得互斥锁pthread_mutex_lock
            printf("%d consumer wait\n",num);
            pthread_cond_wait(&has_product,&mutex);
        }
        //有产品，消费产品
        ready--;
        printf("%d consume product\n",num);
        pthread_mutex_unlock(&mutex);
        sleep(1);
    }
}


void main(){
    //初始化互斥锁和条件变量                                                
    pthread_mutex_init(&mutex,NULL);
    pthread_cond_init(&has_product,NULL);
    printf("init\n");

    int i;
    for(i=0; i