线程与信号，线程与锁

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

pthread_mutex_t number_mutex  = PTHREAD_MUTEX_INITIALIZER;
int             globvar  = 0 ;

void *write_p(void *arg){
    while(1){
        pthread_mutex_lock(&number_mutex);
        globvar++;
        printf("the write is %ld\n",globvar);
        pthread_mutex_unlock(&number_mutex);
        sleep(2);
        
    }
}

void *read_p(void *arg){
    int temp;
    while(1){
        printf("the read is %ld\n",pthread_self());
        pthread_mutex_lock(&number_mutex);
        printf("read = %d\n",globvar);
        sleep(10);
        pthread_mutex_unlock(&number_mutex);
          
    }
}

int main(){
    pthread_t thid1,thid2;
    int err;
    err = pthread_create(&thid1,NULL,read_p,NULL);
    if(err != 0){
        printf("the pthread is error\n");
    }
    sleep(1);
    printf("the mid \n");
    err = pthread_create(&thid2,NULL,write_p,NULL);
    printf("err is %d\n",err);
    if(err != 0){
        printf("the pthread is error\n");
    }
    while(1){
        sleep(1);
    }
   

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

pthread_mutex_t mutex;
pthread_cond_t    cond ;

void *thread1(void *arg){
    pthread_cleanup_push(pthread_mutex_unlock,&mutex);
    while(1){
        printf("thread1 is runing\n");
        pthread_mutex_lock(&mutex);
        pthread_cond_wait(&cond,&mutex);
        printf("thread applied the condiation\n");
        pthread_mutex_unlock(&mutex);
        sleep(4);
    }
    pthread_cleanup_pop(0);
}



void *thread2(void *arg)
{
    while(1){
        printf("thread2 is runing\n");
        pthread_mutex_lock(&mutex);
        pthread_cond_wait(&cond,&mutex);
        printf("thread2 application is condiation\n");
        pthread_mutex_unlock(&mutex);
        sleep(1);
    }
}


int main(void){
    
    pthread_t tid1,tid2;
    printf("condiation variable!\n");
    pthread_mutex_init(&mutex,NULL);
    pthread_cond_init(&cond,NULL);
    pthread_create(&tid1,NULL,thread1,NULL);
    pthread_create(&tid2,NULL,thread2,NULL);
    do{
        pthread_cond_signal(&cond);
        
    }while(1);

    sleep(50);
    pthread_exit(0);
    
}

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

int quitflag ;             //退出标志
sigset_t mask;             //声明一个信号集

pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;            //初始化一个相互排斥锁
pthread_cond_t waitloc = PTHREAD_COND_INITIALIZER;           //初始化一个条件变量

void * thr_fn(void *arg)                                     //处理信号的线程
{
    int err;
    int signo;
    while(1){
        err = sigwait(&mask,&signo);                         //解除信号屏蔽字
        if(err != 0){
            printf("errpr\n");
        }
        switch(signo){                                      //处理不同的信号
            case SIGINT:                                      //处理SIGINT 信号
                printf("interrupt\n");
                break ;
            case SIGQUIT:                                   //处理SIGQUIT 信号
                pthread_mutex_lock(&lock);                  //上锁
                quitflag = 1;                               //假设不改变这个标志值。不会调出循环
                pthread_mutex_unlock(&lock);                //解锁
                pthread_cond_signal(&waitloc);              //等待条件变量引起唤醒此时堵塞

                printf("case \n");
                return 0;
            default :
                printf("unexpected signal %d\n",signo);
                exit(0);
        }
    }
}

int main()
{
    int err;                                                        //标准错误码
    sigset_t oldmask;                                       //声明原先信号集
    pthread_t tid   ;                                       //声明一个线程号

    sigemptyset(&mask);                                   //清空信号集
    sigaddset(&mask,SIGINT);                                //加入SIGINT 进信号集
    sigaddset(&mask,SIGQUIT);                               //加入SIGQUIT 进信号集

    if((err = pthread_sigmask(SIG_BLOCK,&mask,&oldmask)) != 0) //加入线程信号集主线程開始堵塞这两个信号
        printf("printf SIG_BLOCK is error\n");
    
    err = pthread_create(&tid,NULL,thr_fn,0);               //创建信号处理线程，新的线程继承了原来的信号屏蔽字
    if(err != 0){
        printf("create is error\n");
    }

    pthread_mutex_lock(&lock);                                   //加锁
    while(quitflag == 0){                 
        printf("ust \n");
        pthread_cond_wait(&waitloc,&lock);
    }
    pthread_mutex_unlock(&lock);
    printf("like may be\n");
    quitflag = 0;
    printf("change the quitflag\n");
    if(sigprocmask(SIG_SETMASK,&oldmask,NULL) < 0)    //建议完毕工作后将线程屏蔽字还原
        printf("SIG_MASK error");
    exit(0);
}