NEU操作系统实验课4——线程同步

实验要求：

创建两个线程按数字顺序打印10以下自然数，其中一个线程打印1-3及8-10；另一个线程打印4-6。要求使用线程同步机制实现上述打印顺序。

看网上的资料学习了两种写法

C++11的，使用了std::thread

#include <unistd.h>
#include <thread>
#include <iostream>
#include <mutex>
#include<bits/stdc++.h>
void Fun_1();
void Fun_2();
unsigned int counter=0;
std::mutex mtx;

int main()
{
    std::thread thrd_1(Fun_1);
    std::thread thrd_2(Fun_2);
    thrd_1.join();
    thrd_2.join();
    //system("pause");
    return 0;
}

void Fun_1()
{
    while(counter<10){
        if(counter<3||counter>5)continue;
        std::lock_guard<std::mutex> mtx_locker(mtx);
        ++counter;
        std::cout << "Function 1 counting " << counter << "...
";
        usleep(1);
    }
}

void Fun_2()
{
    while(counter<10){
        if(counter>2&&counter<6)continue;
        std::lock_guard<std::mutex> mtx_locker(mtx); 
        ++counter;
        std::cout << "Function 2 counting " << counter << "...
";
        usleep(1);
    }
}

C语言的，使用pthread

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

pthread_mutex_t mutex;
pthread_cond_t cond1;
pthread_cond_t cond2;
int cnt=0;


void hander(void *arg)
{ 
    free(arg);
    (void)pthread_mutex_unlock(&mutex);
}

void *thread1(void *arg)
{
    pthread_cleanup_push(hander,&mutex);
    printf("thread1
1
2
3
");
    pthread_mutex_lock(&mutex);
    pthread_cond_wait(&cond1,&mutex);
    pthread_mutex_unlock(&mutex);
    printf("thread1
7
8
9
10
");
    pthread_cleanup_pop(0);
}

void *thread2(void *arg)
{
    pthread_mutex_lock(&mutex);
    pthread_cond_wait(&cond2,&mutex);
    printf("thread2
4
5
6
");
    pthread_cond_signal(&cond1);
    pthread_mutex_unlock(&mutex);
}

int main()
{
    pthread_t tid1,tid2;
    pthread_mutex_init(&mutex,NULL);
    pthread_cond_init(&cond1,NULL);
    pthread_cond_init(&cond2,NULL);
    pthread_create(&tid1,NULL,thread1,NULL);
    pthread_create(&tid2,NULL,thread2,NULL);
    
    sleep(1);
    pthread_cond_signal(&cond2);
    //sleep(2);
    pthread_exit(0);
    return 0;
}