喜羊羊系列之【线程】互斥锁+信号量

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1. 编写一个基本的多线程程序（主线程里面创建一个子线程）

/*************************************************************************> File Name: 1_homework.c> Author: 梁惠涌> Addr: > Created Time: 2015年04月22日 星期三 15时22分34秒 ************************************************************************/#include<stdio.h>#include<stdlib.h>#include<string.h>#include<unistd.h>#include<pthread.h>    #include <semaphore.h> //sem_t 的声明void *fun1(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        *((int *)arg) += 2;        printf("fun1 the num is: %d \n",*((int*)arg));        sleep(1);    }        pthread_exit(0);      //主线程结束}int main(){    int num=3, ret1;    pthread_t thread1;    ret1 = pthread_create(&thread1, NULL, fun1, (void *)&num);    if(ret1 != 0){        perror("pthread_create1");        exit(0);    }    sleep(1);    printf("=================== main end ================\n");    pthread_exit(0);      //主线程结束}

2. 把上面的程序改为子线程给父线程传递返回值

/*************************************************************************> File Name: 2_homework.c> Author: 梁惠涌> Addr:> Created Time: 2015年04月22日 星期三 15时39分49秒 ************************************************************************/#include<stdio.h>#include<stdlib.h>#include<string.h>#include<unistd.h>#include<pthread.h>    void *fun1(void *arg){    int num=100;    printf("---------------pthread--------------\n");    printf("the num is: %d \n", num);    printf("---------------  end  --------------\n");    pthread_exit((void *)num);      //主线程结束}int main(){    int  ret1, num;    pthread_t thread1;    ret1 = pthread_create(&thread1, NULL, fun1, NULL);    if(ret1 != 0){        perror("pthread_create1");        exit(0);    }    pthread_join(thread1,(void *)&num);    printf("---------------  main  --------------\n");    printf("return the num is: %d \n", (int )num);    printf("---------------   end  --------------\n");        pthread_exit(0);      //主线程结束}

3. 用多线程写一个程序，实现对数据的读写（可以是一个全局变量或其他的数据）

/*************************************************************************> File Name: 3_homework.c> Author: 梁惠涌> Addr: > Created Time: 2015年04月22日 星期三 15时53分00秒 ************************************************************************/#include<stdio.h>#include<stdlib.h>#include<string.h>#include<unistd.h>#include<pthread.h>    #include <semaphore.h> //sem_t 的声明void *fun1(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        *((int *)arg) += 2;        printf("the num write: %d \n",*((int*)arg));        sleep(1);    }        pthread_exit(0);      //主线程结束}void *fun2(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        printf("the num read is: %d \n",*((int*)arg));        sleep(1);    }        pthread_exit(0);      //主线程结束}int main(){    int num=0, ret1;    pthread_t thread1, thread2;    ret1 = pthread_create(&thread1, NULL, fun1, (void *)&num);    if(ret1 != 0){        perror("pthread_create1");        exit(0);    }    ret1 = pthread_create(&thread2, NULL, fun2, (void *)&num);    if(ret1 != 0){        perror("pthread_create2");        exit(0);    }        sleep(1);    printf("=================== main end ================\n");    pthread_exit(0);      //主线程结束}

4. 分别用信号量和互斥锁实现第3个作业的读写互斥

/*************************************************************************> File Name: 4_homework.c> Author: 梁惠涌> Addr:> Created Time: 2015年04月22日 星期三 15时57分54秒 ************************************************************************/#include<stdio.h>#include<stdlib.h>#include<string.h>#include<unistd.h>#include<pthread.h>    #include <semaphore.h> //sem_t 的声明sem_t sem;     //信号量声明pthread_mutex_t mutex;  //互斥锁声明void *fun1(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        sem_wait(&sem);        *((int *)arg) += 2;        printf("==信号量== num write: %d \n",*((int*)arg));        sleep(1);        sem_post(&sem);    }        pthread_exit(0);      //主线程结束}void *fun2(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        sem_wait(&sem);        printf("==信号量== num read is: %d \n",*((int*)arg));        sleep(1);        sem_post(&sem);    }        pthread_exit(0);      //主线程结束}void *fun3(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        pthread_mutex_lock(&mutex);        *((int *)arg) += 2;        printf(">>互斥锁>> num write: %d \n",*((int*)arg));        sleep(1);        pthread_mutex_unlock(&mutex);    }        pthread_exit(0);      //主线程结束}void *fun4(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        pthread_mutex_lock(&mutex);        printf(">>互斥锁>> num read is: %d \n",*((int*)arg));        sleep(1);        pthread_mutex_unlock(&mutex);    }        pthread_exit(0);      //主线程结束}int main(){    //------------------------信号量互斥--------------------    int num1=0, ret1;    pthread_t thread1, thread2;    sem_init(&sem, 0, 1);    ret1 = pthread_create(&thread1, NULL, fun1, (void *)&num1);    if(ret1 != 0){        perror("pthread_create1");        exit(0);    }    ret1 = pthread_create(&thread2, NULL, fun2, (void *)&num1);    if(ret1 != 0){        perror("pthread_create2");        exit(0);    }        //------------------------互斥锁互斥--------------------    int num2=1000, ret2;    pthread_t thread_1, thread_2;    pthread_mutex_init(&mutex, NULL);    ret2 = pthread_create(&thread_1, NULL, fun3, (void *)&num2);    if(ret2!= 0){        perror("pthread_create1");        exit(0);    }    ret1 = pthread_create(&thread_2, NULL, fun4, (void *)&num2);    if(ret2 != 0){        perror("pthread_create2");        exit(0);    }       printf("=================== main end ================\n");    pthread_exit(0);      //主线程结束}

5. 用信号量实现第3个作业的读写同步

/*************************************************************************> File Name: 5_homework.c> Author: 梁惠涌> Addr: > Created Time: 2015年04月22日 星期三 16时36分01秒 ************************************************************************/#include<stdio.h>#include<stdlib.h>#include<string.h>#include<unistd.h>#include<pthread.h>    #include <semaphore.h> //sem_t 的声明sem_t w_sem, r_sem;     //信号量声明void *fun1(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        sem_wait(&w_sem);        *((int *)arg) += 2;        printf(">>>> num write: %d \n",*((int*)arg));        sleep(1);        sem_post(&r_sem);    }        pthread_exit(0);      //主线程结束}void *fun2(void *arg){    pthread_detach( pthread_self() );           //与主线程分离    while(1){        sem_wait(&r_sem);        printf(">>>> num read is: %d \n",*((int*)arg));        sleep(1);        sem_post(&w_sem);    }        pthread_exit(0);      //主线程结束}int main(){    //------------------------信号量互斥--------------------    int num1=0, ret1;    pthread_t thread1, thread2;    sem_init(&w_sem, 0, 1);    sem_init(&r_sem, 0, 0);    ret1 = pthread_create(&thread1, NULL, fun1, (void *)&num1);    if(ret1 != 0){        perror("pthread_create1");        exit(0);    }    ret1 = pthread_create(&thread2, NULL, fun2, (void *)&num1);    if(ret1 != 0){        perror("pthread_create2");        exit(0);    }    printf("=================== main end ================\n");    pthread_exit(0);      //主线程结束}

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喜羊羊系列之【 线程 】互斥锁+信号量

喜羊羊系列之【线程】互斥锁+信号量