1.31 实现五个线程的同步

1.使用互斥锁实现

1>程序代码

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <wait.h>
#include <signal.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <semaphore.h>
#include <sys/msg.h>
#include <sys/shm.h>
#include <sys/un.h>typedef struct sockaddr_in addr_in_t;
typedef struct sockaddr addr_t;
typedef struct sockaddr_un addr_un_t;//创建互斥锁
pthread_mutex_t m;
pthread_mutex_t m1;
pthread_mutex_t m2;
pthread_mutex_t m3;
pthread_mutex_t m4;void* thread_main1(void* arg)
{while(1){pthread_mutex_lock(&m1);printf("1#线程\n");sleep(1);pthread_mutex_unlock(&m2);}
}void* thread_main2(void* arg)
{while(1){pthread_mutex_lock(&m2);printf("2#线程\n");sleep(1);pthread_mutex_unlock(&m3);}
}void* thread_main3(void* arg)
{while(1){pthread_mutex_lock(&m3);printf("3#线程\n");sleep(1);pthread_mutex_unlock(&m4);}
}void* thread_main4(void* arg)
{while(1){pthread_mutex_lock(&m4);printf("4#线程\n");printf("-------------\n");sleep(1);pthread_mutex_unlock(&m);}
}int main(int argc, const char *argv[])
{//初始化互斥锁pthread_mutex_init(&m,NULL);pthread_mutex_init(&m1,NULL);pthread_mutex_init(&m2,NULL);pthread_mutex_init(&m3,NULL);pthread_mutex_init(&m4,NULL);pthread_mutex_lock(&m1);pthread_mutex_lock(&m2);pthread_mutex_lock(&m3);pthread_mutex_lock(&m4);//创建4个分支线程pthread_t id1;pthread_create(&id1,0,thread_main1,0);pthread_detach(id1);pthread_t id2;pthread_create(&id2,0,thread_main2,0);pthread_detach(id2);pthread_t id3;pthread_create(&id3,0,thread_main3,0);pthread_detach(id3);pthread_t id4;pthread_create(&id4,0,thread_main4,0);pthread_detach(id4);//主线程while(1){pthread_mutex_lock(&m);printf("主线程\n");sleep(1);pthread_mutex_unlock(&m1);}//销毁互斥锁pthread_mutex_destroy(&m);pthread_mutex_destroy(&m1);pthread_mutex_destroy(&m2);pthread_mutex_destroy(&m3);pthread_mutex_destroy(&m4);return 0;
}

2>运行效果

2.使用信号量实现

1>程序代码

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <wait.h>
#include <signal.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <semaphore.h>
#include <sys/msg.h>
#include <sys/shm.h>
#include <sys/un.h>typedef struct sockaddr_in addr_in_t;
typedef struct sockaddr addr_t;
typedef struct sockaddr_un addr_un_t;//创建信号量
sem_t s;
sem_t s1;
sem_t s2;
sem_t s3;
sem_t s4;void* thread_main1(void* arg)
{while(1){sem_wait(&s1);printf("1#线程\n");sleep(1);sem_post(&s2);}
}void* thread_main2(void* arg)
{while(1){sem_wait(&s2);printf("2#线程\n");sleep(1);sem_post(&s3);}
}void* thread_main3(void* arg)
{while(1){sem_wait(&s3);printf("3#线程\n");sleep(1);sem_post(&s4);}
}void* thread_main4(void* arg)
{while(1){sem_wait(&s4);printf("4#线程\n");printf("----------------\n");sleep(1);sem_post(&s);}
}int main(int argc, const char *argv[])
{//初始化信号量sem_init(&s,0,1);sem_init(&s1,0,1);sem_init(&s2,0,1);sem_init(&s3,0,1);sem_init(&s4,0,1);sem_wait(&s1);sem_wait(&s2);sem_wait(&s3);sem_wait(&s4);//创建4个分支线程pthread_t id1;pthread_create(&id1,0,thread_main1,0);pthread_detach(id1);pthread_t id2;pthread_create(&id2,0,thread_main2,0);pthread_detach(id2);pthread_t id3;pthread_create(&id3,0,thread_main3,0);pthread_detach(id3);pthread_t id4;pthread_create(&id4,0,thread_main4,0);pthread_detach(id4);//销毁信号量sem_destroy(&s);sem_destroy(&s1);sem_destroy(&s2);sem_destroy(&s3);sem_destroy(&s4);//主线程while(1){sem_wait(&s);printf("主线程\n");sleep(1);sem_post(&s1);}return 0;
}

2>运行效果