思维导图

作业

使用无名信号量实现输出春夏秋冬

#include <myhead.h>
sem_t sem1,sem2,sem3,sem4;
void *fun1()
{
	while(1)
	{
		sem_wait(&sem1);
		sleep(1);
		printf("春\n");
		sem_post(&sem2);
	}
}

void *fun2()
{
	while(1)
	{
		sem_wait(&sem2);
		sleep(1);
		printf("夏\n");
		sem_post(&sem3);
	}
}

void *fun3()
{
	while(1)
	{
		sem_wait(&sem3);
		sleep(1);
		printf("秋\n");
		sem_post(&sem4);
	}
}

void *fun4()
{
	while(1)
	{
		sem_wait(&sem4);
		sleep(1);
		printf("冬\n");
		sem_post(&sem1);
	}
}

int main(int argc, const char *argv[])
{
	//初始化无名信号量
	sem_init(&sem1,0,1);
	sem_init(&sem2,0,0);
	sem_init(&sem3,0,0);
	sem_init(&sem4,0,0);

	//创建4个子线程
	pthread_t tid1,tid2,tid3,tid4;
	if(pthread_create(&tid1,NULL,fun1,NULL)==-1)
	{
		perror("pthread_create");
		return -1;
	}
	if(pthread_create(&tid2,NULL,fun2,NULL)==-1)
	{
		perror("pthread_create");
		return -1;
	}
	if(pthread_create(&tid3,NULL,fun3,NULL)==-1)
	{
		perror("pthread_create");
		return -1;
	}
	if(pthread_create(&tid4,NULL,fun4,NULL)==-1)
	{
		perror("pthread_create");
		return -1;
	}

	//等待子线程运行完成
	pthread_join(tid1,NULL);
	pthread_join(tid2,NULL);
	pthread_join(tid3,NULL);
	pthread_join(tid4,NULL);

	//无名信号量的销毁
	sem_destroy(&sem1);
	sem_destroy(&sem2);
	sem_destroy(&sem3);
	sem_destroy(&sem4);
	return 0;
}

生产者消费者模型使用条件变量实现一遍。

#include <myhead.h>
#define MAX 10
pthread_cond_t cond;
pthread_mutex_t fastmutex;
int k=0;
void *fun1()
{
	for(int i=0;i<MAX;i++)
	{
		sleep(1);
		printf("生产者%ld生产了第%d辆车\n",pthread_self(),++k);
		pthread_cond_signal(&cond);
	}
	pthread_exit(NULL);
}

void *fun2()
{
	pthread_mutex_lock(&fastmutex);
	pthread_cond_wait(&cond,&fastmutex);
	//sleep(1);
	printf("消费者%ld消费了一辆车\n",pthread_self());
	pthread_mutex_unlock(&fastmutex);
	pthread_exit(NULL);
}


int main(int argc, const char *argv[])
{
	//初始化条件变量
	pthread_cond_init(&cond,NULL);
	//初始化互斥锁
	pthread_mutex_init(&fastmutex,NULL);

	//生产者一个，消费者10个
	pthread_t tid1,tid2[MAX];
	if(pthread_create(&tid1,NULL,fun1,NULL)==-1)
	{
		perror("pthread_create");
		return -1;
	}

	for(int i=0;i<MAX;i++)
	{
		if(pthread_create(&tid2[i],NULL,fun2,NULL)==-1)
		{
			perror("pthread_create");
			return -1;
		}
	}

	//等待子线程完成
	pthread_join(tid1,NULL);
	for(int i=0;i<MAX;i++)
	{
		pthread_join(tid2[i],NULL);
	}

	//销毁互斥锁和条件变量
	pthread_mutex_destroy(&fastmutex);
	pthread_cond_destroy(&cond);
	return 0;
}