线程编程（3）

川长思鸟来 2022-07-14 07:58 190阅读 0赞

有四个线程1、2、3、4。线程1的功能就是输出1，线程2的功能就是输出2，以此类推.........现在有四个文件ABCD。初始都为空。现要让四个文件呈如下格式：

A：1 2 3 4 1 2....

B：2 3 4 1 2 3....

C：3 4 1 2 3 4....

D：4 1 2 3 4 1....

请设计程序。

#include <stdio.h>
    #include <stdlib.h>
    #include <pthread.h>
    #include <errno.h>
    
    FILE *f1;
    FILE *f2;
    FILE *f3;
    FILE *f4;
    
    pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
    pthread_cond_t condA_B = PTHREAD_COND_INITIALIZER;
    pthread_cond_t condB_C = PTHREAD_COND_INITIALIZER;
    pthread_cond_t condC_D = PTHREAD_COND_INITIALIZER;
    pthread_cond_t condD_A = PTHREAD_COND_INITIALIZER;
    
    int flaga,flagb,flagc,flagd;
    
    void *th_fun_a(void *arg)
    {
    	int i = 0;
    
    	while(i < 10)
    	{
    		pthread_mutex_lock(&mutex);
    		flaga = 1;
    		pthread_cond_wait(&condD_A,&mutex);
    		flaga = 0;
    
    		f1 = fopen("A.txt","a+");
    		//fseek(f1,0,SEEK_END);
    		fputc('1',f1);
    		fclose(f1);
    		
    		f2 = fopen("B.txt","a+");
    		//fseek(f2,0,SEEK_END);
    		fputc('2',f2);
    		fclose(f2);
    
    		f3 = fopen("C.txt","a+");
    		//fseek(f3,0,SEEK_END);
    		fputc('3',f3);
    		fclose(f3);
    
    		f4 = fopen("D.txt","a+");
    		//fseek(f4,0,SEEK_END);
    		fputc('4',f4);
    		fclose(f4);
    
    		while(!flagb)
    		{
    			pthread_mutex_unlock(&mutex);
    			usleep(50);
    			pthread_mutex_lock(&mutex);
    		}
    
    		pthread_cond_broadcast(&condA_B);
    		pthread_mutex_unlock(&mutex);
    		
    		i++;
    		usleep(50);
    
    	}
    	flaga = 1;
    }
    
    void *th_fun_b(void *arg)
    {
    	int i = 0;
    
    	while(i < 10)
    	{
    		pthread_mutex_lock(&mutex);
    		flagb = 1;
    		pthread_cond_wait(&condA_B,&mutex);
    		flagb = 0;
    
    		f1 = fopen("A.txt","a+");
    		//fseek(f1,0,SEEK_END);
    		fputc('2',f1);
    		fclose(f1);
    		
    		f2 = fopen("B.txt","a+");
    		//fseek(f2,0,SEEK_END);
    		fputc('3',f2);
    		fclose(f2);
    
    		f3 = fopen("C.txt","a+");
    		//fseek(f3,0,SEEK_END);
    		fputc('4',f3);
    		fclose(f3);
    
    		f4 = fopen("D.txt","a+");
    		//fseek(f4,0,SEEK_END);
    		fputc('1',f4);
    		fclose(f4);
    
    		while(!flagc)
    		{
    			pthread_mutex_unlock(&mutex);
    			usleep(50);
    			pthread_mutex_lock(&mutex);
    		}
    
    		pthread_cond_broadcast(&condB_C);
    		pthread_mutex_unlock(&mutex);
    		
    		i++;
    		usleep(50);
    
    	}
    }
    
    void *th_fun_c(void *arg)
    {
    	int i = 0;
    
    	while(i < 10)
    	{
    		pthread_mutex_lock(&mutex);
    		flagc = 1;
    		pthread_cond_wait(&condB_C,&mutex);
    		flagc = 0;
    
    		f1 = fopen("A.txt","a+");
    		//fseek(f1,0,SEEK_END);
    		fputc('3',f1);
    		fclose(f1);
    		
    		f2 = fopen("B.txt","a+");
    		//fseek(f2,0,SEEK_END);
    		fputc('4',f2);
    		fclose(f2);
    
    		f3 = fopen("C.txt","a+");
    		fseek(f3,0,SEEK_END);
    		fputc('1',f3);
    		fclose(f3);
    
    		f4 = fopen("D.txt","a+");
    		//fseek(f4,0,SEEK_END);
    		fputc('2',f4);
    		fclose(f4);
    
    		while(!flagd)
    		{
    			pthread_mutex_unlock(&mutex);
    			usleep(50);
    			pthread_mutex_lock(&mutex);
    		}
    
    		pthread_cond_broadcast(&condC_D);
    		pthread_mutex_unlock(&mutex);
    		
    		i++;
    		usleep(50);
    
    	}
    }
    
    void *th_fun_d(void *arg)
    {
    	int i = 0;
    
    	while(i < 10)
    	{
    		pthread_mutex_lock(&mutex);
    		flagd = 1;
    		pthread_cond_wait(&condC_D,&mutex);
    		flagd = 0;
    
    		f1 = fopen("A.txt","a+");
    		//fseek(f1,0,SEEK_END);
    		fputc('4',f1);
    		fclose(f1);
    		
    		f2 = fopen("B.txt","a+");
    		//fseek(f2,0,SEEK_END);
    		fputc('1',f2);
    		fclose(f2);
    
    		f3 = fopen("C.txt","a+");
    		//fseek(f3,0,SEEK_END);
    		fputc('2',f3);
    		fclose(f3);
    
    		f4 = fopen("D.txt","a+");
    		//fseek(f4,0,SEEK_END);
    		fputc('3',f4);
    		fclose(f4);
    
    		while(!flaga)
    		{
    			pthread_mutex_unlock(&mutex);
    			usleep(50);
    			pthread_mutex_lock(&mutex);
    		}
    
    		pthread_cond_broadcast(&condD_A);
    		pthread_mutex_unlock(&mutex);
    		
    		i++;
    		usleep(50);
    
    	}
    }
    
    int main()
    {
    	pthread_t th[4];
    
    	void *(*th_funs[])(void *) = 
    	{
    		th_fun_a,
    		th_fun_b,
    		th_fun_c,
    		th_fun_d,
    	};
    
    	int i;
    
    	for(i = 0; i < 4; i++)
    	{
    		if(pthread_create(th+i,NULL,th_funs[i],(void *)i) < 0)
    		{
    			fprintf(stderr,"creat:%s\n",strerror(errno));
    			exit(-1);
    		}
    	}
    
    	pthread_mutex_lock(&mutex);
    	while(!flagd)
    	{
    		pthread_mutex_unlock(&mutex);
    		usleep(50);
    		pthread_mutex_lock(&mutex);
    	}
    	printf("hi\n");
    	pthread_cond_broadcast(&condD_A);
    	pthread_mutex_unlock(&mutex);
    
    	for(i = 0; i < 4; i++)
    	{
    		pthread_join(th[i],NULL);
    		printf("process %d finished!\n",i);
    	}
    
        return 0;
    }