C++多进程利用管道进行实时通信

超、凢脫俗 2022-07-14 07:54 137阅读 0赞

声明：本博文用于学习总结及工作心

比较简单，这里就直接贴代码了，代码中有注释：

进程1
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <pthread.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    #include <errno.h>
    #include <unistd.h>
    //创建2个线程分别进行读写
    
    void mkfifo1()
    {
        mkfifo("fifo1", 0666);//创建有名管道 管道名称 八进制权限
        sleep(1);
        return;
    
    }
    //读fifo2
    void *myread(void *arg)
    {
    	printf("thread begin\n");
    	int *rec = (int *)malloc(sizeof(int));
    		char buf[1024];
    		memset(buf, 0, sizeof(buf));
    		int fd = open("./fifo2", O_RDONLY);
    		if(fd < 0)
    		{
    			printf("open fifo error is %s\n", strerror(errno));
    			*rec = -1;
    			pthread_exit((void *)rec);
    			return NULL;
    		}
    		while(1)
    		{
    			if(read(fd, buf, sizeof(buf)) > 0)
    			{
    				if(strncmp(buf, "end", 3) == 0)
    				{
    					pthread_t thr = *((pthread_t *)arg);
    					pthread_cancel(thr);//关闭写线程
    					break;
    				}
    				printf("%s", buf);
    				memset(buf, 0, sizeof(buf));
    			}
    			usleep(1000);
    		}
    		close(fd);
    		*rec = 0;
    		printf("thread end\n");
    		pthread_exit((void *)rec);
    		return NULL;
    }
    //写fifo1
    void *mywrite(void *arg)
    {
    
    	int *rec = (int *)malloc(sizeof(int));
    	char buf[1024];
    	memset(buf, 0, sizeof(buf));
    	int fd = open("./fifo1", O_WRONLY);
    	if(fd < 0)
    	{
    		printf("open fifo error is %s\n", strerror(errno));
    		*rec = -1;
    		pthread_exit((void *)rec);
    		return NULL;
    	}
    	while(1)
    	{
    		read(STDIN_FILENO, buf, sizeof(buf)-1);
    		write(fd, buf, sizeof(buf));
    		if(strncmp(buf, "end", 3) == 0)//输入end结束
    		{
    			pthread_t thr = *((pthread_t *)arg);
    			int n =pthread_cancel(thr);//关闭读线程
    			printf("cancel :%d\n", n);//返回0 取消线程成功
    			break;
    		}
    		memset(buf, 0, sizeof(buf));
    	}
    	printf("write end\n");
    	close(fd);
    	*rec = 0;
    //	pthread_exit((void *)rec);
    	return NULL;
    }
    int main(int arg, char*args[])
    {
    	printf("%s start\n", args[0]);
    	//创建fifo
    	mkfifo1();
    
    	pthread_t thrd1, thrd2;
    	pthread_create(&thrd1, NULL, myread, &thrd2);
    	pthread_create(&thrd2, NULL, mywrite, &thrd1);
    	int *p1 = NULL;
    	int *p2 = NULL;
    	pthread_join(thrd1, (void **)&p1);//等待thrd1结束
    	pthread_join(thrd2, (void **)&p2);//等待thrd2结束
    
    	printf("%s end\n", args[0]);
    	return EXIT_SUCCESS;
    }

进程2
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <pthread.h>
    #include <fcntl.h>
    #include <errno.h>
    #include <unistd.h>
    //创建2个线程分别进行读写
    
    void createfifo2()
    {
    	mkfifo("fifo2", 0666);
    	sleep(1);
    	return;
    }
    
    //读fifo1
    void *myread(void *arg)
    {
    	printf("thread begin\n");
    	int *rec = (int *)malloc(sizeof(int));
    	char buf[1024];
    	memset(buf, 0, sizeof(buf));
    	int fd = open("./fifo1", O_RDONLY);
    	if(fd < 0)
    	{
    		printf("open fifo error is %s\n", strerror(errno));
    		*rec = -1;
    		pthread_exit((void *)rec);
    		return NULL;
    	}
    		while(1)
    		{
    			int len = read(fd, buf, sizeof(buf));
    			if( len> 0)
    			{
    				if(strncmp(buf, "end", 3) == 0)
    				{
    					pthread_t thr = *((pthread_t *)arg);
    					pthread_cancel(thr);
    					break;
    				}
    				printf("%s", buf);
    				memset(buf, 0, sizeof(buf));
    			}
    			usleep(1000);
    		}
    		close(fd);
    		*rec = 0;
    		printf("thread end\n");
    		pthread_exit((void *)rec);
    		return NULL;
    }
    //写fifo2
    void *mywrite(void *arg)
    {
    
    	int *rec = (int *)malloc(sizeof(int));
    	char buf[1024];
    	memset(buf, 0, sizeof(buf));
    	int fd = open("./fifo2", O_WRONLY);
    	if(fd < 0)
    	{
    		printf("open fifo error is %s\n", strerror(errno));
    		*rec = -1;
    		pthread_exit((void *)rec);
    		return NULL;
    	}
    	while(1)
    	{
    		read(STDIN_FILENO, buf, sizeof(buf)-1);
    		write(fd, buf, sizeof(buf));
    		if(strncmp(buf, "end", 3) == 0)//输入end结束
    		{
    			pthread_t thr = *((pthread_t *)arg);
    			pthread_cancel(thr);
    			break;
    		}
    		memset(buf, 0, sizeof(buf));
    	}
    	close(fd);
    	*rec = 0;
    //	pthread_exit((void *)rec);
    	return NULL;
    }
    int main(int arg, char*args[])
    {
    	printf("%s start\n", args[0]);
    	createfifo2();
    	pthread_t thrd1, thrd2;
    	pthread_create(&thrd1, NULL, myread, &thrd2);
    	pthread_create(&thrd2, NULL, mywrite, &thrd1);
    	int *p1 = NULL;
    	int *p2 = NULL;
    	pthread_join(thrd1, (void **)&p1);//等待thrd1结束
    	pthread_join(thrd2, (void **)&p2);//等待thrd2结束
    	printf("%s end\n", args[0]);
    	return EXIT_SUCCESS;
    }

makefile文件
    .SUFFIXES:.c .o
    
    CC=gcc
    SRCS1=thrfifo1.c
    SRCS2=thrfifo2.c
    OBJS1=$(SRCS1:.c=.o)
    OBJS2=$(SRCS2:.c=.o)
    EXEC1=thrfifo1
    EXEC2=thrfifo2
    start: $(OBJS1) $(OBJS2)
    	$(CC) -o $(EXEC1) $(OBJS1) -lpthread
    	$(CC) -o $(EXEC2) $(OBJS2) -lpthread
    	@echo '-----------OK-----------'
    .c.o:
    	$(CC) -Wall -g -o $@ -c $<
    clean:
    	rm -rf $(OBJS1)
    	rm -rf $(OBJS2)