Linux TCP 通信并发-编程知识

多进程

客户端

#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
int main() {//创建套接字int lfd = socket(AF_INET, SOCK_STREAM, 0);if(lfd == -1) {perror("socket");exit(-1);}//连接服务器struct sockaddr_in serveraddr;inet_pton(AF_INET, "192.168.245.129", &serveraddr.sin_addr.s_addr);serveraddr.sin_family = AF_INET;serveraddr.sin_port = htons(9999);int ret = connect(lfd, (struct sockaddr *) &serveraddr, sizeof(serveraddr));if(ret == -1) {perror("connect");_exit(-1);}//通信int i = 0;char receiveBuf[1024] = {0};while(1) {sprintf(receiveBuf, "data: %d\n", i++);write(lfd, receiveBuf, strlen(receiveBuf));sleep(1);int len = read(lfd, receiveBuf, sizeof(receiveBuf));if(len == -1) {perror("read");exit(0);} else if(len > 0) {printf("receive server data: %s\n", receiveBuf);} else if (len == 0) {printf("server closed...");}}close(lfd);
}

服务器端

#define _XOPEN_SOURCE
#include<stdio.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<string.h>
#include<stdlib.h>
#include<signal.h>
#include<wait.h>
#include<errno.h>void recyleChild(int arg) {while(1) {int ret = waitpid(-1, NULL, WNOHANG);if(ret == -1) {break;} else if (ret == 0) {break;} else if (ret > 0) {printf("pid %d is resaved\n", ret);}}
}int main() {//注册信号捕捉函数struct sigaction act;act.sa_flags = 0;sigemptyset(&act.sa_mask);act.sa_handler = recyleChild;sigaction(SIGCHLD, &act, NULL);//创建socketint lfd = socket(AF_INET, SOCK_STREAM, 0);if(lfd == -1) {perror("socket");exit(0);}struct sockaddr_in saddr;saddr.sin_family = AF_INET;saddr.sin_port = htons(9999);saddr.sin_addr.s_addr = INADDR_ANY;//绑定int ret = bind(lfd, (struct sockaddr*)&saddr, sizeof(saddr));if(ret == -1) { perror("bind");exit(0);}//监听ret = listen(lfd, 128);if(ret == -1) { perror("listen");exit(0);}//接受链接while(1) {struct sockaddr_in cliaddr;int len = sizeof(cliaddr);int cfd = accept(lfd, (struct sockaddr*)&cliaddr, &len);   if(cfd == -1) {if(errno == EINTR) {continue;}perror("accept");exit(-1);}//每连接一个，创建一个子进程pid_t pid = fork();if(pid == 0) {char clientIP[16];inet_ntop(AF_INET, &cliaddr.sin_addr.s_addr, clientIP, 16);unsigned short cliPort = ntohs(cliaddr.sin_port);printf("Client Port is %d, client addr is %s\n", cliPort, clientIP);char recvBuf[1024] = {0};while(1) {int len = read(cfd, &recvBuf, sizeof(recvBuf));if(len == -1) {perror("read");return 0;} else if(len > 0) {printf("recv client data : %s \n", recvBuf);} else {printf("closed.....");}write(cfd, &recvBuf, sizeof(recvBuf));}close(cfd);exit(0);}}close(lfd);return 0;
}

多线程

服务器

#define _XOPEN_SOURCE
#include<stdio.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<string.h>
#include<stdlib.h>
#include<errno.h>
#include<pthread.h>struct sockinfo {int fd;struct sockaddr_in saddr;pthread_t tid;
};struct sockinfo sockinfos[128];void* working(void* arg) {struct sockinfo* pinfo = (struct sockinfo*) arg;char clientIP[16];inet_ntop(AF_INET, &pinfo->saddr.sin_addr.s_addr, clientIP, 16);unsigned short cliPort = ntohs(pinfo->saddr.sin_port);printf("Client Port is %d, client addr is %s\n", cliPort, clientIP);char recvBuf[1024] = {0};while(1) {int len = read(pinfo->fd, &recvBuf, sizeof(recvBuf));if(len == -1) {perror("read");return 0;} else if(len > 0) {printf("recv client data : %s \n", recvBuf);} else {printf("closed.....");}write(pinfo->fd, &recvBuf, sizeof(recvBuf));}close(pinfo->fd);exit(0);return NULL;
}int main() {//创建socketint lfd = socket(AF_INET, SOCK_STREAM, 0);if(lfd == -1) {perror("socket");exit(0);}struct sockaddr_in saddr;saddr.sin_family = AF_INET;saddr.sin_port = htons(9999);saddr.sin_addr.s_addr = INADDR_ANY;//绑定int ret = bind(lfd, (struct sockaddr*)&saddr, sizeof(saddr));if(ret == -1) { perror("bind");exit(0);}//监听ret = listen(lfd, 128);if(ret == -1) { perror("listen");exit(0);}//初始化数据int max = sizeof(sockinfos) / sizeof(sockinfos[0]);for(int i = 0; i < max; i++) {memset(&sockinfos[i], 0, sizeof(sockinfos[i]));sockinfos[i].fd = -1;sockinfos[i].tid = -1;}//接受链接while(1) {struct sockaddr_in cliaddr;int len = sizeof(cliaddr);int cfd = accept(lfd, (struct sockaddr*)&cliaddr, &len);   if(cfd == -1) {perror("accept");exit(-1);}struct sockinfo * pinfo;for(int i = 0; i < max; i++) {if(sockinfos[i].fd == -1) {pinfo = &sockinfos[i];break;}if(i == max - 1) {sleep(1);i--;}}pinfo->fd = cfd;memcpy(&pinfo->saddr, &cliaddr, len);//每连接一个，创建一个子进程pthread_create(&pinfo->tid, NULL, working, pinfo);pthread_detach(pinfo->tid);}close(lfd);return 0;
}

客户端

#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
int main() {//创建套接字int lfd = socket(AF_INET, SOCK_STREAM, 0);if(lfd == -1) {perror("socket");exit(-1);}//连接服务器struct sockaddr_in serveraddr;inet_pton(AF_INET, "192.168.245.129", &serveraddr.sin_addr.s_addr);serveraddr.sin_family = AF_INET;serveraddr.sin_port = htons(9999);int ret = connect(lfd, (struct sockaddr *) &serveraddr, sizeof(serveraddr));if(ret == -1) {perror("connect");_exit(-1);}//通信int i = 0;char receiveBuf[1024] = {0};while(1) {sprintf(receiveBuf, "data: %d\n", i++);write(lfd, receiveBuf, strlen(receiveBuf));sleep(1);int len = read(lfd, receiveBuf, sizeof(receiveBuf));if(len == -1) {perror("read");exit(0);} else if(len > 0) {printf("receive server data: %s\n", receiveBuf);} else if (len == 0) {printf("server closed...");}}close(lfd);
}