TCP并发服务器构建
TCP并发服务器构建:
单循环服务器:服务端同一时刻只能处理单个客户端的任务
并发服务器:服务端同一时刻能够处理多个客户端的任务
产生多个套接字可建立多个连接:
TCP服务端并发模型:
1:使用多进程
头文件:
#ifndef __HEAD_H__
#define __HEAD_H__#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h> /* superset of previous */
#include <arpa/inet.h>
#include <pthread.h>#endif
代码
#include "head.h"#define SER_PORT 50000
#define SER_IP "192.168.0.179"int init_tcp_ser()
{int sockfd = socket(AF_INET, SOCK_STREAM, 0);if (sockfd < 0){perror("socket error");return -1;}struct sockaddr_in seraddr;seraddr.sin_family = AF_INET;seraddr.sin_port = htons(SER_PORT);seraddr.sin_addr.s_addr = inet_addr(SER_IP);int ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (ret < 0){perror("bind error");return -1;}ret = listen(sockfd, 100);if (ret < 0){perror("listen error");return -1;}return sockfd;
}void wait_handler(int signo)
{wait(NULL);
}int main(int argc, const char *argv[])
{signal(SIGCHLD, wait_handler);struct sockaddr_in cliaddr;socklen_t clilen = sizeof(cliaddr);int sockfd = init_tcp_ser();if (sockfd < 0){return -1;}while (1){int connfd = accept(sockfd, (struct sockaddr *)&cliaddr, &clilen);if (connfd < 0){perror("accept error");return -1;}pid_t pid = fork();if (pid > 0){}else if (0 == pid){char buff[1024] = {0};while (1){memset(buff, 0, sizeof(buff));size_t cnt = recv(connfd, buff, sizeof(buff), 0);if (cnt < 0){perror("recv error");break;}else if (0 == cnt){printf("[%s : %d] : offline\n", inet_ntoa(cliaddr.sin_addr), ntohs(cliaddr.sin_port));break;}printf("[%s : %d] : %s\n", inet_ntoa(cliaddr.sin_addr), ntohs(cliaddr.sin_port), buff);strcat(buff, "---->ok");cnt = send(connfd, buff, strlen(buff), 0);if (cnt < 0){perror("send error");break;}}close(connfd);}}close(sockfd);return 0;
}
2:使用多线程
#include "head.h"#define SER_PORT 50000
#define SER_IP "192.168.0.179"int init_tcp_ser()
{int sockfd = socket(AF_INET, SOCK_STREAM, 0);if (sockfd < 0){perror("socket error");return -1;}//允许绑定处于TIME_WAIT状态的地址,避免端口占用问题:int optval = 1;setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval));struct sockaddr_in seraddr;seraddr.sin_family = AF_INET;seraddr.sin_port = htons(SER_PORT);seraddr.sin_addr.s_addr = inet_addr(SER_IP);int ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (ret < 0){perror("bind error");return -1;}ret = listen(sockfd, 100);if (ret < 0){perror("listen error");return -1;}return sockfd;
}void *task(void *arg)
{char buff[1024] = {0};int connfd = *((int *)arg);while (1){memset(buff, 0, sizeof(buff));size_t cnt = recv(connfd, buff, sizeof(buff), 0);if (cnt < 0){perror("recv error");break;}else if (0 == cnt){printf("offline\n");break;}printf("%s\n", buff);strcat(buff, "---->ok");cnt = send(connfd, buff, strlen(buff), 0);if (cnt < 0){perror("send error");break;}}close(connfd);
}int main(int argc, const char *argv[])
{pthread_t tid;struct sockaddr_in cliaddr;socklen_t clilen = sizeof(cliaddr);int sockfd = init_tcp_ser();if (sockfd < 0){return -1;}while (1){int connfd = accept(sockfd, (struct sockaddr *)&cliaddr, &clilen);if (connfd < 0){perror("accept error");return -1;}pthread_create(&tid, NULL, task, &connfd);pthread_detach(tid);}close(sockfd);return 0;
}
线程池:
为了解决多线程或者多进程模型,在服务器运行过程,频繁创建和销毁线程(进程)带来的时间消耗问题,基于生产者和消费者编程模型,以及任务队列等,实现的一套多线程框架。
IO多路复用:
对多个文件描述符的读写操作可以复用一个进程。在不创建新的进程和线程的前提下,使用一个进程实现多个文件的读写的同时监测。三种方式:
linux内核监测事件:
1:select实现IO多路复用:
(1)创建文件描述符集合
(2)添加关注的文件描述符到集合
(3)使用select传递集合表给内核,内核检测事件
(4) 当内核监测到时间时,应用层select将解除阻塞,
(5)并将获得相关的事件结果做不同的任务处理

{mkfifo("./myfifo", 0664);int fd = open("./myfifo", O_WRONLY);if (fd < 0){perror("open fifo error");return -1;}while (1){write(fd, "hello world", 11);sleep(1);}close(fd);return 0;
}
#include "head.h"int main(int argc, const char *argv[])
{char buff[1024] = {0};mkfifo("./myfifo", 0664);int fifofd = open("./myfifo", O_RDONLY);if (fifofd < 0){perror("open fifo error");return -1;}//1 创建文件描述符集合表fd_set rdfds;fd_set rdfdstmp;//2. 清空文件描述符集合表FD_ZERO(&rdfds);//3. 添加关注的文件描述符到集合中FD_SET(0, &rdfds);int maxfd = 0;FD_SET(fifofd, &rdfds);maxfd = maxfd > fifofd ? maxfd : fifofd;while (1){rdfdstmp = rdfds;//4. 传递集合表给内核并等待返回到达事件的结果int cnt = select(maxfd+1, &rdfdstmp, NULL, NULL, NULL);if (cnt < 0){perror("select error");return -1;}if (FD_ISSET(0, &rdfdstmp)){fgets(buff, sizeof(buff), stdin); //0printf("STDIN : %s\n", buff);}if (FD_ISSET(fifofd, &rdfdstmp)){memset(buff, 0, sizeof(buff));read(fifofd, buff, sizeof(buff));printf("FIFO : %s\n", buff);}}close(fifofd);return 0;
}
IO多路复用
#include "head.h"#define SER_PORT 50000
#define SER_IP "192.168.0.179"int init_tcp_ser()
{int sockfd = socket(AF_INET, SOCK_STREAM, 0);if (sockfd < 0){perror("socket error");return -1;}struct sockaddr_in seraddr;seraddr.sin_family = AF_INET;seraddr.sin_port = htons(SER_PORT);seraddr.sin_addr.s_addr = inet_addr(SER_IP);int ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (ret < 0){perror("bind error");return -1;}ret = listen(sockfd, 100);if (ret < 0){perror("listen error");return -1;}return sockfd;
}int main(int argc, const char *argv[])
{char buff[1024] = {0};struct sockaddr_in cliaddr;socklen_t clilen = sizeof(cliaddr);int sockfd = init_tcp_ser();if (sockfd < 0){return -1;}//1. 创建文件描述符集合fd_set rdfds;fd_set rdfdstmp;FD_ZERO(&rdfds);//2. 添加关注的文件描述符到集合FD_SET(sockfd, &rdfds);int maxfd = sockfd;while (1){rdfdstmp = rdfds;//3. 传递集合到内核,并等待返回监测结果int cnt = select(maxfd+1, &rdfdstmp, NULL, NULL, NULL);if (cnt < 0){perror("select error");return -1;}//4. 是否有监听套接字事件到达 ----》三次握手已完成,可以acceptif (FD_ISSET(sockfd, &rdfdstmp)){int connfd = accept(sockfd, (struct sockaddr *)&cliaddr, &clilen);if (connfd < 0){perror("accept error");return -1;}FD_SET(connfd, &rdfds);maxfd = maxfd > connfd ? maxfd : connfd;}//5. 是否有通讯套接字事件到达for (int i = sockfd+1; i <= maxfd; i++){if (FD_ISSET(i, &rdfdstmp)){memset(buff, 0, sizeof(buff));ssize_t cnt = recv(i, buff, sizeof(buff), 0);if (cnt < 0){perror("recv error");FD_CLR(i, &rdfds);close(i);continue;}else if (0 == cnt){FD_CLR(i, &rdfds);close(i);continue;}printf("%s\n", buff);strcat(buff, "--->ok");cnt = send(i, buff, strlen(buff), 0);if (cnt < 0){perror("send error");FD_CLR(i, &rdfds);close(i);continue;}}}}close(sockfd);return 0;
}