Linux-TCP并发模型相关函数接口-014

1【TCP】多线程模型

相关函数接口已在前面章节介绍，这里不再赘述

源码示例（1）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}void *HandleTcpClient(void *arg)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;int confd = arg;while (1){memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return NULL;}else if (0 == nsize){return NULL;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return NULL;}}return NULL;
}int main(void)
{int sockfd = 0;int confd = 0;pthread_t tid;pthread_attr_t attr;sockfd = CreateListenSocket("192.168.1.183", 50000);pthread_attr_init(&attr);pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);while (1){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");return -1;}pthread_create(&tid, &attr, HandleTcpClient, confd);}close(sockfd);return 0;
}

2【IO】模型

2.1阻塞IO

相关函数接口已在前面章节介绍，这里不再赘述

2.2非阻塞IO

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}flags = fcntl(fd, F_GETFL);flags |= O_NONBLOCK;fcntl(fd, F_SETFL, flags);flags = fcntl(0, F_GETFL);flags |= O_NONBLOCK;fcntl(0, F_SETFL, flags);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));pret = gets(tmpbuff);if (pret != NULL){printf("STDIN:%s\n", tmpbuff);}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = read(fd, tmpbuff, sizeof(tmpbuff));if (nsize > 0){printf("FIFO:%s\n", tmpbuff);}}close(fd);return 0;
}

2.3异步IO

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int fd = 0;void handler(int signo)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = read(fd, tmpbuff, sizeof(tmpbuff));if (nsize > 0){printf("FIFO:%s\n", tmpbuff);}return;
}int main(void)
{int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};signal(SIGIO, handler);mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}flags = fcntl(fd, F_GETFL);flags |= O_ASYNC;fcntl(fd, F_SETFL, flags);fcntl(fd, F_SETOWN, getpid());while (1){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}close(fd);
}

2.4多路复用IO

2.4.1【select】

2.4.1.1函数原型
【int select(int nfds, fd_set *readfds, fd_set *writefds,fd_set *exceptfds, struct timeval *timeout);】
2.4.1.2函数功能
监听文件描述符集合中是否有文件描述编程ready状态
2.4.1.3函数参数
1.【nfds】：最大文件描述符的值+1 
2.【readfds】：读文件描述符集合
3.【writefds】：写文件描述符集合
4.【exceptfds】：其余文件描述符集合
5.【timeout】：等待的时长【NULL】：表示一直等待
2.4.1.4返回值
【成功】：返回文件描述符集合中的文件描述符个数
【失败】：返回【-1】
2.4.1.5常用的几个函数

1.【FD_CLR】

（1）函数原型：【void FD_CLR(int fd, fd_set *set);】
（2）函数功能: 将文件描述符fd从集合中清除 
（3）函数参数：【fd】：【set】：

（4）返回值：

2.【FD_ISSET】

（1）函数原型：【int  FD_ISSET(int fd, fd_set *set);】
（2）函数功能: 判断文件描述符fd是否仍在集合中
（3）函数参数：【fd】：【set】：
（4）返回值：

3.【FD_SET】

（1）函数原型：【int  FD_ISSET(int fd, fd_set *set);】
（2）函数功能: 将文件描述符fd加入到集合中
（3）函数参数：【fd】：【set】：
（4）返回值：

4.【FD_ZERO】

（1）函数原型：【int  FD_ISSET(int fd, fd_set *set);】
（2）函数功能: 将文件描述符集合清0
（3）函数参数：
【set】：
（4）返回值：

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};fd_set rdfds;fd_set tmpfds;int ret = 0;mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}FD_ZERO(&rdfds);FD_SET(fd, &rdfds);FD_SET(0, &rdfds);while (1){tmpfds = rdfds;ret = select(fd+1, &tmpfds, NULL, NULL, NULL);if (-1 == ret){perror("fail to select");return -1;}if (FD_ISSET(fd, &tmpfds)){memset(tmpbuff, 0, sizeof(tmpbuff));read(fd, tmpbuff, sizeof(tmpbuff));printf("FIFO:%s\n", tmpbuff);}if (FD_ISSET(0, &tmpfds)){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}}close(fd);return 0;
}

源码示例（2）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}int HandleTcpClient(int confd)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}else if (0 == nsize){return 0;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}return nsize;
}int main(void)
{int sockfd = 0;int confd = 0;fd_set rdfds;fd_set tmpfds;int maxfd = 0;int ret = 0;int i = 0;sockfd = CreateListenSocket("192.168.1.183", 50000);FD_ZERO(&rdfds);FD_SET(sockfd, &rdfds);maxfd = sockfd;while (1){tmpfds = rdfds;ret = select(maxfd+1, &tmpfds, NULL, NULL, NULL);if (-1 == ret){perror("fail to select");return -1;}if (FD_ISSET(sockfd, &tmpfds)){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");FD_CLR(sockfd, &rdfds);close(sockfd);continue;}FD_SET(confd, &rdfds);maxfd = maxfd > confd ? maxfd : confd;}for (i = sockfd+1; i <= maxfd; i++){if (FD_ISSET(i, &tmpfds)){ret = HandleTcpClient(i);if (-1 == ret){fprintf(stderr, "handle client failed!\n");FD_CLR(i, &rdfds);close(i);continue;}else if (0 == ret){fprintf(stderr, "client disconnected!\n");FD_CLR(i, &rdfds);close(i);continue;}}}}close(confd);close(sockfd);return 0;
}

2.4.2【poll】

2.4.2.1函数原型
【int poll(struct pollfd *fds, nfds_t nfds, int timeout);】
2.4.2.2函数功能
监听文件描述符集合是否有事件发生
2.4.2.3函数参数
1.【fds】：监听文件描述符集合数组空间首地址
2.【nfds】：监听文件描述符集合元素个数
3.【timeout】：等待的时间【-1】： 一直等待

结构体说明：

struct pollfd {int   fd;/* file descriptor 监听的文件描述符*/short events;/* requested events 要监听的事件*/short revents;/* returned events 实际产生的事件*/
};
//结构体成员介绍
fd:监听的文件描述符
events:要监听的事件  POLLIN:是否可读  POLLOUT:是否可写
revents:实际产生的事件
2.4.2.4返回值
【成功】：返回产生事件的文件描述符个数
【失败】：返回【-1】

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};struct pollfd fds[2];int nready = 0;mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}fds[0].fd = fd;fds[0].events = POLLIN;fds[1].fd = 0;fds[1].events = POLLIN;while (1){nready = poll(fds, 2, -1);if (-1 == nready){perror("fail to poll");return -1;}if (fds[0].revents & POLLIN){memset(tmpbuff, 0, sizeof(tmpbuff));read(fd, tmpbuff, sizeof(tmpbuff));printf("FIFO:%s\n", tmpbuff);}if (fds[1].revents & POLLIN){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}}close(fd);
}

源码示例（2）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}int HandleTcpClient(int confd)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}else if (0 == nsize){return 0;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}return nsize;
}int InitFds(struct pollfd *fds, int maxlen)
{int i = 0;for (i = 0; i < maxlen; i++){fds[i].fd = -1;}return 0;
}int AddFd(struct pollfd *fds, int maxlen, int fd, short env)
{int i = 0;for (i = 0; i < maxlen; i++){if (fds[i].fd == -1){fds[i].fd = fd;fds[i].events = env;break;}}if (i == maxlen){return -1;}return 0;
}int DeleteFd(struct pollfd *fds, int maxlen, int fd)
{int i = 0;for (i = 0; i < maxlen; i++){if (fds[i].fd == fd){fds[i].fd = -1;break;}}return 0;
}int main(void)
{int sockfd = 0;int confd = 0;struct pollfd fds[1024];int nready = 0;int i = 0;int ret = 0;sockfd = CreateListenSocket("192.168.1.183", 50000);InitFds(fds, 1024);AddFd(fds, 1024, sockfd, POLLIN);while (1){nready = poll(fds, 1024, -1);if (-1 == nready){perror("fail to poll");return -1;}for (i = 0; i < 1024; i++){if (fds[i].fd == -1){continue;}if (fds[i].revents & POLLIN && fds[i].fd == sockfd){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");DeleteFd(fds, 1024, sockfd);close(sockfd);continue;}AddFd(fds, 1024, confd, POLLIN);}else if (fds[i].revents & POLLIN && fds[i].fd != sockfd){ret = HandleTcpClient(fds[i].fd);if (-1 == ret){fprintf(stderr, "handle tcp client failed!\n");close(fds[i].fd);DeleteFd(fds, 1024, fds[i].fd);continue;}else if (0 == ret){fprintf(stderr, "client disconnected!\n");close(fds[i].fd);DeleteFd(fds, 1024, fds[i].fd);continue;}}}}close(sockfd);return 0;
}

2.4.3【epoll】

2.4.3.1函数原型

【int epoll_create(int size);】

2.4.3.2函数功能
创建一张内核事件表
2.4.3.3函数参数
【size】：事件的个数
2.4.3.4返回值
【成功】：返回文件描述符
【失败】：返回【-1】

2.4.4【epoll_ctl】

2.4.4.1函数原型

【int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);】

2.4.4.2函数功能

维护epoll时间表

2.4.4.3函数参数
1.【epfd】：事件表的文件描述符
2.【op】：【EPOLL_CTL_ADD】：添加事件【EPOLL_CTL_MOD】：修改事件【EPOLL_CTL_DEL】：删除事件
3.【fd】：操作的文件描述符
4.【event】：事件对应的事件

结构体说明：

typedef union epoll_data {void        *ptr;int          fd;uint32_t     u32;uint64_t     u64;
} epoll_data_t;struct epoll_event {uint32_t     events;      /* Epoll events */epoll_data_t data;        /* User data variable */
};
2.4.4.4返回值
【成功】：返回【0】 
【失败】：返回【-1】

2.4.5【epoll_wait】

2.4.5.1函数原型
【int epoll_wait(int epfd, struct epoll_event *events,int maxevents, int timeout);】
2.4.5.2函数功能
监听事件表中的事件
2.4.5.3函数参数
1.【epfd】：文件描述符
2.【events】：存放实际产生事件的数组空间首地址
3.【maxevents】：最多存放事件的个数
4.【timeout】：设定监听的时间（超过该时间则不再监听）【-1】：一直监听直到有事件发生
2.4.5.4返回值
【成功】：返回产生事件的文件描述符个数
【失败】：返回【-1】
【超时】：如果时间达到仍没有事件发生返回【0】

源码示例（1）：

//【write.c】
int main(void)
{int fd = 0;char tmpbuff[4096] = {0};mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_WRONLY);if (-1 == fd){perror("fail to open");return -1;}while (1){gets(tmpbuff);write(fd, tmpbuff, strlen(tmpbuff));}close(fd);return 0;
}//【read.c】
int main(void)
{int fd = 0;int flags = 0;char *pret = NULL;ssize_t nsize = 0;char tmpbuff[4096] = {0};int epfd = 0;struct epoll_event env;struct epoll_event retenv[2];int nready = 0;int i = 0;mkfifo("/tmp/myfifo", 0664);fd = open("/tmp/myfifo", O_RDONLY);if (-1 == fd){perror("fail to open");return -1;}epfd = epoll_create(2);if (-1 == epfd){perror("fail to epoll_create");return -1;}env.events = EPOLLIN;env.data.fd = fd;epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &env);env.events = EPOLLIN;env.data.fd = 0;epoll_ctl(epfd, EPOLL_CTL_ADD, 0, &env);while (1){nready = epoll_wait(epfd, retenv, 2, -1);if (-1 == nready){perror("fail to epoll_wait");return -1;}for (i = 0; i < nready; i++){if (retenv[i].data.fd == 0){memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);printf("STDIN:%s\n", tmpbuff);}else if (retenv[i].data.fd == fd){memset(tmpbuff, 0, sizeof(tmpbuff));read(fd, tmpbuff, sizeof(tmpbuff));printf("FIFO:%s\n", tmpbuff);}}}close(fd);
}

源码示例（2）：

//【client.c】
int CreateTcpClient(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = connect(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to connect");return -1;}return sockfd;
}int main(void)
{int sockfd = 0;char tmpbuff[4096] = {"hello world"};int cnt = 0;ssize_t nsize = 0;sockfd = CreateTcpClient("192.168.1.183", 50000);while (1){memset(tmpbuff, 0, sizeof(tmpbuff));sprintf(tmpbuff, "hello world --- %d", cnt);cnt++;nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV:%s\n", tmpbuff);}close(sockfd);return 0;
}//【server.c】
int CreateListenSocket(char *pip, int port)
{int ret = 0;int sockfd = 0;struct sockaddr_in seraddr;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}seraddr.sin_family = AF_INET;seraddr.sin_port = htons(port);seraddr.sin_addr.s_addr = inet_addr(pip);ret = bind(sockfd, (struct sockaddr *)&seraddr, sizeof(seraddr));if (-1 == ret){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}return sockfd;
}int HandleTcpClient(int confd)
{char tmpbuff[4096] = {0};ssize_t nsize = 0;memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}else if (0 == nsize){return 0;}sprintf(tmpbuff, "%s ----echo", tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}return nsize;
}int AddFd(int epfd, int fd, uint32_t env)
{struct epoll_event tmpenv;int ret = 0;tmpenv.events = env;tmpenv.data.fd = fd;ret = epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &tmpenv);if (-1 == ret){perror("fail to epoll_ctl");return -1;}return 0;
}int DeleteFd(int epfd, int fd)
{int ret = 0;ret = epoll_ctl(epfd, EPOLL_CTL_DEL, fd, NULL);if (-1 == ret){perror("fail to epoll_ctl");return -1;}return 0;
}int main(void)
{int sockfd = 0;int confd = 0;int epfd = 0;int nready = 0;int i = 0;int ret = 0;struct epoll_event retenv[1024];sockfd = CreateListenSocket("192.168.1.183", 50000);epfd = epoll_create(1024);if (-1 == epfd){perror("fail to epoll_create");return -1;}AddFd(epfd, sockfd, EPOLLIN);while (1){nready = epoll_wait(epfd, retenv, 1024, -1);if (-1 == nready){perror("fail to epoll_wait");return -1;}for (i = 0; i < nready; i++){if (retenv[i].data.fd == sockfd){confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");DeleteFd(epfd, sockfd);close(sockfd);continue;}AddFd(epfd, confd, EPOLLIN);}else if (retenv[i].data.fd != sockfd){ret = HandleTcpClient(retenv[i].data.fd);if (-1 == ret){fprintf(stderr, "handle tcp client failed!\n");DeleteFd(epfd, retenv[i].data.fd);close(retenv[i].data.fd);continue;}else if (0 == ret){fprintf(stderr, "tcp client disconnected!\n");DeleteFd(epfd, retenv[i].data.fd);close(retenv[i].data.fd);continue;}}}}close(epfd);close(sockfd);return 0;
}

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