我个人的Linux TCP server和client测试源码，C语言（2）（★firecat推荐★）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/resource.h>    /*setrlimit */
#define ECHO_SERVER_PORT        1883
#define LISTEN_BACKLOG          16
#define MAX_EVENT_COUNT         32
#define BUF_SIZE                2048
#define MAXCONN                 60000
int set_fdlimit()
{
    //设置每个进程允许打开的最大文件数
    //这项功能等价于linux终端命令 "ulimit -n 102400"
    struct rlimit rt;
    rt.rlim_max = rt.rlim_cur = MAXCONN;
    if (setrlimit(RLIMIT_NOFILE, &rt) == -1)
    {
        perror("setrlimit error");
        return -1;
    }
    return 0;
}
int main() {
    //设置每个进程允许打开的最大文件数,socket
    if (set_fdlimit() < 0)
    {
        return -1;
    }
    int ret, i;
    int server_fd, client_fd, epoll_fd;
    int ready_count;
    struct sockaddr_in server_addr;
    struct sockaddr_in client_addr;
    socklen_t addr_len;
    struct epoll_event event;
    struct epoll_event* event_array;
    char* buf;
    event_array = (struct epoll_event*)
                    malloc(sizeof(struct epoll_event)*MAX_EVENT_COUNT);
    buf = (char*)malloc(sizeof(char)*BUF_SIZE);
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(ECHO_SERVER_PORT);
    server_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(server_fd == -1) {
        perror("create socket failed.\n");
        return 1;
    }
    //一个端口释放后会等待两分钟之后才能再被使用，SO_REUSEADDR是让端口释放后立即就可以被再次使用。
    int reuse_addr = 1;
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &reuse_addr, sizeof(reuse_addr)) == -1)
    {
        return -1;
    }
    ret = bind(server_fd, (struct sockaddr*)&server_addr, sizeof(server_addr));
    if(ret == -1) {
        perror("bind failed.\n");
        return 1;
    }
    ret = listen(server_fd, LISTEN_BACKLOG);
    if(ret == -1) {
        perror("listen failed.\n");
        return 1;
    }
    fprintf(stderr,"listen on,fd=%d\n",server_fd);
    epoll_fd = epoll_create(1);
    if(epoll_fd == -1) {
        perror("epoll_create failed.\n");
        return 1;
    }
    event.events = EPOLLIN;
    event.data.fd = server_fd;
    ret = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, server_fd, &event);
    if(ret == -1) {
        perror("epoll_ctl failed.\n");
        return 1;
    }
    while(1) {
        ready_count = epoll_wait(epoll_fd, event_array, MAX_EVENT_COUNT, -1);
        if(ready_count == -1) {
            perror("epoll_wait failed.\n");
            return 1;
        }
        for(i = 0; i < ready_count; i++) {
            if(event_array[i].data.fd == server_fd) {
                client_fd = accept(server_fd,
                            (struct sockaddr*)&client_addr, &addr_len);
                if(client_fd == -1) {
                    perror("accept failed.\n");
                    return 1;
                }
                event.events = EPOLLIN;
                event.data.fd = client_fd;
                ret = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client_fd, &event);
                if(ret == -1) {
                    perror("epoll_ctl failed.\n");
                    return 1;
                }
                fprintf(stderr,"accept,fd=%d\n",client_fd);
            }
            else {
                ret = recv(event_array[i].data.fd, buf, BUF_SIZE, 0);
                if(ret <= 0) {
                    close(event_array[i].data.fd);
                    epoll_ctl(epoll_fd, EPOLL_CTL_DEL,
                              event_array[i].data.fd, &event);
                    continue;
                }
                ret = send(event_array[i].data.fd, buf, (size_t)ret, 0);
                if(ret == -1) {
                    perror("send failed.\n");
                }
            }
        } // for each event
    } // while(1)
    close(epoll_fd);
    close(server_fd);
    free(event_array);
    free(buf);
    return 0;
}