c++ 实现一个 tcp 高性能网络服务器

#include <iostream>#include <cstring>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#include <sys/epoll.h>
#define MAX_EVENTS 1024#define BUF_SIZE 4096
using namespace std;
int main(int argc, char* argv[]){    int listen_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    if (listen_fd == -1) {        cerr << "Failed to create socket" << endl;        return -1;    }
struct sockaddr_in server_addr;memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_port = htons(12345);server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(listen_fd, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {    cerr << "Failed to bind socket" << endl;    return -1;}
if (listen(listen_fd, 5) == -1) {    cerr << "Failed to listen" << endl;    return -1;}
int epoll_fd = epoll_create(MAX_EVENTS);if (epoll_fd == -1) {    cerr << "Failed to create epoll" << endl;    return -1;}
struct epoll_event ev, events[MAX_EVENTS];ev.events = EPOLLIN; // 监听可读事件ev.data.fd = listen_fd;if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, listen_fd, &ev) == -1) {    cerr << "Failed to add listen socket to epoll" << endl;    return -1;}
while (true) {    int nfds = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);    if (nfds == -1) {        cerr << "Failed to wait for epoll events" << endl;        break;    }
    for (int i = 0; i < nfds; ++i) {        int fd = events[i].data.fd;
        if (fd == listen_fd) { // 新连接            struct sockaddr_in client_addr;            socklen_t len = sizeof(client_addr);            int client_fd = accept(listen_fd, (sockaddr*)&client_addr, &len);            if (client_fd == -1) {                cerr << "Failed to accept client socket" << endl;                continue;            }            cout << "New client connected: " << inet_ntoa(client_addr.sin_addr) << ":" << ntohs(client_addr.sin_port) << endl;
            ev.events = EPOLLIN | EPOLLET; // 监听可读事件和边沿触发            ev.data.fd = client_fd;            if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client_fd, &ev) == -1) {                cerr << "Failed to add client socket to epoll" << endl;                close(client_fd);            }        } else { // 有数据可读            char buf[BUF_SIZE];            int nread = read(fd, buf, BUF_SIZE);            if (nread == -1) {                cerr << "Failed to read data from socket" << endl;                epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, NULL); // 删除该socket                close(fd);            } else if (nread == 0) {                cout << "Client disconnected" << endl;                epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, NULL); // 删除该socket                close(fd);            } else {                cout << "Received data from client: " << buf << endl;                write(fd, buf, nread); // 原样返回            }        }    }}
close(epoll_fd);close(listen_fd);
return 0;