C++实现使用epoll实现一个通用的服务器压力测试程序 代码或者函数

以下是使用 epoll 实现的服务器压力测试程序的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define MAX_EVENTS 1024
#define BUFFER_SIZE 1024

void error_exit(const char *msg) {
    perror(msg);
    exit(EXIT_FAILURE);
}

int create_socket(const char *ip, int port) {
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        error_exit("Error creating socket");
    }

    struct sockaddr_in server_addr;
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(port);
    server_addr.sin_addr.s_addr = inet_addr(ip);

    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        error_exit("Error connecting to server");
    }

    return sockfd;
}

int main(int argc, char *argv[]) {
    if (argc < 4) {
        printf("Usage: %s <ip> <port> <concurrency>\n", argv[0]);
        return 1;
    }

    const char *ip = argv[1];
    const int port = atoi(argv[2]);
    const int concurrency = atoi(argv[3]);

    int epoll_fd = epoll_create1(0);
    if (epoll_fd < 0) {
        error_exit("Error creating epoll file descriptor");
    }

    struct epoll_event ev, events[MAX_EVENTS];
    char buffer[BUFFER_SIZE];
    int sockets[concurrency];
    int i, n, nfds;

    for (i = 0; i < concurrency; i++) {
        int sockfd = create_socket(ip, port);
        sockets[i] = sockfd;

        ev.events = EPOLLIN | EPOLLET;  // Set edge-triggered mode
        ev.data.fd = sockfd;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sockfd, &ev) < 0) {
            error_exit("Error adding socket to epoll");
        }
    }

    while (1) {
        nfds = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);
        if (nfds < 0) {
            error_exit("Error waiting for events");
        }

        for (n = 0; n < nfds; n++) {
            int sockfd = events[n].data.fd;
            int len = read(sockfd, buffer, BUFFER_SIZE);
            if (len < 0) {
                error_exit("Error reading from socket");
            }

            if (len == 0) {
                close(sockfd);
                ev.data.fd = sockfd;
                if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, sockfd, &ev) < 0) {
                    error_exit("Error removing socket from epoll");
                }

                int new_sockfd = create_socket(ip, port);
                sockets[n] = new_sockfd;

                ev.events = EPOLLIN | EPOLLET;  // Set edge-triggered mode
                ev.data.fd = new_sockfd;
                if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, new_sockfd, &ev) < 0) {
                    error_exit("Error adding socket to epoll");
                }
            }
        }
    }

    for (i = 0; i < concurrency; i++) {
        close(sockets[i]);
    }

    close(epoll_fd);

    return 0;
}

该程序创建了一个 epoll 实例并向其中添加了一些套接字。它使用边缘触发模式，这意味着当套接字上有数据可读时，程序会立即收到通知。在每个套接字上读取数据时，如果读取失败或读取到的字节数为0，则关闭该套接字并创建一个新套接字，然后将其添加到 epoll 实例中。这样，程序就可以不断地创建和关闭套接字以模拟大量的并发连接。