linux下进行epoll的简单使用

先做一个简单实例：

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

#include <iostream>

#include "../epollctl.hpp"

void handlerClient(int clientFd) {
  std::string msg;
  if (not EchoServer::RecvMsg(clientFd, msg)) {
    return;
  }
  EchoServer::SendMsg(clientFd, msg);
}

int main(int argc, char *argv[]) {
  if (argc != 3) {
    std::cout << "invalid input" << std::endl;
    std::cout << "example: ./Epoll 0.0.0.0 1688" << std::endl;
    return -1;
  }
  int sockFd = EchoServer::CreateListenSocket(argv[1], atoi(argv[2]), false);
  if (sockFd < 0) {
    return -1;
  }
  epoll_event events[2048];
  int epollFd = epoll_create(1024);
  if (epollFd < 0) {
    perror("epoll_create failed");
    return -1;
  }
  EchoServer::Conn conn(sockFd, epol