文章目录


libevent （三）libevent 事件处理_事件处理

事件处理逻辑流程图

libevent （三）libevent 事件处理_运维_02

测试了libevent 事件处理(linux，Ctrl+C与kill)

#include <iostream>
#include <event2/event.h>
#ifndef _WIN32
#include <signal.h>
#endif // !_


using namespace std;

//sock文件描述符， which事件类型， arg传递的参数
static void Ctrl_C(int sock, short which, void* arg) {
  cout << "INPUT:>> Ctrl+C" << endl;
}

static void Kill(int sock, short which, void* arg) {
  cout << "INPUT:>> Kill" << endl;
  //如果处于非待决
  event* ev = (event*)arg;
  if (!evsignal_pending(ev, NULL))
  {
    event_del(ev);
    event_add(ev, NULL);
  }
}

int main(int argc, char** argv) {
#if _WIN32
  //windowns 初始化socket库
  WSADATA wsa;
  WSAStartup(MAKEWORD(2, 2), &wsa);
#else
  //linux 忽略管道信号，发送数据给已关闭的socket
  if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
    return 1;
#endif
  event_base* base = event_base_new();

#ifndef _WIN32
  //添加信号Ctrl+C 处于no_pending(隐藏的状态：EV_SIGNAL|EV_PERSIST)
  event* c_signal = evsignal_new(base, SIGINT, Ctrl_C, base);
  if (!c_signal){
    cerr << "SIGINT evsignal_new failed \n";
    return -1;
  }

  //添加事件到pending
  if (event_add(c_signal, 0) != 0) {
    cerr << "SIGINT event_add failed \n";
    return -1;
  }

  //添加kill信号 (非持久，一次性, event_self_cbarg传递当前event)
  event* k_signal = event_new(base, SIGTERM, EV_SIGNAL, Kill, event_self_cbarg());
  if (!k_signal) {
    cerr << "k_signal evsignal_new failed \n";
    return -1;
  }

  //添加事件到pending
  if (event_add(k_signal, 0) != 0) {
    cerr << "SIGINT k_signal failed \n";
    return -1;
  }

  //进入事件主循环
  event_base_dispatch(base);
  event_free(c_signal);
  event_base_free(base);
#endif // _WIN32
#ifdef _WIN32
  WSACleanup();
#endif // _WIN32
  return 0;
}

效果如下：

libevent （三）libevent 事件处理_linux_03