libevent（四）定时器

文章目录

定时器

#include <iostream>
#include <event2/event.h>
#ifndef _WIN32
#include <signal.h>
#endif
using namespace std;

static timeval t1 = { 1,0 };


void timer1(int sock, short which, void *arg) {
  cout << "[timer1]" << flush;
  event* ev = (event*)arg;
  if (!evtimer_pending(ev,&t1)){
    evtimer_del(ev);
    evtimer_add(ev, &t1);
  }
}

void timer2(int sock, short which, void* arg) {
  cout << "[timer2]" << flush;
}


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();
  
  //定时器处理(非持久事件只进入一次)
  event* ev1 = evtimer_new(base, timer1, event_self_cbarg());
  if (!ev1)
  {
    cout << "evtimer_new ev1 failed!" << endl;
    return -1;
  }
  evtimer_add(ev1, &t1);


  static timeval t2;
  t2.tv_sec = 1;
  t2.tv_usec = 200000; //微秒
  event* ev2 = event_new(base, -1, EV_PERSIST, timer2, 0);
  event_add(ev2, &t2);


  //进入事件主循环
  event_base_dispatch(base);
  event_base_free(base);

#ifdef _WIN32
  WSACleanup();
#endif // _WIN32
  return 0;
}

定时器优化

#include <iostream>
#include <event2/event.h>
#include <thread>
#ifndef _WIN32
#include <signal.h>
#endif
using namespace std;

static timeval t1 = { 1,0 };


void timer1(int sock, short which, void *arg) {
  cout << "[timer1]" << flush;
  event* ev = (event*)arg;
  if (!evtimer_pending(ev,&t1)){
    evtimer_del(ev);
    evtimer_add(ev, &t1);
  }
}


void timer2(int sock, short which, void* arg) {
  cout << "[timer2]" << flush;
  this_thread::sleep_for(3000ms);//睡眠3秒
}


void timer3(int sock, short which, void* arg) {
  cout << "[timer3]" << flush;
}


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();
  
  //定时器处理(非持久事件只进入一次)
  event* ev1 = evtimer_new(base, timer1, event_self_cbarg());
  if (!ev1)
  {
    cout << "evtimer_new ev1 failed!" << endl;
    return -1;
  }
  evtimer_add(ev1, &t1);

  //定时器处理(持久事件)
  static timeval t2;
  t2.tv_sec = 1;
  t2.tv_usec = 200000; //微秒
  event* ev2 = event_new(base, -1, EV_PERSIST, timer2, 0);
  event_add(ev2, &t2);//插入删除性能O(logN)

  //超时优化，性能优化， 默认event用二叉堆存储（二叉树,OlogN）
  //优化到双向队列，插入删除O(1)
  static timeval tv_in = { 3,0 };
  const timeval* t3;
  t3 = event_base_init_common_timeout(base, &tv_in);
  event* ev3 = event_new(base, -1, EV_PERSIST, timer3, 0);
  event_add(ev3, t3); //插入删除性能O(1)


  //进入事件主循环
  event_base_dispatch(base);
  event_base_free(base);

#ifdef _WIN32
  WSACleanup();
#endif // _WIN32
  return 0;
}