Question

我是libev的新手，我很难理解它。我之前使用过select（），poll（）和epoll（），它们很容易理解和实现。我现在想从epoll切换到libev。以下是我目前正在使用的epoll -

short int state[10000];       // stores the events for all fd
state[fd] |= current_state    // Update state for the fd, current_state could be either EPOLLIN or EPOLLOUT but not both
/* attempt to add fd to epoll for monitoring. If fd already exists, then just modify the events */
ev.events = state[fd];    
ev.data.fd = fd;
epollctl = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev);

if(epollctl == -1 && errno == EEXIST)
  epollctl = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &ev);
while(1)
{
  num = epoll_wait (epollfd, events, 100000 , -1);
  for(i = 0, i < num, ++i)
  {
    /* process the read and tell epoll to not notify anymore read events for given fd */
    if(events[i].events & EPOLLIN)
    {      
      process_read (m, m->read, events[i].data.fd );
      state[events[i].data.fd] &= ~(EPOLLIN)         
      ev.events = state[events[i].data.fd]
      ev.data.fd = events[i].data.fd;
      epollctl = epoll_ctl(epollfd, EPOLL_CTL_MOD, events[i].data.fd, &ev);
    }
    /* process the write and tell epoll to not notify anymore write events for given fd */
    if(events[i].events & EPOLLOUT)
    {
      process_write (m, m->write, events[i].data.fd );
      state[events[i].data.fd] &= ~(EPOLLOUT)         
      ev.events = state[events[i].data.fd] 
      ev.data.fd = events[i].data.fd;
      epollctl = epoll_ctl(epollfd, EPOLL_CTL_MOD, events[i].data.fd, &ev);
    }
    /* remove fd from epoll on error */
    if(events[i].events & EPOLLERR)
      epollctl = epoll_ctl(epollfd, EPOLL_CTL_DEL, events[i].data.fd, &ev);
  }
}

这不是完整的代码，在发布此处时故意省略了错误检查和其他不相关的内容，因此您可以专注于逻辑。我正在寻找libev等效方法来实现以下目标 -

添加fd进行监控
从监控中删除fd
修改已被监控的fd的事件（READ / WRITE）。

有人可以为我提供上述epoll代码的粗略的libev等效模板，我将非常感激。

从民意调查/ epoll移民到Libev

0 个答案: