opt(event):优化select引擎去除kHupEvent

Author: hevake

modules/event/engines/select/fd_event.cpp

@@ -77,9 +77,6 @@ bool SelectFdEvent::enable()
     if (events_ & kExceptEvent)
         ++d_->except_event_num;
 
-    if (events_ & kHupEvent)
-        ++d_->hup_event_num;
-
     d_->fd_events.push_back(this);
 
     is_enabled_ = true;
@@ -100,9 +97,6 @@ bool SelectFdEvent::disable()
     if (events_ & kExceptEvent)
         --d_->except_event_num;
 
-    if (events_ & kHupEvent)
-        --d_->hup_event_num;
-
     auto iter = std::find(d_->fd_events.begin(), d_->fd_events.end(), this);
     d_->fd_events.erase(iter);
 
@@ -137,13 +131,6 @@ void SelectFdEvent::OnEventCallback(bool is_readable, bool is_writable, bool is_
 
 void SelectFdEvent::onEvent(short events)
 {
-    /**
-     * 由于EPOLLHUP会一直触发，所以无论事件有没有监听HupEvent，只要发生了EPOLLHUB事件，
-     * 对应fd所有的事件都要强制disable()。否则会导致Loop空跑问题。
-     */
-    if (events & kHupEvent)
-        disable();
-
     if (events_ & events) {
         if (is_stop_after_trigger_)
             disable();

modules/event/engines/select/loop.cpp

@@ -123,7 +123,7 @@ int SelectLoop::fillFdSets(fd_set &read_set, fd_set &write_set, fd_set &except_s
             is_this_fd_used = true;
         }
 
-        if (data->except_event_num > 0 || data->hup_event_num > 0) {
+        if (data->except_event_num > 0) {
             FD_SET(fd, &except_set);
             is_this_fd_used = true;
         }

modules/event/engines/select/types.h

@@ -35,7 +35,6 @@ struct SelectFdSharedData {
     int read_event_num = 0;     //!< 监听可读事件的FdEvent个数
     int write_event_num = 0;    //!< 监听可写事件的FdEvent个数
     int except_event_num = 0;   //!< 监听异常事件的FdEvent个数
-    int hup_event_num = 0;      //!< 监听挂起事件的FdEvent个数
 
     std::vector<SelectFdEvent*> fd_events;
 };