void TimerQueue::handleRead() {
loop_->assertInLoopThread();
Timestamp now(Timestamp::now());
readTimerfd(timerfd_, now);
std::vector<Entry> expired = getExpired(now);
callingExpiredTimers_ = true;
cancelingTimers_.clear();
// safe to callback outside critical section
for (std::vector<Entry>::iterator it = expired.begin();
it != expired.end(); ++it) {
it->second->run();
}
callingExpiredTimers_ = false;
reset(expired, now);
}
/*
struct pollfd {
int fd; // file descriptor
short events; // requested events
short revents; // returned events
};
*/
void Timer::start()
{
setTimerfd(timerfd_, val_, interval_);
isStarted_ = true;
struct pollfd pfd;
pfd.fd = timerfd_;
pfd.events = POLLIN; // 监听输入事件
uint64_t val;
int ret;
while(isStarted_)
{
ret = ::poll(&pfd, 1, 5000); // 可以认为pfd是大小为1的数组
if(ret == -1)
{
if(errno == EINTR)
{
continue; // 出错情况为遇到中断信号，继续poll
}
ERR_EXIT("poll");
}
else if (ret == 0) // 超时
{
printf("timeout \n");
}
else
{
if (pfd.revents == POLLIN) // 判断此fd是否是监听的read事件（这边较为严禁，实际上只监听一个描述符是可以不加这条判断语句）
{
readTimerfd(timerfd_); // 取走timerfd_的字节
callback_(); // 用户逻辑
}
}
}
}
