如何关闭计时器频道？

Question

I have a timer which is reset by certain events. A go function listens to the channel using range. How do I close the channel so that for loop exits?

func resetTimer(){
        if rf.electionTimer != nil {
             rf.electionTimer.Stop()
        }
}

rf.electionTimer = time.NewTimer(electionTime) 


for _ = range rf.electionTimer.C {
  // Do something
}

Answer 1

Use a channel to signal when the loop should exit.

rf.done := make(chan struct{})
rf.electionTimer = time.NewTimer(electionTime) 

func stopTimer(){
    if rf.electionTimer != nil {
         rf.electionTimer.Stop()
         close(rf.done)
    }
}

Select on both the signal channel and the timer channel in a loop. Break out of the loop when signal channel is closed.

loop:
    for {
        select {
        case t := <-rf.electionTimer.C:
            // Do something
        case <-rf.done:
            break loop
        }
    }

Note that it does not make sense to use a loop in the question or this answer if the application does not call Reset on the timer. If the timer is not reset, then only one value will be sent to the timer's channel.