Go from introduction to actual combat - task cancellation (note)

Task cancellation code display

func isCancelled(cancelChan chan struct{
    }) bool {
    
	select {
    
	case <-cancelChan:
		return true
	default:
		return false
	}
}

func cancel1(cancelChan chan struct{
    }) {
    
	cancelChan <- struct{
    }{
    }
}
func cancel2(cancelChan chan struct{
    }) {
    
	close(cancelChan)
}

func TestCancel(t *testing.T) {
    
	cancelChan := make(chan struct{
    }, 0)
	for i := 0; i < 5; i++ {
    
		go func(i int, cancelCh chan struct{
    }) {
    
			for {
    
				if isCancelled(cancelCh) {
    
					break
				}
				time.Sleep(time.Millisecond * 5)
			}
			fmt.Println(i, "Done")
		}(i, cancelChan)
	}
	cancel2(cancelChan)
	time.Sleep(time.Second * 1)
}

call cancel1(cancelChan)

call cancel2(cancelChan)

Only one method can be canceled channel, If both are closed, you need to write more times, and the coupling is high ; Close by method 2 channel I can take all of them channel close , Low coupling