Go从入门到实战——任务的取消（笔记）

任务取消代码展示

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)
}

调用cancel1(cancelChan)

调用cancel2(cancelChan)

方法一只能取消一个channel，如果都关闭需要多写几次耦合度高；通过方法二关闭channel可以将所有的channel关闭，同时耦合度低