代码主要测试 golang中 channel的生产者和接受者的使用方式

Demo1:

package ch8



import (

	"fmt"

	"sync"

	"testing"

)



func Producer(ch chan int, wg *sync.WaitGroup) {

	//生产者

	go func() {

		for i := 0; i < 50; i++ {

			ch <- i

		}

		close(ch)

		wg.Done()

	}()

}



func Consumer(ch chan int, wg *sync.WaitGroup) {

	//消费者

	go func() {

		for {

			if data, ok := <-ch; ok {

				fmt.Println(data)

			} else {

				break

			}

		}

		wg.Done()

	}()

}



func TestChannel(t *testing.T) {

	var wg sync.WaitGroup

	ch := make(chan int, 1)

	wg.Add(1)

	Producer(ch, &wg)

	wg.Add(1)

	Consumer(ch, &wg)

	wg.Add(1)

	Consumer(ch, &wg)

	wg.Add(1)

	Consumer(ch, &wg)



	wg.Wait()

}

Demo2:

package gy_close



import (

	"fmt"

	"testing"

	"time"

)



func isCancelled(cancelChan chan struct{}) bool {

	select {

	case <-cancelChan:

		return true

	default:

		return false

	}

}



func cancel_1(cancelChan chan struct{}) {

	cancelChan <- struct{}{}

}



func cancel_2(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, "Cancelled")

		}(i, cancelChan)

	}

	cancel_2(cancelChan)

	time.Sleep(time.Second * 1)

}