股票代碼告訴goroutine它是通過它的ticker.C停止的嗎？

Question

package main 
import "fmt" 
import "time" 

func main() { 
    ticker := time.NewTicker(time.Millisecond * 500) 
    go func() { 
     for t := range ticker.C { 
      fmt.Println("Tick at", t) 
     } 
     fmt.Println("ticker stopped") 
    }() 
    time.Sleep(time.Second * 5) 
    ticker.Stop() 
    time.Sleep(time.Second * 5) 
} 

我以爲當我打電話給ticker.Stop（）時，ticker.C應該告訴goroutine它已經結束，所以for循環應該結束，但它看起來不像那樣，字符串「ticker stopped」從不打印。

Answer 1

正如JimB指出的那樣，time.Ticker指定Stop（）不會關閉頻道，to prevent a read from the channel succeeding incorrectly.您最好的選擇可能是退出頻道。

package main 

import "fmt" 
import "time" 

func main() { 
    ticker := time.NewTicker(time.Millisecond * 500) 
    quit := make(chan struct{}) 
    go func() { 
     for { 
      select { 
      case t := <-ticker.C: 
       fmt.Println("Tick at", t) 
      case <-quit: 
       fmt.Println("ticker stopped") 
       return 
      } 
     } 
    }() 
    time.Sleep(time.Second * 5) 
    ticker.Stop() 
    close(quit) 
    time.Sleep(time.Second * 5) 
} 

https://play.golang.org/p/xTKNkMtdIf