Go语言利用time.After实现超时控制的方法详解

// After waits for the duration to elapse and then sends the current time
// on the returned channel.
// It is equivalent to NewTimer(d).C.
// The underlying Timer is not recovered by the garbage collector
// until the timer fires. If efficiency is a concern, use NewTimer
// instead and call Timer.Stop if the timer is no longer needed.
func After(d Duration) <-chan Time {
 return NewTimer(d).C
}

package main
import (
 "time"
 "fmt"
)
func main() {
 ch := make(chan string)
 go func() {
 time.Sleep(time.Second * 2)
 ch <- "result"
 }()
 select {
 case res := <-ch:
 fmt.Println(res)
 case <-time.After(time.Second * 1):
 fmt.Println("timeout")
 }
}