channel
func main() {
ch := make(chan struct{})
http.HandleFunc("/test", func(writer http.ResponseWriter, request *http.Request) {
go func() {
for {
time.Sleep(time.Second * 2)
fmt.Println("123")
ch <- struct{}{}
}
}()
ch <- struct{}{}
writer.Write([]byte("hello yu"))
})
log.Fatal(http.ListenAndServe(":8080", nil))
}
不能退出-只会阻塞到 ch <- struct{}{} 里面
使用 Context
http.HandleFunc("/test", func(writer http.ResponseWriter, request *http.Request) {
go func() {
for {
select {
case <-request.Context().Done():
fmt.Println("已结束")
return
default:
time.Sleep(time.Second * 2)
fmt.Println("123")
}
}
}()
writer.Write([]byte("hello yu"))
})
log.Fatal(http.ListenAndServe(":8080", nil))
context包用法
ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
defer cancel()
for {
select {
case <-ctx.Done():
fmt.Println(ctx.Err().Error()) //context deadline exceeded
return
default:
time.Sleep(time.Second * 2)
fmt.Println(123)
}
}
规定此段程序执行时间3s钟.
