1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
| package main
import ( "context" "fmt" "sync" "time" )
func test(wg *sync.WaitGroup, ctx context.Context, jobId int) { defer wg.Done() for i := 0; i < 5; i++ { select { case <-ctx.Done(): fmt.Printf("任务Id:%d,异常退出\n", jobId) return default: fmt.Printf("任务Id:%d,执行第%d次\n", jobId, i) if jobId > 2 { time.Sleep(time.Second * 5) } else { time.Sleep(time.Second * 2) }
} } }
func main() { ctx, cancel := context.WithCancel(context.Background()) wg := new(sync.WaitGroup) go func() { time.Sleep(time.Second * 20) cancel() }() for i := 0; i < 5; i++ { wg.Add(1) go test(wg, ctx, i)
if i < 1 { wg.Wait() select { case <-ctx.Done(): fmt.Println("main1 异常退出") return default: fmt.Println("1 select") } } } wg.Wait() select { case <-ctx.Done(): fmt.Println("main2 异常退出") return default: fmt.Println("2 select") } select {} }
|