fatal error: all goroutines are asleep - deadlock!

    1. func worker(id int, jobCh <-chan int, sendCh chan<- int) {
    2.     for j := range jobCh {
    3.         fmt.Printf("worker-%d, start job-%d\n", id, j)
    4.         time.Sleep(time.Second * time.Duration(3*j))
    5.         fmt.Printf("worker-%d, end job-%d\n", id, j)
    6.         sendCh <- j * 2
    7.     }
    8. }
    10. func main() {
    11.     jobCh := make(chan int, 100)
    12.     sendCh := make(chan int, 100)
    13.     for w := 1; w <= 3; w++ {
    14.         go worker(w, jobCh, sendCh)
    15.     }
    16.     for j := 1; j <= 3; j++ {
    17.         jobCh <- j
    18.     }
    20.     // sendCh <- 1
    21.     //================1====================
    22.     // for s := range sendCh {
    23.     //     fmt.Printf("get %d\n", s)
    24.     // }
    25.     //================2====================
    26.     for a := 1; a <= 4; a++ {
    27.         t1 := time.Now().Second()
    28.         fmt.Printf("get time %d\n", t1)
    29.         s, ok := <-sendCh
    30.         if !ok {
    31.             break
    32.         }
    33.         t2 := time.Now().Second()
    34.         fmt.Printf("get time %d, %d\n", t2, t1-t2)
    35.         fmt.Printf("get %d\n", s)
    37.     }
    38.     sendCh <- 4 * 2
    39.     //================3====================
    40.     // for {
    41.     //     s, ok := <-sendCh
    42.     //     if !ok {
    43.     //         fmt.Print(s)
    44.     //         break
    45.     //     }
    46.     //     fmt.Printf("get %d\n", s)
    47.     // }
    48.     //================4====================
    49.     // time.Sleep(time.Second * 5)
    50.     // for {
    51.     //     breakFlag := 0
    52.     //     select {
    54.     //     case s := <-sendCh:
    55.     //         fmt.Printf("get %d\n", s)
    56.     //     default:
    57.     //         fmt.Println("channel is empty !")
    58.     //         breakFlag = 1
    59.     //     }
    60.     //     if breakFlag == 1 {
    61.     //         break
    62.     //     }
    63.     // }
    64.     close(jobCh)
    65.     close(sendCh)
    66. }