实际上你的协程可能来不及执行wg.Add(1)主程就退出了，而且你的go func() {}是个死循环只不过你的主程没有去等待这个协程才没有卡住

嗯，理解，有什么补救办法吗，我改了另外一种方式，

package main

import (
    "fmt"
    "sync"
)

func main() {

    ch2 := make(chan int, 1000)
    var wg sync.WaitGroup
    wg.Add(4)
    go testThreadSate01(ch2, &wg)
    go testThreadSate02(ch2, &wg)
    go testThreadSate03(ch2, &wg)
    go func(wg *sync.WaitGroup) {
        for {
            select {
            case res := <-ch2:
                if res == 28 {
                    break
                }
            case resGt := <-ch2:
                if resGt > 28 {
                    fmt.Println("有bug ！")
                    wg.Done()
                }
            default:
            }
        }
    }(&wg)

    wg.Wait()
    fmt.Println("main done")

}
func testThreadSate03(ch chan int, wg *sync.WaitGroup) {
    defer wg.Done()
    for j := 21; j <= 30; j++ {
        ch <- j
    }
}
func testThreadSate01(ch chan int, wg *sync.WaitGroup) {
    defer wg.Done()
    for j := 0; j <= 10; j++ {
        ch <- j
    }
}
func testThreadSate02(ch chan int, wg *sync.WaitGroup) {
    defer wg.Done()
    //time.Sleep(1 * time.Microsecond)
    for j := 11; j <= 20; j++ {
        ch <- j
    }
}

这样吧。。

func main() {

    ch2 := make(chan int, 1000)
    var wg sync.WaitGroup
    wg.Add(3)
    go testThreadSate01(ch2, &wg)
    go testThreadSate02(ch2, &wg)
    go testThreadSate03(ch2, &wg)
    wg.Wait()
    for {
        select {
        case resGt := <-ch2:
            if resGt > 28 {
                fmt.Println("有bug ！")
                goto OUT
            }
        default:
        }
    }
OUT:
    fmt.Println("----")
    fmt.Println("main done")

}

break跳出的是select，不是for循环；select会随机执行满足条件的语句，感觉case resGt := <-ch2:有概率一次都不执行，然后程序卡住。

完整版

package main

import (
    "fmt"
    "sync"
    "time"
)

func main() {
    ch2 := make(chan int, 1000)
    var wg sync.WaitGroup
    wg.Add(4)
    go testThreadSate01(ch2, &wg)
    go testThreadSate02(ch2, &wg)
    go testThreadSate03(ch2, &wg)

    go func(wg *sync.WaitGroup) {
        for {
            select {
            case resGt := <-ch2:
                if resGt > 28 {
                    fmt.Println("bug:lwq")
                    goto OUT
                }
                fmt.Println(resGt)
            }
        }
    OUT:
        wg.Done()
        fmt.Println("----")

    }(&wg)
    wg.Wait()
    fmt.Println("all groutine done")
    fmt.Println("main done")


}

func testThreadSate03(ch chan int, wg *sync.WaitGroup) {
    defer wg.Done()
    time.Sleep(1 * time.Second)
    for j := 21; j <= 30; j++ {
        ch <- j
    }
}
func testThreadSate01(ch chan int, wg *sync.WaitGroup) {
    defer wg.Done()
    for j := 0; j <= 10; j++ {
        ch <- j
    }
}
func testThreadSate02(ch chan int, wg *sync.WaitGroup) {
    defer wg.Done()

    for j := 11; j <= 20; j++ {
        ch <- j
    }
}

完整优化wgDone传值版

package main

import (
    "fmt"
    "sync"
    "time"
)

func main() {
    ch2 := make(chan int, 1000)
    var wg sync.WaitGroup
    wg.Add(4)

    go testThreadSate01(ch2, wg.Done)
    go testThreadSate02(ch2, wg.Done)
    go testThreadSate03(ch2, wg.Done)
    go func(wg *sync.WaitGroup) {
        for {
            select {
            case resGt := <-ch2:
                if resGt > 28 {
                    fmt.Println("bug:lwq")
                    goto OUT
                }
                fmt.Println(resGt)
            }
        }
    OUT:
        wg.Done()
        fmt.Println("----")

    }(&wg)
    wg.Wait()
    fmt.Println("all groutine done")
    fmt.Println("main done")

}

func testThreadSate03(ch chan int, wgDone func()) {
    wgDone()
    time.Sleep(1 * time.Second)
    for j := 21; j <= 30; j++ {
        ch <- j
    }
}
func testThreadSate01(ch chan int, wgDone func()) {
    wgDone()
    for j := 0; j <= 10; j++ {
        ch <- j
    }
}
func testThreadSate02(ch chan int, wgDone func()) {
    wgDone()
    for j := 11; j <= 20; j++ {
        ch <- j
    }
}