我正在嘗試使用通道在golang中實(shí)現(xiàn)一個(gè)簡(jiǎn)單的并行化示例。代碼嘗試實(shí)現(xiàn)并行映射函數(shù)。使通道也進(jìn)行了緩沖，以減輕對(duì)通道阻塞性質(zhì)的約束。但代碼仍然會(huì)導(dǎo)致死鎖。func pmmap(inp []int, f func(int) int, p int) {    var wg sync.WaitGroup    var output []chan int    tot := len(inp)    out := make(chan int, tot)    slice := tot / p    for i := 0; i < p; i++ {        temp := make(chan int, slice)        output = append(output, temp)        start_ind := slice * i        end_ind := start_ind + slice        fmt.Println(start_ind, end_ind)        wg.Add(1)        go func(si, ei int, out chan int, wg *sync.WaitGroup) {            fmt.Println("goroutine started with ", si, ei)            for ind := si; ind < ei; ind++ {                out <- f(inp[ind])            }            wg.Done()        }(start_ind, end_ind, output[i], &wg)    }    wg.Add(1)    go func(wg *sync.WaitGroup) {        for i := 0; i < p; i++ {            for val := range output[i] {                out <- val            }            close(output[i])        }        wg.Done()    }(&wg)    wg.Add(1)    go func(wg *sync.WaitGroup) {        for i := range out {            fmt.Println(i)        }        wg.Done()    }(&wg)    time.Sleep(time.Second * 6)    wg.Wait()    close(out)}func add4(i int) int {    return i + 4}func main() {    temp := []int{}    for i := 1; i <= 20; i++ {        temp = append(temp, i)    }    pmmap(temp, add4, 2)}從上面代碼的輸出中，我得到死鎖是因?yàn)橥ǖ垒敵鯷1]從未被讀取。但我不知道為什么0 1010 20goroutine started with  0 10goroutine started with  10 20567891011121314fatal error: all goroutines are asleep - deadlock!