[golang] go中如何监听一组channels

go中如何监听一组channels

reflect.Select

func Select(cases []SelectCase) (chosen int, recv Value, recvOK bool)

cases := make([]reflect.SelectCase, len(chans))
for i, ch := range chans {
    cases[i] = reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(ch)}
}
chosen, value, ok := reflect.Select(cases)
// ok will be true if the channel has not been closed.
ch := chans[chosen]
msg := value.String()

“aggregate” channel

agg := make(chan string)
for _, ch := range chans {
  go func(c chan string) {
    for msg := range c {
      agg <- msg
    }
  }(ch)
}

select {
case msg <- agg:
    fmt.Println("received ", msg)
}

benchmark

...
BenchmarkReflectSelect         1    5265109013 ns/op
BenchmarkGoSelect             20      81911344 ns/op
ok      command-line-arguments  9.463s