检查Go中首先完成什么任务？

Question

I was wondering if it's possible to do a task (like a function, with different arguments, e.g. int multipliers) run at the same time, and a variable which receive the return value of the first task finished. Someone has any idea? :D

Answer 1

Here is a basic example though there are plenty of others on the internet... https://play.golang.org/p/R__dk09Ymh

package main

import "fmt"
import "time"

func main() {
        a := make(chan bool)
        b := make(chan bool)
    go MySleep(5000, a)
    go MySleep(1000, b)

    select {
        case _ = <-a:
             fmt.Println("a returned first")
        case _ = <-b:
            fmt.Println("b returned first")
    }
}

func MySleep(t int, sig chan bool) {
    time.Sleep(time.Duration(t))
    close(sig)
    return
}

You can extend this to do whatever you want. For example if you want to spin of some arbitrary number of goroutines N and not stop until they're all complete then you could wrap the select in a for and add a flag to indicate that each goroutine has sent on it's channel. Note that a well made program would also have communication in the other direction so you can shut down your workers.