golang 协程并发编程

package main

import (
    "fmt"
    "strconv"
    "time"
)

type Task struct {
    Name string
    Cnt int
}

var taskChan = make(chan Task,1000)
var retChan = make(chan Task,1000)


func main()  {
    go startRoutines(10000)
    go handlResult()
    go produce()
    time.Sleep(1*time.Minute)
}


func startRoutines(n int)  {
    for i:=0;i<n;i++{
        go doSomeThing()
    }
}

func handlResult()  {
    for {
        select {
            case  r := <- retChan:
            fmt.Println(r)
        }
    }
}


func doSomeThing()  {
    for {
        select{
            case t := <-taskChan:
                for i:=0;i<1000000;i++{
                    t.Cnt++
                }
                retChan <- t
        }

    }
}

func produce()  {
    for i:=0;i<100000;i++{
        t := Task{
            Name: "task_"+strconv.Itoa(i),
            Cnt:  i,
        }
        taskChan <- t
    }
}