[Go] 利用channel實現簡單的工做池

先啓動固定數量的goroutine,每一個goroutine都在從channel中獲取數據,若是這個channel爲空,就阻塞等待在那裏
channel中傳遞一個Car類型,這個類型主要負責具體作的任務
也就是channel就是運輸通道,在這個通道上傳遞Car這樣一個汽車,來一輛車就處理這輛車的工做,沒有車過來那這些工人就在那等着

 

package main

import (
    "log"
    "sync"
    "time"
)

type Pool struct {
    workerNum int
    road      chan *Car
    wg        sync.WaitGroup
}

//初始化這個對象
func NewPool(wn int) *Pool {
    return &Pool{workerNum: wn, road: make(chan *Car)}
}

//往channel添加具體任務
func (p *Pool) AddCar(f *Car) {
    p.road <- f
}

//goroutine去工做
func (p *Pool) work(workId int) {
    for f := range p.road {
        log.Println("workId:", workId, "start")
        f.do()
        log.Println("workId:", workId, "done")
    }
    p.wg.Done()
}

//建立goroutine等着接工做
func (p *Pool) Run() {
    for i := 0; i < p.workerNum; i++ {
        go p.work(i)
        p.wg.Add(1)
    }
    p.wg.Wait()
}

func (p *Pool) colse() {
    close(p.road)
}

func main() {
    pool := NewPool(5)
    go func() {
        //模擬要作10件事
        for i := 0; i < 10; i++ {
            car := Car{
                param: i,
            }
            pool.AddCar(&car)
        }
        pool.colse()
    }()
    pool.Run()
}

/*具體作的事經過這個來傳遞*/
type Car struct {
    param int
}

func (c *Car) do() error {
    log.Println(time.Now(), c.param)
    return nil
}