timeout demo with problem……

gistfile1.go

package main

import (
	"fmt"
	"math/rand"
	"sync"
	"time"
)

const (
	MaxGoRoutineCount = 10
)

var (
	result   chan string        = make(chan string, MaxGoRoutineCount)        // 收集结果的chan
	jobQueue chan time.Duration = make(chan time.Duration, MaxGoRoutineCount) // 分发任务的chan
)

// goroutine 超时 demo
func main() {
	var wg sync.WaitGroup
	wg.Add(MaxGoRoutineCount)
	rand.Seed(time.Now().Unix())
	for i := 0; i < MaxGoRoutineCount; i++ {
		go hello(&wg)
	}

	go func() {
		for i := 0; i < 1000; i++ { // 有1000个任务要分配出去
			jobQueue <- time.Duration(rand.Intn(10)) * time.Second
		}
		close(jobQueue)
	}()

	go func() {
		i := 0
		for v := range result {
			fmt.Println("Result", i, ":", v)
			i++
		}
	}()

	wg.Wait()
	close(result)
}

func hello(wg *sync.WaitGroup) {
	defer wg.Done()
	for seconds := range jobQueue { // 死循环, 但是不担心，直到真正有任务之前都卡在这里, 且在关闭workLoad 的时候，所有goroutine 都会离开for 循环
		fmt.Println("job:", seconds.Seconds(), "start")

		select {
		case <-time.After(seconds): // 这个任务要处理n 秒……这里就可能和实际遇到的不一样……意味着真正的任务得再放到某个goroutine 里处理
			fmt.Println("job:", seconds.Seconds(), "success")
			result <- "success!"
		case <-time.After(5 * time.Second): // 设置5秒超时
			result <- "over time!!!"
			fmt.Println("job:", seconds.Seconds(), "timeout")
			continue
		}
	}
}