golang控制协程数量

发表于
人活一生，值得爱的东西很多，不要因为一个不满意，就灰心

DEMO1

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for _,v := range Uins{
    // Query the corresponding user information for each UIN
    go getUserInfo(v)
}

DEMO2

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func main(a){
  // Create an empty structure channel with size 512
  channel := make(chan struct{},512)
  / / create a sync. WaitGroup
  var wg sync.WaitGroup
  // Wg is the length of Uins
  wg.Add(len(Uins))
  for_,v:= range Uins{
      channel <- struct{} {}// Pass WG as a parameter to the coroutine
      go getUserInfo(v,channel,&wg)
  }
  // block until wg is 0
  wg.Wait()
  return
}


func getUserInfo(v int,channel chan struct{},wg *sync.WaitGroup){
    defer func(a) {
    	// Wargaming is reduced by 1 before return
        wg.Done()
		<-channel
	}()
    /**
    业务逻辑  
    **/
}

DEMO3

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package main

import (
	"fmt"
	"sync"
)

func main() {
	count := 10
	sum := 100
	wg := sync.WaitGroup{}

	c := make(chan struct{}, count)
	defer close(c)

	for i:=0; i<sum;i++{
		wg.Add(1)
		go func(j int) {
			defer wg.Done()
			c <- struct{}{}
			fmt.Println(j)
		}(i)
		<- c
	}
	wg.Wait()
}

DEMO4

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package main

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

func main() {

	maxnum := make(chan struct{}, 5)
	setPool(maxnum)

	wg := sync.WaitGroup{}
	wg.Add(5)

	go func() {
		for {
			wg.Wait()
			fmt.Println("=======发放5个任务=========")
			setPool(maxnum)
			wg.Add(5)
		}
	}()


	for {
		<-maxnum
		 go func() {
		 	defer wg.Done()
		 	myJob()
		 }()
	}

}

func setPool(ch chan struct{}) {
	for i:=0; i<5; i++ {
		ch <- struct{}{}
	}
}

func myJob() {
	time.Sleep(time.Second * 3)
	fmt.Println(rand.Intn(100))
}