go 创建携程池，开启并发

地址；https://github.com/panjf2000/ants

采用蚂蚁池开源的SDK，ants 是一个高性能且低损耗的 goroutine 池

package main

import (
   "fmt"
   "sync"
   "sync/atomic"
   "time"

   "github.com/panjf2000/ants"
)

var sum int32

func myFunc(i interface{}) {
   n := i.(int32)
   atomic.AddInt32(&sum, n)
   fmt.Printf("run with %d
", n)
}

func demoFunc() {
   time.Sleep(10 * time.Millisecond)
   fmt.Println("Hello World!")
}

func main() {
   defer ants.Release()

   runTimes := 1000

   // Use the common pool.
   var wg sync.WaitGroup
   syncCalculateSum := func() {
      demoFunc()
      wg.Done()
   }
   for i := 0; i < runTimes; i++ {
      wg.Add(1)
      _ = ants.Submit(syncCalculateSum)
   }
   wg.Wait()
   fmt.Printf("running goroutines: %d
", ants.Running())
   fmt.Printf("finish all tasks.
")

   // Use the pool with a method,
   // set 10 to the capacity of goroutine pool and 1 second for expired duration.
   fn := func(i interface{}) {
      myFunc(i)
      wg.Done()
   }
   var mmm []func(i ants.Options)

   fno := func(i ants.Options) {
      i.PreAlloc = false
      i.MaxBlockingTasks = 100
   }
   mmm = append(mmm, fno)

   var hhh ants.Option  // 设置携程
   lll :=  &ants.Options{}
   lll.PreAlloc = false
   lll.MaxBlockingTasks = 100
   hhh(lll)
   p, _ := ants.NewPoolWithFunc(10, fn, hhh)
   defer p.Release()
   // Submit tasks one by one.
   for i := 0; i < runTimes; i++ {
      wg.Add(1)
      _ = p.Invoke(int32(i))
   }
   wg.Wait()
   fmt.Printf("running goroutines: %d
", p.Running())
   fmt.Printf("finish all tasks, result is %d
", sum)
   if sum != 499500 {
      panic("the final result is wrong!!!")
   }
}