golang并发编程的实现

func main(){
  ch := make(chan int)
  
  go func(ch chan int){
    ch <-222
  }(ch)
  
  println(<-ch)
}

func main() {
  ch := make(chan int, 1) //长度为1的缓冲管道也是有缓冲管道
  ch <- 333
  go func(ch chan int) {
    println(<-ch)
  }(ch)
  ch <- 333
}

func main() {
  var wg sync.WaitGroup
  ch := make(chan int, 1000)
  for i := 0; i < 1000; i++ {
    wg.Add(1)
    go doSomething(i, &wg, ch)
  }
  wg.Wait()
  fmt.Println("all done")
  for i := 0; i < 1000; i++ {
    dd := <-ch
    fmt.Println("from ch:"+strconv.Itoa(dd))
  }
}

func doSomething(index int, wg *sync.WaitGroup, ch chan int) {
  defer wg.Done()
  fmt.Println("start done:" + strconv.Itoa(index))
  //time.Sleep(20 * time.Millisecond)
  ch <- index
}