package main import ( _"os" "fmt" "time" )

func main() { for i:=0; i<50; i++ { c := make(chan int) go func( index int,cp chan int ) {// //for { fmt.Println("before send to chan,index is ",index) cp<-0 // will block fmt.Println("after send,index) //} }(i,c)//

go func(cp chan int ){
		time.Sleep(5*time.Second)
		<-cp
	}(c)
}
time.Sleep(10*time.Second)
//select{}

}