non-blocking channel options _ golang

Basic sends and receives on channels are blocking. However, we can use select with a default clause to implement non-blocking sends, receives, and even non-blocking multi-way selects

package main

import (
"fmt"
)

func main() {

message := make(chan string)
signals := make(chan bool)

select {
case msg := <-message:
fmt.Println("received message", msg)
default:
fmt.Println("no message received")
}

msg := "hi"

select {
case message <- msg:
fmt.Println("sent message", msg)
default:
fmt.Println("no message sent")
}

select {
case msg := <-message:
fmt.Println("received message", msg)
case sig := <-signals:
fmt.Println("received signal", sig)
default:
fmt.Println("no activity")
}

}

no message received
no message sent
no activity

总结 :

　　1:....