Go 的全局退出监听

经常会有全局监听退出信号的需求，例如编写的 HTTP 服务或者 gRPC 服务需要监听退出信号时就可以使用这个方式

// signal.go
package util

import (
    "log"
    "os"
    "os/signal"
    "syscall"
)

// RegisterExitHandlers is used to register exit handlers
func RegisterExitHandlers(cancelFunc func()) (stop chan struct{}) {
    var exitSignals = []os.Signal{os.Interrupt, syscall.SIGTERM} // SIGTERM is POSIX specific

    stop = make(chan struct{})
    s := make(chan os.Signal, len(exitSignals))
    signal.Notify(s, exitSignals...)

    go func() {
        // Wait for a signal from the OS before dispatching
        // a stop signal to all other goroutines observing this channel.
        <-s
        log.Println("exit signal received")
        if cancelFunc != nil {
            cancelFunc()
        }
        close(stop)
    }()

    return stop
}

使用的时候也很简单

package main

import (
    "context"
    "log"
    "stgo/util"
)

func main() {
    log.Println("Starting...")
    _, cancel := context.WithCancel(context.Background())
    stop := util.RegisterExitHandlers(cancel)
    defer cancel()

    // here is something server.

    <-stop
    log.Panicln("Goodbye")
}

这样就能监听 ctrl + c 的退出信号了