signal-test.go

package main

import (
	"fmt"
	"os"
	"os/signal"
	"sync/atomic"
	"syscall"
)

func main() {
	fmt.Println("start")
	fmt.Println("pid =", os.Getpid())
	sigs := make(chan os.Signal, 1)

	signal.Notify(sigs, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)

	done := make(chan bool, 100)

	var n uint64 = 0
	finish := func(s string) {
		atomic.AddUint64(&n, 1)
		fmt.Println("finish:", s, "n =", atomic.LoadUint64(&n))
	}
	go func() {
		sig := <-sigs
		fmt.Println()
		fmt.Println(sig)
		finish("sig handler")
		done <- true
	}()

	defer finish("defer")

	fmt.Println("awaiting signal")
	wait := func () {
            fmt.Println("in wait")
            select {
            case <- done:
                fmt.Println("done pulled")
            }
        }

	wait()
	fmt.Println("exiting")
}

$ go run signal-test.go 
start
pid = 2290876
awaiting signal
in wait
^C
interrupt
finish: sig handler n = 1
done pulled
exiting
finish: defer n = 2