ctx_listen.go

package main

import (
	"context"
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	exit := make(chan os.Signal, 1)
	signal.Notify(exit, os.Interrupt, syscall.SIGTERM)

	go longBackgroundWorker(ctx)

	<-exit
	cancel()
	// the sleep to show the ctx std output before exiting immediately.
	time.Sleep(1 * time.Second)
}

// longBackgroundWorker is an example function to demonstrate
// the context cancel listen event.
func longBackgroundWorker(ctx context.Context) {
	// a ticker is created for simulating a continuous process.
	ticker := time.NewTicker(1 * time.Second)
	for {
		select {
		case <-ticker.C:
			// This can be a file streaming service,
			// database transactions etc.
			fmt.Println("I am a long running process")
		case <-ctx.Done():
			// you could cancel or save the checkpoint 
			// of the long-running process in this scenario.
			fmt.Println("Canceling the last running process.")
			ticker.Stop()
			return
		}
	}
}