Example for using a named mutex with github.com/juju/mutex

example.go

package main

import (
	"errors"
	"log"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/juju/mutex/v2"
)

type realtime struct{}

func (r realtime) After(d time.Duration) <-chan time.Time {
	c := make(chan time.Time)
	go func() {
		time.Sleep(d)
		c <- time.Now()
	}()
	return c
}

func (r realtime) Now() time.Time {
	return time.Now()
}

func main() {
	log.Println("Trying to acquire mutex...")
	r, err := mutex.Acquire(mutex.Spec{Name: "dummy123", Clock: realtime{}, Delay: 100 * time.Millisecond, Timeout: 250 * time.Millisecond})
	if errors.Is(err, mutex.ErrTimeout) {
		log.Println("There is already an instance running")
		os.Exit(1)
	} else if err != nil {
		log.Fatal(err)
	}
	defer r.Release()
	log.Println("Mutex acquired. Running...")
	sc := make(chan os.Signal, 1)
	signal.Notify(sc, syscall.SIGINT, syscall.SIGTERM, os.Interrupt)
	<-sc
}