//go:build linux || darwin || freebsd || openbsd || netbsd || dragonfly

package common

import (
	"os"
	"syscall"
)

func lockPersistentFile() (func(), error) {
	file, err := os.OpenFile("persistent.lock", os.O_CREATE|os.O_RDWR, 0600)
	if err != nil {
		return nil, err
	}
	if err := syscall.Flock(int(file.Fd()), syscall.LOCK_EX); err != nil {
		file.Close()
		return nil, err
	}
	return func() { syscall.Flock(int(file.Fd()), syscall.LOCK_UN); file.Close() }, nil
}