procLockFileEx = modkernel32.NewProc("LockFileEx")
)

const (
	// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx
	lockFileExclusiveLock   = 2
	lockFileFailImmediately = 1

	// see https://msdn.microsoft.com/en-us/library/windows/desktop/ms681382(v=vs.85).aspx
	errLockViolation syscall.Errno = 0x21
)

// lockedOpenFile is an internal function.