Symfony Lock Component does not lock – how to fix?

i upgraded recently to Symfony 3.4.x, refactor LockHandler because of deprecation warning and fall into strange behaviour.

Code in command before refactoring:

class FooCommand
{
    protected function configure() { /* ... does not matter ... */ }
    protected function lock() : bool
    {
        $resource = $this->getName();
        $lock     = new SymfonyComponentFilesystemLockHandler($resource);

        return $lock->lock();
    }
    protected function execute()
    {
        if (!$this->lock()) return 0;

        // Execute some task
    }
}

And it prevents to run two command at the same time – second just finishes without doing job. That is good.

But after suggested refactoring it allows to run many commands simultaneously. This is FAIL. How to prevent execution? New code:

class FooCommand
{
    protected function configure() { /* ... does not matter ... */ }
    protected function lock() : bool
    {
        $resource = $this->getName();
        $store    = new SymfonyComponentLockFlockStore(sys_get_temp_dir());
        $factory  = new SymfonyComponentLockFactory($store);
        $lock     = $factory->createLock($resource);

        return $lock->acquire();
    }
    protected function execute()
    {
        if (!$this->lock()) return 0;

        // Execute some task
    }
}

NB #1: I don’t care about many servers or so, just one instance of application.

NB #2: If process was killed then new command must unlock and run.

Answer

You must use the LockableTrait trait

    use SymfonyComponentConsoleCommandLockableTrait;
    use SymfonyComponentConsoleCommandCommand

    class FooCommand  extends Command
    {
        use LockableTrait;
.....
protected function execute(InputInterface $input, OutputInterface $output)
    {
        if (!$this->lock()) {
            $output->writeln('The command is already running in another process.');

            return 0;
        }
// If you prefer to wait until the lock is released, use this:
        // $this->lock(null, true);

        // ...

        // if not released explicitly, Symfony releases the lock
        // automatically when the execution of the command ends
        $this->release();

}