amqp-interop with enqueue/amqp-lib not responding to SIGINT

[Tarinu]

What steps will reproduce the problem?

1. Make sure PCNTL extension is installed.
2. Configure queue using enqueue/amqp-lib so it can create the connection with RabbitMQ

   return [
       'bootstrap' => ['queue'],
       'components' => [
           'queue' => [
               'class' => \yii\queue\amqp_interop\Queue::class,
               'driver' => yii\queue\amqp_interop\Queue::ENQUEUE_AMQP_LIB,
               'host' => 'localhost',
               'port' => 5672,
               'user' => 'guest',
               'password' => 'guest',
               'queueName' => 'test',
           ],
       ],
   ];

3. Run php yii queue/listen
4. Send SIGINT (CTRL+C)

What's expected?

Listener should stop running

What do you get instead?

Nothing happens, disconnect event isn't sent to RabbitMQ.

Additional info

Queue is completely empty so it's not waiting for a job to finish before exiting.

This seems to happen because amqp-tools overwrites these signals with custom handlers. Setting up handlers as described in php-amqplib docs seems to stop the process as I'd expect it to.

Q	A
Yii version	2.0.35
Yii-queue version	2.3.0
enqueue/amqp-lib version	0.10.1
PHP version	7.4.5
Operating system	Debian 10

[samdark]

@Tarinu seems you have a solution. Do you have some time to prepare a pull request?

[Tarinu]

I can look into it tomorrow evening. I wasn't sure if the solution I found was the best way of going about solving the issue. Could it cause problems when used together with other queues, since they also register their own signal handlers?

[samdark]

Can't say for sure. Needs testing.

[ptheofan]

Any ETA when this will be released to stable? Not being able to ctrl+c makes development process very tedious

Also, systemd cannot restart the service unless I kill -9 it (or a timeout occurs and it kills the process)

btw, why on earth would this bug be marked as an enhancement?

[samdark]

Travis build that fails makes it not that easy to test if something is broken. Have you tested the code in the pull request locally?

[ptheofan]

It's currently on staging and working like a charm. I actually extended the base class and added it in the init function until the repo is updated. Besides a couple of mostly cosmetic changes, it's basically a copy/paste of the patch.

This is the actual code running on staging for the past 8 hours (PHP 7.4)

Cosmetic changes

1. the callback function is now declared as static function
2. added a space right after use
3. added the is_callable check && is_callable($oldHandler)) { to be on the safe side as per PHP documentation regarding return value.

I've also annotated them as review remarks on the PR for clarity.

class Queue extends \yii\queue\amqp_interop\Queue
{
    public function init(): void
    {
        parent::init();

        if (extension_loaded('pcntl') && PHP_MAJOR_VERSION >= 7) {
            // https://github.com/php-amqplib/php-amqplib#unix-signals
            $signals = [SIGTERM, SIGQUIT, SIGINT, SIGHUP];

            foreach($signals as $signal) {
                $oldHandler = null;
                // This got added in php 7.1 and might not exist on all supported versions
                if(function_exists('pcntl_signal_get_handler')) {
                    $oldHandler = pcntl_signal_get_handler($signal);
                }

                pcntl_signal($signal, static function ($signal) use ($oldHandler) {
                    if($oldHandler && is_callable($oldHandler)) {
                        $oldHandler($signal);
                    }

                    pcntl_signal($signal, SIG_DFL);
                    posix_kill(posix_getpid(), $signal);
                });
            }
        }
    }
}