AMQP function consume() is a blocking function with a callback, Is it possible to set a timeout for consume() function, so after specific amount of time it doesn't block anymore and the code execution completes ?
Yes, here's how:
$amqp = new AMQPConnection($your_connection_params);
$amqp->setTimeout($seconds);
Then when you call consume() on a queue, if no messages arrive within the timeout period, an AMQPException will be thrown from consume() with the message, "Resource temporarily unavailable". If you ever break out of consume() or hit a timeout, be sure to call cancel() on the queue object to properly reset the consumer. In order to do this, you need to generate a globally unique consumer tag and pass it in as an undocumented, third parameter to consume:
$tag = uniqid() . microtime(true);
$queue->consume($callback, $flags, $tag);
$queue->cancel($tag);
That way, you can call consume() again later without weird issues that will make your head spin.