Are php ticks non-blocking

Question

I randomly came across things like:

<?php
    declare(ticks=1);

    // using a function as the callback
    register_tick_function('my_function', true);

    // using an object->method
    $object = new my_class();
    register_tick_function(array(&$object, 'my_method'), true);
?>

Which can be found at register_tick_function.

I wanted to know if using this in php was blocking or not?

EDIT: What I mean by this if I have more then one php tick running started on the same thread is it able to handle IO in the background while the other ticks run or does it need to wait for each tick to give over control?

Answer 1

Tick functions are blocking. PHP in general does not (natively) support parallel execution in the same request. So no, you will not be able to handle IO in the background, or something like that.

What ticks does is more or less inserting calls to the tick function after every statement. So what you get is something like this:

tick();
$a = 1;
tick();
$b = 2;
tick();
// ...

And it will behave just like that :)

Though, just so you understand whether or not this is actually significant: When a callback is executed in JS (e.g. a timeout / event is fired), then it's just as blocking.