frankenphp: fix loop increment and break behavior

[tamcy]

The current Runtime doesn't behavior as documented.

        } while ($ret && (-1 === $this->loopMax || ++$loops <= $this->loopMax));

Found two issues in my testing, hence this PR:

1. when $ret is true (which seems to be always the case?), the remaining conditions won't be evaluated, so $loops will never increment.
2. Setting $loopMax to 1 will result in 2 requests be handled before resetting.

I'm not very sure of what $ret does (I thought this will return false when an unrecoverable error occurs, turns out it won't), but in anyway it dosen't sound right for the number of request not incrementing when the response is a successful one.

[alexander-schranz]

@dunglas can you have a look at this.

[dunglas]

Good catch.

[dunglas]

$ret is used to terminate gracefully the worker script when FrankenPHP is stopped.

[tamcy]

After a night I reread my points and found point 1 to be ridiculous - the interpreter should evaluate the second condition because it's an AND!

Here's the story: yesterday, I spent more than an hour trying to figure out why the runtime won't reset itself even when FRANKENPHP_LOOP_MAX is set to 1 when worker number is 1. I found that the $loop variable doesn't increase at all in the original version by placing logs here and there, also after the do-while loop, and also found that the loop doesn't exist at all. Not until I move the loop increment from while to the loop. I wasn't sure why I jumped to this absurd conclusion, perhaps I got irrational due to the behavior.

(The following codes work as expected.)

<?php
class Foo
{
    private $loopMax = 10;
    public function run()
    {
        $loops = 0;
        do {
            echo "loop $loops\n";
            $ret = true;

            gc_collect_cycles();

        } while ($ret && (-1 === $this->loopMax || ++$loops < $this->loopMax));
    }
}


$foo = new Foo();
$foo->run();

I request to put this PR on hold. The second fix is still correct; I'd like to fix my commit message first.

Sorry for the inconvenience caused.

[tamcy]

The loop increment is indeed working fine. I've submitted #174 as a replacement. Sorry for the false alarm!