I've done some other test for this specific bug and I've discovered more,


If i do something like this 
-----------------------------
<?php
$start = time();
sleep(20);
echo "Execution time: ".(time()-$start)."s";
?>

and then i reload fpm, the script’s execution will stop immediately reporting the execution time elapsed form the launch of the script and the fpm reload


Else if i do something like that:
-----------------------------
<?php
$start = time();
for($i=0; $i<20; $i++) {
	sleep(1);
}
echo "Execution time: ".(time()-$start)."s";
?>

and reload FPM, he won’t be serve any other request for the amount of seconds of the cicle, (20 sec) but will terminate the execution of the script correctly.
The most terrifying thing is that if I have this kind of cicle with heavy computation and I launch a reload, all the websites under the pool will be unreachable until the script with the heavy cicle will finish.