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Date: Mon, 27 Jun 2016 18:05:44 +0700
Message-ID: <CAEZPtU6k+h8xvTLtKmPZKyzYxNNXL4=aD26KOryMJ2MfDOY6BA@mail.gmail.com>
To: Joe Watkins <pthreads@pthreads.org>
Cc: Bob Weinand <bobwei9@hotmail.com>, PHP internals <internals@lists.php.net>, 
	Dmitry Stogov <dmitry@zend.com>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [PHP-DEV] [RFC] Asynchronous Signal Handling (withiut TICKs and
 any additional overhead).
From: pierre.php@gmail.com (Pierre Joye)

On Mon, Jun 27, 2016 at 5:08 PM, Joe Watkins <pthreads@pthreads.org> wrote:
> Morning,
>
>     How is the impact wider than ext/pcntl ?

The implementation is only in pctnl. The feature is used indirectly by
the engine and makes it a core feature. Quote from the RFC:

"Zend Engine in PHP 7.1 was extended with ability of safe time-out and
interrupt handling. Actually, PHP VM checks for EG(vm_interrupt) flag
on each loop iteration, user function entry or internal function exit,
and call callback function if necessary.

I propose to use this ability to implement asynchronous signal
handling. Registered signal handlers are going to be called at some
points during user script execution without any overhead."

and the test:

<?php
ini_set("pcntl.async_signals", "1");
pcntl_signal(SIGTERM, function ($signo) { echo "Signal handler called!\n"; });

echo "Start!\n";
posix_kill(posix_getpid(), SIGTERM);
$i = 0; // dummy
echo "Done!\n";

It affects how signals are handled within the engine, obvioulsy.

I have no doubt that this RFC will be accepted, by large, so it is not
a big issue. However it does affect the engine so the 2/3 rule
applies.

Cheers,
-- 
Pierre

@pierrejoye | http://www.libgd.org