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Date: Sun, 3 Jan 2021 11:49:52 -0600
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To: =?UTF-8?Q?Olle_H=C3=A4rstedt?= <olleharstedt@gmail.com>
Cc: PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Does PHP ever stack allocate?
From: pollita@php.net (Sara Golemon)

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On Sun, Jan 3, 2021 at 10:37 AM Olle H=C3=A4rstedt <olleharstedt@gmail.com>
wrote:
> Thanks Sara! I realize I should have been more precise: Can PHP
> allocate non-reference counted memory that automatically is freed when
> leaving scope, similar to what Go does with escape analysis?
>

It seems like you're conflating userspace variables and their underlying
data storage mechanisms and while the two are related and have naturally
similar semantics, they're not really the same thing and trying to
generically talk about both at the same time is only going to add to
confusion.

If you're talking about userspace variables... Yeah.  They're scope bound
and destructed/freed on scope exit.  Nearly every language does some form
of this because to not do so would be leaky and awful.

If you're talking about internal memory allocators, then the idea of
"automatically freed" is a red-herring.  It's an illusion created by some
languages to cover up the quite explicit mechanisms in place to handle data
lifetimes.  PHP does its form of this as well using a combination of stack
and heap allocators as appropriate.

-Sara

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