Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:113091
MIME-Version: 1.0
Date: Fri, 5 Feb 2021 17:03:12 +0300
Message-ID: <CAPVMwwshrC64Tuj8uocMK7bHVFQANzE=NGGB3uZ4rvXp-9dr+g@mail.gmail.com>
To: PHP Internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary="0000000000008e4c9b05ba9748fe"
Subject: [PHP-DEV] Inheritance Cache
From: dmitrystogov@gmail.com (Dmitry Stogov)

--0000000000008e4c9b05ba9748fe
Content-Type: text/plain; charset="UTF-8"

Hi,

I'm glad to present the result of my recent work - Inheritance Cache.

https://github.com/php/php-src/pull/6627

This is a new transparent technology that eliminates overhead of PHP class
inheritance.

PHP  classes are compiled and cached (by opcahce) separately, however their
"linking" was done at run-time - on each request. The process of "linking"
may involve a number of compatibility checks and borrowing
methods/properties/constants form parent and traits. This takes significant
time, but the result is the same on each request.

Inheritance Cache performs "linking" for unique set of all the depending
classes (parent, interfaces, traits, property types, method types involved
into compatibility checks) once and stores result in opcache shared memory.
As a part of the this patch, I removed limitations for immutable classes
(unresolved constants, typed properties and covariant type checks). So now
all classes stored in opcache are "immutable". They may be lazily loaded
into process memory, if necessary, but this usually occurs just once (on
first linking).

The patch shows 8% improvement on Symphony "Hello World" app.

I'm going to merge this patch into master on next week.
Please review and give your comments.

Thanks. Dmitry.

--0000000000008e4c9b05ba9748fe--