I've posted a few times to this list and may do so some more, so as a
courtesy I though that I should give a short intro on me and what I am
doing here. By way of a personal background, I retired early from HP
five years ago due to ill-health though I have since recovered. I was a
Distinguished SE for what that was worth, and have been programming
C/C++ and PHP for a LONG time. Now I am a gentleman of leisure (AKA old
fart) and now do it for pleasure only.
One thing about PHP that has always puzzled me was that we've never
developed a good opcode caching solution for CGI and CLI use as the
various opcode caches are add-on extensions rather than PHP core and
really targeted for high-volume single UID environments. I see two main
problems with this:
-
Multi-account service providers must employ UID based mandatory
separation of processes, and no other shared approach meets even minimal
security requirements. -
Whilst opcode caching only applies and an option for some PHP
runtime environments and not all, it is not properly architected into
the PHP compile and run environment, and hence the opcode caches -- by
necessity -- seem to include quite a few clumsy workarounds to be able
to run. Opcode caching or at least a clear interface to such caches
should be a PHP core feature for all execution modes.
What I've been doing for the last six months is to develop a Lightweight
Program Cache (LPC) extension optimised for CGI and CLI use to get a
better understanding of the problems and possible approaches to address
these. LPC started life as a fork of APC, but has turned into a
stripped-down rewrite. I see this primarily as a demonstrator and a
vehicle for my really getting to grips with the internals of the PHP
compiler and execution engine. If anyone is interest or wants to get an
overview of how PHP code caches work have a read of:
https://github.com/TerryE/php-extensions/blob/master/lpc/TECHNOTES.txt
I doubt that it will ever be anything more than beta code so I don't
need a VCS account or any other karmas. Nonetheless it does essentially
work -- it roughly doubles the throughput of MediaWiki with no memory
leaks. However, it is a long way away from being at a level where I
would suggest anyone pull the repository and plays with it. I am still
at Zend 2.3 and I need still need to roll in the extra 2.4 functional
changes. It fails the PHP test suite for some extensions, and I am
currently tracking down a bunch of issues from the php5/Zend/test
failures (yup -- one advantage of running in CLI mode is that I can test
the extension against the entire PHP test suite in two passes -- one to
build the per-script caches and a repeat to run against the cache version).
Anyway, regards to you all, Terry Ellison