The last several months, I’ve been working very deeply with PHP—specifically—compiling the PHP core itself, and looking for avenues for optimization. This is the first of four posts about the journey I’ve been on with PHP.
I get started building PHP
"It is a bad plan that admits of no modification" – Publilius Syrus
I started working with building PHP itself about a year ago. Initially, I was trying to put together an environment to compile up the PHP stack so that I could do some debugging, and track down a few faults that we were encountering in some of the PHP applications that we were trying to modify to use the SQL Server PHP driver that the SQL Server team here at Microsoft was creating.
Once I began to work with the source code, I found out very quickly that on top of having a hard time recreating the exact same binaries that the community build process generated, there were a large number of dependent libraries that were available in binary-only form which were kept in a zip file that was passed around from developer to developer. That seemed a little odd for an open-source project but I can certainly understand that over time, unless someone is working hard to keep it all together, these things happen.
Around the same time, the community had started to invest a time and effort to 'clean up' the dependencies for building PHP on Windows, and move towards supporting VC9 (Visual Studio 2008) as an officially supported compiler.
In order to help in this process, I built out some testing environments in our Lab, which would let me compile up PHP on Windows and Linux, in order to get decent and reliable test results which we could use to identify any shortcomings that we could address. This includes benchmarking not just the core PHP executable, but replicable and comparable testing of PHP applications such as WordPress, MediaWiki, Gallery and phpBB.
PHP 5.3 on Windows: Not your father's PHP
"I'm looking for a lot of men who have an infinite capacity to not know what can't be done." – Henry Ford
For PHP 5.3, Pierre (and others) had gone out and found up-to-date versions of all the dependencies, brought them together, and managed to get them compiling with VC6 and VC9. They had posted these in binary and source form to the PHP Windows Internals site, which allows anyone to rebuild the PHP stack on Windows, and theoretically, get the same results as the 'official' build.
Jumping in at that point was much easier than it had been, as all you had to do was download the binaries of the libraries, check out the source code, and run a few commands at the command line, and presto you had your PHP executables.
At this point Pierre and I played around with the build flags on VC9 and found some settings that gave some pretty significant improvements to the speed of PHP vs. the speed of the VC6 version—and a lot of speed improvements to vs. the old 5.2x line of PHP.
In Part II, I’ll talk about the going one step further with optimization.