# Apache 2 support - Thread: https://externals.io/message/2923 - Original archive: https://news-web.php.net/php.internals/2923 - Started by Marc Richards on 2003-06-28T05:52:29+00:00 - Messages: 8 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #2923 — Marc Richards — 2003-06-28T05:52:29+00:00 URL: https://externals.io/message/2923#2923 I apologies if this is the wrong place for asking. Is non-experimental Apache2 support planned for PHP 5? Marc --- ## #2924 — Rasmus Lerdorf — 2003-06-28T06:02:25+00:00 URL: https://externals.io/message/2923#2924 · In reply to: #2923 > I apologies if this is the wrong place for asking. Is non-experimental > Apache2 support planned for PHP 5? Nope. Until someone sits down and goes through every 3rd-party library that can be linked into PHP on every platform and identifies whether or not they are threadsafe and under which conditions they remain threadsafe, using PHP in a threaded web server on UNIX is going to remain experimental. You can of course stick with non-threaded prefork mode, in which case you basically have Apache-1.3.x. Nobody so far have been motivated to test Apache2-prefork+PHP extensively, so even that combination is going to remain experimental. The basic problem here is that the average UNIX library has not been written with thread safety in mind. You can write very good specific threaded programs on UNIX, but it is extremely difficult to write something which can potentially link in hundreds of random libraries and expect them to all be threadsafe. -Rasmus --- ## #2925 — Matt Parlane — 2003-06-28T06:10:15+00:00 URL: https://externals.io/message/2923#2925 · In reply to: #2924 Rasmus Lerdorf wrote: > Nope. Until someone sits down and goes through every 3rd-party library > that can be linked into PHP on every platform and identifies whether or > not they are threadsafe and under which conditions they remain threadsafe, > using PHP in a threaded web server on UNIX is going to remain > experimental. From that, can I assume that using PHP by itself with no external libraries is stable with Apache 2? Is there a short list of some common extensions that do work reliably with Apache 2? (eg MySQL, GD etc...) Matt --- ## #2926 — Rasmus Lerdorf — 2003-06-28T06:17:43+00:00 URL: https://externals.io/message/2923#2926 · In reply to: #2925 > > […] > > From that, can I assume that using PHP by itself with no external > libraries is stable with Apache 2? It might be. We don't know and since none of us (that I know of at least) would dream of running that combination in our own production environments we won't know for a while. Until there is some compelling feature above and beyond what can be done in the tried and true Apache-1.3.x code, I don't see this situation changing. > Is there a short list of some common extensions that do work reliably > with Apache 2? (eg MySQL, GD etc...) Nope. Make one. It's not all that easy to create such a list. Just take a single library and go through it and tell me if it is threadsafe. Can you do that? Do you know what to look for? If it is threadsafe on one platform, do you think it is threadsafe on another? Does it depend on which version of libc is on a platform? Does it depend on how it was compiled? We could of course mutex every call to every external function. Then we could be reasonably sure it would work, and at the same time we could be sure that it was much slower than running it non-threaded. -Rasmus --- ## #2932 — Dmitri Dmitrienko — 2003-06-28T09:58:24+00:00 URL: https://externals.io/message/2923#2932 · In reply to: #2926 > We could of course mutex every call to every external function. Then we > could be reasonably sure it would work, and at the same time we could be > sure that it was much slower than running it non-threaded. Any crash in an area protected by mutex would leave this mutex in non-released state and all the rest threads trying to access that area would be blocked forever. Remember the problem of Win95<->Win 3.1 interoperability ? BTW, is there any way for checking if a library does not create nor use any global variables ? May be just running nm with non-stripped .so objects and inspecting the resulting list ? Any other ideas ? -Dmitri. --- ## #2934 — Sascha Schumann — 2003-06-28T10:35:13+00:00 URL: https://externals.io/message/2923#2934 · In reply to: #2932 > > […] > > Any crash in an area protected by mutex would leave this mutex in > non-released state and all the rest threads trying to access that area would > be blocked forever. A crash in a multi-threaded program most likely leads to the termination of the process, so this is a non-issue. > BTW, is there any way for checking if a library does not create nor use any > global variables ? May be just running nm with non-stripped .so objects and > inspecting the resulting list ? Any other ideas ? nm displays global variables, including static function-scope variables. However, you cannot discern whether their use is save unless you audit the source code. The latter is also necessary, because a function can rely on external non-reentrant functions which renders the caller itself non-reentrant. - Sascha --- ## #2955 — Wojtek Meler — 2003-06-28T19:00:54+00:00 URL: https://externals.io/message/2923#2955 · In reply to: #2925 Matt Parlane wrote: > From that, can I assume that using PHP by itself with no external > libraries is stable with Apache 2? I don't think so... http://bugs.php.net/bug.php?id=16820 is still open. But if you don't limit time for scripts it should work. regards, Wojtek --- ## #2966 — Dmitri Dmitrienko — 2003-06-29T10:10:19+00:00 URL: https://externals.io/message/2923#2966 · In reply to: #2934 > > […] we > > […] be > > […] would > > […] > > A crash in a multi-threaded program most likely leads to the > termination of the process, so this is a non-issue. Okay. Suppose it's the best solution to avoid hangs.... :-) > > […] any > > […] and > > […] > > nm displays global variables, including static function-scope > variables. However, you cannot discern whether their use is > save unless you audit the source code. I agree but I meant different thing. Everybody understand that sources must be audited but nobody want to do it just because they are too big and all the process would be just wasting the time. At least withought cliear understanding what to do after a snapshot is audited. Nobody would like to do the same work twice. Look, if a library (or function) does not use global variables nor call to other functions that are explicitly marked as a non-reentrant (should a list be opened for it?), this library can be safely used in multithreaded environment and thus the list of remained code to be audited can be made fewer. Isn't it ? Don't you agree that it's nearly impossible to audit all the code including all the extensions. Even if anybody audited a particular snapshot of all sources what to do with it after other people have made modifications ? I believe there must be an automated process that should be tightly integrated in to building scripts. As a result we should get a list of all functions with one of the following "CLEAR" "TO BE AUDITED" "NON REENTRANT". Any further ideas ? -dmitri.