Is this still happening with latest CVS checkout?

Well,
over time this started to happen with other extensions as well. So right now, I'm not even trying to compile a dynamic version anymore.

I'll do this over the weekend though. Would you prefer to know the bundled gd results or the external?

Ah, I missed that 'shared' point here. Reclassified..
If it happens with other extensions too..well, then
it's bit bigger issue.

btw. Why would you send apache a 'SIGUSR1'? And SIGHUP
hasn't ever worked when PHP is compiled as DSO, you should
stop/start instead of 'restart'. 

--Jani

SIGUSR1: to keep status info, for /server-status and not to piss off users, downloading stuff around midnight, while we are rotating the logs.

SIGHUP normally works ok, when php is compiled as DSO. And 'stop and start' is just not an option.

I have two hunches, developed by trying about every compilation scheme I could think of:
1) non-libtool compiled libs are problematic, openssl being the one that comes to mind instantly.

2) php as a dso is ok, even shared modules, as long as those shared modules don't contain other shared modules, which are not part of the 'extension', like gd, needing libjpeg/libz or  libcurl needing openssl. Strangely enough, sablot/expat combination is fine again.

Just a status update: does this happen with today's CVS checkout?

Tried again today. Problem persists.

Updated version.

Please try using this CVS snapshot:

  http://snaps.php.net/php4-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-latest.zip

Sorry - but I can't retry:
mdev@valygar.idg.nl ~/_src/php4-200210160300
$ gmake install
Installing PHP SAPI module
[activating module `php4' in /apache/conf/httpd.conf]
cp libs/libphp4.so /apache/libexec/libphp4.so
cp: libs/libphp4.so: No such file or directory
apxs:Break: Command failed with rc=1
gmake: *** [install-sapi] Error 1

mdev@valygar.idg.nl ~/_src/php4-200210160300
$ ls libs
libphp4.a       libphp4.la

mdev@valygar.idg.nl ~/_src/php4-200210160300
$ cat configure-cmd.sh
#!/bin/sh

./configure \
        --prefix=/php \
        --with-mysql=/weblib/local \
        --with-zlib-dir=/usr \
        --with-gd=php \
        --with-jpeg-dir=/weblib/local \
        --with-freetype-dir=/weblib/local \
        --enable-sockets \
        --with-apxs=/apache/bin/apxs

Ok - user error. Jpeg has a libtool from the stoneages. Replacing that with a 1.4 release, correctly builds a shared version, which will then create libs/libphp4.so.

However - the problem with the signals remains.

And I guess you have shared extensions loaded in your php.ini when this happens? And if not, it works fine?

I tried on my machine (linux :) these:

./apachectl restart
./apachectl graceful

And both worked fine. I don't have any shared extensions in my php.ini

Nope - wrong guess :-).
It is not just GD. When I removed GD from the below configuration, it still didn't work.
The following works correctly:
./configure \
        --prefix=/php \
        --disable-mbstring \
        --with-zlib=/usr \
        --with-zlib-dir=/usr \
        --with-apxs=/apache/bin/apxs

I'll use --disable-all and make a list of extensions that have/expose these problems. Maybe there's a common factor.

Ok, just a quick status update:
The 'old' gd still exposes the problem. The bundled gd does not, in contradiction to my previous report. This was actually caused because, the bundled MySQL lib, is OK, BUT an external mysql lib (3.23.53) also exposes the problem.

Since I tried both, with the same zlib option, and both MySQL libs have been linked with the same zlib, it cannot be a zlib problem.

I've created a php script, to test this :-).
Output is as follows:
============================================================
 RESULTS SIGTEST
------------------------------------------------------------
                           Mysql bundled: OK
                          Mysql external: NOT OK
                         Aspell external: NOT OK
                              GD bundled: OK
                             XML Bundled: OK
                            XML external: OK
                           XSLT external: NOT OK
                          Iconv external: OK
                   GNU gettext, external: OK
                        OpenSSL external: NOT OK
              Curl external, without SSL: NOT OK
                 Curl external, with SSL: NOT OK
============================================================

The commonalities seem to be, that the modules which fail, load more than 1 external shared library. MySQL loads zlib, Aspell loads several aspell libs, OpenSSL has -lssl and -lcrypt and curl loads -lssl ("Curl external, without SSL", simply means --with-openssl was not given. -lssl and -lcrypt are still linked in).
The only exceptions to this, are the Bundled GD, which is compiled with libjpeg, libpng, libz and libfreetype and the Bundled MySQL.

The common factors with these is, that libphp4.so doesn't call libgd/libmysqlclient, but has this code built in.

Concluding this goes wrong when there are 2 levels of dynamic loading:
apache -> libphp4 -> libfoo -> libbar

It reminded me of bug in BSD/OS 4.x series, on how symbols are resolved:
http://www.geocrawler.com/archives/3/127/1999/5/0/1795873/

Can somebody experience in this, take a look if it makes any sense in comparison to what PHP is doing?

Not sure whether this has nothing to do with this bug,
but take a look in Apache 1.3.27 sources,  src/main/http_main.c file and look for WORKAROUND_SOLARIS_BUG. You could try defining that and recompile apache (make clean && make) to see if it has any effect?

Thanx Jani, but it's not the cause. I've tried it regardless and it doesn't help.

It's defenitely a linker issue, although a ktrace doesn't reveal much info.

I tried searching for similar issues in other projects
and found this document:
http://www.pix.net/software/bsdos/elf_faq.html#How%20do%20I%20build%20a%20program%20that%20dynamically%20loads%20a%20shared%20object%20(with%20dlopen(3)

Basically what I read about BSDi's support for dlopen() was
not really promising. 

Could you try compiling PHP as static module in Apache to
see if the problem really is the "double" dlopen:

  Apache-dlopen(PHP-dlopen(curl.so))

(when PHP is build as static module, the first dlopen() is nuked of course :)

Melvyn, your comment got lost due to that db corruption we had..can you please re-add it?

And most likely nothing we can do about anyway. :)