Re: resend: [mp2] bug report - heap management error in mod_perl on Windows

[Randy Kobes <suppressed>]

On Sat, 29 Dec 2007, Tom Donovan wrote:

> mod_perl re-defines "perl_free" as "free" in modperl_perl_includes.h:69.
>
> This causes an attempt to use the native Windows free() function to release 
> memory
> which should be released by the perl_free() function located in PerlXXX.dll.
>
> The specific call is in modperl_perl.c:186, function modperl_perl_destruct()
> which gets called during the Apache/APR config pool cleanup.
>
> The symptoms are:
>    When Apache 2.2 with mod_perl is run in a debugger, the following 
> exception is reported
>    during pool cleanup:
>
> 	"Invalid Address specified to RtlFreeHeap"
>
> Some indirect symptoms also observed are:
>    Apache graceful restarts do not always work on Windows when mod_perl is 
> loaded.
>    Apache shutdown takes longer on Windows when mod_perl is loaded.
>
> The symptoms are the same whether Apache, mod_perl, and Perl are built
> with Visual C++ 6.0 or Visual C++ 2005 (in any combination).
>
> Note that Apache 2.2.6 or Apache from the SVN 2.2.x branch cannot run 
> mod_perl
> without an additional patch for file descriptors.
> see Apache bug 43534 - 
> http://issues.apache.org/bugzilla/show_bug.cgi?id=43534
>
> If you wish to track down the preprocessor definitions, it may be helpful to 
> know:
>
>    USE_LARGE_FILES is defined in C:\perl\lib\CORE\config.h:4418
>    malloc          is defined in C:\perl\lib\CORE\win32iop.h:291 as 
> win32_malloc
>    free            is defined in C:\perl\lib\CORE\win32iop.h:294 as 
> win32_free
>
> The following mod_perl patch corrects the problem on Windows (Win2k sp4)
> for mod_perl (trunk or v2.0.3) with Apache (SVN 2.2.x branch or 2.2.6)
> built with Visual C++ (v6.0 or v2005).
>
> Regards,
> -tom-

Hi Tom,
    Thanks for the detailed report, and patch. I tried out
the patch with perl-5.8.8, compiled against Apache/2.2.4,
and all the tests passed. However, the restart problem
still remains; evidently,
  http://issues.apache.org/bugzilla/show_bug.cgi?id=43534
or something equivalent must still be applied. I'm
heistant though to apply this to fix a problem in
the svn httpd sources, which are subject to change;
also, I'd like to understand better the reasons behind the
original definitions of perl_malloc and perl_free in
modperl_perl_includes.h (I seem to recall this was
needed for older versions of Perl, but it may now
be unnecessary). Thus, unless others think otherwise,
I think it'd be better to wait for an http release
candidate that demonstrates the problem.

--
best regards,
Randy Kobes