Re: Porting Bricolage to mp2: TransHandler Interference

["David E. Wheeler" <suppressed>]

On Apr 24, 2008, at 02:20, Torsten Foertsch wrote:

> Well, I think I can shed some light on that mystery. When you use
> the "perl-script" handler instead of "modperl" then your C-level  
> response
> handler is modperl_response_handler_cgi (see src/modules/perl/ 
> mod_perl.c).
> This function calls modperl_env_request_populate (see modperl_env.c)  
> and that
> calls ap_add_cgi_vars (see httpd.../server/util_script.c). All that  
> happens
> in the response phase *before* the PerlResponseHandler is called.

Well, I'm no C coder, but I get the idea. Sure enough, when I use the  
"perl-script" handler (as we've been doing for mod_perl 1, of course),  
I see:

Trans: /workflow/profile/desk/101/101/
Trans: /101/
Cleanup: /101/
Response: /workflow/profile/desk/101/101/
Cleanup: /workflow/profile/desk/101/101/

But when I switch to the "modperl" handler (which was a simple find- 
and-replace, thank you very much), I see:

Trans: /workflow/profile/desk/101/101/
Response: /workflow/profile/desk/101/101/
Cleanup: /workflow/profile/desk/101/101/

*So* much better! So already Bricolage is better running on mod_perl 2  
than on mod_perl 1. :-)

> Why the subreq is not set up if your transhandler is not used I can  
> only
> guess. Maybe it sets $r->path_info explicitly maybe it sets $r- 
> >filename so
> that the standard maptostorage handler sets path_info. But path_info  
> is
> probably empty if your transhandler is not used.

It is odd, but it does seem like the perl-script handler is doing  
something different if I've installed a TransHandler.

> Further I recall a problem/bug that if the PerlCleanupHandler is the  
> only
> configured Perl handler for a request it is not called. But that  
> does not
> seem to hit you since you have a (Trans|Access)Handler at least. If  
> you think
> that may be the case try the threading mod_perl branch. There the  
> problem is
> solved (http://svn.apache.org/repos/asf/perl/modperl/branches/threading 
> ).
> That branch still does not work with perl 5.10.

I don't think that's related, but it's good to know that there is  
ongoing work on this stuff.

Thanks a million for the detailed explanation!

Best,

David