Re: perl FCGI segmentation fault using ithreads ...

Sven Verdoolaege wrote:

>>Master perl
>> -> load FCGI
>>   -> create FCGI handle
>>     -> accept FCGI socket
>>       -> create new interpreter thread
>>         ->request
>>         ->request
>>    
>>
>
>What does "request" refer to ?
>  
>

It refers to $request->accept(), that there are two represents that the 
multiplicity is happening at that level.

>>If threading is giving you segfaults, it is a fairly safe bet that the 
>>FCGI.pm module is not re-entrant.
>>    
>>
>
>Not sure what you mean here, but the FCGI module should be thread-safe,
>if you're using the thread-safe interface.
>Which our friend, btw, isn't.
>  
>

Well, there you have it.  If you use the non-thread safe version of the 
FCGI module, you get non-rentrant-like bugs :-).

Igor, in the FCGI.pm distribution there is a file called threaded.PL, 
which is built into threaded.fpl by the module build process.  This 
script does several things which no doubt add to the reentrancy of the code:

  - creates a new thread before creating a new FastCGI request object
  - uses localised filehandles for input, output, error and the process 
environment.

The script can be browsed at 
http://search.cpan.org/src/SKIMO/FCGI-0.67/threaded.PL

You might be hard pressed to find a module that can extract CGI requests 
without assuming that it's safe to read %ENV and/or standard input.  I 
had to write one myself, it's on (or will shortly be on) CPAN at;

http://search.cpan.org/dist/PSA/

The PSA::Request::CGI is the one that will encapsulate the input 
request.  You might even be able to use the acceptor class in a threaded 
environment.

Sam.
___________________________________
fastcgi-developers mailing list
http://fastcgi.com/fastcgi-developers/