RE: [PATCH] Fix for bug #7617: race condition causes 3 second CGI delay

[Bill Stoddard <bi...@wstoddard.com>]

Kai,
Thanks for the patch. I will be committing it later this evening.

For future reference APR patches to APR should be posted to dev@apr.apache.org.

Thanks again.
Bill

> 
> When running my newly installed apache 2.0.40 on my RedHat
> 8.0 linux box, I noticed some strange 3-second delays 
> for clients using keepalives after running CGI scripts 
> before the next request was processed.
> 
> Some debugging led me to the conclusion that I experienced
> the same race-condition as described as #7616 in the bug 
> database. I.e. after running the CGI script, apache finds
> the subprocess to still be active, sends it a SIGINT and
> then blocks for three whole seconds before sending a SIGKILL.
> Meanwhile, the client using keep-alives is kept waiting
> for those three seconds until the next request is processed.
> What a waste of time, considering the CGI script actually 
> exited almost immediately after the SIGINT was sent.
> 
> I confirmed this same behaviour to be present in version 2.0.43, 
> and saw the need to make a fix to this. Apache 1.3.27 has
> very similar code, so the same patch could be easily modified
> to work with that version as well!
> 
> Please find enclosed a patch against the 2.0.40 source tree 
> (should work well on 2.0.43 also) that fixes this unnecessary
> delay. The patch makes apache check the status of the subprocesses 
> in 0.1 second intervals, until either a total of three seconds
> have elapsed or all subprocesses have exited. Any subprocesses 
> still running after 3 seconds are then SIGKILLed as before.
> 
> Hope this quick fix can make it into the official version!
> 
> Best regards,
> 	Kai
> 
> --
> Kai.Risku@arrak.fi       Oy Arrak Software Ab    
> GSM  +358-40-767 8282    http://www.arrak.fi
>