develooper Front page | perl.perl5.porters | Postings from November 2003

Re: 5.8.2 and 5.8.n binary compatibility

Thread Previous
Stas Bekman
November 4, 2003 01:22
Re: 5.8.2 and 5.8.n binary compatibility
Message ID:
Alan Burlison wrote:
> Stas Bekman wrote:
>> Alan, your worries have been accounted for. This is precisely the 
>> reason I wanted to have a test that mounts an attack on stashes. So we 
>> now test that mod_perl 2.0 works just fine if and when such attack 
>> happens. Notice that I talk only about stashes, since that's where the 
>> black magic overlaps with mod_perl functionality. All other hashes in 
>> the "user" space should have no effect on mod_perl.
>> It just proves again how important is to write tests before you start 
>> solving a problem. We saw mod_perl 2.0 goes broken immediately after 
>> plan C was implemented. Though once Nick changed the threshold for 
>> rehashing from 4 to 14 the breakage has disappeared, because the 
>> normal tests didn't happen to trigger it (that's where your worry 
>> kicks in). Now that we have a specific test that mounts the attack and 
>> it verifies that the attack was successful (to prevent cases of future 
>> changes in the rehashing algorithm) we are covered 100%. If we didn't 
>> have this test you indeed would have seen random failures reported by 
>> users some time later.
> Thanks Stas, now I feel all warm and cozy ;-)


>> I doubt that plan C affects any other projects, that don't mess with 
>> hashing internals like mod_perl does, any different that they get 
>> affected by changes in 5.8.1. So if Tk and DBI did fine with 5.8.1 
>> they will do just as fine with 5.8.2 (assuming of course that they 
>> don't mimic mod_perl ;)
> Nice job BTW, you and Nick deserve a lot of thanks for all the effort 
> you have put in to nail this.

Nick is the one who nailed it down. I was just testing, asking lots of silly 
questions and trying to make perl emulate U32 logic ;)

Stas Bekman            JAm_pH ------> Just Another mod_perl Hacker     mod_perl Guide --->

Thread Previous Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at | Group listing | About