Re: [BUGS] BUG #5412: test case produced, possible race condition. - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [BUGS] BUG #5412: test case produced, possible race condition.
Date
Msg-id 15044.1271281059@sss.pgh.pa.us
Whole thread Raw
In response to Re: [BUGS] BUG #5412: test case produced, possible race condition.  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: [BUGS] BUG #5412: test case produced, possible race condition.  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-hackers
"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> What this suggests is that CLOBBER_CACHE_ALWAYS is actually too
>> strong to provide a thorough test of cache flush hazards.  Maybe
>> we need an alternate setting along the lines of
>> CLOBBER_CACHE_SOMETIMES that would randomly choose whether or not
>> to flush at any given opportunity. But if such a setup did produce
>> a crash, it'd be awfully hard to reproduce for investigation. 
>> Ideas?
> Seed the random number generator such that each run of the test gets
> the same "random" numbers?  Or *allow* the seed to be set, with the
> default being a random seed which is logged so that it can be forced
> for a repeat of the run?

The seed alone wouldn't be enough to duplicate the behavior, since
the behavior of random() typically varies across platforms.  So we
might get a report and still be unable to reproduce it.
        regards, tom lane


pgsql-hackers by date:

Previous
From: "Kevin Grittner"
Date:
Subject: Re: gist README typo
Next
From: "Kevin Grittner"
Date:
Subject: Re: [BUGS] BUG #5412: test case produced, possible race condition.