Re: Regression in Pool 2.13.0

On Sat, Dec 27, 2025, 18:09 Phil Steitz <[email protected]> wrote:

> I updated the changelog and I think we are ready for a patch release.
>

OK sounds good. I'll get to that today.

Gary


> Phil
>
> On Sat, Dec 27, 2025 at 12:24 PM Gary Gregory <[email protected]>
> wrote:
>
> > That all sounds good. I can create a release candidate anytime if you
> want.
> >
> > Gary
> >
> > On Sat, Dec 27, 2025 at 1:43 PM Phil Steitz <[email protected]>
> wrote:
> > >
> > > Given that the regression reported in POOL-427 is significant, I think
> we
> > > should move quickly to validate the fix for the regression (or revert
> > back
> > > to the previous version of the method) and create a patch release as
> soon
> > > as possible.  The investigations around POOL-413 are great and should
> > > continue in parallel.  It would be great if we could discuss ideas for
> > how
> > > to address the core issue there here instead of spread across PRs.
> > >
> > > Phil
> > >
> > > On Sat, Dec 27, 2025 at 11:10 AM Phil Steitz <[email protected]>
> > wrote:
> > >
> > > > I just reverted the added sync in PR #452, which violates the "no
> > factory
> > > > methods while holding locks" invariant.  Strangely, the added tests
> for
> > > > POOL-426 still pass.  I think the race condition is still present and
> > the
> > > > general problem in POOL-413 remains unresolved.
> > > >
> > > > On Thu, Dec 25, 2025 at 3:55 PM Phil Steitz <[email protected]>
> > wrote:
> > > >
> > > >> The fix for POOL-425 included in the 2.13.0 release introduced a
> > > >> regression that makes addObject no-op when maxIdle is set to a
> > negative
> > > >> value (no limit).  The POOL-425 fix also failed to account for a
> race
> > > >> condition reported in POOL-426.
> > > >>
> > > >> I have created a PR https://github.com/apache/commons-pool/pull/452
> > that addresses
> > > >> both issues.  To avoid the race condition, I had to add
> > synchronization to
> > > >> addObject.  I tried several ways to avoid the race by modifying
> > create (as
> > > >> suggested by Raju Gupta, the OP for POOL-426) but I could not find a
> > way to
> > > >> do that safely without introducing other issues.  I don't see the
> > added
> > > >> sync in addObject as critical as this method is not used in hot code
> > paths
> > > >> internally and the lock that it acquires is the same lock that
> create
> > will
> > > >> subsequently acquire if it proceeds to add an object.
> > > >>
> > > >> The regression could be addressed in a simpler way by just fixing
> the
> > > >> error in the code (failure to check for negative maxIdle).   If
> there
> > are
> > > >> any doubts about the PR above, I am happy to make that simple
> > change.  In
> > > >> any case, we should patch this quickly as it will likely break some
> > apps
> > > >> that use addObject with maxIdle unilimited.
> > > >>
> > > >> Thanks, all, and sorry for my mistake in the POOL-425 fix.
> > > >>
> > > >> Phil
> > > >>
> > > >
> >
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