On Thu, 15 Sept 2022 at 12:36, Japin Li <japi...@hotmail.com> wrote: > > > On Thu, 15 Sep 2022 at 18:04, Simon Riggs <simon.ri...@enterprisedb.com> > wrote: > > On Wed, 14 Sept 2022 at 15:21, Alvaro Herrera <alvhe...@alvh.no-ip.org> > > wrote: > >> > >> On 2022-Aug-30, Simon Riggs wrote: > >> > >> > 001_new_isolation_tests_for_subxids.v3.patch > >> > Adds new test cases to master without adding any new code, specifically > >> > addressing the two areas of code that are not tested by existing tests. > >> > This gives us a baseline from which we can do test driven development. > >> > I'm hoping this can be reviewed and committed fairly smoothly. > >> > >> I gave this a quick run to confirm the claimed increase of coverage. It > >> checks out, so pushed. > > > > Thank you. > > > > So now we just have the main part of the patch, reattached here for > > the auto patch tester's benefit. > > Hi Simon, > > Thanks for the updated patch, here are some comments.
Thanks for your comments.
> There is a typo,
> s/SubTransGetTopMostTransaction/SubTransGetTopmostTransaction/g.
>
> + * call SubTransGetTopMostTransaction() if that xact
> overflowed;
>
>
> Is there a punctuation mark missing on the following first line?
>
> + * 2. When IsolationIsSerializable() we sometimes need to
> access topxid
> + * This occurs only when SERIALIZABLE is requested by app
> user.
>
>
> When we use function name in comments, some places we use parentheses,
> but others do not use it. Why? I think, we should keep them consistent,
> at least in the same commit.
>
> + * 3. When TransactionIdSetTreeStatus will use a status of
> SUB_COMMITTED,
> + * which then requires us to consult subtrans to find
> parent, which
> + * is needed to avoid race condition. In this case we ask
> Clog/Xact
> + * module if TransactionIdsAreOnSameXactPage(). Since we
> start a new
> + * clog page every 32000 xids, this is usually <<1% of
> subxids.
I've reworded those comments, hoping to address all of your above points.
> Maybe we declaration a topxid to avoid calling GetTopTransactionId()
> twice when we should set subtrans parent?
>
> + TransactionId subxid =
> XidFromFullTransactionId(s->fullTransactionId);
> + TransactionId topxid = GetTopTransactionId();
> ...
> + if (MyProc->subxidStatus.overflowed ||
> + IsolationIsSerializable() ||
> + !TransactionIdsAreOnSameXactPage(topxid, subxid))
> + {
> ...
> + SubTransSetParent(subxid, topxid);
> + }
Seems a minor point, but I've done this anyway.
Thanks for the review.
v10 attached
--
Simon Riggs http://www.EnterpriseDB.com/
002_minimize_calls_to_SubTransSetParent.v10.patch
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