Postgres Pro
Downloads
Home   >   mailing lists

Thread: pgsql: Reorder actions in ProcArrayApplyRecoveryInfo()

pgsql: Reorder actions in ProcArrayApplyRecoveryInfo()

From
Alexander Korotkov
Date:
Reorder actions in ProcArrayApplyRecoveryInfo()

Since 5a1dfde8334b, 2PC filenames use FullTransactionId.  Thus, it needs to
convert TransactionId to FullTransactionId in StandbyTransactionIdIsPrepared()
using TransamVariables->nextXid.  However, ProcArrayApplyRecoveryInfo()
first releases locks with usage StandbyTransactionIdIsPrepared(), then advances
TransamVariables->nextXid.  This sequence of actions could cause errors.
This commit makes ProcArrayApplyRecoveryInfo() advance
TransamVariables->nextXid before releasing locks.

Reported-by: Thomas Munro, Michael Paquier
Discussion: https://postgr.es/m/CA%2BhUKGLj_ve1_pNAnxwYU9rDcv7GOhsYXJt7jMKSA%3D5-6ss-Cw%40mail.gmail.com
Discussion: https://postgr.es/m/Zadp9f4E1MYvMJqe%40paquier.xyz

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/c64086b79dbad19e4ee0af8d19e835111aa87bd5

Modified Files
--------------
src/backend/storage/ipc/procarray.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

Re: pgsql: Reorder actions in ProcArrayApplyRecoveryInfo()

From
Tom Lane
Date:
Alexander Korotkov <akorotkov@postgresql.org> writes:
> Reorder actions in ProcArrayApplyRecoveryInfo()

I'm seeing this warning since this commit:

procarray.c: In function 'ProcArrayApplyRecoveryInfo':
procarray.c:1172:17: warning: declaration of 'xid' shadows a previous local [-Wshadow=compatible-local]
   TransactionId xid = running->xids[i];
                 ^~~
procarray.c:1056:16: note: shadowed declaration is here
  TransactionId xid;
                ^~~

            regards, tom lane

Re: pgsql: Reorder actions in ProcArrayApplyRecoveryInfo()

From
Alexander Korotkov
Date:
On Fri, Jan 19, 2024 at 6:08 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Alexander Korotkov <akorotkov@postgresql.org> writes:
> > Reorder actions in ProcArrayApplyRecoveryInfo()
>
> I'm seeing this warning since this commit:
>
> procarray.c: In function 'ProcArrayApplyRecoveryInfo':
> procarray.c:1172:17: warning: declaration of 'xid' shadows a previous local [-Wshadow=compatible-local]
>    TransactionId xid = running->xids[i];
>                  ^~~
> procarray.c:1056:16: note: shadowed declaration is here
>   TransactionId xid;
>                 ^~~

Thank you for reporting.  Must be fixed in 448a3331d9.

------
Regards,
Alexander Korotkov