From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | pgsql-committers(at)lists(dot)postgresql(dot)org |
Subject: | pgsql: Fix SPI's handling of errors during transaction commit. |
Date: | 2022-06-22 16:12:18 |
Message-ID: | E1o42xm-001ISP-BE@gemulon.postgresql.org |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-committers |
Fix SPI's handling of errors during transaction commit.
SPI_commit previously left it up to the caller to recover from any error
occurring during commit. Since that's complicated and requires use of
low-level xact.c facilities, it's not too surprising that no caller got
it right. Let's move the responsibility for cleanup into spi.c. Doing
that requires redefining SPI_commit as starting a new transaction, so
that it becomes equivalent to SPI_commit_and_chain except that you get
default transaction characteristics instead of preserving the prior
transaction's characteristics. We can make this pretty transparent
API-wise by redefining SPI_start_transaction() as a no-op. Callers
that expect to do something in between might be surprised, but
available evidence is that no callers do so.
Having made that API redefinition, we can fix this mess by having
SPI_commit[_and_chain] trap errors and start a new, clean transaction
before re-throwing the error. Likewise for SPI_rollback[_and_chain].
Some cleanup is also needed in AtEOXact_SPI, which was nowhere near
smart enough to deal with SPI contexts nested inside a committing
context.
While plperl and pltcl need no changes beyond removing their now-useless
SPI_start_transaction() calls, plpython needs some more work because it
hadn't gotten the memo about catching commit/rollback errors in the
first place. Such an error resulted in longjmp'ing out of the Python
interpreter, which leaks Python stack entries at present and is reported
to crash Python 3.11 altogether. Add the missing logic to catch such
errors and convert them into Python exceptions.
This is a back-patch of commit 2e517818f. That's now aged long enough
to reduce the concerns about whether it will break something, and we
do need to ensure that supported branches will work with Python 3.11.
Peter Eisentraut and Tom Lane
Discussion: https://postgr.es/m/3375ffd8-d71c-2565-e348-a597d6e739e3@enterprisedb.com
Discussion: https://postgr.es/m/17416-ed8fe5d7213d6c25@postgresql.org
Branch
------
REL_11_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/2f6b8c287b881fd33168d8c15c56f71163ff3ba6
Modified Files
--------------
doc/src/sgml/spi.sgml | 43 ++---
src/backend/executor/spi.c | 204 ++++++++++++++++------
src/backend/tcop/postgres.c | 2 -
src/backend/utils/mmgr/portalmem.c | 2 +-
src/include/executor/spi.h | 1 -
src/pl/plperl/expected/plperl_transaction.out | 48 +++++
src/pl/plperl/plperl.c | 2 -
src/pl/plperl/sql/plperl_transaction.sql | 32 ++++
src/pl/plpgsql/src/pl_exec.c | 2 -
src/pl/plpython/expected/plpython_transaction.out | 67 ++++++-
src/pl/plpython/plpy_plpymodule.c | 30 ----
src/pl/plpython/plpy_spi.c | 94 ++++++++++
src/pl/plpython/plpy_spi.h | 3 +
src/pl/plpython/sql/plpython_transaction.sql | 30 ++++
src/pl/tcl/expected/pltcl_transaction.out | 49 ++++++
src/pl/tcl/pltcl.c | 2 -
src/pl/tcl/sql/pltcl_transaction.sql | 37 ++++
17 files changed, 524 insertions(+), 124 deletions(-)
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2022-06-22 17:14:34 | pgsql: amcheck: Fix incorrect use of VARATT_IS_COMPRESSED. |
Previous Message | Peter Eisentraut | 2022-06-22 12:27:28 | pgsql: doc: Clean up title case use |