49c2c5fcb1
While removing the use of SHM_QUEUE from predicate.c, in 96003717645, I made
two mistakes in GetSafeSnapshotBlockingPids():
- Removed the check for output_size
- Previously, when the first loop didn't find a matching proc, sxact would be
NULL. But with naive use of dlist_foreach() it ends up as the value of the
last iteration.
The second issue is the cause of occasional failures in the deadlock-hard and
deadlock-soft isolation tests that we have been observing on CI. The issue was
very hard to reproduce, as it requires the transactions.sql regression test to
run at the same time as the deadlock-{hard,soft} isolation test.
I did not find other similar mistakes in 96003717645.
Discussion: https://postgr.es/m/20230208221145.bwzhancellclrgia@awork3.anarazel.de
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.