OSSForks/postgres
1
0
Fork 0
mirror of https://github.com/zebrajr/postgres.git synced 2025-12-06 12:20:15 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity
Mirror of the official PostgreSQL GIT repository. Note that this is just a *mirror* - we don't work with pull requests on github. To contribute, please see https://wiki.postgresql.org/wiki/Submitting_a_Patch
56,621 Commits 34 Branches 537 Tags 1,009 MiB
C 85.1%
PLpgSQL 6%
Perl 4.6%
Yacc 1.2%
Meson 0.7%
Other 2.2%
5ffb7c7750
Go to file
Thomas Munro 5ffb7c7750 De-pessimize ConditionVariableCancelSleep(). 
Commit b91dd9de was concerned with a theoretical problem with our
non-atomic condition variable operations.  If you stop sleeping, and
then cancel the sleep in a separate step, you might be signaled in
between, and that could be lost.  That doesn't matter for callers of
ConditionVariableBroadcast(), but callers of ConditionVariableSignal()
might be upset if a signal went missing like this.

Commit bc971f4025 interacted badly with that logic, because it doesn't
use ConditionVariableSleep(), which would normally put us back in the
wait list.  ConditionVariableCancelSleep() would be confused and think
we'd received an extra signal, and try to forward it to another backend,
resulting in wakeup storms.

New idea: ConditionVariableCancelSleep() can just return true if we've
been signaled.  Hypothetical users of ConditionVariableSignal() would
then still have a way to deal with rare lost signals if they are
concerned about that problem.

Back-patch to 16, where bc971f4025 arrived.

Reported-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/2840876b-4cfe-240f-0a7e-29ffd66711e7%40enterprisedb.com
2023-08-15 10:23:47 +12:00
config Use native CRC instructions on 64-bit LoongArch 2023-08-10 11:36:15 +07:00
contrib Show GIDs of two-phase commit commands as constants in pg_stat_statements 2023-08-12 10:44:15 +09:00
doc Change custom wait events to use dynamic shared hash tables 2023-08-14 14:47:27 +09:00
src De-pessimize ConditionVariableCancelSleep(). 2023-08-15 10:23:47 +12:00
.cirrus.yml ci: macos: Remove use of -Dsegsize_blocks=6 2023-08-12 15:08:07 -07:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.editorconfig Add .editorconfig 2019-12-18 09:13:13 +01:00
.git-blame-ignore-revs Add b334612b8 to .git-blame-ignore-revs. 2023-06-20 09:52:52 -04:00
.gitattributes gitattributes: Ignore imported pg_bsd_indent code for whitespace checks 2023-02-22 09:00:28 +01:00
.gitignore Update top-level .gitignore. 2022-12-04 15:23:00 -05:00
aclocal.m4 autoconf: Move export_dynamic determination to configure 2022-12-06 18:55:28 -08:00
configure Use native CRC instructions on 64-bit LoongArch 2023-08-10 11:36:15 +07:00
configure.ac Use native CRC instructions on 64-bit LoongArch 2023-08-10 11:36:15 +07:00
COPYRIGHT Update copyright for 2023 2023-01-02 15:00:37 -05:00
GNUmakefile.in Integrate pg_bsd_indent into our build/test infrastructure. 2023-02-12 12:22:21 -05:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Dynamically find correct installation docs in Makefile. 2022-01-19 14:48:25 +01:00
meson_options.txt meson: Attach colon to keyword argument 2023-06-29 12:53:41 +02:00
meson.build Use native CRC instructions on 64-bit LoongArch 2023-08-10 11:36:15 +07:00
README Canonicalize some URLs 2020-02-10 20:47:50 +01:00
README.git Canonicalize some URLs 2020-02-10 20:47:50 +01:00

README 

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/.