Go to file
Alvaro Herrera 61461a300c
libpq: Add encrypted and non-blocking query cancellation routines
The existing PQcancel API uses blocking IO, which makes PQcancel
impossible to use in an event loop based codebase without blocking the
event loop until the call returns.  It also doesn't encrypt the
connection over which the cancel request is sent, even when the original
connection required encryption.

This commit adds a PQcancelConn struct and assorted functions, which
provide a better mechanism of sending cancel requests; in particular all
the encryption used in the original connection are also used in the
cancel connection.  The main entry points are:

- PQcancelCreate creates the PQcancelConn based on the original
  connection (but does not establish an actual connection).
- PQcancelStart can be used to initiate non-blocking cancel requests,
  using encryption if the original connection did so, which must be
  pumped using
- PQcancelPoll.
- PQcancelReset puts a PQcancelConn back in state so that it can be
  reused to send a new cancel request to the same connection.
- PQcancelBlocking is a simpler-to-use blocking API that still uses
  encryption.

Additional functions are
 - PQcancelStatus, mimicks PQstatus;
 - PQcancelSocket, mimicks PQcancelSocket;
 - PQcancelErrorMessage, mimicks PQerrorMessage;
 - PQcancelFinish, mimicks PQfinish.

Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Denis Laxalde <denis.laxalde@dalibo.com>
Discussion: https://postgr.es/m/AM5PR83MB0178D3B31CA1B6EC4A8ECC42F7529@AM5PR83MB0178.EURPRD83.prod.outlook.com
2024-03-12 17:32:25 +01:00
config Remove AIX support 2024-02-28 15:17:23 +04:00
contrib Fix deparsing of Consts in postgres_fdw ORDER BY 2024-03-11 12:27:11 +13:00
doc libpq: Add encrypted and non-blocking query cancellation routines 2024-03-12 17:32:25 +01:00
src libpq: Add encrypted and non-blocking query cancellation routines 2024-03-12 17:32:25 +01:00
.cirrus.star Remove duplicate words in docs and code comments. 2023-10-09 09:18:47 +05:30
.cirrus.tasks.yml ci: Add test coverage of different pg_upgrade modes 2024-02-19 09:31:23 +01:00
.cirrus.yml ci: Make compute resources for CI configurable 2023-08-23 15:15:28 -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 a few recent commits to .git-blame-ignore-revs. 2024-03-05 14:15:06 -06:00
.gitattributes Remove non-existing file from .gitattributes 2024-02-16 11:39:09 +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 Add --copy-file-range option to pg_upgrade. 2024-03-06 12:01:01 +13:00
configure.ac Add --copy-file-range option to pg_upgrade. 2024-03-06 12:01:01 +13:00
COPYRIGHT Update copyright for 2024 2024-01-03 20:49:05 -05:00
GNUmakefile.in Combine headerscheck and cpluspluscheck scripts 2024-03-10 07:56:17 +01:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Remove AIX support 2024-02-28 15:17:23 +04:00
meson_options.txt Add backend support for injection points 2024-01-22 10:15:50 +09:00
meson.build Add --copy-file-range option to pg_upgrade. 2024-03-06 12:01:01 +13:00
README.md Convert README to Markdown. 2024-02-28 14:53:52 -06:00

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.

Copyright and license information can be found in the file COPYRIGHT.

General documentation about this version of PostgreSQL can be found at: https://www.postgresql.org/docs/devel/
In particular, information about building PostgreSQL from the source code can be found at: https://www.postgresql.org/docs/devel/installation.html

The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.