Tom Lane db01c90b2f Silence Valgrind leakage complaints in more-or-less-hackish ways. These changes don't actually fix any leaks. They just make sure that Valgrind will find pointers to data structures that remain allocated at process exit, and thus not falsely complain about leaks. In particular, we are trying to avoid situations where there is no pointer to the beginning of an allocated block (except possibly within the block itself, which Valgrind won't count). * Because dynahash.c never frees hashtable storage except by deleting the whole hashtable context, it doesn't bother to track the individual blocks of elements allocated by element_alloc(). This results in "possibly lost" complaints from Valgrind except when the first element of each block is actively in use. (Otherwise it'll be on a freelist, but very likely only reachable via "interior pointers" within element blocks, which doesn't satisfy Valgrind.) To fix, if we're building with USE_VALGRIND, expend an extra pointer's worth of space in each element block so that we can chain them all together from the HTAB header. Skip this in shared hashtables though: Valgrind doesn't track those, and we'd need additional locking to make it safe to manipulate a shared chain. While here, update a comment obsoleted by `9c911ec06`. * Put the dlist_node fields of catctup and catclist structs first. This ensures that the dlist pointers point to the starts of these palloc blocks, and thus that Valgrind won't consider them "possibly lost". * The postmaster's PMChild structs and the autovac launcher's avl_dbase structs also have the dlist_node-is-not-first problem, but putting it first still wouldn't silence the warning because we bulk-allocate those structs in an array, so that Valgrind sees a single allocation. Commonly the first array element will be pointed to only from some later element, so that the reference would be an interior pointer even if it pointed to the array start. (This is the same issue as for dynahash elements.) Since these are pretty simple data structures, I don't feel too bad about faking out Valgrind by just keeping a static pointer to the array start. (This is all quite hacky, and it's not hard to imagine usages where we'd need some other idea in order to have reasonable leak tracking of structures that are only accessible via dlist_node lists. But these changes seem to be enough to silence this class of leakage complaints for the moment.) * Free a couple of data structures manually near the end of an autovacuum worker's run when USE_VALGRIND, and ensure that the final vac_update_datfrozenxid() call is done in a non-permanent context. This doesn't have any real effect on the process's total memory consumption, since we're going to exit as soon as that last transaction is done. But it does pacify Valgrind. * Valgrind complains about the postmaster's socket-files and lock-files lists being leaked, which we can silence by just not nulling out the static pointers to them. * Valgrind seems not to consider the global "environ" variable as a valid root pointer; so when we allocate a new environment array, it claims that data is leaked. To fix that, keep our own statically-allocated copy of the pointer, similarly to the previous item. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/285483.1746756246@sss.pgh.pa.us		10 months ago
.github	Add CODE_OF_CONDUCT.md, CONTRIBUTING.md, and SECURITY.md.	2 years ago
config	Don't put library-supplied -L/-I switches before user-supplied ones.	10 months ago
contrib	Allow resetting unknown custom GUCs with reserved prefixes.	10 months ago
doc	Simplify options in pg_dump and pg_restore.	10 months ago
src	Silence Valgrind leakage complaints in more-or-less-hackish ways.	10 months ago
.cirrus.star	Remove duplicate words in docs and code comments.	3 years ago
.cirrus.tasks.yml	Hide ICU C++ APIs from pg_locale.h	11 months ago
.cirrus.yml	ci: Test NetBSD and OpenBSD	1 year ago
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.editorconfig	Add script to keep .editorconfig in sync with .gitattributes	1 year ago
.git-blame-ignore-revs	Add commit `1d1612aec7` to .git-blame-ignore-revs.	10 months ago
.gitattributes	Add script to keep .editorconfig in sync with .gitattributes	1 year ago
.gitignore	Update top-level .gitignore.	4 years ago
.mailmap	Add a Git .mailmap file	2 years ago
COPYRIGHT	Align organization wording in copyright statement	1 year ago
GNUmakefile.in	Allow selecting the git revision to be packaged by "make dist".	2 years ago
HISTORY	…
Makefile	Remove AIX support	2 years ago
README.md	Revise the style of a paragraph in README.md.	2 years ago
aclocal.m4	autoconf: Move export_dynamic determination to configure	4 years ago
configure	Fix ./configure checks with __cpuidex() and __cpuid()	10 months ago
configure.ac	Fix ./configure checks with __cpuidex() and __cpuid()	10 months ago
meson.build	Fix ./configure checks with __cpuidex() and __cpuid()	10 months ago
meson_options.txt	Add support for basic NUMA awareness	1 year ago

README.md

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.

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/.