Until now BufferDesc.state was not allowed to be modified while the buffer
header spinlock was held. This meant that operations like unpinning buffers
needed to use a CAS loop, waiting for the buffer header spinlock to be
released before updating.
The benefit of that restriction is that it allowed us to unlock the buffer
header spinlock with just a write barrier and an unlocked write (instead of a
full atomic operation). That was important to avoid regressions in
48354581a4. However, since then the hottest buffer header spinlock uses have
been replaced with atomic operations (in particular, the most common use of
PinBuffer_Locked(), in GetVictimBuffer() (formerly in BufferAlloc()), has been
removed in 5e89985928).
This change will allow, in a subsequent commit, to release buffer pins with a
single atomic-sub operation. This previously was not possible while such
operations were not allowed while the buffer header spinlock was held, as an
atomic-sub would not have allowed a race-free check for the buffer header lock
being held.
Using atomic-sub to unpin buffers is a nice scalability win, however it is not
the primary motivation for this change (although it would be sufficient). The
primary motivation is that we would like to merge the buffer content lock into
BufferDesc.state, which will result in more frequent changes of the state
variable, which in some situations can cause a performance regression, due to
an increased CAS failure rate when unpinning buffers. The regression entirely
vanishes when using atomic-sub.
Naively implementing this would require putting CAS loops in every place
modifying the buffer state while holding the buffer header lock. To avoid
that, introduce UnlockBufHdrExt(), which can set/add flags as well as the
refcount, together with releasing the lock.
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/fvfmkr5kk4nyex56ejgxj3uzi63isfxovp2biecb4bspbjrze7@az2pljabhnff
We must tell init about each role name we plan to connect as,
else SSPI auth fails. Similar to previous patches such as
14793f471, 973542866.
Oversight in 208927e65, per buildfarm member drongo.
(Although that was back-patched to v13, the test script
only exists in v16 and up.)
pg_prewarm() currently checks for SELECT privileges on the target
relation. However, indexes do not have access rights of their own,
so a role may be denied permission to prewarm an index despite
having the SELECT privilege on its parent table. This commit fixes
this by locking the parent table before the index (to avoid
deadlocks) and checking for SELECT on the parent table. Note that
the code is largely borrowed from
amcheck_lock_relation_and_check().
An obvious downside of this change is the extra AccessShareLock on
the parent table during prewarming, but that isn't expected to
cause too much trouble in practice.
Author: Ayush Vatsa <ayushvatsa1810@gmail.com>
Co-authored-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://postgr.es/m/CACX%2BKaMz2ZoOojh0nQ6QNBYx8Ak1Dkoko%3DD4FSb80BYW%2Bo8CHQ%40mail.gmail.com
Backpatch-through: 13
This set of changes removes the list of available buffers and instead simply
uses the clock-sweep algorithm to find and return an available buffer. This
also removes the have_free_buffer() function and simply caps the
pg_autoprewarm process to at most NBuffers.
While on the surface this appears to be removing an optimization it is in fact
eliminating code that induces overhead in the form of synchronization that is
problematic for multi-core systems.
The main reason for removing the freelist, however, is not the moderate
improvement in scalability, but that having the freelist would require
dedicated complexity in several upcoming patches. As we have not been able to
find a case benefiting from the freelist...
Author: Greg Burd <greg@burd.me>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/70C6A5B5-2A20-4D0B-BC73-EB09DD62D61C@getmailspring.com
There are two ways for shared libraries to allocate their own
LWLock tranches. One way is to call RequestNamedLWLockTranche() in
a shmem_request_hook, which requires the library to be loaded via
shared_preload_libraries. The other way is to call
LWLockNewTrancheId(), which is not subject to the same
restrictions. However, LWLockNewTrancheId() does require each
backend to store the tranche's name in backend-local memory via
LWLockRegisterTranche(). This API is a little cumbersome and leads
to things like unhelpful pg_stat_activity.wait_event values in
backends that haven't loaded the library.
This commit moves these LWLock tranche names to shared memory, thus
eliminating the need for each backend to call
LWLockRegisterTranche(). Instead, the tranche name must be
provided to LWLockNewTrancheId(), which immediately makes the name
available to all backends. Since the tranche name array is
append-only, lookups can ordinarily avoid locking as long as their
local copy of the LWLock counter is greater than the requested
tranche ID.
One downside of this approach is that we now have a hard limit on
both the length of tranche names (NAMEDATALEN-1 bytes) and the
number of dynamically-allocated tranches (256). Besides a limit of
NAMEDATALEN-1 bytes for tranche names registered via
RequestNamedLWLockTranche(), no such limits previously existed. We
could avoid these new limits by using dynamic shared memory, but
the complexity involved didn't seem worth it. We briefly
considered making the tranche limit user-configurable but
ultimately decided against that, too. Since there is still a lot
of time left in the v19 development cycle, it's possible we will
revisit this choice.
Author: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAA5RZ0vvED3naph8My8Szv6DL4AxOVK3eTPS0qXsaKi%3DbVdW2A%40mail.gmail.com
An assertion test added in commit 049ef33 could fail when pg_prewarm()
was called on objects without storage, such as partitioned tables.
This resulted in the following failure in assert-enabled builds:
Failed Assert("RelFileNumberIsValid(rlocator.relNumber)")
Note that, in non-assert builds, pg_prewarm() just failed with an error
in that case, so there was no ill effect in practice.
This commit fixes the issue by having pg_prewarm() raise an error early
if the specified object has no storage. This approach is similar to
the fix in commit 4623d7144 for pg_freespacemap.
Back-patched to v17, where the issue was introduced.
Author: Masahiro Ikeda <ikedamsh@oss.nttdata.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/e082e6027610fd0a4091ae6d033aa117@oss.nttdata.com
Backpatch-through: 17
Index vacuuming and [auto]prewarm AIO concurrency should be governed by
maintenance_io_concurrency. As such, pass those read stream users the
READ_STREAM_MAINTENANCE flag which will calculate their read stream
distance with maintenance_io_concurrency instead of
effective_io_concurrency. This was an oversight in the original commits
making those operations use the read stream API.
Discussion: https://postgr.es/m/flat/CAAKRu_aopDxTo4b41Mt_7Zc-z0_ngocrY8SFCCY6Aph1HgwuNw%40mail.gmail.com
Make a read stream for each valid fork of each valid relation
represented in the autoprewarm dump file and prewarm those blocks
through the read stream API instead of by directly invoking
ReadBuffer().
Co-authored-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Co-authored-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Andrey M. Borodin <x4mmm@yandex-team.ru> (earlier versions)
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com> (earlier versions)
Reviewed-by: Matheus Alcantara <mths.dev@pm.me> (earlier versions)
Discussion: https://postgr.es/m/flat/CAN55FZ3n8Gd%2BhajbL%3D5UkGzu_aHGRqnn%2BxktXq2fuds%3D1AOR6Q%40mail.gmail.com
Autoprewarm prewarms blocks from a dump file representing the contents
of shared buffers at the time it was dumped. It uses a sorted array of
BlockInfoRecords, each representing a block from one of the cluster's
databases and tables.
autoprewarm_database_main() prewarms all the blocks from a single
database. It is optimized to ensure we don't try to open the same
relation or fork over and over again if it has been dropped or is
invalid. The main loop handled this by carefully setting various local
variables to sentinel values when a run of blocks should be skipped.
This method won't work with the read stream API. The read stream
callback must be able to advance the current position in the
BlockInfoRecord array to allow for reading ahead additional blocks,
however a read stream maps 1-1 with a relation and fork combination. So,
the main loop in autoprewarm_database_main() must also advance the
position in the array of BlockInfoRecords to skip invalid relations and
forks. This split control doesn't fit well with the current flow control
in autoprewarm_database_main()
To make it compatible with the read stream API, change
autoprewarm_database_main() to explicitly fast-forward in the
BlockInfoRecords array past the blocks belonging to an invalid relation
or fork.
This commit only implements the new control flow -- it does not use the
read stream API.
Co-authored-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Co-authored-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/flat/CAN55FZ3n8Gd%2BhajbL%3D5UkGzu_aHGRqnn%2BxktXq2fuds%3D1AOR6Q%40mail.gmail.com
autoprewarm_database_main() prewarms blocks from the same database. It
is passed an array of sorted BlockInfoRecords and a start and stop index
into the array. The range represented should include only blocks
belonging to global objects or blocks from a single database. Remove an
unnecessary check that the current block is from the same database and
add an assert to ensure this invariant remains. Doing so removes a
special case that makes future refactoring to accommodate read
streamifying autoprewarm easier.
Noticed off-list by Andres Freund
While prewarming blocks from a dump file, autoprewarm_database_main()
mistakenly ignored tablespace when detecting the beginning of the next
relation to prewarm. Because RelFileNumbers are only unique within a
tablespace, autoprewarm could miss prewarming blocks from a
relation with the same RelFileNumber in a different tablespace.
Though this situation is likely rare in practice, it's best to make the
code correct. Do so by explicitly checking for the RelFileNumber when
detecting a new relation.
Reported-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/97c36982-603b-494a-95f4-aaf2a12ac27e%40iki.fi
Submitting IO in larger batches can be more efficient than doing so
one-by-one, particularly for many small reads. It does, however, require
the ReadStreamBlockNumberCB callback to abide by the restrictions of AIO
batching (c.f. pgaio_enter_batchmode()). Basically, the callback may not:
a) block without first calling pgaio_submit_staged(), unless a
to-be-waited-on lock cannot be part of a deadlock, e.g. because it is
never held while waiting for IO.
b) directly or indirectly start another batch pgaio_enter_batchmode()
As this requires care and is nontrivial in some cases, batching is only
used with explicit opt-in.
This patch adds an explicit flag (READ_STREAM_USE_BATCHING) to read_stream and
uses it where appropriate.
There are two cases where batching would likely be beneficial, but where we
aren't using it yet:
1) bitmap heap scans, because the callback reads the VM
This should soon be solved, because we are planning to remove the use of
the VM, due to that not being sound.
2) The first phase of heap vacuum
This could be made to support batchmode, but would require some care.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
It seems potentially useful to label our shared libraries with version
information, now that a facility exists for retrieving that. This
patch labels them with the PG_VERSION string. There was some
discussion about using semantic versioning conventions, but that
doesn't seem terribly helpful for modules with no SQL-level presence;
and for those that do have SQL objects, we typically expect them
to support multiple revisions of the SQL definitions, so it'd still
not be very helpful.
I did not label any of src/test/modules/. It seems unnecessary since
we don't install those, and besides there ought to be someplace that
still provides test coverage for the original PG_MODULE_MAGIC macro.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/dd4d1b59-d0fe-49d5-b28f-1e463b68fa32@gmail.com
After further review, we want to move in the direction of always
quoting GUC names in error messages, rather than the previous (PG16)
wildly mixed practice or the intermittent (mid-PG17) idea of doing
this depending on how possibly confusing the GUC name is.
This commit applies appropriate quotes to (almost?) all mentions of
GUC names in error messages. It partially supersedes a243569bf6 and
8d9978a717, which had moved things a bit in the opposite direction
but which then were abandoned in a partial state.
Author: Peter Smith <smithpb2250@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAHut%2BPv-kSN8SkxSdoHano_wPubqcg5789ejhCDZAcLFceBR-w%40mail.gmail.com
This enum was used to determine the first ID to use when assigning a
custom wait event for extensions, which is always 1. It was kept so
as it would be possible to add new in-core wait events in the category
"Extension". There is no such thing currently, so let's remove this
enum until a case justifying it pops up. This makes the code simpler
and easier to understand.
This has as effect to switch back autoprewarm.c to use PG_WAIT_EXTENSION
rather than WAIT_EVENT_EXTENSION, on par with v16 and older stable
branches.
Thinko in c9af054653.
Reported-by: Peter Eisentraut
Discussion: https://postgr.es/m/195c6c45-abce-4331-be6a-e87724e1d060@eisentraut.org
Commit abb0b4fc03 moved the shared state for autoprewarm to a
dynamic shared memory (DSM) segment, but it left apw_detach_shmem()
in the on_shmem_exit callback list for the autoprewarm leader
process. This is a problem because shmem_exit() detaches all the
DSM segments prior to calling the on_shmem_exit callbacks, thus
producing segfaults in the exit path for the autoprewarm leader
process.
To fix, move apw_detach_shmem() to the before_shmem_exit callback
list. This commit also adds a check to pg_prewarm's test that the
server shut down normally. It might be worth making this a common
check for all shutdowns in TAP tests, but that is left as a future
exercise.
Reported-by: Andres Freund
Reviewed-by: Andres Freund, Álvaro Herrera
Discussion: https://postgr.es/m/20240122204117.swton324xcoodnyi%40awork3.anarazel.de
Besides showcasing the DSM registry, this prevents pg_prewarm from
stealing from the main shared memory segment's extra buffer space
when autoprewarm_start_worker() and autoprewarm_dump_now() are used
without loading the module via shared_preload_libraries.
Suggested-by: Michael Paquier
Reviewed-by: Bharath Rupireddy
Discussion: https://postgr.es/m/20231205034647.GA2705267%40nathanxps13
There are a lot of Perl scripts in the tree, mostly code generation
and TAP tests. Occasionally, these scripts produce warnings. These
are probably always mistakes on the developer side (true positives).
Typical examples are warnings from genbki.pl or related when you make
a mess in the catalog files during development, or warnings from tests
when they massage a config file that looks different on different
hosts, or mistakes during merges (e.g., duplicate subroutine
definitions), or just mistakes that weren't noticed because there is a
lot of output in a verbose build.
This changes all warnings into fatal errors, by replacing
use warnings;
by
use warnings FATAL => 'all';
in all Perl files.
Discussion: https://www.postgresql.org/message-id/flat/06f899fd-1826-05ab-42d6-adeb1fd5e200%40eisentraut.org
Quotes are applied to GUCs in a very inconsistent way across the code
base, with a mix of double quotes or no quotes used. This commit
removes double quotes around all the GUC names that are obviously
referred to as parameters with non-English words (use of underscore,
mixed case, etc).
This is the result of a discussion with Álvaro Herrera, Nathan Bossart,
Laurenz Albe, Peter Eisentraut, Tom Lane and Daniel Gustafsson.
Author: Peter Smith
Discussion: https://postgr.es/m/CAHut+Pv-kSN8SkxSdoHano_wPubqcg5789ejhCDZAcLFceBR-w@mail.gmail.com
Since C99, there can be a trailing comma after the last value in an
enum definition. A lot of new code has been introducing this style on
the fly. Some new patches are now taking an inconsistent approach to
this. Some add the last comma on the fly if they add a new last
value, some are trying to preserve the existing style in each place,
some are even dropping the last comma if there was one. We could
nudge this all in a consistent direction if we just add the trailing
commas everywhere once.
I omitted a few places where there was a fixed "last" value that will
always stay last. I also skipped the header files of libpq and ecpg,
in case people want to use those with older compilers. There were
also a small number of cases where the enum type wasn't used anywhere
(but the enum values were), which ended up confusing pgindent a bit,
so I left those alone.
Discussion: https://www.postgresql.org/message-id/flat/386f8c45-c8ac-4681-8add-e3b0852c1620%40eisentraut.org
The following changes are done:
- Addition of WaitEventBufferPin and WaitEventExtension, that hold a
list of wait events related to each category.
- Addition of two functions that encapsulate the list of wait events for
each category.
- Rename BUFFER_PIN to BUFFERPIN (only this wait event class used an
underscore, requiring a specific rule in the automation script).
These changes make a bit easier the automatic generation of all the code
and documentation related to wait events, as all the wait event
categories are now controlled by consistent structures and functions.
Author: Bertrand Drouvot
Discussion: https://postgr.es/m/c6f35117-4b20-4c78-1df5-d3056010dcf5@gmail.com
Discussion: https://postgr.es/m/77a86b3a-c4a8-5f5d-69b9-d70bbf2e9b98@gmail.com
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
In order to have the option to use O_DIRECT/FILE_FLAG_NO_BUFFERING in a
later commit, we need the addresses of user space buffers to be well
aligned. The exact requirements vary by OS and file system (typically
sectors and/or memory pages). The address alignment size is set to
4096, which is enough for currently known systems: it matches modern
sectors and common memory page size. There is no standard governing
O_DIRECT's requirements so we might eventually have to reconsider this
with more information from the field or future systems.
Aligning I/O buffers on memory pages is also known to improve regular
buffered I/O performance.
Three classes of I/O buffers for regular data pages are adjusted:
(1) Heap buffers are now allocated with the new palloc_aligned() or
MemoryContextAllocAligned() functions introduced by commit 439f6175.
(2) Stack buffers now use a new struct PGIOAlignedBlock to respect
PG_IO_ALIGN_SIZE, if possible with this compiler. (3) The buffer
pool is also aligned in shared memory.
WAL buffers were already aligned on XLOG_BLCKSZ. It's possible for
XLOG_BLCKSZ to be configured smaller than PG_IO_ALIGNED_SIZE and thus
for O_DIRECT WAL writes to fail to be well aligned, but that's a
pre-existing condition and will be addressed by a later commit.
BufFiles are not yet addressed (there's no current plan to use O_DIRECT
for those, but they could potentially get some incidental speedup even
in plain buffered I/O operations through better alignment).
If we can't align stack objects suitably using the compiler extensions
we know about, we disable the use of O_DIRECT by setting PG_O_DIRECT to
0. This avoids the need to consider systems that have O_DIRECT but
can't align stack objects the way we want; such systems could in theory
be supported with more work but we don't currently know of any such
machines, so it's easier to pretend there is no O_DIRECT support
instead. That's an existing and tested class of system.
Add assertions that all buffers passed into smgrread(), smgrwrite() and
smgrextend() are correctly aligned, unless PG_O_DIRECT is 0 (= stack
alignment tricks may be unavailable) or the block size has been set too
small to allow arrays of buffers to be all aligned.
Author: Thomas Munro <thomas.munro@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/CA+hUKGK1X532hYqJ_MzFWt0n1zt8trz980D79WbjwnT-yYLZpg@mail.gmail.com
This is similar to 7d25958, and this commit takes care of all the
remaining inconsistencies between the initial value used in the C
variable associated to a GUC and its default value stored in the GUC
tables (as of pg_settings.boot_val).
Some of the initial values of the GUCs updated rely on a compile-time
default. These are refactored so as the GUC table and its C declaration
use the same values. This makes everything consistent with other
places, backend_flush_after, bgwriter_flush_after, port,
checkpoint_flush_after doing so already, for example.
Extracted from a larger patch by Peter Smith. The spots updated in the
modules are from me.
Author: Peter Smith, Michael Paquier
Reviewed-by: Nathan Bossart, Tom Lane, Justin Pryzby
Discussion: https://postgr.es/m/CAHut+PtHE0XSfjjRQ6D4v7+dqzCw=d+1a64ujra4EX8aoc_Z+w@mail.gmail.com
Most code prints PIDs as %d, but some code tried to print them as long
or unsigned long. While this is in theory allowed, the fact that PIDs
fit into int is deeply baked into all PostgreSQL code, so these random
deviations don't accomplish anything except confusion.
Note that we still need casts from pid_t to int, because on 64-bit
MinGW, pid_t is long long int. (But per above, actually supporting
that range in PostgreSQL code would be major surgery and probably not
useful.)
Discussion: https://www.postgresql.org/message-id/289c2e45-c7d9-5ce4-7eff-a9e2a33e1580@enterprisedb.com
The generated resource files aren't exactly the same ones as the old
buildsystems generate. Previously "InternalName" and "OriginalFileName" were
mostly wrong / not set (despite being required), but that was hard to fix in
at least the make build. Additionally, the meson build falls back to a
"auto-generated" description when not set, and doesn't set it in a few cases -
unlikely that anybody looks at these descriptions in detail.
Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
There are still some alignment-related failures in the buildfarm,
which might or might not be able to be fixed quickly, but I've also
just realized that it increased the size of many WAL records by 4 bytes
because a block reference contains a RelFileLocator. The effect of that
hasn't been studied or discussed, so revert for now.
RelFileNumbers are now assigned using a separate counter, instead of
being assigned from the OID counter. This counter never wraps around:
if all 2^56 possible RelFileNumbers are used, an internal error
occurs. As the cluster is limited to 2^64 total bytes of WAL, this
limitation should not cause a problem in practice.
If the counter were 64 bits wide rather than 56 bits wide, we would
need to increase the width of the BufferTag, which might adversely
impact buffer lookup performance. Also, this lets us use bigint for
pg_class.relfilenode and other places where these values are exposed
at the SQL level without worrying about overflow.
This should remove the need to keep "tombstone" files around until
the next checkpoint when relations are removed. We do that to keep
RelFileNumbers from being recycled, but now that won't happen
anyway. However, this patch doesn't actually change anything in
this area; it just makes it possible for a future patch to do so.
Dilip Kumar, based on an idea from Andres Freund, who also reviewed
some earlier versions of the patch. Further review and some
wordsmithing by me. Also reviewed at various points by Ashutosh
Sharma, Vignesh C, Amul Sul, Álvaro Herrera, and Tom Lane.
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Autoconf is showing its age, fewer and fewer contributors know how to wrangle
it. Recursive make has a lot of hard to resolve dependency issues and slow
incremental rebuilds. Our home-grown MSVC build system is hard to maintain for
developers not using Windows and runs tests serially. While these and other
issues could individually be addressed with incremental improvements, together
they seem best addressed by moving to a more modern build system.
After evaluating different build system choices, we chose to use meson, to a
good degree based on the adoption by other open source projects.
We decided that it's more realistic to commit a relatively early version of
the new build system and mature it in tree.
This commit adds an initial version of a meson based build system. It supports
building postgres on at least AIX, FreeBSD, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows (however only gcc is supported on aix, solaris). For
Windows/MSVC postgres can now be built with ninja (faster, particularly for
incremental builds) and msbuild (supporting the visual studio GUI, but
building slower).
Several aspects (e.g. Windows rc file generation, PGXS compatibility, LLVM
bitcode generation, documentation adjustments) are done in subsequent commits
requiring further review. Other aspects (e.g. not installing test-only
extensions) are not yet addressed.
When building on Windows with msbuild, builds are slower when using a visual
studio version older than 2019, because those versions do not support
MultiToolTask, required by meson for intra-target parallelism.
The plan is to remove the MSVC specific build system in src/tools/msvc soon
after reaching feature parity. However, we're not planning to remove the
autoconf/make build system in the near future. Likely we're going to keep at
least the parts required for PGXS to keep working around until all supported
versions build with meson.
Some initial help for postgres developers is at
https://wiki.postgresql.org/wiki/Meson
With contributions from Thomas Munro, John Naylor, Stone Tickle and others.
Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20211012083721.hvixq4pnh2pixr3j@alap3.anarazel.de
This is preparatory work for a project to increase the number of bits
in a RelFileNumber from 32 to 56.
Along the way, introduce static inline accessor functions for a couple
of BufferTag fields.
Dilip Kumar, reviewed by me. The overall patch series has also had
review at various times from Andres Freund, Ashutosh Sharma, Hannu
Krosing, Vignesh C, Álvaro Herrera, and Tom Lane.
Discussion: http://postgr.es/m/CAFiTN-trubju5YbWAq-BSpZ90-Z6xCVBQE8BVqXqANOZAF1Znw@mail.gmail.com
After commit 089480c07, it's necessary for background worker entry
points to be marked PGDLLEXPORT, else they aren't findable by
LookupBackgroundWorkerFunction(). Since pg_prewarm lacks any
regression tests, it's not surprising its worker entry points were
overlooked. (A quick search turned up no other such oversights.)
I added some documentation pointing out the need for this, too.
Robins Tharakan and Tom Lane
CAEP4nAzndnQv3-1QKb=D-hLoK3Rko12HHMFHHtdj2GQAUXO3gw@mail.gmail.com
This replaces all MemSet() calls with struct initialization where that
is easily and obviously possible. (For example, some cases have to
worry about padding bits, so I left those.)
(The same could be done with appropriate memset() calls, but this
patch is part of an effort to phase out MemSet(), so it doesn't touch
memset() calls.)
Reviewed-by: Ranier Vilela <ranier.vf@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/9847b13c-b785-f4e2-75c3-12ec77a3b05c@enterprisedb.com
We have been using the term RelFileNode to refer to either (1) the
integer that is used to name the sequence of files for a certain relation
within the directory set aside for that tablespace/database combination;
or (2) that value plus the OIDs of the tablespace and database; or
occasionally (3) the whole series of files created for a relation
based on those values. Using the same name for more than one thing is
confusing.
Replace RelFileNode with RelFileNumber when we're talking about just the
single number, i.e. (1) from above, and with RelFileLocator when we're
talking about all the things that are needed to locate a relation's files
on disk, i.e. (2) from above. In the places where we refer to (3) as
a relfilenode, instead refer to "relation storage".
Since there is a ton of SQL code in the world that knows about
pg_class.relfilenode, don't change the name of that column, or of other
SQL-facing things that derive their name from it.
On the other hand, do adjust closely-related internal terminology. For
example, the structure member names dbNode and spcNode appear to be
derived from the fact that the structure itself was called RelFileNode,
so change those to dbOid and spcOid. Likewise, various variables with
names like rnode and relnode get renamed appropriately, according to
how they're being used in context.
Hopefully, this is clearer than before. It is also preparation for
future patches that intend to widen the relfilenumber fields from its
current width of 32 bits. Variables that store a relfilenumber are now
declared as type RelFileNumber rather than type Oid; right now, these
are the same, but that can now more easily be changed.
Dilip Kumar, per an idea from me. Reviewed also by Andres Freund.
I fixed some whitespace issues, changed a couple of words in a
comment, and made one other minor correction.
Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com
Currently, preloaded libraries are expected to request additional
shared memory and LWLocks in _PG_init(). However, it is not unusal
for such requests to depend on MaxBackends, which won't be
initialized at that time. Such requests could also depend on GUCs
that other modules might change. This introduces a new hook where
modules can safely use MaxBackends and GUCs to request additional
shared memory and LWLocks.
Furthermore, this change restricts requests for shared memory and
LWLocks to this hook. Previously, libraries could make requests
until the size of the main shared memory segment was calculated.
Unlike before, we no longer silently ignore requests received at
invalid times. Instead, we FATAL if someone tries to request
additional shared memory or LWLocks outside of the hook.
Nathan Bossart and Julien Rouhaud
Discussion: https://postgr.es/m/20220412210112.GA2065815%40nathanxps13
Discussion: https://postgr.es/m/Yn2jE/lmDhKtkUdr@paquier.xyz
Commit 75d22069e tried to throw a warning for setting a custom GUC whose
prefix belongs to a previously-loaded extension, if there is no such GUC
defined by the extension. But that caused unstable behavior with
parallel workers, because workers don't necessarily load extensions and
GUCs in the same order their leader did. To make that work safely, we
have to completely disallow the case. We now actually remove any such
GUCs at the time of initial extension load, and then throw an error not
just a warning if you try to add one later. While this might create a
compatibility issue for a few people, the improvement in error-detection
capability seems worth it; it's hard to believe that there's any good
use-case for choosing such GUC names.
This also un-reverts 5609cc01c (Rename EmitWarningsOnPlaceholders() to
MarkGUCPrefixReserved()), since that function's old name is now even
more of a misnomer.
Florin Irion and Tom Lane
Discussion: https://postgr.es/m/1902182.1640711215@sss.pgh.pa.us
Andres Freund