The code has been assuming already in a few places that the initial
recursion nesting depth is 0, and the recent changes in hba.c (mainly
783e8c6) have relies on this assumption in more places. The maximum
recursion nesting level is assumed to be 10 for hba.c and GUCs.
Author: Julien Rouhaud
Discussion: https://postgr.es/m/20221124090724.n7amf5kpdhx6vb76@jrouhaud
We're running out of bits for new permissions. This change doubles the
number of permissions we can accomodate from 16 to 32, so the
forthcoming new ones for vacuum/analyze don't exhaust the pool.
Nathan Bossart
Reviewed by: Bharath Rupireddy, Kyotaro Horiguchi, Stephen Frost, Robert
Haas, Mark Dilger, Tom Lane, Corey Huinker, David G. Johnston, Michael
Paquier.
Discussion: https://postgr.es/m/20220722203735.GB3996698@nathanxps13
The lwlock wait queue scalability issue fixed in a4adc31f690 was quite hard to
find because of the exponential backoff and because we adjust spins_per_delay
over time within a backend.
To make it easier to find similar issues in the future, add a wait event for
the pg_usleep() in perform_spin_delay(). Showing a wait event while spinning
without sleeping would increase the overhead of spinlocks, which we do not
want.
We may at some later point want to have more granular wait events, but that'd
be a substantial amount of work. This provides at least some insights into
something currently hard to observe.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
https://postgr.es/m/20221120204310.xywrhyxyytsajuuq@awork3.anarazel.de
This switch impacts 9 patterns related to a SQL-mandated special syntax
for function calls:
- LOCALTIME [ ( typmod ) ]
- LOCALTIMESTAMP [ ( typmod ) ]
- CURRENT_TIME [ ( typmod ) ]
- CURRENT_TIMESTAMP [ ( typmod ) ]
- CURRENT_DATE
Five new entries are added to pg_proc to compensate the removal of
SQLValueFunction to provide backward-compatibility and making this
change transparent for the end-user (for example for the attribute
generated when a keyword is specified in a SELECT or in a FROM clause
without an alias, or when specifying something else than an Iconst to
the parser).
The parser included a set of checks coming from the files in charge of
holding the C functions used for the SQLValueFunction calls (as of
transformSQLValueFunction()), which are now moved within each function's
execution path, so this reduces the dependencies between the execution
and the parsing steps. As of this change, all the SQL keywords use the
same paths for their work, relying only on COERCE_SQL_SYNTAX. Like
fb32748, no performance difference has been noticed, while the perf
profiles get reduced with ExecEvalSQLValueFunction() gone.
Bump catalog version.
Reviewed-by: Corey Huinker, Ted Yu
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
Similar to how the INHERIT option controls whether or not the
permissions of the granted role are automatically available to the
grantee, the new SET permission controls whether or not the grantee
may use the SET ROLE command to assume the privileges of the granted
role.
In addition, the new SET permission controls whether or not it
is possible to transfer ownership of objects to the target role
or to create new objects owned by the target role using commands
such as CREATE DATABASE .. OWNER. We could alternatively have made
this controlled by the INHERIT option, or allow it when either
option is given. An advantage of this approach is that if you
are granted a predefined role with INHERIT TRUE, SET FALSE, you
can't go and create objects owned by that role.
The underlying theory here is that the ability to create objects
as a target role is not a privilege per se, and thus does not
depend on whether you inherit the target role's privileges. However,
it's surely something you could do anyway if you could SET ROLE
to the target role, and thus making it contingent on whether you
have that ability is reasonable.
Design review by Nathan Bossat, Wolfgang Walther, Jeff Davis,
Peter Eisentraut, and Stephen Frost.
Discussion: http://postgr.es/m/CA+Tgmob+zDSRS6JXYrgq0NWdzCXuTNzT5eK54Dn2hhgt17nm8A@mail.gmail.com
Instead of dozens of mostly-duplicate pg_foo_aclcheck() functions,
write one common function object_aclcheck() that can handle almost all
of them. We already have all the information we need, such as which
system catalog corresponds to which catalog table and which column is
the ACL column.
There are a few pg_foo_aclcheck() that don't work via the generic
function and have special APIs, so those stay as is.
I also changed most pg_foo_aclmask() functions to static functions,
since they are not used outside of aclchk.c.
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Antonin Houska <ah@cybertec.at>
Discussion: https://www.postgresql.org/message-id/flat/95c30f96-4060-2f48-98b5-a4392d3b6066@enterprisedb.com
The code in charge of listing and classifying a set of configuration
files in a directory was located in guc-file.l, being used currently for
GUCs under "include_dir". This code is planned to be used for an
upcoming feature able to include configuration files for ident and HBA
files from a directory, similarly to GUCs. In both cases, the file
names, suffixed by ".conf", have to be ordered alphabetically. This
logic is moved to a new file, called conffiles.c, so as it is easier to
share this facility between GUCs and the HBA/ident parsing logic.
Author: Julien Rouhaud, Michael Paquier
Discussion: https://postgr.es/m/Y2IgaH5YzIq2b+iR@paquier.xyz
We have various requirements when using a dlist_head to keep track of the
number of items in the list. This, traditionally, has been done by
maintaining a counter variable in the calling code. Here we tidy this up
by adding "dclist", which is very similar to dlist but also keeps track of
the number of items stored in the list.
Callers may use the new dclist_count() function when they need to know how
many items are stored. Obtaining the count is an O(1) operation.
For simplicity reasons, dclist and dlist both use dlist_node as their node
type and dlist_iter/dlist_mutable_iter as their iterator type. dclists
have all of the same functionality as dlists except there is no function
named dclist_delete(). To remove an item from a list dclist_delete_from()
must be used. This requires knowing which dclist the given item is stored
in.
Additionally, here we also convert some dlists where additional code
exists to keep track of the number of items stored and to make these use
dclists instead.
Author: David Rowley
Reviewed-by: Bharath Rupireddy, Aleksander Alekseev
Discussion: https://postgr.es/m/CAApHDvrtVxr+FXEX0VbViCFKDGxA3tWDgw9oFewNXCJMmwLjLg@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
Here we add a new 'copy' parameter to tuplesort_getdatum so that we can
instruct the function not to datumCopy() byref Datums before returning.
Similar to 91e9e89dc, this can provide significant performance
improvements in nodeSort when sorting by a single byref column and the
sort's targetlist contains only that column.
This allows us to re-enable Datum sorts for byref types which was disabled
in 3a5817695 due to a reported memory leak.
Additionally, here we slightly optimize DISTINCT aggregates so that we no
longer perform any datumCopy() when we find the current value not to be
distinct from the previous value. Previously the code would always take a
copy of the most recent Datum and pfree the previous value, even when the
values were the same. Testing shows a small but noticeable performance
increase when aggregate transitions are skipped due to the current
transition value being the same as the prior one.
Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvqS6wC5U==k9Hd26E4EQXH3QR67-T4=Q1rQ36NGvjfVSg@mail.gmail.com
Discussion: https://postgr.es/m/CAApHDvqHonfe9G1cVaKeHbDx70R_zCrM3qP2AGXpGrieSKGnhA@mail.gmail.com
The previous patch made addition of new GUCs cheap, but other GUC
operations aren't improved and indeed get a bit slower, because
hash_seq_search() is slower than just scanning a pointer array.
However, most performance-critical GUC operations only need
to touch a relatively small fraction of the GUCs; especially
so for AtEOXact_GUC(). We can improve matters at the cost
of a bit more space by adding dlist or slist links to the
GUC data structures. This patch invents lists that track
(1) all GUCs with non-default "source";
(2) all GUCs with nonempty state stack (implying they've
been changed in the current transaction);
(3) all GUCs due for reporting to the client.
All of guc.c's performance-critical cases can make use of one or
another of these lists to avoid searching the whole hash table.
In particular, the stack list means that transaction end
doesn't take time proportional to the number of GUCs, but
only to the number changed in the current transaction.
Discussion: https://postgr.es/m/2982579.1662416866@sss.pgh.pa.us
This gets rid of bsearch() in favor of hashed lookup. The main
advantage is that it becomes far cheaper to add new GUCs, since
we needn't re-sort the pointer array. Adding N new GUCs had
been O(N^2 log N), but now it's closer to O(N). We need to
sort only in SHOW ALL and equivalent functions, which are
hopefully not performance-critical to anybody.
Also, merge GetNumConfigOptions() into get_guc_variables(),
because in a world where the set of GUCs isn't fairly static
you really want to consider those two results as tied together
not independent.
Discussion: https://postgr.es/m/2982579.1662416866@sss.pgh.pa.us
The only real argument for using malloc directly was that we needed
the ability to not throw error on OOM; but mcxt.c grew that feature
awhile ago.
Keeping the data in a memory context improves accountability and
debuggability --- for example, without this it's almost impossible
to detect memory leaks in the GUC code with anything less costly
than valgrind. Moreover, the next patch in this series will add a
hash table for GUC lookup, and it'd be pretty silly to be using
palloc-dependent hash facilities alongside malloc'd storage of the
underlying data.
This is a bit invasive though, in particular causing an API break
for GUC check hooks that want to modify the GUC's value or use an
"extra" data structure. They must now use guc_malloc() and
guc_free() instead of malloc() and free(). Failure to change
affected code will result in assertion failures or worse; but
thanks to recent effort in the mcxt infrastructure, it shouldn't
be too hard to diagnose such oversights (at least in assert-enabled
builds).
One note is that this changes ParseLongOption() to return short-lived
palloc'd not malloc'd data. There wasn't any caller for which the
previous definition was better.
Discussion: https://postgr.es/m/2982579.1662416866@sss.pgh.pa.us
We lack a version of repalloc() that supports MCXT_ALLOC_NO_OOM
semantics, so invent repalloc_extended() with the usual set of
flags. repalloc_huge() becomes a legacy wrapper for that.
Also, fix dynahash.c so that it can support HASH_ENTER_NULL
requests when using the default palloc-based allocator.
The only reason it didn't do that already was the lack of the
MCXT_ALLOC_NO_OOM option when that code was written, ages ago.
While here, simplify a few overcomplicated tests in mcxt.c.
Discussion: https://postgr.es/m/2982579.1662416866@sss.pgh.pa.us
Previously PgStat_StatReplSlotEntry contained the slotname, which was mainly
used when writing out the stats during shutdown, to identify the slot in the
serialized data (at runtime the index in ReplicationSlotCtl->replication_slots
is used, but that can change during a restart). Unfortunately the slotname was
overwritten when the slot's stats were reset.
That turned out to only cause "real" problems if the slot was active during
the reset, triggering an assertion failure at the next
pgstat_report_replslot(). In other paths the stats were re-initialized during
pgstat_acquire_replslot().
Fix this by removing slotname from PgStat_StatReplSlotEntry. Instead we can
get the slot's name from the slot itself. Besides fixing a bug, this also is
architecturally cleaner (a name is not really statistics). This is safe
because stats, for a slot removed while shut down, will not be restored at
startup.
In 15 the slotname is not removed, but renamed, to avoid changing the stats
format. In master, bump PGSTAT_FILE_FORMAT_ID.
This commit does not contain a test for the fix. I think this can only be
tested by a tap test starting pg_recvlogical in the background and checking
pg_recvlogical's output. That type of test is notoriously hard to be reliable,
so committing it shortly before the release is wrapped seems like a bad idea.
Reported-by: Jaime Casanova <jcasanov@systemguards.com.ec>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/YxfagaTXUNa9ggLb@ahch-to
Backpatch: 15-, where the bug was introduced in 5891c7a8ed8f
Commit c6e0fe1f2 was a shade too trusting that any pointer passed
to pfree, repalloc, etc will point at a valid chunk. Notably,
passing a pointer that was actually obtained from malloc tended
to result in obscure assertion failures, if not worse. (On FreeBSD
I've seen such mistakes take down the entire cluster, seemingly as
a result of clobbering shared memory.)
To improve matters, extend the mcxt_methods[] array so that it
has entries for every possible MemoryContextMethodID bit-pattern,
with the currently unassigned ID codes pointing to error-reporting
functions. Then, fiddle with the ID assignments so that patterns
likely to be associated with bad pointers aren't valid ID codes.
In particular, we should avoid assigning bit patterns 000 (zeroed
memory) and 111 (wipe_mem'd memory).
It turns out that on glibc (Linux), malloc uses chunk headers that
have flag bits in the same place we keep MemoryContextMethodID,
and that the bit patterns 000, 001, 010 are the only ones we'll
see as long as the backend isn't threaded. So we can have very
robust detection of pfree'ing a malloc-assigned block on that
platform, at least so long as we can refrain from using up those
ID codes. On other platforms, we don't have such a good guarantee,
but keeping 000 reserved will be enough to catch many such cases.
While here, make GetMemoryChunkMethodID() local to mcxt.c, as there
seems no need for it to be exposed even in memutils_internal.h.
Patch by me, with suggestions from Andres Freund and David Rowley.
Discussion: https://postgr.es/m/2910981.1665080361@sss.pgh.pa.us
MemoryContextContains is no longer reliable in the wake of c6e0fe1f2,
because there's no longer very much redundancy in chunk headers.
(It wasn't *completely* reliable even before that, as there was a
chance of a false positive if you passed it something that didn't
point to an mcxt chunk at all. But it was generally good enough.)
Hence, remove it. There is no remaining core code that requires it.
Extensions that have been using it might be able to substitute a
test like "GetMemoryChunkContext(ptr) == context", recognizing that
this explicitly requires that the pointer point to some chunk.
Tom Lane and David Rowley
Discussion: https://postgr.es/m/1913788.1664898906@sss.pgh.pa.us
This optional parameter can be specified in cases where there are nested
PG_TRY() statements within a function in order to stop the compiler from
issuing warnings about shadowed local variables when compiling with
-Wshadow. The optional parameter is used as a suffix on the variable
names declared within the PG_TRY(), PG_CATCH(), PG_FINALLY() and
PG_END_TRY() macros. The parameter, if specified, must be the same in
each component macro of the given PG_TRY() block.
This also adjusts the single case where we have nested PG_TRY() statements
to add a parameter to the inner-most PG_TRY().
This reduces the number of compiler warnings when compiling with
-Wshadow=compatible-local from 5 down to 1.
Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvqWGMdB_pATeUqE=JCtNqNxObPOJ00jFEa2_sZ20j_Wvg@mail.gmail.com
This reverts commit db0d67db2401eb6238ccc04c6407a4fd4f985832 and
several follow-on fixes. The idea of making a cost-based choice
of the order of the sorting columns is not fundamentally unsound,
but it requires cost information and data statistics that we don't
really have. For example, relying on procost to distinguish the
relative costs of different sort comparators is pretty pointless
so long as most such comparator functions are labeled with cost 1.0.
Moreover, estimating the number of comparisons done by Quicksort
requires more than just an estimate of the number of distinct values
in the input: you also need some idea of the sizes of the larger
groups, if you want an estimate that's good to better than a factor of
three or so. That's data that's often unknown or not very reliable.
Worse, to arrive at estimates of the number of calls made to the
lower-order-column comparison functions, the code needs to make
estimates of the numbers of distinct values of multiple columns,
which are necessarily even less trustworthy than per-column stats.
Even if all the inputs are perfectly reliable, the cost algorithm
as-implemented cannot offer useful information about how to order
sorting columns beyond the point at which the average group size
is estimated to drop to 1.
Close inspection of the code added by db0d67db2 shows that there
are also multiple small bugs. These could have been fixed, but
there's not much point if we don't trust the estimates to be
accurate in-principle.
Finally, the changes in cost_sort's behavior made for very large
changes (often a factor of 2 or so) in the cost estimates for all
sorting operations, not only those for multi-column GROUP BY.
That naturally changes plan choices in many situations, and there's
precious little evidence to show that the changes are for the better.
Given the above doubts about whether the new estimates are really
trustworthy, it's hard to summon much confidence that these changes
are better on the average.
Since we're hard up against the release deadline for v15, let's
revert these changes for now. We can always try again later.
Note: in v15, I left T_PathKeyInfo in place in nodes.h even though
it's unreferenced. Removing it would be an ABI break, and it seems
a bit late in the release cycle for that.
Discussion: https://postgr.es/m/TYAPR01MB586665EB5FB2C3807E893941F5579@TYAPR01MB5866.jpnprd01.prod.outlook.com
Up to now, the ID values returned by pg_stat_get_backend_idset() and
used by pg_stat_get_backend_activity() and allied functions were just
indexes into a local array of sessions seen by the last stats refresh.
This is problematic for a few reasons. The "ID" of a session can vary
over its existence, which is surprising. Also, while these numbers
often match the "backend ID" used for purposes like temp schema
assignment, that isn't reliably true. We can fairly cheaply switch
things around to make these numbers actually be the sessions' backend
IDs. The added test case illustrates that with this definition, the
temp schema used by a given session can be obtained given its PID.
While here, delete some dead code that guarded against getting
a NULL return from pgstat_fetch_stat_local_beentry(). That can't
happen as long as the caller is careful to pass an in-range array
index, as all the callers are. (This code may not have been dead
when written, but it surely is now.)
Nathan Bossart
Discussion: https://postgr.es/m/20220815205811.GA250990@nathanxps13
The previous macro implementations just cast the argument to a target
type but did not check whether the input type was appropriate. The
function implementation can do better type checking of the input type.
For the *GetDatumFast() macros, converting to an inline function
doesn't work in the !USE_FLOAT8_BYVAL case, but we can use
AssertVariableIsOfTypeMacro() to get a similar level of type checking.
Reviewed-by: Aleksander Alekseev <aleksander@timescale.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/8528fb7e-0aa2-6b54-85fb-0c0886dbd6ed%40enterprisedb.com
Buildfarm member crake ran headerscheck, which complained about
a missing include here.
Defect introduced by commit 2f47715cc8649f854b1df28dfc338af9801db217.
Previously, these were declared in postgres_ext.h, but they are not
needed nearly so widely as the OID declarations, so that doesn't
necessarily make sense. Also, because postgres_ext.h is included
before most of c.h has been processed, the previous location creates
some problems for a pending patch.
Patch by me, reviewed by Dilip Kumar.
Discussion: http://postgr.es/m/CA+TgmoYc8oevMqRokZQ4y_6aRn-7XQny1JBr5DyWR_jiFtONHw@mail.gmail.com
Push the units fields over to the left so that all the single-bit
flags can be together. I considered rearranging the single-bit
flags to try to group flags with similar purposes, but eventually
decided that that involved too many judgment calls.
Discussion: https://postgr.es/m/17385-9ee529fb091f0ce5@postgresql.org
Previously, the transaction-property GUCs such as transaction_isolation
could be reset after starting a transaction, because we marked them
as GUC_NO_RESET_ALL but still allowed a targeted RESET. That leads to
assertion failures or worse, because those properties aren't supposed
to change after we've acquired a transaction snapshot.
There are some NO_RESET_ALL variables for which RESET is okay, so
we can't just redefine the semantics of that flag. Instead introduce
a separate GUC_NO_RESET flag. Mark "seed", as well as the transaction
property GUCs, as GUC_NO_RESET.
We have to disallow GUC_ACTION_SAVE as well as straight RESET, because
otherwise a function having a "SET transaction_isolation" clause can
still break things: the end-of-function restore action is equivalent
to a RESET.
No back-patch, as it's conceivable that someone is doing something
this patch will forbid (like resetting one of these GUCs at transaction
start, or "CREATE FUNCTION ... SET transaction_read_only = 1") and not
running into problems with it today. Given how long we've had this
issue and not noticed, the side effects in non-assert builds can't be
too serious.
Per bug #17385 from Andrew Bille.
Masahiko Sawada
Discussion: https://postgr.es/m/17385-9ee529fb091f0ce5@postgresql.org
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
Fix selfuncs.h cpluspluscheck complaint, without reintroducing a
parameter name inconsistency (restore the original declaration names,
and then make corresponding function definitions consistent with that).
Oversight in commit a601366a.
Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Andres Freund <andres@anarazel.de>
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in optimizer, parser,
utility, libpq, and "commands" code, as well as in remaining library
code. Do the same for all code related to frontend programs (with the
exception of pg_dump/pg_dumpall related code).
Like other recent commits that cleaned up function parameter names, this
commit was written with help from clang-tidy. Later commits will handle
ecpg and pg_dump/pg_dumpall.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com
guc.c has grown to be one of our largest .c files, making it
a bottleneck for compilation. It's also acquired a bunch of
knowledge that'd be better kept elsewhere, because of our not
very good habit of putting variable-specific check hooks here.
Hence, split it up along these lines:
* guc.c itself retains just the core GUC housekeeping mechanisms.
* New file guc_funcs.c contains the SET/SHOW interfaces and some
SQL-accessible functions for GUC manipulation.
* New file guc_tables.c contains the data arrays that define the
built-in GUC variables, along with some already-exported constant
tables.
* GUC check/assign/show hook functions are moved to the variable's
home module, whenever that's clearly identifiable. A few hard-
to-classify hooks ended up in commands/variable.c, which was
already a home for miscellaneous GUC hook functions.
To avoid cluttering a lot more header files with #include "guc.h",
I also invented a new header file utils/guc_hooks.h and put all
the GUC hook functions' declarations there, regardless of their
originating module. That allowed removal of #include "guc.h"
from some existing headers. The fallout from that (hopefully
all caught here) demonstrates clearly why such inclusions are
best minimized: there are a lot of files that, for example,
were getting array.h at two or more levels of remove, despite
not having any connection at all to GUCs in themselves.
There is some very minor code beautification here, such as
renaming a couple of inconsistently-named hook functions
and improving some comments. But mostly this just moves
code from point A to point B and deals with the ensuing
needs for #include adjustments and exporting a few functions
that previously weren't exported.
Patch by me, per a suggestion from Andres Freund; thanks also
to Michael Paquier for the idea to invent guc_funcs.c.
Discussion: https://postgr.es/m/587607.1662836699@sss.pgh.pa.us
This adds additional variants of palloc, pg_malloc, etc. that
encapsulate common usage patterns and provide more type safety.
Specifically, this adds palloc_object(), palloc_array(), and
repalloc_array(), which take the type name of the object to be
allocated as its first argument and cast the return as a pointer to
that type. There are also palloc0_object() and palloc0_array()
variants for initializing with zero, and pg_malloc_*() variants of all
of the above.
Inspired by the talloc library.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/bb755632-2a43-d523-36f8-a1e7a389a907@enterprisedb.com
The reverts the following and makes some associated cleanups:
commit f79b803dc: Common SQL/JSON clauses
commit f4fb45d15: SQL/JSON constructors
commit 5f0adec25: Make STRING an unreserved_keyword.
commit 33a377608: IS JSON predicate
commit 1a36bc9db: SQL/JSON query functions
commit 606948b05: SQL JSON functions
commit 49082c2cc: RETURNING clause for JSON() and JSON_SCALAR()
commit 4e34747c8: JSON_TABLE
commit fadb48b00: PLAN clauses for JSON_TABLE
commit 2ef6f11b0: Reduce running time of jsonb_sqljson test
commit 14d3f24fa: Further improve jsonb_sqljson parallel test
commit a6baa4bad: Documentation for SQL/JSON features
commit b46bcf7a4: Improve readability of SQL/JSON documentation.
commit 112fdb352: Fix finalization for json_objectagg and friends
commit fcdb35c32: Fix transformJsonBehavior
commit 4cd8717af: Improve a couple of sql/json error messages
commit f7a605f63: Small cleanups in SQL/JSON code
commit 9c3d25e17: Fix JSON_OBJECTAGG uniquefying bug
commit a79153b7a: Claim SQL standard compliance for SQL/JSON features
commit a1e7616d6: Rework SQL/JSON documentation
commit 8d9f9634e: Fix errors in copyfuncs/equalfuncs support for JSON node types.
commit 3c633f32b: Only allow returning string types or bytea from json_serialize
commit 67b26703b: expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.
The release notes are also adjusted.
Backpatch to release 15.
Discussion: https://postgr.es/m/40d2c882-bcac-19a9-754d-4299e1d87ac7@postgresql.org
Robert Haas reported that his older clang compiler didn't like the two
Asserts which were verifying that the given MemoryContextMethodID was <=
MEMORY_CONTEXT_METHODID_MASK when building with
-Wtautological-constant-out-of-range-compare. In my (David's) opinion,
the compiler is wrong to warn about that. Newer versions of clang don't
warn about the out of range enum value, so perhaps this was a bug that has
now been fixed. To keep older clang versions happy, let's just cast the
enum value to int to stop the compiler complaining.
The main reason for the Asserts mentioned above to exist are to inform
future developers which are adding new MemoryContexts if they run out of
bit space in MemoryChunk to store the MemoryContextMethodID. As pointed
out by Tom Lane, it seems wise to also add a comment to the header for
that enum to document the restriction on these enum values.
Additionally, also fix an incorrect usage of UINT64CONST() which was
introduced in c6e0fe1f2.
Author: Robert Haas, David Rowley
Discussion: https://postgr.es/m/CA+TgmoYGG2C7Vbw1cjkQRRBL3zOk8SmhrQnsJgzscX=N9AwPrw@mail.gmail.com
This reverts commit df0f4feef. It turns out the problem which was causing
the 32-bit ARM and PPC animals to fail was due to a MAXALIGN problem in
slab.c. This was fixed by d5ee4db0e. The padding that was added in
df0f4feef would only do anything on machines where uint64 was not aligned
to 8 bytes. The 32-bit machines which were failing are not in that
category, so revert this commit.
Discussion: https://postgr.es/m/3209100.1661787561@sss.pgh.pa.us
Buildfarm animals skate, grison and mamba are Assert failing on the
pointer being given to repalloc not being MAXALIGNED. c6e0fe1f2a made
changes in that area.
All of these animals are 32-bit with a MAXIMUM_ALIGNOF of 8 and a
SIZEOF_VOID_P of 4. I suspect that the pointer is not properly aligned due
to the lack of padding in the MemoryChunk struct.
Here we add the same type of padding that was previously used in
AllocChunkData and GenerationChunk that c6e0fe1f2a neglected to add.
Discussion: https://postgr.es/m/CAA4eK1%2B1JyW5TiL%3DyV-3Uq1CrfnTyn0Xrk5uArt31Z%3D8rgPhXQ%40mail.gmail.com
Whenever we palloc a chunk of memory, traditionally, we prefix the
returned pointer with a pointer to the memory context to which the chunk
belongs. This is required so that we're able to easily determine the
owning context when performing operations such as pfree() and repalloc().
For the AllocSet context, prior to this commit we additionally prefixed
the pointer to the owning context with the size of the chunk. This made
the header 16 bytes in size. This 16-byte overhead was required for all
AllocSet allocations regardless of the allocation size.
For the generation context, the problem was worse; in addition to the
pointer to the owning context and chunk size, we also stored a pointer to
the owning block so that we could track the number of freed chunks on a
block.
The slab allocator had a 16-byte chunk header.
The changes being made here reduce the chunk header size down to just 8
bytes for all 3 of our memory context types. For small to medium sized
allocations, this significantly increases the number of chunks that we can
fit on a given block which results in much more efficient use of memory.
Additionally, this commit completely changes the rule that pointers to
palloc'd memory must be directly prefixed by a pointer to the owning
memory context and instead, we now insist that they're directly prefixed
by an 8-byte value where the least significant 3-bits are set to a value
to indicate which type of memory context the pointer belongs to. Using
those 3 bits as an index (known as MemoryContextMethodID) to a new array
which stores the methods for each memory context type, we're now able to
pass the pointer given to functions such as pfree() and repalloc() to the
function specific to that context implementation to allow them to devise
their own methods of finding the memory context which owns the given
allocated chunk of memory.
The reason we're able to reduce the chunk header down to just 8 bytes is
because of the way we make use of the remaining 61 bits of the required
8-byte chunk header. Here we also implement a general-purpose MemoryChunk
struct which makes use of those 61 remaining bits to allow the storage of
a 30-bit value which the MemoryContext is free to use as it pleases, and
also the number of bytes which must be subtracted from the chunk to get a
reference to the block that the chunk is stored on (also 30 bits). The 1
additional remaining bit is to denote if the chunk is an "external" chunk
or not. External here means that the chunk header does not store the
30-bit value or the block offset. The MemoryContext can use these
external chunks at any time, but must use them if any of the two 30-bit
fields are not large enough for the value(s) that need to be stored in
them. When the chunk is marked as external, it is up to the MemoryContext
to devise its own means to determine the block offset.
Using 3-bits for the MemoryContextMethodID does mean we're limiting
ourselves to only having a maximum of 8 different memory context types.
We could reduce the bit space for the 30-bit value a little to make way
for more than 3 bits, but it seems like it might be better to do that only
if we ever need more than 8 context types. This would only be a problem
if some future memory context type which does not use MemoryChunk really
couldn't give up any of the 61 remaining bits in the chunk header.
With this MemoryChunk, each of our 3 memory context types can quickly
obtain a reference to the block any given chunk is located on. AllocSet
is able to find the context to which the chunk is owned, by first
obtaining a reference to the block by subtracting the block offset as is
stored in the 'hdrmask' field and then referencing the block's 'aset'
field. The Generation context uses the same method, but GenerationBlock
did not have a field pointing back to the owning context, so one is added
by this commit.
In aset.c and generation.c, all allocations larger than allocChunkLimit
are stored on dedicated blocks. When there's just a single chunk on a
block like this, it's easy to find the block from the chunk, we just
subtract the size of the block header from the chunk pointer. The size of
these chunks is also known as we store the endptr on the block, so we can
just subtract the pointer to the allocated memory from that. Because we
can easily find the owning block and the size of the chunk for these
dedicated blocks, we just always use external chunks for allocation sizes
larger than allocChunkLimit. For generation.c, this sidesteps the problem
of non-external MemoryChunks being unable to represent chunk sizes >= 1GB.
This is less of a problem for aset.c as we store the free list index in
the MemoryChunk's spare 30-bit field (the value of which will never be
close to using all 30-bits). We can easily reverse engineer the chunk size
from this when needed. Storing this saves AllocSetFree() from having to
make a call to AllocSetFreeIndex() to determine which free list to put the
newly freed chunk on.
For the slab allocator, this commit adds a new restriction that slab
chunks cannot be >= 1GB in size. If there happened to be any users of
slab.c which used chunk sizes this large, they really should be using
AllocSet instead.
Here we also add a restriction that normal non-dedicated blocks cannot be
1GB or larger. It's now not possible to pass a 'maxBlockSize' >= 1GB
during the creation of an AllocSet or Generation context. Allocations can
still be larger than 1GB, it's just these will always be on dedicated
blocks (which do not have the 1GB restriction).
Author: Andres Freund, David Rowley
Discussion: https://postgr.es/m/CAApHDvpjauCRXcgcaL6+e3eqecEHoeRm9D-kcbuvBitgPnW=vw@mail.gmail.com
SUSv3 <netinet/in.h> defines struct sockaddr_in6, and all targeted Unix
systems have it. Windows has it in <ws2ipdef.h>. Remove the configure
probe, the macro and a small amount of dead code.
Also remove a mention of IPv6-less builds from the documentation, since
there aren't any.
This is similar to commits f5580882 and 077bf2f2 for Unix sockets. Even
though AF_INET6 is an "optional" component of SUSv3, there are no known
modern operating system without it, and it seems even less likely to be
omitted from future systems than AF_UNIX.
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA+hUKGKErNfhmvb_H0UprEmp4LPzGN06yR2_0tYikjzB-2ECMw@mail.gmail.com
