In the case where the target timestamp is before the origin timestamp
and their difference is already an exact multiple of the stride, the
code incorrectly subtracted the stride anyway.
Also detect several integer-overflow cases that previously produced
bogus results. (The submitted patch tried to avoid overflow, but
I'm not convinced it's right, and problematic cases are so far out of
the plausibly-useful range that they don't seem worth sweating over.
Let's just use overflow-detecting arithmetic and throw errors.)
timestamp_bin() and timestamptz_bin() are basically identical and
so had identical bugs. Fix both.
Report and patch by Moaaz Assali, adjusted some by me. Back-patch
to v14 where date_bin() was introduced.
Discussion: https://postgr.es/m/CALkF+nvtuas-2kydG-WfofbRSJpyODAJWun==W-yO5j2R4meqA@mail.gmail.com
More precisely, what we do here is make the SLRU cache sizes
configurable with new GUCs, so that sites with high concurrency and big
ranges of transactions in flight (resp. multixacts/subtransactions) can
benefit from bigger caches. In order for this to work with good
performance, two additional changes are made:
1. the cache is divided in "banks" (to borrow terminology from CPU
caches), and algorithms such as eviction buffer search only affect
one specific bank. This forestalls the problem that linear searching
for a specific buffer across the whole cache takes too long: we only
have to search the specific bank, whose size is small. This work is
authored by Andrey Borodin.
2. Change the locking regime for the SLRU banks, so that each bank uses
a separate LWLock. This allows for increased scalability. This work
is authored by Dilip Kumar. (A part of this was previously committed as
d172b717c6f4.)
Special care is taken so that the algorithms that can potentially
traverse more than one bank release one bank's lock before acquiring the
next. This should happen rarely, but particularly clog.c's group commit
feature needed code adjustment to cope with this. I (Álvaro) also added
lots of comments to make sure the design is sound.
The new GUCs match the names introduced by bcdfa5f2e2 in the
pg_stat_slru view.
The default values for these parameters are similar to the previous
sizes of each SLRU. commit_ts, clog and subtrans accept value 0, which
means to adjust by dividing shared_buffers by 512 (so 2MB for every 1GB
of shared_buffers), with a cap of 8MB. (A new slru.c function
SimpleLruAutotuneBuffers() was added to support this.) The cap was
previously 1MB for clog, so for sites with more than 512MB of shared
memory the total memory used increases, which is likely a good tradeoff.
However, other SLRUs (notably multixact ones) retain smaller sizes and
don't support a configured value of 0. These values based on
shared_buffers may need to be revisited, but that's an easy change.
There was some resistance to adding these new GUCs: it would be better
to adjust to memory pressure automatically somehow, for example by
stealing memory from shared_buffers (where the caches can grow and
shrink naturally). However, doing that seems to be a much larger
project and one which has made virtually no progress in several years,
and because this is such a pain point for so many users, here we take
the pragmatic approach.
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Author: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Amul Sul, Gilles Darold, Anastasia Lubennikova,
Ivan Lazarev, Robert Haas, Thomas Munro, Tomas Vondra,
Yura Sokolov, Васильев Дмитрий (Dmitry Vasiliev).
Discussion: https://postgr.es/m/2BEC2B3F-9B61-4C1D-9FB5-5FAB0F05EF86@yandex-team.ru
Discussion: https://postgr.es/m/CAFiTN-vzDvNz=ExGXz6gdyjtzGixKSqs0mKHMmaQ8sOSEFZ33A@mail.gmail.com
There isn't a lot of user demand for AIX support, we have a bunch of
hacks to work around AIX-specific compiler bugs and idiosyncrasies,
and no one has stepped up to the plate to properly maintain it.
Remove support for AIX to get rid of that maintenance overhead. It's
still supported for stable versions.
The acute issue that triggered this decision was that after commit
8af2565248, the AIX buildfarm members have been hitting this
assertion:
TRAP: failed Assert("(uintptr_t) buffer == TYPEALIGN(PG_IO_ALIGN_SIZE, buffer)"), File: "md.c", Line: 472, PID: 2949728
Apperently the "pg_attribute_aligned(a)" attribute doesn't work on AIX
for values larger than PG_IO_ALIGN_SIZE, for a static const variable.
That could be worked around, but we decided to just drop the AIX support
instead.
Discussion: https://www.postgresql.org/message-id/20240224172345.32@rfd.leadboat.com
Reviewed-by: Andres Freund, Noah Misch, Thomas Munro
Allocating from a free list or from a block which contains enough space
already, we deem to be common code paths and want to optimize for those.
Having to allocate a new block, either a normal block or a dedicated one
for a large allocation, we deem to be less common, therefore we class
that as "cold". Both cold paths require a malloc so are going to be
slower as a result of that regardless.
The main motivation here is to remove the calls to malloc() in the hot
path and because of this, the compiler is now free to not bother setting
up the stack frame in AllocSetAlloc(), thus making the hot path much
cheaper.
Author: Andres Freund
Reviewed-by: David Rowley
Discussion: https://postgr.es/m/20210719195950.gavgs6ujzmjfaiig@alap3.anarazel.de
This is in the same spirit as ef5e2e9085, updating this time some
arrays in parser.c, relpath.c, guc_tables.c and pg_dump_sort.c so as the
order of their elements has no need to match the enum structures they
are based on anymore.
Author: Jelte Fennema-Nio
Reviewed-by: Jian He, Japin Li
Discussion: https://postgr.es/m/CAGECzQT3caUbcCcszNewCCmMbCuyP7XNAm60J3ybd6PN5kH2Dw@mail.gmail.com
This is a followup to commit 66ea94e8e6.
Error mssages concerning incorrect formats for date-time types are
unified and parameterized, instead of using a fully separate error
message for each type.
Similarly, error messages regarding numeric and string arguments to
certain items are standardized, and instead of saying that the argument
is out of range simply say that it is invalid. The actual invalid
arguments to these itesm are now shown in the error message.
Error messages relating to numeric inputs of Nan or Infinity are
made more informative.
Jeevan Chalke and Kyotaro Horiguchi, with some input from Tom Lane.
Discussion: https://postgr.es/m/20240129.121200.235012930453045390.horikyota.ntt@gmail.com
Many modern compilers are able to optimize function calls to functions
where the parameters of the called function match a leading subset of
the calling function's parameters. If there are no instructions in the
calling function after the function is called, then the compiler is free
to avoid any stack frame setup and implement the function call as a
"jmp" rather than a "call". This is called sibling call optimization.
Here we adjust the memory allocation functions in mcxt.c to allow this
optimization. This requires moving some responsibility into the memory
context implementations themselves. It's now the responsibility of the
MemoryContext to check for malloc failures. This is good as it both
allows the sibling call optimization, but also because most small and
medium allocations won't call malloc and just allocate memory to an
existing block. That can't fail, so checking for NULLs in that case
isn't required.
Also, traditionally it's been the responsibility of palloc and the other
allocation functions in mcxt.c to check for invalid allocation size
requests. Here we also move the responsibility of checking that into the
MemoryContext. This isn't to allow the sibling call optimization, but
more because most of our allocators handle large allocations separately
and we can just add the size check when doing large allocations. We no
longer check this for non-large allocations at all.
To make checking the allocation request sizes and ERROR handling easier,
add some helper functions to mcxt.c for the allocators to use.
Author: Andres Freund
Reviewed-by: David Rowley
Discussion: https://postgr.es/m/20210719195950.gavgs6ujzmjfaiig@alap3.anarazel.de
Presently, string keys are not well-supported for dshash tables.
The dshash code always copies key_size bytes into new entries'
keys, and dshash.h only provides compare and hash functions that
forward to memcmp() and tag_hash(), both of which do not stop at
the first NUL. This means that callers must pad string keys so
that the data beyond the first NUL does not adversely affect the
results of copying, comparing, and hashing the keys.
To better support string keys in dshash tables, this commit does
a couple things:
* A new copy_function field is added to the dshash_parameters
struct. This function pointer specifies how the key should be
copied into new table entries. For example, we only want to copy
up to the first NUL byte for string keys. A dshash_memcpy()
helper function is provided and used for all existing in-tree
dshash tables without string keys.
* A set of helper functions for string keys are provided. These
helper functions forward to strcmp(), strcpy(), and
string_hash(), all of which ignore data beyond the first NUL.
This commit also adjusts the DSM registry's dshash table to use the
new helper functions for string keys.
Reviewed-by: Andy Fan
Discussion: https://postgr.es/m/20240119215941.GA1322079%40nathanxps13
A couple of dshash_create() callers provide 0 for the 'void *arg'
argument, which might give readers the incorrect impression that
this is some sort of "flags" parameter.
Reviewed-by: Andy Fan
Discussion: https://postgr.es/m/20240119215941.GA1322079%40nathanxps13
By enabling slot synchronization, all the failover logical replication
slots on the primary (assuming configurations are appropriate) are
automatically created on the physical standbys and are synced
periodically. The slot sync worker on the standby server pings the primary
server at regular intervals to get the necessary failover logical slots
information and create/update the slots locally. The slots that no longer
require synchronization are automatically dropped by the worker.
The nap time of the worker is tuned according to the activity on the
primary. The slot sync worker waits for some time before the next
synchronization, with the duration varying based on whether any slots were
updated during the last cycle.
A new parameter sync_replication_slots enables or disables this new
process.
On promotion, the slot sync worker is shut down by the startup process to
drop any temporary slots acquired by the slot sync worker and to prevent
the worker from trying to fetch the failover slots.
A functionality to allow logical walsenders to wait for the physical will
be done in a subsequent commit.
Author: Shveta Malik, Hou Zhijie based on design inputs by Masahiko Sawada and Amit Kapila
Reviewed-by: Masahiko Sawada, Bertrand Drouvot, Peter Smith, Dilip Kumar, Ajin Cherian, Nisha Moond, Kuroda Hayato, Amit Kapila
Discussion: https://postgr.es/m/514f6f2f-6833-4539-39f1-96cd1e011f23@enterprisedb.com
Since the size of the string representation of an uuid is fixed, there
is no benefit in using a StringInfo. This commit simplifies uuid_oud()
to not rely on a StringInfo, where avoiding the overhead of the string
manipulation makes the function substantially faster.
A COPY TO on a relation with one UUID attribute can show up to a 40%
speedup when the bottleneck is the COPY computation with uuid_out()
showing up at the top of the profiles (numbered measure here, Laurenz
has mentioned something closer to 20% faster runtimes), for example when
the data is fully in shared buffers or the OS cache.
Author: Laurenz Albe
Reviewed-by: Andres Freund, Michael Paquier
Description: https://postgr.es/m/679d5455cbbb0af667ccb753da51a475bae1eaed.camel@cybertec.at
Commit 6b80394781 introduced integer comparison functions designed
to be as efficient as possible while avoiding overflow. This
commit makes use of these functions in many of the in-tree qsort()
comparators to help ensure transitivity. Many of these comparator
functions should also see a small performance boost.
Author: Mats Kindahl
Reviewed-by: Andres Freund, Fabrízio de Royes Mello
Discussion: https://postgr.es/m/CA%2B14426g2Wa9QuUpmakwPxXFWG_1FaY0AsApkvcTBy-YfS6uaw%40mail.gmail.com
Thanks to commit 3b00fdba9f, this check in the SIGTERM handler for
the startup process is now obsolete and can be removed. Instead of
leaving around the dead function write_stderr_signal_safe(), I've
opted to just remove it for now.
This partially reverts commit 97550c0711.
Reviewed-by: Andres Freund, Noah Misch
Discussion: https://postgr.es/m/20231121212008.GA3742740%40nathanxps13
Presently, we rely on each individual signal handler to save the
initial value of errno and then restore it before returning if
needed. This is easily forgotten and, if missed, often goes
undetected for a long time.
In commit 3b00fdba9f, we introduced a wrapper signal handler
function that checks whether MyProcPid matches getpid(). This
commit moves the aforementioned errno restoration code from the
individual signal handlers to the new wrapper handler so that we no
longer need to worry about missing it.
Reviewed-by: Andres Freund, Noah Misch
Discussion: https://postgr.es/m/20231121212008.GA3742740%40nathanxps13
Previously, an interval microseconds field close to INT64_MAX or
INT64_MIN could overflow, producing a result with not even the
correct sign, while being rounded to match a precision specification.
This seems worth fixing, but not worth back-patching, in part
because the ereturn() notation doesn't exist very far back.
Report and patch by Joseph Koshakow (some cosmetic mods by me)
Discussion: https://postgr.es/m/CAAvxfHfpuLgqJYzkUcher466Z1LpmE+5Sm+zc8L6zKCOQ+6TDQ@mail.gmail.com
Timezones are not immutable and so neither is any function that relies on
them. In commit 66ea94e8, we introduced a few methods which do casting
from one time to another and thus may involve the current timezone. To
preserve the immutability of jsonpath functions currently marked
immutable, disallow these methods from being called from non-TZ aware
functions.
Jeevan Chalke, per a report from Jian He.
Since its introduction, pg_get_expr() has intended to silently
return NULL if called with an invalid relation OID, as can happen
when scanning the catalogs concurrently with relation drops.
However, there is a race condition: we check validity of the OID
at the start, but it could get dropped just afterward, leading to
failures. This is the cause of some intermittent instability we're
seeing in a proposed new test case, and presumably it's a hazard in
the field as well.
We can fix this by AccessShareLock-ing the target relation for the
duration of pg_get_expr(). Since we don't require any permissions
on the target relation, this is semantically a bit undesirable. But
it turns out that the set_relation_column_names() subroutine already
takes a transient AccessShareLock on that relation, and has done since
commit 2ffa740be in 2012. Given the lack of complaints about that, it
seems like there should be no harm in holding the lock a bit longer.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/31ddcc01-a71b-4e8c-9948-01d1c47293ca@eisentraut.org
The TransactionIdInRecentPast() should return false for all the transactions
older than TransamVariables->oldestClogXid. However, the function contains
a bug in comparison FullTransactionId to TransactionID allowing full
transactions between nextXid - 2^32 and oldestClogXid - 2^31.
This commit fixes TransactionIdInRecentPast() by turning the oldestClogXid into
FullTransactionId first, then performing the comparison.
Backpatch to all supported versions.
Reported-by: Egor Chindyaskin
Bug: 18212
Discussion: https://postgr.es/m/18212-547307f8adf57262%40postgresql.org
Author: Karina Litskevich
Reviewed-by: Kyotaro Horiguchi
Backpatch-through: 12
A ResourceOwnerEnlarge() call was missing. That led to an error:
ERROR: ResourceOwnerRemember called but array was full
and an assertion failure, if you tried to extend a temp relation again
after a failure. Alexander's test case used running out of disk space
to trigger the original failure.
This bug was introduced in the large ResourceOwner rewrite commit
b8bff07daa. Before that, the UnpinLocalBuffer() call guaranteed that
the subsequent PinLocalBuffer() will succeed, but after the rewrite,
releasing an old resource doesn't guarantee that there is space for a
new one.
Add a comment explaining why the UnpinBuffer + PinBuffer calls in
BufferAlloc(), with no ResourceOwnerEnlarge() in between, are safe.
Reported-by: Alexander Lakhin
Discussion: https://www.postgresql.org/message-id/dc574fea-c83e-a600-08cd-10881762e4fa@gmail.com
An OS crash could leave PG_VERSION empty or missing. The same symptom
appeared in a backup by block device snapshot, taken after the next
checkpoint and before the OS flushes the PG_VERSION blocks. Device
snapshots are not a documented backup method, however. Back-patch to
v15, where commit 9c08aea6a3 introduced
STRATEGY=WAL_LOG and made it the default.
Discussion: https://postgr.es/m/20240130195003.0a.nmisch@google.com
Restoring a base backup taken in the middle of CreateDirAndVersionFile()
or write_relmap_file() would lose the function's effects. The symptom
was absence of the database directory, PG_VERSION file, or
pg_filenode.map. If missing the directory, recovery would fail. Either
missing file would not fail recovery but would render the new database
unusable. Fix CreateDirAndVersionFile() with the transam/README "action
first and then write a WAL entry" strategy. That has a side benefit of
moving filesystem mutations out of a critical section, reducing the ways
to PANIC. Fix the write_relmap_file() call with a lock acquisition, so
it interacts with checkpoints like non-CREATE DATABASE calls do.
Back-patch to v15, where commit 9c08aea6a3
introduced STRATEGY=WAL_LOG and made it the default.
Discussion: https://postgr.es/m/20240130195003.0a.nmisch@google.com
This impacts the statistics retrieved in transactions for the following
views when updating the value of stats_fetch_consistency, leading to
behaviors contrary to what is documented since 605994651b as an update
of this parameter should discard all statistics snapshot data:
- pg_stat_archiver
- pg_stat_bgwriter
- pg_stat_checkpointer
- pg_stat_io
- pg_stat_slru
- pg_stat_wal
For example, updating stats_fetch_consistency from "snapshot" to "cache"
in a transaction did not re-fetch any fresh data, using data cached from
the time when "snapshot" was in use.
Author: Shinya Kato
Discussion: https://postgr.es/m/d77fc5190d4dbe1738d77231488e768b@oss.nttdata.com
Backpatch-through: 15
After calling smgropen(), it was not clear how long you could continue
to use the result, because various code paths including cache
invalidation could call smgrclose(), which freed the memory.
Guarantee that the object won't be destroyed until the end of the
current transaction, or in recovery, the commit/abort record that
destroys the underlying storage.
smgrclose() is now just an alias for smgrrelease(). It closes files
and forgets all state except the rlocator, but keeps the SMgrRelation
object valid.
A new smgrdestroy() function is used by rare places that know there
should be no other references to the SMgrRelation.
The short version:
* smgrclose() is now just an alias for smgrrelease(). It releases
resources, but doesn't destroy until EOX
* smgrdestroy() now frees memory, and should rarely be used.
Existing code should be unaffected, but it is now possible for code that
has an SMgrRelation object to use it repeatedly during a transaction as
long as the storage hasn't been physically dropped. Such code would
normally hold a lock on the relation.
This also replaces the "ownership" mechanism of SMgrRelations with a
pin counter. An SMgrRelation can now be "pinned", which prevents it
from being destroyed at end of transaction. There can be multiple pins
on the same SMgrRelation. In practice, the pin mechanism is only used
by the relcache, so there cannot be more than one pin on the same
SMgrRelation. Except with swap_relation_files XXX
Author: Thomas Munro, Heikki Linnakangas
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://www.postgresql.org/message-id/CA%2BhUKGJ8NTvqLHz6dqbQnt2c8XCki4r2QvXjBQcXpVwxTY_pvA@mail.gmail.com
predicate.c has been using SerialSLRULock (the control lock for its SLRU
structure) to coordinate access to SerialControlData, another of its
numerous shared memory structures; this is unnecessary and confuses
further SLRU scalability work. Create a separate LWLock to cover
SerialControlData.
Extracted from a larger patch from the same author, and some additional
changes by Álvaro.
Author: Dilip Kumar <dilip.kumar@enterprisedb.com>
Discussion: https://postgr.es/m/CAFiTN-vzDvNz=ExGXz6gdyjtzGixKSqs0mKHMmaQ8sOSEFZ33A@mail.gmail.com
libxml2 changed the required signature of error handler callbacks
to make the passed xmlError struct "const". This is causing build
failures on buildfarm member caiman, and no doubt will start showing
up in the field quite soon. Add a version check to adjust the
declaration of xml_errorHandler() according to LIBXML_VERSION.
2.12.x also produces deprecation warnings for contrib/xml2/xpath.c's
assignment to xmlLoadExtDtdDefaultValue. I see no good reason for
that to still be there, seeing that we disabled external DTDs (at a
lower level) years ago for security reasons. Let's just remove it.
Back-patch to all supported branches, since they might all get built
with newer libxml2 once it gets a bit more popular. (The back
branches produce another deprecation warning about xpath.c's use of
xmlSubstituteEntitiesDefault(). We ought to consider whether to
back-patch all or part of commit 65c5864d7 to silence that. It's
less urgent though, since it won't break the buildfarm.)
Discussion: https://postgr.es/m/1389505.1706382262@sss.pgh.pa.us
This adds a new "Memory:" line under the "Planning:" group (which
currently only has "Buffers:") when the MEMORY option is specified.
In order to make the reporting reasonably accurate, we create a separate
memory context for planner activities, to be used only when this option
is given. The total amount of memory allocated by that context is
reported as "allocated"; we subtract memory in the context's freelists
from that and report that result as "used". We use
MemoryContextStatsInternal() to obtain the quantities.
The code structure to show buffer usage during planning was not in
amazing shape, so I (Álvaro) modified the patch a bit to clean that up
in passing.
Author: Ashutosh Bapat
Reviewed-by: David Rowley, Andrey Lepikhov, Jian He, Andy Fan
Discussion: https://www.postgresql.org/message-id/CAExHW5sZA=5LJ_ZPpRO-w09ck8z9p7eaYAqq3Ks9GDfhrxeWBw@mail.gmail.com
We perform addition of the days field of an interval via
arithmetic on the Julian-date representation of the timestamp's date.
This step is subject to int32 overflow, and we also should not let
the Julian date become very negative, for fear of weird results from
j2date. (In the timestamptz case, allow a Julian date of -1 to pass,
since it might convert back to zero after timezone rotation.)
The additions of the months and microseconds fields could also
overflow, of course. However, I believe we need no additional
checks there; the existing range checks should catch such cases.
The difficulty here is that j2date's magic modular arithmetic could
produce something that looks like it's in-range.
Per bug #18313 from Christian Maurer. This has been wrong for
a long time, so back-patch to all supported branches.
Discussion: https://postgr.es/m/18313-64d2c8952d81e84b@postgresql.org
This reverts commit 2197d06224, following a discussion over a Coverity
report where issues like the "Billion laugh attack" could cause the
backend to waste CPU and memory even if a client applied checks on the
size of the data given in input, and libxml2 does not offer guarantees
that input limits are respected under XML_PARSE_HUGE.
Discussion: https://postgr.es/m/ZbHlgrPLtBZyr_QW@paquier.xyz
Formerly, these were only supported in to_char(), but there seems
little reason for that restriction. We should at least have enough
support to permit round-tripping the output of to_char().
In that spirit, TZ accepts either zone abbreviations or numeric
(HH or HH:MM) offsets, which are the cases that to_char() can output.
In an ideal world we'd make it take full zone names too, but
that seems like it'd introduce an unreasonable amount of ambiguity,
since the rules for POSIX-spec zone names are so lax.
OF is a subset of this, accepting only HH or HH:MM.
One small benefit of this improvement is that we can simplify
jsonpath's executeDateTimeMethod function, which no longer needs
to consider the HH and HH:MM cases separately. Moreover, letting
it accept zone abbreviations means it will accept "Z" to mean UTC,
which is emitted by JSON.stringify() for example.
Patch by me, reviewed by Aleksander Alekseev and Daniel Gustafsson
Discussion: https://postgr.es/m/1681086.1686673242@sss.pgh.pa.us
Remove a buggy and unnecessary test, along with an unnecessary pstrdup()
and a line of dead code.
Per report, diagnosis and fix from Tom Lane
Discussion: https://postgr.es/m/439811.1706211069@sss.pgh.pa.us
This commit implements ithe jsonpath .bigint(), .boolean(),
.date(), .decimal([precision [, scale]]), .integer(), .number(),
.string(), .time(), .time_tz(), .timestamp(), and .timestamp_tz()
methods.
.bigint() converts the given JSON string or a numeric value to
the bigint type representation.
.boolean() converts the given JSON string, numeric, or boolean
value to the boolean type representation. In the numeric case, only
integers are allowed. We use the parse_bool() backend function
to convert a string to a bool.
.decimal([precision [, scale]]) converts the given JSON string
or a numeric value to the numeric type representation. If precision
and scale are provided for .decimal(), then it is converted to the
equivalent numeric typmod and applied to the numeric number.
.integer() and .number() convert the given JSON string or a
numeric value to the int4 and numeric type representation.
.string() uses the datatype's output function to convert numeric
and various date/time types to the string representation.
The JSON string representing a valid date/time is converted to the
specific date or time type representation using jsonpath .date(),
.time(), .time_tz(), .timestamp(), .timestamp_tz() methods. The
changes use the infrastructure of the .datetime() method and perform
the datatype conversion as appropriate. Unlike the .datetime()
method, none of these methods accept a format template and use ISO
DateTime format instead. However, except for .date(), the
date/time related methods take an optional precision to adjust the
fractional seconds.
Jeevan Chalke, reviewed by Peter Eisentraut and Andrew Dunstan.
This adds a Node *escontext parameter to it and a bunch of functions
downstream to it, replacing any ereport()s in that path by either
errsave() or ereturn() as appropriate. This also adds code to those
functions where necessary to return early upon encountering a soft
error.
The changes here are mainly intended to suppress errors in the
functions of jsonfuncs.c. Functions in any external modules, such as
arrayfuncs.c, that those functions may in turn call are not changed
here based on the assumption that the various checks in jsonfuncs.c
functions should ensure that only values that are structurally valid
get passed to the functions in those external modules. An exception
is made for domain_check() to allow handling domain constraint
violation errors softly.
For testing, this adds a function jsonb_populate_record_valid(),
which returns true if jsonb_populate_record() would finish without
causing an error for the provided JSON object, false otherwise. Note
that jsonb_populate_record() internally calls populate_record(),
which in turn uses populate_record_field().
Extracted from a much larger patch to add SQL/JSON query functions.
Author: Nikita Glukhov <n.gluhov@postgrespro.ru>
Author: Teodor Sigaev <teodor@sigaev.ru>
Author: Oleg Bartunov <obartunov@gmail.com>
Author: Alexander Korotkov <aekorotkov@gmail.com>
Author: Andrew Dunstan <andrew@dunslane.net>
Author: Amit Langote <amitlangote09@gmail.com>
Reviewers have included (in no particular order) Andres Freund,
Alexander Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers,
Zihong Yu, Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby,
Álvaro Herrera, Jian He, Peter Eisentraut
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Discussion: https://postgr.es/m/abd9b83b-aa66-f230-3d6d-734817f0995d%40postgresql.org
Discussion: https://postgr.es/m/CA+HiwqHROpf9e644D8BRqYvaAPmgBZVup-xKMDPk-nd4EpgzHw@mail.gmail.com
Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com
This commit fixes an error message that failed to show the correct
function and library names when a function cannot be loaded.
While on it, adjust the call to load_external_function() so as this
ERROR can be reached, by making load_external_function() return NULL
rather than fail if a function cannot be found for a given injection
point.
Thinkos in d86d20f0ba.
1. The memcpy()s in InjectionPointAttach() would copy garbage from
beyond the end of input string to the buffer in shared memory. You
won't usually notice, but if there is not enough valid mapped memory
beyond the end of the string, the read of unmapped memory will
segfault. This was flagged by the Cirrus CI build with address
sanitizer enabled.
2. The memcpy() in injection_point_cache_add() failed to copy the NULL
terminator.
Discussion: https://www.postgresql.org/message-id/0615a424-b726-4157-afa7-4245629f9512%40iki.fi
Injection points are a new facility that makes possible for developers
to run custom code in pre-defined code paths. Its goal is to provide
ways to design and run advanced tests, for cases like:
- Race conditions, where processes need to do actions in a controlled
ordered manner.
- Forcing a state, like an ERROR, FATAL or even PANIC for OOM, to force
recovery, etc.
- Arbitrary sleeps.
This implements some basics, and there are plans to extend it more in
the future depending on what's required. Hence, this commit adds a set
of routines in the backend that allows developers to attach, detach and
run injection points:
- A code path calling an injection point can be declared with the macro
INJECTION_POINT(name).
- InjectionPointAttach() and InjectionPointDetach() to respectively
attach and detach a callback to/from an injection point. An injection
point name is registered in a shmem hash table with a library name and a
function name, which will be used to load the callback attached to an
injection point when its code path is run.
Injection point names are just strings, so as an injection point can be
declared and run by out-of-core extensions and modules, with callbacks
defined in external libraries.
This facility is hidden behind a dedicated switch for ./configure and
meson, disabled by default.
Note that backends use a local cache to store callbacks already loaded,
cleaning up their cache if a callback has found to be removed on a
best-effort basis. This could be refined further but any tests but what
we have here was fine with the tests I've written while implementing
these backend APIs.
Author: Michael Paquier, with doc suggestions from Ashutosh Bapat.
Reviewed-by: Ashutosh Bapat, Nathan Bossart, Álvaro Herrera, Dilip
Kumar, Amul Sul, Nazir Bilal Yavuz
Discussion: https://postgr.es/m/ZTiV8tn_MIb_H2rE@paquier.xyz
