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* Create infrastructure to reliably prevent leakage of PGresults.Tom Lane12 days
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 232d8caea fixed a case where postgres_fdw could lose track of a PGresult object, resulting in a process-lifespan memory leak. But I have little faith that there aren't other potential PGresult leakages, now or in future, in the backend modules that use libpq. Therefore, this patch proposes infrastructure that makes all PGresults returned from libpq act as though they are palloc'd in the CurrentMemoryContext (with the option to relocate them to another context later). This should greatly reduce the risk of careless leaks, and it also permits removal of a bunch of code that attempted to prevent such leaks via PG_TRY blocks. This patch adds infrastructure that wraps each PGresult in a "libpqsrv_PGresult" that provides a memory context reset callback to PQclear the PGresult. Code using this abstraction is inherently memory-safe to the same extent as we are accustomed to in most backend code. Furthermore, we add some macros that automatically redirect calls of the libpq functions concerned with PGresults to use this infrastructure, so that almost no source-code changes are needed to wheel this infrastructure into place in all the backend code that uses libpq. Perhaps in future we could create similar infrastructure for PGconn objects, but there seems less need for that. This patch just creates the infrastructure and makes relevant code use it, including reverting 232d8caea in favor of this mechanism. A good deal of follow-on simplification is possible now that we don't have to be so cautious about freeing PGresults, but I'll put that in a separate patch. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com> Discussion: https://postgr.es/m/2976982.1748049023@sss.pgh.pa.us
* Swap order of extern/static and pg_nodiscardPeter Eisentraut2025-03-14
| | | | | | | | | | | | | | | | | | When pg_nodiscard was first added, the C standard draft had it as a function specifier, and so the code comment about placement was written with that in mind. The final C23 standard has it as an attribute and the placement rules are a bit different for that. Specifically, it needs to be before extern or static. (Or at least both current clang and gcc require that.) So just swap these. (To be clear: The current implementation with gcc attributes doesn't care. This change is just for maximum forward compatibility for non-gcc compilers.) This also keeps the order consistent with the previously introduced pg_noreturn. Also update the code comment to reflect the mentioned developments since its introduction. Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/pxr5b3z7jmkpenssra5zroxi7qzzp6eswuggokw64axmdixpnk@zbwxuq7gbbcw
* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Simplify newNode() by removing special casesHeikki Linnakangas2023-12-19
| | | | | | | | | | | | | | | | | | | | | - Remove MemoryContextAllocZeroAligned(). It was supposed to be a faster version of MemoryContextAllocZero(), but modern compilers turn the MemSetLoop() into a call to memset() anyway, making it more or less identical to MemoryContextAllocZero(). That was the only user of MemSetTest, MemSetLoop, so remove those too, as well as palloc0fast(). - Convert newNode() to a static inline function. When this was originally originally written, it was written as a macro because testing showed that gcc didn't inline the size check as we intended. Modern compiler versions do, and now that it just calls palloc0() there is no size-check to inline anyway. One nice effect is that the palloc0() takes one less argument than MemoryContextAllocZeroAligned(), which saves a few instructions in the callers of newNode(). Reviewed-by: Peter Eisentraut, Tom Lane, John Naylor, Thomas Munro Discussion: https://www.postgresql.org/message-id/b51f1fa7-7e6a-4ecc-936d-90a8a1659e7c@iki.fi
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Add palloc_aligned() to allow aligned memory allocationsDavid Rowley2022-12-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This introduces palloc_aligned() and MemoryContextAllocAligned() which allow callers to obtain memory which is allocated to the given size and also aligned to the specified alignment boundary. The alignment boundaries may be any power-of-2 value. Currently, the alignment is capped at 2^26, however, we don't expect values anything like that large. The primary expected use case is to align allocations to perhaps CPU cache line size or to maybe I/O page size. Certain use cases can benefit from having aligned memory by either having better performance or more predictable performance. The alignment is achieved by requesting 'alignto' additional bytes from the underlying allocator function and then aligning the address that is returned to the requested alignment. This obviously does waste some memory, so alignments should be kept as small as what is required. It's also important to note that these alignment bytes eat into the maximum allocation size. So something like: palloc_aligned(MaxAllocSize, 64, 0); will not work as we cannot request MaxAllocSize + 64 bytes. Additionally, because we're just requesting the requested size plus the alignment requirements from the given MemoryContext, if that context is the Slab allocator, then since slab can only provide chunks of the size that's specified when the slab context is created, then this is not going to work. Slab will generate an error to indicate that the requested size is not supported. The alignment that is requested in palloc_aligned() is stored along with the allocated memory. This allows the alignment to remain intact through repalloc() calls. Author: Andres Freund, David Rowley Reviewed-by: Maxim Orlov, Andres Freund, John Naylor Discussion: https://postgr.es/m/CAApHDvpxLPUMV1mhxs6g7GNwCP6Cs6hfnYQL5ffJQTuFAuxt8A%40mail.gmail.com
* Add repalloc0 and repalloc0_arrayPeter Eisentraut2022-11-12
| | | | | | | | These zero out the space added by repalloc. This is a common pattern that is quite hairy to code by hand. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/b66dfc89-9365-cb57-4e1f-b7d31813eeec@enterprisedb.com
* Make some minor improvements in memory-context infrastructure.Tom Lane2022-10-14
| | | | | | | | | | | | | | | 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
* Expand palloc/pg_malloc API for more type safetyPeter Eisentraut2022-09-12
| | | | | | | | | | | | | | | | | 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
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Add pg_nodiscard decorations to some functionsPeter Eisentraut2020-11-11
| | | | | | | | Especially for the list API such as lappend() forgetting to assign the return value is a common problem. Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/e3753562-99cd-b65f-5aca-687dfd1ec2fc@2ndquadrant.com
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* chomp PQerrorMessage() in backend usesPeter Eisentraut2017-02-27
| | | | | | | | PQerrorMessage() returns an error message with a trailing newline, but in backend use (dblink, postgres_fdw, libpqwalreceiver), we want to have the error message without that for emitting via ereport(). To simplify that, add a function pchomp() that returns a pstrdup'ed string with the trailing newline characters removed.
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Rely on inline functions even if that causes warnings in older compilers.Andres Freund2015-08-05
| | | | | | | | | | | | | | | | | | | | | | | | | So far we have worked around the fact that some very old compilers do not support 'inline' functions by only using inline functions conditionally (or not at all). Since such compilers are very rare by now, we have decided to rely on inline functions from 9.6 onwards. To avoid breaking these old compilers inline is defined away when not supported. That'll cause "function x defined but not used" type of warnings, but since nobody develops on such compilers anymore that's ok. This change in policy will allow us to more easily employ inline functions. I chose to remove code previously conditional on PG_USE_INLINE as it seemed confusing to have code dependent on a define that's always defined. Blacklisting of compilers, like in c53f73879f, now has to be done differently. A platform template can define PG_FORCE_DISABLE_INLINE to force inline to be defined empty. Discussion: 20150701161447.GB30708@awork2.anarazel.de
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Add palloc_extended for frontend and backend.Fujii Masao2015-04-03
| | | | | | | | | | This commit also adds pg_malloc_extended for frontend. These interfaces can be used to control at a lower level memory allocation using an interface similar to MemoryContextAllocExtended. For example, the callers can specify MCXT_ALLOC_NO_OOM if they want to suppress the "out of memory" error while allocating the memory and handle a NULL return value. Michael Paquier, reviewed by me.
* Tweak __attribute__-wrapping macros for better pgindent results.Tom Lane2015-03-26
| | | | | | | | | | | | | | | | | | | | | This improves on commit bbfd7edae5aa5ad5553d3c7e102f2e450d4380d4 by making two simple changes: * pg_attribute_noreturn now takes parentheses, ie pg_attribute_noreturn(). Likewise pg_attribute_unused(), pg_attribute_packed(). This reduces pgindent's tendency to misformat declarations involving them. * attributes are now always attached to function declarations, not definitions. Previously some places were taking creative shortcuts, which were not merely candidates for bad misformatting by pgindent but often were outright wrong anyway. (It does little good to put a noreturn annotation where callers can't see it.) In any case, if we would like to believe that these macros can be used with non-gcc compilers, we should avoid gratuitous variance in usage patterns. I also went through and manually improved the formatting of a lot of declarations, and got rid of excessively repetitive (and now obsolete anyway) comments informing the reader what pg_attribute_printf is for.
* Add macros wrapping all usage of gcc's __attribute__.Andres Freund2015-03-11
| | | | | | | | | | | | | | | | | | | | Until now __attribute__() was defined to be empty for all compilers but gcc. That's problematic because it prevents using it in other compilers; which is necessary e.g. for atomics portability. It's also just generally dubious to do so in a header as widely included as c.h. Instead add pg_attribute_format_arg, pg_attribute_printf, pg_attribute_noreturn macros which are implemented in the compilers that understand them. Also add pg_attribute_noreturn and pg_attribute_packed, but don't provide fallbacks, since they can affect functionality. This means that external code that, possibly unwittingly, relied on __attribute__ defined to be empty on !gcc compilers may now run into warnings or errors on those compilers. But there shouldn't be many occurances of that and it's hard to work around... Discussion: 54B58BA3.8040302@ohmu.fi Author: Oskari Saarenmaa, with some minor changes by me.
* Move memory context callback declarations into palloc.h.Tom Lane2015-03-01
| | | | | | | | | | Initial experience with this feature suggests that instances of MemoryContextCallback are likely to propagate into some widely-used headers over time. As things stood, that would result in pulling memutils.h or at least memnodes.h into common headers, which does not seem desirable. Instead, let's decide that this feature is part of the "ordinary palloc user" API rather than the "specialized context management" API, and as such should be declared in palloc.h not memutils.h.
* Provide a way to supress the "out of memory" error when allocating.Robert Haas2015-01-30
| | | | | | | | Using the new interface MemoryContextAllocExtended, callers can specify MCXT_ALLOC_NO_OOM if they are prepared to handle a NULL return value. Michael Paquier, reviewed and somewhat revised by me.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Can't completely get rid of #ifndef FRONTEND in palloc.h :-(Tom Lane2014-04-27
| | | | | | | | | pg_controldata includes postgres.h not postgres_fe.h, so utils/palloc.h must be able to compile in a "#define FRONTEND" context. It appears that Solaris Studio is smart enough to persuade us to define PG_USE_INLINE, but not smart enough to not make a copy of unreferenced static functions; which leads to an unsatisfied reference to CurrentMemoryContext. So we need an #ifndef FRONTEND around that declaration. Per buildfarm.
* Don't #include utils/palloc.h in common/fe_memutils.h.Tom Lane2014-04-26
| | | | | | | | | | | | | | | | | | | | | This breaks the principle that common/ ought not depend on anything in the server, not only code-wise but in the headers. The only arguable advantage is avoidance of duplication of half a dozen extern declarations, and even that is rather dubious, considering that the previous coding was wrong about which declarations to duplicate: it exposed pnstrdup() to frontend code even though no such function is provided in fe_memutils.c. On the same principle, don't #include utils/memutils.h in the frontend build of psprintf.c. This requires duplicating the definition of MaxAllocSize, but that seems fine to me: there's no a-priori reason why frontend code should use the same size limit as the backend anyway. In passing, clean up some rather odd layout and ordering choices that were imposed on palloc.h to reduce the number of #ifdefs required by the previous approach. Per gripe from Christoph Berg. There's still more work to do to make include/common/ clean, but this part seems reasonably noncontroversial.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Use improved vsnprintf calling logic in more places.Tom Lane2013-10-24
| | | | | | | | | | | | | | | | | | | | | | When we are using a C99-compliant vsnprintf implementation (which should be most places, these days) it is worth the trouble to make use of its report of how large the buffer needs to be to succeed. This patch adjusts stringinfo.c and some miscellaneous usages in pg_dump to do that, relying on the logic recently added in libpgcommon's psprintf.c. Since these places want to know the number of bytes written once we succeed, modify the API of pvsnprintf() to report that. There remains near-duplicate logic in pqexpbuffer.c, but since that code is in libpq, psprintf.c's approach of exit()-on-error isn't appropriate for use there. Also note that I didn't bother touching the multitude of places that call (v)snprintf without any attempt to provide a resizable buffer. Release-note-worthy incompatibility: the API of appendStringInfoVA() changed. If there's any third-party code that's calling that directly, it will need tweaking along the same lines as in this patch. David Rowley and Tom Lane
* Get rid of use of asprintf() in favor of a more portable implementation.Tom Lane2013-10-22
| | | | | | | | | | | | | | | | asprintf(), aside from not being particularly portable, has a fundamentally badly-designed API; the psprintf() function that was added in passing in the previous patch has a much better API choice. Moreover, the NetBSD implementation that was borrowed for the previous patch doesn't work with non-C99-compliant vsnprintf, which is something we still have to cope with on some platforms; and it depends on va_copy which isn't all that portable either. Get rid of that code in favor of an implementation similar to what we've used for many years in stringinfo.c. Also, move it into libpgcommon since it's not really libpgport material. I think this patch will be enough to turn the buildfarm green again, but there's still cosmetic work left to do, namely get rid of pg_asprintf() in favor of using psprintf(). That will come in a followon patch.
* Add use of asprintf()Peter Eisentraut2013-10-13
| | | | | | | | | Add asprintf(), pg_asprintf(), and psprintf() to simplify string allocation and composition. Replacement implementations taken from NetBSD. Reviewed-by: Álvaro Herrera <alvherre@2ndquadrant.com> Reviewed-by: Asif Naeem <anaeem.it@gmail.com>
* Permit super-MaxAllocSize allocations with MemoryContextAllocHuge().Noah Misch2013-06-27
| | | | | | | | | | | | | The MaxAllocSize guard is convenient for most callers, because it reduces the need for careful attention to overflow, data type selection, and the SET_VARSIZE() limit. A handful of callers are happy to navigate those hazards in exchange for the ability to allocate a larger chunk. Introduce MemoryContextAllocHuge() and repalloc_huge(). Use this in tuplesort.c and tuplestore.c, enabling internal sorts of up to INT_MAX tuples, a factor-of-48 increase. In particular, B-tree index builds can now benefit from much-larger maintenance_work_mem settings. Reviewed by Stephen Frost, Simon Riggs and Jeff Janes.
* pgindent run for release 9.3Bruce Momjian2013-05-29
| | | | | This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
* Add pg_xlogdump contrib programAlvaro Herrera2013-02-22
| | | | | | | | This program relies on rm_desc backend routines and the xlogreader infrastructure to emit human-readable rendering of WAL records. Author: Andres Freund, with many reworks by Álvaro Reviewed (in a much earlier version) by Peter Eisentraut
* Create libpgcommon, and move pg_malloc et al to itAlvaro Herrera2013-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | libpgcommon is a new static library to allow sharing code among the various frontend programs and backend; this lets us eliminate duplicate implementations of common routines. We avoid libpgport, because that's intended as a place for porting issues; per discussion, it seems better to keep them separate. The first use case, and the only implemented by this patch, is pg_malloc and friends, which many frontend programs were already using. At the same time, we can use this to provide palloc emulation functions for the frontend; this way, some palloc-using files in the backend can also be used by the frontend cleanly. To do this, we change palloc() in the backend to be a function instead of a macro on top of MemoryContextAlloc(). This was previously believed to cause loss of performance, but this implementation has been tweaked by Tom and Andres so that on modern compilers it provides a slight improvement over the previous one. This lets us clean up some places that were already with localized hacks. Most of the pg_malloc/palloc changes in this patch were authored by Andres Freund. Zoltán Böszörményi also independently provided a form of that. libpgcommon infrastructure was authored by Álvaro.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Rename USE_INLINE to PG_USE_INLINEAlvaro Herrera2012-10-09
| | | | | | The former name was too likely to conflict with symbols from external headers; and, as seen in recent buildfarm failures in member spoonbill, it has now happened at least in plpython.
* Add support for easily declaring static inline functionsAlvaro Herrera2012-10-08
| | | | | | | We already had those, but they forced modules to spell out the function bodies twice. Eliminate some duplicates we had already grown. Extracted from a somewhat larger patch from Andres Freund.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* Don't expose the inline definition of MemoryContextSwitchTo when FRONTEND isTom Lane2010-02-13
| | | | | | defined. Its reference to CurrentMemoryContext causes link failures on some platforms, evidently because the inline function gets compiled despite lack of use. Per buildfarm member warthog.
* Support inlining various small performance-critical functions on non-GCCTom Lane2010-02-13
| | | | | | | | | compilers, by applying a configure check to see if the compiler will accept an unreferenced "static inline foo ..." function without warnings. It is believed that such warnings are the only reason not to declare inlined functions in headers, if the compiler understands "inline" at all. Kurt Harriman
* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Update copyright for 2009.Bruce Momjian2009-01-01
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