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path: root/src/backend/storage/ipc/dsm_impl.c
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* Fix failure-to-read-man-page in commit 899bd785c.Tom Lane2017-09-26
| | | | | | | | | | | | | | | | | | | | posix_fallocate() is not quite a drop-in replacement for fallocate(), because it is defined to return the error code as its function result, not in "errno". I (tgl) missed this because RHEL6's version seems to set errno as well. That is not the case on more modern Linuxen, though, as per buildfarm results. Aside from fixing the return-convention confusion, remove the test for ENOSYS; we expect that glibc will mask that for posix_fallocate, though it does not for fallocate. Keep the test for EINTR, because POSIX specifies that as a possible result, and buildfarm results suggest that it can happen in practice. Back-patch to 9.4, like the previous commit. Thomas Munro Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
* Avoid SIGBUS on Linux when a DSM memory request overruns tmpfs.Tom Lane2017-09-25
| | | | | | | | | | | | | | | | | | | | | On Linux, shared memory segments created with shm_open() are backed by swap files created in tmpfs. If the swap file needs to be extended, but there's no tmpfs space left, you get a very unfriendly SIGBUS trap. To avoid this, force allocation of the full request size when we create the segment. This adds a few cycles, but none that we wouldn't expend later anyway, assuming the request isn't hugely bigger than the actual need. Make this code #ifdef __linux__, because (a) there's not currently a reason to think the same problem exists on other platforms, and (b) applying posix_fallocate() to an FD created by shm_open() isn't very portable anyway. Back-patch to 9.4 where the DSM code came in. Thomas Munro, per a bug report from Amul Sul Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
* Don't trust CreateFileMapping() to clear the error code on success.Tom Lane2016-09-23
| | | | | | | | | | | | | We must test GetLastError() even when CreateFileMapping() returns a non-null handle. If that value were left over from some previous system call, we might be fooled into thinking the segment already existed. Experimentation on Windows 7 suggests that CreateFileMapping() clears the error code on success, but it is not documented to do so, so let's not rely on that happening in all Windows releases. Amit Kapila Discussion: <20811.1474390987@sss.pgh.pa.us>
* Retry DSM control segment creation if Windows indicates access denied.Robert Haas2016-09-20
| | | | | | | | | | | | | | | Otherwise, attempts to run multiple postmasters running on the same machine may fail, because Windows sometimes returns ERROR_ACCESS_DENIED rather than ERROR_ALREADY_EXISTS when there is an existing segment. Hitting this bug is much more likely because of another defect not fixed by this patch, namely that dsm_postmaster_startup() uses random() which returns the same value every time. But that's not a reason not to fix this. Kyotaro Horiguchi and Amit Kapila, reviewed by Michael Paquier Discussion: <CAA4eK1JyNdMeF-dgrpHozDecpDfsRZUtpCi+1AbtuEkfG3YooQ@mail.gmail.com>
* Fix copy/pasto in file identificationSimon Riggs2016-09-12
| | | | Daniel Gustafsson
* Fix typos.Robert Haas2016-03-15
| | | | Oskari Saarenmaa
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Don't use function definitions looking like old-style ones.Andres Freund2015-08-15
| | | | | | | This fixes a bunch of somewhat pedantic warnings with new compilers. Since by far the majority of other functions definitions use the (void) style it just seems to be consistent to do so as well in the remaining few places.
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Use mmap MAP_NOSYNC option to limit shared memory writesBruce Momjian2015-03-21
| | | | | | | mmap() is rarely used for shared memory, but when it is, this option is useful, particularly on the BSDs. Patch by Sean Chittenden
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* "Pin", rather than "keep", dynamic shared memory mappings and segments.Robert Haas2014-10-30
| | | | | | | | | | Nobody seemed concerned about this naming when it originally went in, but there's a pending patch that implements the opposite of dsm_keep_mapping, and the term "unkeep" was judged unpalatable. "unpin" has existing precedent in the PostgreSQL code base, and the English language, so use this terminology instead. Per discussion, back-patch to 9.4.
* Assorted message fixes and improvementsPeter Eisentraut2014-09-05
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* Remove unnecessary cleanup code.Robert Haas2014-05-22
| | | | | | | This is all inside a block guarded by op == DSM_OP_ATTACH, so it can never be the case that op == DSM_OP_CREATE. Reported by Coverity.
* 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.
* Try to fix spurious DSM failures on Windows.Robert Haas2014-04-16
| | | | | | | | Apparently, Windows can sometimes return an error code even when the operation actually worked just fine. Rearrange the order of checks according to what appear to be the best practices in this area. Amit Kapila
* Fix whitespacePeter Eisentraut2014-03-16
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* Allow dynamic shared memory segments to be kept until shutdown.Robert Haas2014-03-10
| | | | | Amit Kapila, reviewed by Kyotaro Horiguchi, with some further changes by me.
* Allow use of "z" flag in our printf calls, and use it where appropriate.Tom Lane2014-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | Since C99, it's been standard for printf and friends to accept a "z" size modifier, meaning "whatever size size_t has". Up to now we've generally dealt with printing size_t values by explicitly casting them to unsigned long and using the "l" modifier; but this is really the wrong thing on platforms where pointers are wider than longs (such as Win64). So let's start using "z" instead. To ensure we can do that on all platforms, teach src/port/snprintf.c to understand "z", and add a configure test to force use of that implementation when the platform's version doesn't handle "z". Having done that, modify a bunch of places that were using the unsigned-long hack to use "z" instead. This patch doesn't pretend to have gotten everyplace that could benefit, but it catches many of them. I made an effort in particular to ensure that all uses of the same error message text were updated together, so as not to increase the number of translatable strings. It's possible that this change will result in format-string warnings from pre-C99 compilers. We might have to reconsider if there are any popular compilers that will warn about this; but let's start by seeing what the buildfarm thinks. Andres Freund, with a little additional work by me
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Flag mmap implemenation of dynamic shared memory as resize-capable.Robert Haas2013-12-02
| | | | Error noted by Heikki Linnakangas
* Fix format code used to print dsm request sizes.Robert Haas2013-11-04
| | | | Per report from Peter Eisentraut.
* Avoid too-large shift on 32-bit Windows.Robert Haas2013-10-30
| | | | | | | Apparently, shifts greater than or equal to the width of the type are undefined, and can surprisingly produce a non-zero value. Amit Kapila, with a comment by me.
* Modify dynamic shared memory code to use Size rather than uint64.Robert Haas2013-10-28
| | | | This is more consistent with what we do elsewhere.
* Suppress a couple of compiler warnings seen with older gcc versions.Tom Lane2013-10-22
| | | | | | | | | | | | To wit, bgworker.c: In function `RegisterDynamicBackgroundWorker': bgworker.c:761: warning: `generation' might be used uninitialized in this function dsm_impl.c: In function `dsm_impl_op': dsm_impl.c:197: warning: control reaches end of non-void function Neither of these represent actual bugs, but we may as well tweak the code so that more compilers can tell that. This won't change the generated code on compilers that do recognize that the cases are unreachable.
* In dsm_impl_windows, don't error out when the segment already exists.Robert Haas2013-10-14
| | | | | | | This is the behavior of the other implementations, and the behavior expected by the callers of this function. Amit Kapila
* Fix incorrect use of shm_unlink where unlink should be used.Robert Haas2013-10-10
| | | | Per buildfarm.
* Allow dynamic allocation of shared memory segments.Robert Haas2013-10-09
Patch by myself and Amit Kapila. Design help from Noah Misch. Review by Andres Freund.