Commit Graph

26202 Commits

Author SHA1 Message Date
Tom Lane 9222cd84b0 Remove no-longer-referenced src/port/gethostname.c.
This file hasn't been part of any build since 2005, and even before that
wasn't used unless you configured --with-krb4 (and had a machine without
gethostname(2), obviously).  What's more, we haven't actually called
gethostname anywhere since then, either (except in thread_test.c, whose
testing of this function is probably pointless).  So we don't need it.
2015-01-24 12:13:57 -05:00
Alvaro Herrera f2789ab84e Fix assignment operator thinko
Pointed out by Michael Paquier
2015-01-24 11:15:56 -03:00
Robert Haas d1747571b6 Fix typos, update README.
Peter Geoghegan
2015-01-23 15:06:53 -05:00
Alvaro Herrera a179232047 vacuumdb: enable parallel mode
This mode allows vacuumdb to open several server connections to vacuum
or analyze several tables simultaneously.

Author: Dilip Kumar.  Some reworking by Álvaro Herrera
Reviewed by: Jeff Janes, Amit Kapila, Magnus Hagander, Andres Freund
2015-01-23 15:02:45 -03:00
Robert Haas 5cefbf5a6c Don't use abbreviated keys for the final merge pass.
When we write tuples out to disk and read them back in, the abbreviated
keys become non-abbreviated, because the readtup routines don't know
anything about abbreviation.  But without this fix, the rest of the
code still thinks the abbreviation-aware compartor should be used,
so chaos ensues.

Report by Andrew Gierth; patch by Peter Geoghegan.
2015-01-23 11:58:31 -05:00
Robert Haas 6a3c6ba0ba Add an explicit cast to Size to hyperloglog.c
MSVC generates a warning here; we hope this will make it happy.

Report by Michael Paquier.  Patch by David Rowley.
2015-01-23 11:44:51 -05:00
Tom Lane eb213acfe2 Prevent duplicate escape-string warnings when using pg_stat_statements.
contrib/pg_stat_statements will sometimes run the core lexer a second time
on submitted statements.  Formerly, if you had standard_conforming_strings
turned off, this led to sometimes getting two copies of any warnings
enabled by escape_string_warning.  While this is probably no longer a big
deal in the field, it's a pain for regression testing.

To fix, change the lexer so it doesn't consult the escape_string_warning
GUC variable directly, but looks at a copy in the core_yy_extra_type state
struct.  Then, pg_stat_statements can change that copy to disable warnings
while it's redoing the lexing.

It seemed like a good idea to make this happen for all three of the GUCs
consulted by the lexer, not just escape_string_warning.  There's not an
immediate use-case for callers to adjust the other two AFAIK, but making
it possible is easy enough and seems like good future-proofing.

Arguably this is a bug fix, but there doesn't seem to be enough interest to
justify a back-patch.  We'd not be able to back-patch exactly as-is anyway,
for fear of breaking ABI compatibility of the struct.  (We could perhaps
back-patch the addition of only escape_string_warning by adding it at the
end of the struct, where there's currently alignment padding space.)
2015-01-22 18:11:00 -05:00
Peter Eisentraut f5f2c2de16 Fix whitespace 2015-01-22 16:57:16 -05:00
Alvaro Herrera 972bf7d6f1 Tweak BRIN minmax operator class
In the union support proc, we were not checking the hasnulls flag of
value A early enough, so it could be skipped if the "allnulls" flag in
value B is set.  Also, a check on the allnulls flag of value "B" was
redundant, so remove it.

Also change inet_minmax_ops to not be the default opclass for type inet,
as a future inclusion operator class would be more useful and it's
pretty difficult to change default opclass for a datatype later on.
(There is no catversion bump for this catalog change; this shouldn't be
a problem.)

Extracted from a larger patch to add an "inclusion" operator class.

Author: Emre Hasegeli
2015-01-22 17:01:09 -03:00
Robert Haas d060e07fa9 Repair brain fade in commit b181a91981.
The split between which things need to happen in the C-locale case and
which needed to happen in the locale-aware case was a few bricks short
of a load.  Try to fix that.
2015-01-22 12:51:20 -05:00
Bruce Momjian 59367fdf97 adjust ACL owners for REASSIGN and ALTER OWNER TO
When REASSIGN and ALTER OWNER TO are used, both the object owner and ACL
list should be changed from the old owner to the new owner. This patch
fixes types, foreign data wrappers, and foreign servers to change their
ACL list properly;  they already changed owners properly.

BACKWARD INCOMPATIBILITY?

Report by Alexey Bashtanov
2015-01-22 12:36:55 -05:00
Robert Haas b181a91981 More fixes for abbreviated keys infrastructure.
First, when LC_COLLATE = C, bttext_abbrev_convert should use memcpy()
rather than strxfrm() to construct the abbreviated key, because the
authoritative comparator uses memcpy().  If we do anything else here,
we might get inconsistent answers, and the buildfarm says this risk
is not theoretical.  It should be faster this way, too.

Second, while I'm looking at bttext_abbrev_convert, convert a needless
use of goto into the loop it's trying to implement into an actual
loop.

Both of the above problems date to the original commit of abbreviated
keys, commit 4ea51cdfe8.

Third, fix a bogus assignment to tss->locale before tss is set up.
That's a new goof in commit b529b65d1b.
2015-01-22 11:58:58 -05:00
Robert Haas b529b65d1b Heavily refactor btsortsupport_worker.
Prior to commit 4ea51cdfe8, this function
only had one job, which was to decide whether we could avoid trampolining
through the fmgr layer when performing sort comparisons.  As of that
commit, it has a second job, which is to decide whether we can use
abbreviated keys.  Unfortunately, those two tasks are somewhat intertwined
in the existing coding, which is likely why neither Peter Geoghegan nor
I noticed prior to commit that this calls pg_newlocale_from_collation() in
cases where it didn't previously.  The buildfarm noticed, though.

To fix, rewrite the logic so that the decision as to which comparator to
use is more cleanly separated from the decision about abbreviation.
2015-01-22 10:54:16 -05:00
Alvaro Herrera 813ffc0ef9 reinit.h: Fix typo in identification comment
Author: Sawada Masahiko
2015-01-22 12:26:51 -03:00
Robert Haas 1be4eb1b2d Disable abbreviated keys on Windows.
Most of the Windows buildfarm members (bowerbird, hamerkop, currawong,
jacana, brolga) are unhappy with yesterday's abbreviated keys patch,
although there are some (narwhal, frogmouth) that seem OK with it.
Since there's no obvious pattern to explain why some are working and
others are failing, just disable this across-the-board on Windows for
now.  This is a bit unfortunate since the optimization will be a big
win in some cases, but we can't leave the buildfarm broken.
2015-01-20 20:32:21 -05:00
Bruce Momjian f259e71dbe tools/ccsym: update for modern versions of gcc
This dumps the predefined preprocessor macros
2015-01-20 13:02:58 -05:00
Robert Haas f32a1fa462 Add strxfrm_l to list of functions where Windows adds an underscore.
Per buildfarm failure on bowerbird after last night's commit
4ea51cdfe8.

Peter Geoghegan
2015-01-20 10:52:01 -05:00
Tom Lane aa719391d5 In pg_regress, remove the temporary installation upon successful exit.
This results in a very substantial reduction in disk space usage during
"make check-world", since that sequence involves creation of numerous
temporary installations.  It should also help a bit in the buildfarm, even
though the buildfarm script doesn't create as many temp installations,
because the current script misses deleting some of them; and anyway it
seems better to do this once in one place rather than expecting that
script to get it right every time.

In 9.4 and HEAD, also undo the unwise choice in commit b1aebbb6a8
to report strerror(errno) after a rmtree() failure.  rmtree has already
reported that, possibly for multiple failures with distinct errnos; and
what's more, by the time it returns there is no good reason to assume
that errno still reflects the last reportable error.  So reporting errno
here is at best redundant and at worst badly misleading.

Back-patch to all supported branches, so that future revisions of the
buildfarm script can rely on this behavior.
2015-01-19 23:44:19 -05:00
Tom Lane 75b48e1fff Adjust "pgstat wait timeout" message to be a translatable LOG message.
Per discussion, change the log level of this message to be LOG not WARNING.
The main point of this change is to avoid causing buildfarm run failures
when the stats collector is exceptionally slow to respond, which it not
infrequently is on some of the smaller/slower buildfarm members.

This change does lose notice to an interactive user when his stats query
is looking at out-of-date stats, but the majority opinion (not necessarily
that of yours truly) is that WARNING messages would probably not get
noticed anyway on heavily loaded production systems.  A LOG message at
least ensures that the problem is recorded somewhere where bulk auditing
for the issue is possible.

Also, instead of an untranslated "pgstat wait timeout" message, provide
a translatable and hopefully more understandable message "using stale
statistics instead of current ones because stats collector is not
responding".  The original text was written hastily under the assumption
that it would never really happen in practice, which we now know to be
unduly optimistic.

Back-patch to all active branches, since we've seen the buildfarm issue
in all branches.
2015-01-19 23:01:33 -05:00
Andres Freund 2d115e47c8 Fix various shortcomings of the new PrivateRefCount infrastructure.
As noted by Tom Lane the improvements in 4b4b680c3d had the problem
that in some situations we searched, entered and modified entries in
the private refcount hash while holding a spinlock. I had tried to
keep the logic entirely local to PinBuffer_Locked(), but that's not
really possible given it's called with a spinlock held...

Besides being disadvantageous from a performance point of view, this
also has problems with error handling safety. If we failed inserting
an entry into the hashtable due to an out of memory error, we'd error
out with a held spinlock. Not good.

Change the way private refcounts are manipulated: Before a buffer can
be tracked an entry has to be reserved using
ReservePrivateRefCountEntry(); then, if a entry is not found using
GetPrivateRefCountEntry(), it can be entered with
NewPrivateRefCountEntry().

Also take advantage of the fact that PinBuffer_Locked() currently is
never called for buffers that already have been pinned by the current
backend and don't search the private refcount entries for preexisting
local pins. That results in a small, but measurable, performance
improvement.

Additionally make ReleaseBuffer() always call UnpinBuffer() for shared
buffers. That avoids duplicating work in an eventual UnpinBuffer()
call that already has been done in ReleaseBuffer() and also saves some
code.

Per discussion with Tom Lane.

Discussion: 15028.1418772313@sss.pgh.pa.us
2015-01-19 23:59:41 +01:00
Robert Haas 4ea51cdfe8 Use abbreviated keys for faster sorting of text datums.
This commit extends the SortSupport infrastructure to allow operator
classes the option to provide abbreviated representations of Datums;
in the case of text, we abbreviate by taking the first few characters
of the strxfrm() blob.  If the abbreviated comparison is insufficent
to resolve the comparison, we fall back on the normal comparator.
This can be much faster than the old way of doing sorting if the
first few bytes of the string are usually sufficient to resolve the
comparison.

There is the potential for a performance regression if all of the
strings to be sorted are identical for the first 8+ characters and
differ only in later positions; therefore, the SortSupport machinery
now provides an infrastructure to abort the use of abbreviation if
it appears that abbreviation is producing comparatively few distinct
keys.  HyperLogLog, a streaming cardinality estimator, is included in
this commit and used to make that determination for text.

Peter Geoghegan, reviewed by me.
2015-01-19 15:28:27 -05:00
Robert Haas 1605291b6c Typo fix.
Etsuro Fujita
2015-01-19 11:36:48 -05:00
Robert Haas 9d54b93239 BRIN typo fix.
Amit Langote
2015-01-19 08:34:29 -05:00
Peter Eisentraut cb4a3b0410 Install shared libraries also in bin on cygwin, mingw
This was previously only done for libpq, not it's done for all shared
libraries.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-01-18 22:36:40 -05:00
Tom Lane 75df6dc083 Fix ancient thinko in default table rowcount estimation.
The code used sizeof(ItemPointerData) where sizeof(ItemIdData) is correct,
since we're trying to account for a tuple's line pointer.  Spotted by
Tomonari Katsumata (bug #12584).

Although this mistake is of very long standing, no back-patch, since it's
a relatively harmless error and changing it would risk changing default
planner behavior in stable branches.  (I don't see any change in regression
test outputs here, but the buildfarm may think differently.)
2015-01-18 17:04:11 -05:00
Noah Misch 4c34dcf97f Activate low-volume optional logging during regression test runs.
Elaborated from an idea by Andres Freund.
2015-01-18 14:08:09 -05:00
Andres Freund 525b84c576 Fix use of already freed memory when dumping a database's security label.
pg_dump.c:dumDatabase() called ArchiveEntry() with the results of a a
query that was PQclear()ed a couple lines earlier.

Backpatch to 9.2 where security labels for shared objects where
introduced.
2015-01-18 16:04:10 +01:00
Andres Freund ff44fba46c Replace walsender's latch with the general shared latch.
Relying on the normal shared latch simplifies interrupt/signal
handling because we can rely on all signal handlers setting the proc
latch. That in turn allows us to avoid the use of
ImmediateInterruptOK, which arguably isn't correct because
WaitLatchOrSocket isn't declared to be immediately interruptible.

Also change sections that wait on the walsender's latch to notice
interrupts quicker/more reliably and make them more consistent with
each other.

This is part of a larger "get rid of ImmediateInterruptOK" series.

Discussion: 20150115020335.GZ5245@awork2.anarazel.de
2015-01-17 13:00:42 +01:00
Tom Lane 20af53d719 Show sort ordering options in EXPLAIN output.
Up to now, EXPLAIN has contented itself with printing the sort expressions
in a Sort or Merge Append plan node.  This patch improves that by
annotating the sort keys with COLLATE, DESC, USING, and/or NULLS FIRST/LAST
whenever nondefault sort ordering options are used.  The output is now a
reasonably close approximation of an ORDER BY clause equivalent to the
plan's ordering.

Marius Timmer, Lukas Kreft, and Arne Scheffer; reviewed by Mike Blackwell.
Some additional hacking by me.
2015-01-16 18:19:00 -05:00
Heikki Linnakangas 9402869160 Advance backend's advertised xmin more aggressively.
Currently, a backend will reset it's PGXACT->xmin value when it doesn't
have any registered snapshots left. That covered the common case that a
transaction in read committed mode runs several queries, one after each
other, as there would be no snapshots active between those queries.
However, if you hold cursors across each of the query, we didn't get a
chance to reset xmin.

To make that better, keep all the registered snapshots in a pairing heap,
ordered by xmin so that it's always quick to find the snapshot with the
smallest xmin. That allows us to advance PGXACT->xmin whenever the oldest
snapshot is deregistered, even if there are others still active.

Per discussion originally started by Jeff Davis back in 2009 and more
recently by Robert Haas.
2015-01-17 01:15:23 +02:00
Tom Lane 779fdcdeee Improve new caching logic in tbm_add_tuples().
For no significant extra complexity, we can cache knowledge that the
target page is lossy, and save a hash_search per iteration in that
case as well.  This probably makes little difference, since the extra
rechecks that must occur when pages are lossy are way more expensive
than anything we can save here ... but we might as well do it if we're
going to cache anything.
2015-01-16 13:28:30 -05:00
Andres Freund f5ae3ba482 Make tbm_add_tuples more efficient by caching the last acccessed page.
When adding a large number of tuples to a TID bitmap using
tbm_add_tuples() sometimes a lot of time was spent looking up a page's
entry in the bitmap's internal hashtable.

Improve efficiency by caching the last accessed page, while iterating
over the passed in tuples, hoping consecutive tuples will often be on
the same page.  In many cases that's a good bet, and in the rest the
added overhead isn't big.

Discussion: 54479A85.8060309@sigaev.ru

Author: Teodor Sigaev
Reviewed-By: David Rowley
2015-01-16 17:47:59 +01:00
Heikki Linnakangas aa1d2fc5e9 Another attempt at fixing Windows Norwegian locale.
Previous fix mapped "Norwegian (Bokmål)" locale, which contains a non-ASCII
character, to the pure ASCII alias "norwegian-bokmal". However, it turns
out that more recent versions of the CRT library, in particular MSVCR110
(Visual Studio 2012), changed the behaviour of setlocale() so that if
you pass "norwegian-bokmal" to setlocale, it returns "Norwegian_Norway".

That meant trouble, when setlocale(..., NULL) first returned
"Norwegian (Bokmål)_Norway", which we mapped to "norwegian-bokmal_Norway",
but another call to setlocale(..., "norwegian-bokmal_Norway") returned
"Norwegian_Norway". That caused PostgreSQL to think that they are different
locales, and therefore not compatible. That caused initdb to fail at
CREATE DATABASE.

Older CRT versions seem to accept "Norwegian_Norway" too, so change the
mapping to return "Norwegian_Norway" instead of "norwegian-bokmal".

Backpatch to 9.2 like the previous attempt. We haven't made a release that
includes the previous fix yet, so we don't need to worry about changing the
locale of existing clusters from "norwegian-bokmal" to "Norwegian_Norway".
(Doing any mapping like this at all requires changing the locale of
existing databases; the release notes need to include instructions for
that).
2015-01-16 13:28:19 +02:00
Noah Misch 28df6a0df0 Update "pg_regress --no-locale" for Darwin and Windows.
Commit 894459e59f revealed this option to
be broken for NLS builds on Darwin, but "make -C contrib/unaccent check"
and the buildfarm client rely on it.  Fix that configuration by
redefining the option to imply LANG=C on Darwin.  In passing, use LANG=C
instead of LANG=en on Windows; since only postmaster startup uses that
value, testers are unlikely to notice the change.  Back-patch to 9.0,
like the predecessor commit.
2015-01-16 01:27:31 -05:00
Tom Lane c480cb9d24 Fix use-of-already-freed-memory problem in EvalPlanQual processing.
Up to now, the "child" executor state trees generated for EvalPlanQual
rechecks have simply shared the ResultRelInfo arrays used for the original
execution tree.  However, this leads to dangling-pointer problems, because
ExecInitModifyTable() is all too willing to scribble on some fields of the
ResultRelInfo(s) even when it's being run in one of those child trees.
This trashes those fields from the perspective of the parent tree, because
even if the generated subtree is logically identical to what was in use in
the parent, it's in a memory context that will go away when we're done
with the child state tree.

We do however want to share information in the direction from the parent
down to the children; in particular, fields such as es_instrument *must*
be shared or we'll lose the stats arising from execution of the children.
So the simplest fix is to make a copy of the parent's ResultRelInfo array,
but not copy any fields back at end of child execution.

Per report from Manuel Kniep.  The added isolation test is based on his
example.  In an unpatched memory-clobber-enabled build it will reliably
fail with "ctid is NULL" errors in all branches back to 9.1, as a
consequence of junkfilter->jf_junkAttNo being overwritten with $7f7f.
This test cannot be run as-is before that for lack of WITH syntax; but
I have no doubt that some variant of this problem can arise in older
branches, so apply the code change all the way back.
2015-01-15 18:52:58 -05:00
Heikki Linnakangas 49b04188f8 Fix thinko in re-setting wal_log_hints flag from a parameter-change record.
The flag is supposed to be copied from the record. Same issue with
track_commit_timestamps, but that's master-only.

Report and fix by Petr Jalinek. Backpatch to 9.4, where wal_log_hints was
added.
2015-01-15 20:52:41 +02:00
Tom Lane 8e166e164c Rearrange explain.c's API so callers need not embed sizeof(ExplainState).
The folly of the previous arrangement was just demonstrated: there's no
convenient way to add fields to ExplainState without breaking ABI, even
if callers have no need to touch those fields.  Since we might well need
to do that again someday in back branches, let's change things so that
only explain.c has to have sizeof(ExplainState) compiled into it.  This
costs one extra palloc() per EXPLAIN operation, which is surely pretty
negligible.
2015-01-15 13:39:33 -05:00
Tom Lane a5cd70dcbc Improve performance of EXPLAIN with large range tables.
As of 9.3, ruleutils.c goes to some lengths to ensure that table and column
aliases used in its output are unique.  Of course this takes more time than
was required before, which in itself isn't fatal.  However, EXPLAIN was set
up so that recalculation of the unique aliases was repeated for each
subexpression printed in a plan.  That results in O(N^2) time and memory
consumption for large plan trees, which did not happen in older branches.

Fortunately, the expensive work is the same across a whole plan tree,
so there is no need to repeat it; we can do most of the initialization
just once per query and re-use it for each subexpression.  This buys
back most (not all) of the performance loss since 9.2.

We need an extra ExplainState field to hold the precalculated deparse
context.  That's no problem in HEAD, but in the back branches, expanding
sizeof(ExplainState) seems risky because third-party extensions might
have local variables of that struct type.  So, in 9.4 and 9.3, introduce
an auxiliary struct to keep sizeof(ExplainState) the same.  We should
refactor the APIs to avoid such local variables in future, but that's
material for a separate HEAD-only commit.

Per gripe from Alexey Bashtanov.  Back-patch to 9.3 where the issue
was introduced.
2015-01-15 13:18:12 -05:00
Andres Freund 6cfd5086e1 Blindly try to fix a warning in s_lock.h when compiling with gcc on HPPA.
The possibly, depending on compiler settings, generated warning was
"warning: `S_UNLOCK' redefined".

The hppa spinlock implementation doesn't follow the rules of s_lock.h
and provides a gcc specific implementation outside of the the part of
the file that's supposed to do that.  It does so to avoid duplication
between the HP compiler and gcc. That unfortunately means that
S_UNLOCK is already defined when the HPPA specific section is reached.

Undefine the generic fallback S_UNLOCK definition inside the HPPA
section. That's far from pretty, but has the big advantage of being
simple. If somebody is interested to fix this in a prettier way...

This presumably got broken in the course of 0709b7ee72.

Discussion: 20150114225919.GY5245@awork2.anarazel.de

Per complaint from Tom Lane.
2015-01-15 13:26:25 +01:00
Andres Freund 59f71a0d0b Add a default local latch for use in signal handlers.
To do so, move InitializeLatchSupport() into the new common process
initialization functions, and add a new global variable MyLatch.

MyLatch is usable as soon InitPostmasterChild() has been called
(i.e. very early during startup). Initially it points to a process
local latch that exists in all processes. InitProcess/InitAuxiliaryProcess
then replaces that local latch with PGPROC->procLatch. During shutdown
the reverse happens.

This is primarily advantageous for two reasons: For one it simplifies
dealing with the shared process latch, especially in signal handlers,
because instead of having to check for MyProc, MyLatch can be used
unconditionally. For another, a later patch that makes FEs/BE
communication use latches, now can rely on the existence of a latch,
even before having gone through InitProcess.

Discussion: 20140927191243.GD5423@alap3.anarazel.de
2015-01-14 18:45:22 +01:00
Tom Lane fd3d894e4e Remove duplicate specification of -Ae for HP-UX C compiler.
Autoconf has known about automatically selecting -Ae when needed for
quite some time now, so remove the redundant addition in template/hpux.
Noted while setting up buildfarm member pademelon.
2015-01-13 22:52:11 -05:00
Andres Freund 0139dea8f1 Remove some dead IsUnderPostmaster code from bootstrap.c.
Since commit 626eb02198 has introduced the auxiliary process
infrastructure, bootstrap_signals() was never used when forked from
postmaster.

Remove the IsUnderPostmaster specific code, and add a appropriate
assertion.
2015-01-14 00:37:02 +01:00
Andres Freund 31c453165b Commonalize process startup code.
Move common code, that was duplicated in every postmaster child/every
standalone process, into two functions in miscinit.c.  Not only does
that already result in a fair amount of net code reduction but it also
makes it much easier to remove more duplication in the future. The
prime motivation wasn't code deduplication though, but easier addition
of new common code.
2015-01-14 00:33:14 +01:00
Andres Freund 2be82dcf17 Make logging_collector=on work with non-windows EXEC_BACKEND again.
Commit b94ce6e80 reordered postmaster's startup sequence so that the
tempfile directory is only cleaned up after all the necessary state
for pg_ctl is collected.  Unfortunately the chosen location is after
the syslogger has been started; which normally is fine, except for
!WIN32 EXEC_BACKEND builds, which pass information to children via
files in the temp directory.

Move the call to RemovePgTempFiles() to just before the syslogger has
started. That's the first child we fork.

Luckily EXEC_BACKEND is pretty much only used by endusers on windows,
which has a separate method to pass information to children. That
means the real world impact of this bug is very small.

Discussion: 20150113182344.GF12272@alap3.anarazel.de

Backpatch to 9.1, just as the previous commit was.
2015-01-14 00:14:53 +01:00
Heikki Linnakangas e922a13058 Spell the X072 feature correctly, was missing "with".
Also use lower-case for a few more features, to be consistent with the
others and with the SQL spec.
2015-01-13 16:08:55 +02:00
Andres Freund 14e8803f10 Add barriers to the latch code.
Since their introduction latches have required barriers in SetLatch
and ResetLatch - but when they were introduced there wasn't any
barrier abstraction. Instead latches were documented to rely on the
callsites to provide barrier semantics.

Now that the barrier support looks halfway complete, add the necessary
barriers to both latch implementations.

Also remove a now superflous lock acquisition from syncrep.c and a
superflous (and insufficient) barrier from freelist.c. There might be
other cases that can now be simplified, but those are the only ones
I've seen on a quick scan.

We might want to backpatch this at some later point, but right now the
barrier infrastructure in the backbranches isn't totally on par with
master.

Discussion: 20150112154026.GB2092@awork2.anarazel.de
2015-01-13 12:58:43 +01:00
Andres Freund 4bad60e3fd Allow latches to wait for socket writability without waiting for readability.
So far WaitLatchOrSocket() required to pass in WL_SOCKET_READABLE as
that solely was used to indicate error conditions, like EOF. Waiting
for WL_SOCKET_WRITEABLE would have meant to busy wait upon socket
errors.

Adjust the API to signal errors by returning the socket as readable,
writable or both, depending on WL_SOCKET_READABLE/WL_SOCKET_WRITEABLE
being specified.  It would arguably be nicer to return WL_SOCKET_ERROR
but that's not possible on platforms and would probably also result in
more complex callsites.

This previously had explicitly been forbidden in e42a21b9e6, as
there was no strong use case at that point. We now are looking into
making FE/BE communication use latches, so changing this makes sense.

There also are some portability concerns because there cases of older
platforms where select(2) is known to, in violation of POSIX, not
return a socket as writable after the peer has closed it.  So far the
platforms where that's the case provide a working poll(2). If we find
one where that's not the case, we'll need to add a workaround for that
platform.

Discussion: 20140927191243.GD5423@alap3.anarazel.de
Reviewed-By: Heikki Linnakangas, Noah Misch
2015-01-13 12:58:43 +01:00
Heikki Linnakangas 3dfce37627 Fix typos in comment.
Plus some tiny wordsmithing of not-quite-typos.
2015-01-13 10:32:38 +02:00
Tom Lane 7391e2513f Fix some functions that were declared static then defined not-static.
Per testing with a compiler that whines about this.
2015-01-12 16:08:43 -05:00
Tom Lane 5b3ce2c911 Avoid unexpected slowdown in vacuum regression test.
I noticed the "vacuum" regression test taking really significantly longer
than it used to on a slow machine.  Investigation pointed the finger at
commit e415b469b3, which added creation of
an index using an extremely expensive index function.  That function was
evidently meant to be applied only twice ... but the test re-used an
existing test table, which up till a couple lines before that had had over
two thousand rows.  Depending on timing of the concurrent regression tests,
the intervening VACUUMs might have been unable to remove those
recently-dead rows, and then the index build would need to create index
entries for them too, leading to the wrap_do_analyze() function being
executed 2000+ times not twice.  Avoid this by using a different table
that is guaranteed to have only the intended two rows in it.

Back-patch to 9.0, like the commit that created the problem.
2015-01-12 15:13:53 -05:00