Several upcoming performance/scalability improvements require atomic
operations. This new API avoids the need to splatter compiler and
architecture dependent code over all the locations employing atomic
ops.
For several of the potential usages it'd be problematic to maintain
both, a atomics using implementation and one using spinlocks or
similar. In all likelihood one of the implementations would not get
tested regularly under concurrency. To avoid that scenario the new API
provides a automatic fallback of atomic operations to spinlocks. All
properties of atomic operations are maintained. This fallback -
obviously - isn't as fast as just using atomic ops, but it's not bad
either. For one of the future users the atomics ontop spinlocks
implementation was actually slightly faster than the old purely
spinlock using implementation. That's important because it reduces the
fear of regressing older platforms when improving the scalability for
new ones.
The API, loosely modeled after the C11 atomics support, currently
provides 'atomic flags' and 32 bit unsigned integers. If the platform
efficiently supports atomic 64 bit unsigned integers those are also
provided.
To implement atomics support for a platform/architecture/compiler for
a type of atomics 32bit compare and exchange needs to be
implemented. If available and more efficient native support for flags,
32 bit atomic addition, and corresponding 64 bit operations may also
be provided. Additional useful atomic operations are implemented
generically ontop of these.
The implementation for various versions of gcc, msvc and sun studio have
been tested. Additional existing stub implementations for
* Intel icc
* HUPX acc
* IBM xlc
are included but have never been tested. These will likely require
fixes based on buildfarm and user feedback.
As atomic operations also require barriers for some operations the
existing barrier support has been moved into the atomics code.
Author: Andres Freund with contributions from Oskari Saarenmaa
Reviewed-By: Amit Kapila, Robert Haas, Heikki Linnakangas and Álvaro Herrera
Discussion: CA+TgmoYBW+ux5-8Ja=Mcyuy8=VXAnVRHp3Kess6Pn3DMXAPAEA@mail.gmail.com,
20131015123303.GH5300@awork2.anarazel.de,
20131028205522.GI20248@awork2.anarazel.de
The PGAC_FUNC_SNPRINTF_SIZE_T_SUPPORT test was broken by
ce486056ec. Among others it made the UINT64_FORMAT macro to be
defined in c.h, instead of directly being defined by configure.
This lead to the replacement printf being used on all platforms for a
while. Which seems to work, because this was only used due to
different profiles ;)
Fix by relying on INT64_MODIFIER instead.
Instead of just erroring out when a tool is missing, wrap the call with
the "missing" script that we are already using for bison, flex, and
perl, so that the users get a useful error message.
Commit a16bac36ec let "configure" detect
the system getaddrinfo() when building under 64-bit MinGW-w64. However,
src/include/port/win32/sys/socket.h assumes all native Windows
configurations use our replacement. This change placates buildfarm
member jacana until we establish a plan for getaddrinfo() on Windows.
We have had INT64_FORMAT and UINT64_FORMAT for a long time, but that's not
good enough if you want something more exotic, like "%20lld".
Abhijit Menon-Sen, per Andres Freund's suggestion.
This refactoring is in preparation for adding support for other SSL
implementations, with no user-visible effects. There are now two #defines,
USE_OPENSSL which is defined when building with OpenSSL, and USE_SSL which
is defined when building with any SSL implementation. Currently, OpenSSL is
the only implementation so the two #defines go together, but USE_SSL is
supposed to be used for implementation-independent code.
The libpq SSL code is changed to use a custom BIO, which does all the raw
I/O, like we've been doing in the backend for a long time. That makes it
possible to use MSG_NOSIGNAL to block SIGPIPE when using SSL, which avoids
a couple of syscall for each send(). Probably doesn't make much performance
difference in practice - the SSL encryption is expensive enough to mask the
effect - but it was a natural result of this refactoring.
Based on a patch by Martijn van Oosterhout from 2006. Briefly reviewed by
Alvaro Herrera, Andreas Karlsson, Jeff Janes.
With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, PostgreSQL
backends can crash at exit. Raise a warning during "configure" based on
the compile-time OpenLDAP version number, and test the crash scenario in
the dblink test suite. Back-patch to 9.0 (all supported versions).
Apparently we still build against OpenSSL so old that it doesn't
have this function, so add an autoconf check for it to make the
buildfarm happy. If the function doesn't exist, always return
that compression is disabled, since presumably the actual
compression functionality is always missing.
For now, hardcode the function as present on MSVC, since we should
hopefully be well beyond those old versions on that platform.
ws2_32 is the new version of the library that should be used, as
it contains the require functionality from wsock32 as well as some
more (which is why some binaries were already using ws2_32).
Michael Paquier, reviewed by MauMau
Almost ten years ago, commit e48322a6d6 broke
the logic in ACX_PTHREAD by looping through all the possible flags rather
than stopping with the first one that would work. This meant that
$acx_pthread_ok was no longer meaningful after the loop; it would usually
be "no", whether or not we'd found working thread flags. The reason nobody
noticed is that Postgres doesn't actually use any of the symbols set up
by the code after the loop. Rather than complicate things some more to
make it work as designed, let's just remove all that dead code, and thereby
save a few cycles in each configure run.
Support for running postgres on Alpha hasn't been tested for a long
while. Due to Alpha's uniquely lax cache coherency model it's a hard
to develop for platform (especially blindly!) and thought to be
unlikely to currently work correctly.
As Alpha is the only supported architecture for Tru64 drop support for
it as well. Tru64's support has ended 2012 and it has been in
maintenance-only mode for much longer.
Also remove stray references to __ksr__ and ultrix defines.
This function is pervasive on free software operating systems; import
NetBSD's implementation. Back-patch to 8.4, like the commit that will
harness it.
Bison >=3.0 issues warnings about
%name-prefix="base_yy"
instead of the now preferred
%name-prefix "base_yy"
but the latter doesn't work with Bison 2.3 or less. So for now we
silence the deprecation warnings.
As of Xcode 5.0, Apple isn't including the Python framework as part of the
SDK-level files, which means that linking to it might fail depending on
whether Xcode thinks you've selected a specific SDK version. According to
their Tech Note 2328, they've basically deprecated the framework method of
linking to libpython and are telling people to link to the shared library
normally. (I'm pretty sure this is in direct contradiction to the advice
they were giving a few years ago, but whatever.) Testing says that this
approach works fine at least as far back as OS X 10.4.11, so let's just
rip out the framework special case entirely. We do still need a special
case to decide that OS X provides a shared library at all, unfortunately
(I wonder why the distutils check doesn't work ...). But this is still
less of a special case than before, so it's fine.
Back-patch to all supported branches, since we'll doubtless be hearing
about this more as more people update to recent Xcode.
Allow the contrib/uuid-ossp extension to be built atop any one of these
three popular UUID libraries. (The extension's name is now arguably a
misnomer, but we'll keep it the same so as not to cause unnecessary
compatibility issues for users.)
We would not normally consider a change like this post-beta1, but the issue
has been forced by our upgrade to autoconf 2.69, whose more rigorous header
checks are causing OSSP's header files to be rejected on some platforms.
It's been foreseen for some time that we'd have to move away from depending
on OSSP UUID due to lack of upstream maintenance, so this is a down payment
on that problem.
While at it, add some simple regression tests, in hopes of catching any
major incompatibilities between the three implementations.
Matteo Beccati, with some further hacking by me
Usually the search would find plain "tclsh" without any trouble,
but some installations might only have the version-numbered flavor
of that program.
No compatibility problems have been reported with 8.6, so we might
as well back-patch this to all active branches.
Christoph Berg
This test used to just define an unused static inline function and check
whether that causes a warning. But newer clang versions warn about
unused static inline functions when defined inside a .c file, but not
when defined in an included header, which is the case we care about.
Change the test to cope.
Andres Freund
The comment added by ed011d9754 used #,
which means it gets copied into configure, but it doesn't make sense
there. So use dnl, which gets dropped when creating configure.
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
krb5 has been deprecated since 8.3, and the recommended way to do
Kerberos authentication is using the GSSAPI authentication method
(which is still fully supported).
libpq retains the ability to identify krb5 authentication, but only
gives an error message about it being unsupported. Since all authentication
is initiated from the backend, there is no need to keep it at all
in the backend.
Defining this symbol causes OS X 10.5 to use a buggy version of readdir(),
which can sometimes fail with EINVAL if the previously-fetched directory
entry has been deleted or renamed. In later OS X versions that bug has
been repaired, but we still don't need the #define because it's on by
default. So this is just an all-around bad idea, and we can do without it.
This can be used to mark custom built binaries with an extra version
string such as a git describe identifier or distribution package release
version.
From: Oskari Saarenmaa <os@ohmu.fi>
Remove the use of the following macros, which are obsolescent according
to the Autoconf documentation:
- AC_C_CONST
- AC_C_STRINGIZE
- AC_C_VOLATILE
- AC_FUNC_MEMCMP
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.
Development of IRIX has been discontinued, and support is scheduled
to end in December of 2013. Therefore, there will be no supported
versions of this operating system by the time PostgreSQL 9.4 is
released. Furthermore, we have no maintainer for this platform.
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>
make maintainer-check was obscure and rarely called in practice, and
many breakages were missed. Fold everything that make maintainer-check
used to do into the normal build. Specifically:
- Call duplicate_oids when genbki.pl is called.
- Check for tabs in SGML files when the documentation is built.
- Run msgfmt with the -c option during the regular build. Add an
additional configure check to see whether we are using the GNU
version. (make maintainer-check probably used to fail with non-GNU
msgfmt.)
Keep maintainer-check as around as phony target for the time being in
case anyone is calling it. But it won't do anything anymore.
This reverts commit 269e780822
and commit 5b571bb8c8.
Unfortunately, the initial patch had insufficient performance testing,
and resulted in a regression.
Per report by Thom Brown.
The configure script's test for <sys/ucred.h> did not work on OpenBSD,
because on that platform <sys/param.h> has to be included first.
As a result, socket peer authentication was disabled on that platform.
Problem introduced in commit be4585b1c2.
Andres Freund, slightly simplified by me.
This function is more efficient than actually writing out zeroes to
the new file, per microbenchmarks by Jon Nelson. Also, it may reduce
the likelihood of WAL file fragmentation.
Jon Nelson, with review by Andres Freund, Greg Smith and me.
This is just neatnik-ism, since all the tests in the code are #ifdefs,
but we shouldn't specify symbols as "Define to 1 ..." and then not
actually define them that way.
The main change here is to call security_compute_create_name_raw()
rather than security_compute_create_raw(). This ups the minimum
requirement for libselinux from 2.0.99 to 2.1.10, but it looks
like most distributions will have picked that up before 9.3 is out.
KaiGai Kohei
In commit 71450d7fd6, we added code to inform
suitably-intelligent compilers that ereport() doesn't return if the elevel
is ERROR or higher. This patch extends that to elog(), and also fixes a
double-evaluation hazard that the previous commit created in ereport(),
as well as reducing the emitted code size.
The elog() improvement requires the compiler to support __VA_ARGS__, which
should be available in just about anything nowadays since it's required by
C99. But our minimum language baseline is still C89, so add a configure
test for that.
The previous commit assumed that ereport's elevel could be evaluated twice,
which isn't terribly safe --- there are already counterexamples in xlog.c.
On compilers that have __builtin_constant_p, we can use that to protect the
second test, since there's no possible optimization gain if the compiler
doesn't know the value of elevel. Otherwise, use a local variable inside
the macros to prevent double evaluation. The local-variable solution is
inferior because (a) it leads to useless code being emitted when elevel
isn't constant, and (b) it increases the optimization level needed for the
compiler to recognize that subsequent code is unreachable. But it seems
better than not teaching non-gcc compilers about unreachability at all.
Lastly, if the compiler has __builtin_unreachable(), we can use that
instead of abort(), resulting in a noticeable code savings since no
function call is actually emitted. However, it seems wise to do this only
in non-assert builds. In an assert build, continue to use abort(), so that
the behavior will be predictable and debuggable if the "impossible"
happens.
These changes involve making the ereport and elog macros emit do-while
statement blocks not just expressions, which forces small changes in
a few call sites.
Andres Freund, Tom Lane, Heikki Linnakangas
I notice that plperl's makefile adds the -I for $perl_archlibexp/CORE
at the end of CPPFLAGS not the beginning. It seems somewhat unlikely
that the include search order has anything to do with why buildfarm
member okapi is failing, but I'm about out of other ideas.
It appears that perl_embed_ldflags should already mention all the libraries
that are required by libperl.so itself. So let's try the test link with
just those and not the other LIBS we've found up to now. This should
more nearly reproduce what will happen when plperl is linked, and perhaps
will fix buildfarm member okapi's problem.
Although most platforms seem to package Perl in such a way that these files
are present even in basic Perl installations, Debian does not. Hence, make
an effort to fail during configure rather than build if --with-perl was
given and these files are lacking. Per gripe from Josh Berkus.
This means we can now construct a configure test for the library
presence. Previously these parameters were only figured out at
build time in plperl's GnuMakefile.
Pre-Lion versions of Apple's linker don't allow space between -F and its
argument. (Snow Leopard is nice enough to tell you that in so many words,
but older versions just fail with very obscure link errors, as seen on
buildfarm member locust for instance.) Oversight in commit
fc8745070a.
Andres Freund