Improve the documentation around weak-memory-ordering risks, and do a pass
of general editorialization on the comments in the latch code. Make the
Windows latch code more like the Unix latch code where feasible; in
particular provide the same Assert checks in both implementations.
Fix poorly-placed WaitLatch call in syncrep.c.
This patch resolves, for the moment, concerns around weak-memory-ordering
bugs in latch-related code: we have documented the restrictions and checked
that existing calls meet them. In 9.2 I hope that we will install suitable
memory barrier instructions in SetLatch/ResetLatch, so that their callers
don't need to be quite so careful.
detect postmaster death. Postmaster keeps the write-end of the pipe open,
so when it dies, children get EOF in the read-end. That can conveniently
be waited for in select(), which allows eliminating some of the polling
loops that check for postmaster death. This patch doesn't yet change all
the loops to use the new mechanism, expect a follow-on patch to do that.
This changes the interface to WaitLatch, so that it takes as argument a
bitmask of events that it waits for. Possible events are latch set, timeout,
postmaster death, and socket becoming readable or writeable.
The pipe method behaves slightly differently from the kill() method
previously used in PostmasterIsAlive() in the case that postmaster has died,
but its parent has not yet read its exit code with waitpid(). The pipe
returns EOF as soon as the process dies, but kill() continues to return
true until waitpid() has been called (IOW while the process is a zombie).
Because of that, change PostmasterIsAlive() to use the pipe too, otherwise
WaitLatch() would return immediately with WL_POSTMASTER_DEATH, while
PostmasterIsAlive() would claim it's still alive. That could easily lead to
busy-waiting while postmaster is in zombie state.
Peter Geoghegan with further changes by me, reviewed by Fujii Masao and
Florian Pflug.
For consistency, have all non-ASCII characters from contributors'
names in the source be in UTF-8. But remove some other more
gratuitous uses of non-ASCII characters.
Also, we removed the display of the current value of
max_connections/MaxBackends from some messages earlier, because it was
confusing, so do that in the remaining one as well.
Most of these cast DWORD to int or unsigned int for printf type handling.
This is safe even on 64 bit architectures because a DWORD is always 32 bits.
In one case a variable is initialised to keep the compiler happy.
Remove the hard-wired assumption that __mips__ (and only __mips__) lacks
dlopen in FreeBSD and OpenBSD. This assumption is outdated at least for
OpenBSD, as per report from an anonymous 9.1 tester. We can perfectly well
use HAVE_DLOPEN instead to decide which code to use.
Some other cosmetic adjustments to make freebsd.c, netbsd.c, and openbsd.c
exactly alike.
than replication_timeout (a new GUC) milliseconds. The TCP timeout is often
too long, you want the master to notice a dead connection much sooner.
People complained about that in 9.0 too, but with synchronous replication
it's even more important to notice dead connections promptly.
Fujii Masao and Heikki Linnakangas
Fix broken test for pre-existing postmaster, caused by wrong code for
appending lines to the lockfile; don't write a failed listen_address
setting into the lockfile; don't arbitrarily change the location of the
data directory in the lockfile compared to previous releases; provide more
consistent and useful definitions of the socket path and listen_address
entries; avoid assuming that pg_ctl has the same DEFAULT_PGSOCKET_DIR as
the postmaster; assorted code style improvements.
Since we're not multithreaded it only provides marginally useful
information, and it does require a newer version of the Platform SDK
than we target. We may want to reconsider this in the future along
with a fix for MinGW.
Add support for collecting "minidump" style crash dumps on
Windows, by setting up an exception handling filter. Crash
dumps will be generated in PGDATA/crashdumps if the directory
is created (the existance of the directory is used as on/off
switch for the generation of the dumps).
Craig Ringer and Magnus Hagander
dynamic pool of event handles, we can permanently assign one for each
shared latch. Thanks to that, we no longer need a separate shared memory
block for latches, and we don't need to know in advance how many shared
latches there is, so you no longer need to remember to update
NumSharedLatches when you introduce a new latch to the system.
wait until it is set. Latches can be used to reliably wait until a signal
arrives, which is hard otherwise because signals don't interrupt select()
on some platforms, and even when they do, there's race conditions.
On Unix, latches use the so called self-pipe trick under the covers to
implement the sleep until the latch is set, without race conditions. On
Windows, Windows events are used.
Use the new latch abstraction to sleep in walsender, so that as soon as
a transaction finishes, walsender is woken up to immediately send the WAL
to the standby. This reduces the latency between master and standby, which
is good.
Preliminary work by Fujii Masao. The latch implementation is by me, with
helpful comments from many people.
It turns out that some platforms return ENOMEM for a request that violates
SHMALL, whereas we were assuming that ENOSPC would always be used for that.
Apparently the latter is a Linuxism while ENOMEM is the BSD tradition.
Extend the ENOMEM hint to suggest that raising SHMALL might be needed.
Per gripe from A.M.
Backpatch to 9.0, but not further, because this doesn't seem important
enough to warrant creating extra translation work in the stable branches.
(If it were, we'd have figured this out years ago.)
linking both executables and shared libraries, and we add on LDFLAGS_EX when
linking executables or LDFLAGS_SL when linking shared libraries. This
provides a significantly cleaner way of dealing with link-time switches than
the former behavior. Also, make sure that the various platform-specific
%.so: %.o rules incorporate LDFLAGS and LDFLAGS_SL; most of them missed that
before. (I did not add these variables for the platforms that invoke $(LD)
directly, however. It's not clear if we can do that safely, since for the
most part we assume these variables use CC command-line syntax.)
Per gripe from Aaron Swenson and subsequent investigation.
returns EINVAL for an existing shared memory segment. Although it's not
terribly sensible, that behavior does meet the POSIX spec because EINVAL
is the appropriate error code when the existing segment is smaller than the
requested size, and the spec explicitly disclaims any particular ordering of
error checks. Moreover, it does in fact happen on OS X and probably other
BSD-derived kernels. (We were able to talk NetBSD into changing their code,
but purging that behavior from the wild completely seems unlikely to happen.)
We need to distinguish collision with a pre-existing segment from invalid size
request in order to behave sensibly, so it's worth some extra code here to get
it right. Per report from Gavin Kistner and subsequent investigation.
Back-patch to all supported versions, since any of them could get used
with a kernel having the debatable behavior.
and use this in pq_getbyte_if_available.
It's only a limited implementation which swithes the whole emulation layer
no non-blocking mode, but that's enough as long as non-blocking is only
used during a short period of time, and only one socket is accessed during
this time.
There was a race condition where the receiving pipe could be closed by the
child thread if the main thread was pre-empted before it got a chance to
create a new one, and the dispatch thread ran to completion during that time.
One symptom of this is that rows in pg_listener could be dropped under
heavy load.
Analysis and original patch by Radu Ilie, with some small
modifications by Magnus Hagander.
This is more in keeping with modern practice, and is a first step towards
porting to Win64 (which has sizeof(pointer) > sizeof(long)).
Tsutomu Yamada, Magnus Hagander, Tom Lane
that memory allocated by starting third party DLLs doesn't end up
conflicting with it.
Hopefully this solves the long-time issue with "could not reattach
to shared memory" errors on Win32.
Patch from Tsutomu Yamada and me, based on idea from Trevor Talbot.
it fails because the shared memory segment already exists. This
means it can take up to 10 seconds before it reports the error
if it *does* exist, but hopefully it will make the system capable
of restarting even when the server is under high load.
to make sure that the error code is reset, as a precaution in
case the API doesn't properly reset it on success. This could
be necessary, since we check the error value even if the function
doesn't fail for specific success cases.
using the system functions all the time. (These files are now just copies
of the osf.* files.) The homebrew functions were not getting used anyway
on AIX versions that have dlopen(), that is 4.3 and up, so they are not
needed on any AIX that is even remotely supported by the vendor anymore.
We'd have probably left them here anyway, except some questions were
raised about the copyright.
in the Global\ namespace, because it caused permission errors on
a lot of platforms.
We need to come up with something better for 8.4, but for now
revert to the pre-8.3.4 behaviour.
This basically takes some build system code that was previously labeled
"Solaris" and ties it to the compiler rather than the operating system.
Author: Julius Stroffek <Julius.Stroffek@Sun.COM>
corrupted. (Neither is very important if SIGTERM is used to shut down the
whole database cluster together, but there's a problem if someone tries to
SIGTERM individual backends.) To do this, introduce new infrastructure
macros PG_ENSURE_ERROR_CLEANUP/PG_END_ENSURE_ERROR_CLEANUP that take care
of transiently pushing an on_shmem_exit cleanup hook. Also use this method
for createdb cleanup --- that wasn't a shared-memory-corruption problem,
but SIGTERM abort of createdb could leave orphaned files lying around.
Backpatch as far as 8.2. The shmem corruption cases don't exist in 8.1,
and the createdb usage doesn't seem important enough to risk backpatching
further.
errdetail except the string goes only to the server log, replacing the normal
errdetail there. This provides a reasonably clean way of dealing with error
details that are too security-sensitive or too bulky to send to the client.
This commit just adds the infrastructure --- actual uses to follow.
whether to execute an immediate interrupt, rather than testing whether
LockWaitCancel() cancelled a lock wait. The old way misclassified the case
where we were blocked in ProcWaitForSignal(), and arguably would misclassify
any other future additions of new ImmediateInterruptOK states too. This
allows reverting the old kluge that gave LockWaitCancel() a return value,
since no callers care anymore. Improve comments in the various
implementations of PGSemaphoreLock() to explain that on some platforms, the
assumption that semop() exits after a signal is wrong, and so we must ensure
that the signal handler itself throws elog if we want cancel or die interrupts
to be effective. Per testing related to bug #3883, though this patch doesn't
solve those problems fully.
Perhaps this change should be back-patched, but since pre-8.3 branches aren't
really relying on autovacuum to respond to SIGINT, it doesn't seem critical
for them.
SHGetFolderPath.
This removes the direct dependency on shell32.dll and user32.dll, which
eats a lot of "desktop heap" for each backend that's started. The
desktop heap is a very limited resource, causing backends to no
longer start once it's been exhausted.
We still have indirect depdendencies on user32.dll through third party
libraries, but those can't easily be removed.
Dave Page
This is a Linux kernel bug that apparently exists in every extant kernel
version: sometimes shmctl() will fail with EIDRM when EINVAL is correct.
We were assuming that EIDRM indicates a possible conflict with pre-existing
backends, and refusing to start the postmaster when this happens. Fortunately,
there does not seem to be any case where Linux can legitimately return EIDRM
(it doesn't track shmem segments in a way that would allow that), so we can
get away with just assuming that EIDRM means EINVAL on this platform.
Per reports from Michael Fuhr and Jon Lapham --- it's a bit surprising
we have not seen more reports, actually.
to be cases when at least Windows 2000 can do this even though select
just indicated that the socket is readable.
Per report and analysis from Cyril VELTER.
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
input in the stats collector. Our select() emulation is apparently buggy
for UDP sockets :-(. This should resolve problems with stats collection
(and hence autovacuum) failing under more than minimal load. Diagnosis
and patch by Magnus Hagander.
Patch probably needs to be back-ported to 8.1 and 8.0, but first let's
see if it makes the buildfarm happy...
FormatMessage() (This should have been in 8.2.0, patched to 8.2.X and
HEAD):
I think this problem to be complex....
http://archives.postgresql.org/pgsql-hackers/2006-11/msg00042.php
FormatMessage of windows cannot consider the encoding of the database.
However, I should try the solution now. It is necessary to clear the
problem.
Multi character-code exists together in message and log. It doesn't
consider
the data base encoding that the user intended....
The user in multi-byte country can try this.
http://inet.winpg.jp/~saito/pg_bug/MessageCheck.c
That is, it is likely to become it in this manner.(Japanese)
http://inet.winpg.jp/~saito/pg_bug/FormatMessage998.png
Hiroshi Saito
1) pgwin32_waitforsinglesocket(): WaitForMultipleObjectsEx now called with
finite timeout (100ms) in case of FP_WRITE and UDP socket. If timeout occurs
then pgwin32_waitforsinglesocket() tries to write empty packet goes to
WaitForMultipleObjectsEx again.
2) pgwin32_send(): add loop around WSASend and pgwin32_waitforsinglesocket().
The reason is: for overlapped socket, 'ok' result from
pgwin32_waitforsinglesocket() isn't guarantee that socket is still free,
it can become busy again and following WSASend call will fail with
WSAEWOULDBLOCK error.
See http://archives.postgresql.org/pgsql-hackers/2006-10/msg00561.php
as micro-seconds, rather than as 100 microseconds, as it does now. This
actually fixes all setitimer calls on Win32, but statement_timeout is
the most visible fix.
Backpatch to 8.1.X. 8.0 works as documented.
pg_usleep at all. Instead call the replacement function in
port/win32/signal.c by that name. Avoids tricky macro-redefinition
logic and suppresses a compiler warning; furthermore it ensures that
no one can accidentally use the non-signal-aware version of pg_usleep
in a Windows backend.
o remove many WIN32_CLIENT_ONLY defines
o add WIN32_ONLY_COMPILER define
o add 3rd argument to open() for portability
o add include/port/win32_msvc directory for
system includes
Magnus Hagander
more compliant with the error message style guide. In particular,
errdetail should begin with a capital letter and end with a period,
whereas errmsg should not. I also fixed a few related issues in
passing, such as fixing the repeated misspelling of "lexeme" in
contrib/tsearch2 (per Tom's suggestion).
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
to the main thread. This allows removal of WaitForSingleObjectEx() calls
from the main thread, thereby allowing us to re-enable Qingqing Zhou's
CHECK_FOR_INTERRUPTS performance improvement. Qingqing, Magnus, et al.
a kernel call unless there's some evidence of a pending signal. This should
bring its performance on Windows into line with the Unix version. Problem
diagnosis and patch by Qingqing Zhou. Minor stylistic tweaks by moi ...
if it's broken, it's my fault.
level for unrecognized win32 error codes to LOG, and make messages
conform to style guide. Per old suggestion from Qingqing Zhou, which
seems to have gotten lost in the shuffle.
to 'Size' (that is, size_t), and install overflow detection checks in it.
This allows us to remove the former arbitrary restrictions on NBuffers
etc. It won't make any difference in a 32-bit machine, but in a 64-bit
machine you could theoretically have terabytes of shared buffers.
(How efficiently we could manage 'em remains to be seen.) Similarly,
num_temp_buffers, work_mem, and maintenance_work_mem can be set above
2Gb on a 64-bit machine. Original patch from Koichi Suzuki, additional
work by moi.
> >> 3) I restarted the postmaster both times. I got this error
> both times.
> >> :25: ERROR: could not load library "C:/Program
> >> Files/PostgreSQL/8.0/lib/testtrigfuncs.dll": dynamic load error
>
> > Yes. We really need to look at fixing that error message. I had
> > forgotten it completely :-(
>
> > Bruce, you think we can sneak that in after feature freeze? I would
> > call it a bugfix :-)
>
> Me too. That's been on the radar for awhile --- please do
> send in a patch.
Here we go, that wasn't too hard :-)
Apart from adding the error handling, it does one more thing: it changes
the errormode when loading the DLLs. Previously if a DLL was broken, or
referenced other DLLs that couldn't be found, a popup dialog box would
appear on the screen. Which had to be clicked before the backend could
continue. This patch also disables the popup error message for DLL
loads.
I think this is something we should consider doing for the entire
backend - disable those popups, and say we deal with it ourselves. What
do you other win32 hackers thinnk about this?
In the meantime, this patch fixes the error msgs. Please apply for 8.1
and please consider a backpatch to 8.0.
Magnus Hagander
before we can invoke fork() -- flush stdio buffers, save and restore the
profiling timer on Linux with LINUX_PROFILE, and handle BeOS stuff. This
patch moves that code into a single function, fork_process(), instead of
duplicating it at the various callsites of fork().
This patch doesn't address the EXEC_BACKEND case; there is room for
further cleanup there.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
to shared memory as soon as possible, ie, right after read_backend_variables.
The effective difference from the original code is that this happens
before instead of after read_nondefault_variables(), which loads GUC
information and is apparently capable of expanding the backend's memory
allocation more than you'd think it should. This should fix the
failure-to-attach-to-shared-memory reports we've been seeing on Windows.
Also clean up a few bits of unnecessarily grotty EXEC_BACKEND code.
even uglier than it was already :-(. Also, on Windows only, use temporary
shared memory segments instead of ordinary files to pass over critical
variable values from postmaster to child processes. Magnus Hagander
> pg specific, like "PostgreSQL.1". I have not done this since a new compile
> would not detect a running old beta. But now would be the time (or never).
Zeugswetter Andreas
shared memory segment ID. If we can't access the existing shmem segment,
it must not be relevant to our data directory. If we can access it,
then attach to it and check for an actual match to the data directory.
This should avoid some cases of failure-to-restart-after-boot without
introducing any significant risk of failing to detect a still-running
old backend.
- remove another senseless "extern" keyword that was applied to a
function definition
- change a foo more function signatures from "some_type foo()" to
"some_type foo(void)"
- rewrite another K&R style function definition
- make the type of the "action" function pointer in the KeyWord struct
in src/backend/utils/adt/formatting.c more precise
* Links with -leay32 and -lssleay32 instead of crypto and ssl. On win32,
"crypto and ssl" is only used for static linking.
* Initializes SSL in the backend and not just in the postmaster. We
cannot pass the SSL context from the postmaster through the parameter
file, because it contains function pointers.
* Split one error check in be-secure.c. Previously we could not tell
which of three calls actually failed. The previous code also returned
incorrect error messages if SSL_accept() failed - that function needs to
use SSL_get_error() on the return value, can't just use the error queue.
* Since the win32 implementation uses non-blocking sockets "behind the
scenes" in order to deliver signals correctly, implements a version of
SSL_accept() that can handle this. Also, add a wait function in case
SSL_read or SSL_write() needs more data.
Magnus Hagander
>>GetLastError will
>>> give much more details than errno.
>>
>>How much more, really? That mapping table gave me the impression that
>>the win32 error codes aren't all that much more detailed than errno...
>
>The mapping table is not complete. My winerror.h from the SDK
>lists 2209
>error codes, whereas errno.h lists 42...
>
>I still don't think we'll get that much more stuff. Right now,
>the Win32
>code paths that actually use the more advanced functions already write
>out the error number in case something happens. We can keep doing that
>for the other paths (ereport the error *number* when the mapping does
>not have a match). The map to errno will catch almost all cases, I
>think. And in the corner cases we can do with just the number, and use
>"net helpmsg" to get the actual message when checking...
Here's an attempt on this. new file goes in backend/port/win32.
Magnus Hagander
about a third, make it work on non-Windows platforms again. (But perhaps
I broke the WIN32 code, since I have no way to test that.) Fold all the
paths that fork postmaster child processes to go through the single
routine SubPostmasterMain, which takes care of resurrecting the state that
would normally be inherited from the postmaster (including GUC variables).
Clean up some places where there's no particularly good reason for the
EXEC and non-EXEC cases to work differently. Take care of one or two
FIXMEs that remained in the code.
* removed a few redundant defines
* get_user_name safe under win32
* rationalized pipe read EOF for win32 (UPDATED PATCH USED)
* changed all backend instances of sleep() to pg_usleep
- except for the SLEEP_ON_ASSERT in assert.c, as it would exceed a
32-bit long [Note to patcher: If a SLEEP_ON_ASSERT of 2000 seconds is
acceptable, please replace with pg_usleep(2000000000L)]
I added a comment to that part of the code:
/*
* It would be nice to use pg_usleep() here, but only does 2000 sec
* or 33 minutes, which seems too short.
*/
sleep(1000000);
Claudio Natoli
It works on the principle of turning sockets into non-blocking, and then
emulate blocking behaviour on top of that, while allowing signals to
run. Signals are now implemented using an event instead of APCs, thus
getting rid of the issue of APCs not being compatible with "old style"
sockets functions.
It also moves the win32 specific code away from pqsignal.h/c into
port/win32, and also removes the "thread style workaround" of the APC
issue previously in place.
In order to make things work, a few things are also changed in pgstat.c:
1) There is now a separate pipe to the collector and the bufferer. This
is required because the pipe will otherwise only be signalled in one of
the processes when the postmaster goes down. The MS winsock code for
select() must have some kind of workaround for this behaviour, but I
have found no stable way of doing that. You really are not supposed to
use the same socket from more than one process (unless you use
WSADuplicateSocket(), in which case the docs specifically say that only
one will be flagged).
2) The check for "postmaster death" is moved into a separate select()
call after the main loop. The previous behaviour select():ed on the
postmaster pipe, while later explicitly saying "we do NOT check for
postmaster exit inside the loop".
The issue was that the code relies on the same select() call seeing both
the postmaster pipe *and* the pgstat pipe go away. This does not always
happen, and it appears that useing WSAEventSelect() makes it even more
common that it does not.
Since it's only called when the process exits, I don't think using a
separate select() call will have any significant impact on how the stats
collector works.
Magnus Hagander
* Mostly, casting etc to remove compilation warnings in win32 only code.
* main.c: set _IONBF to stdout/stderr under win32 (under win32, _IOLBF
defaults to full buffering)
* pg_resetxlog/Makefile: ensures dirmod.o gets cleaned (got bitten by
this when, after "make clean"ing, switching compilation between Ming +
Cygwin)
Claudio Natoli
* Changes incorrect CYGWIN defines to __CYGWIN__
* Some localtime returns NULL checks (when unchecked cause SEGVs under
Win32
regression tests)
* Rationalized CreateSharedMemoryAndSemaphores and
AttachSharedMemoryAndSemaphores (Bruce, I finally remembered to do it);
requires attention.
Claudio Natoli
applied, deadlock detection and statement_timeout now works.
The file timer.c goes into src/backend/port/win32/.
The patch also removes two lines of "printf debugging" accidentally left
in pqsignal.h, in the console control handler.
Magnus Hagander
Natoli and Bruce Momjian (and some cosmetic fixes from Neil Conway).
Changes:
- remove duplicate signal definitions from pqsignal.h
- replace pqkill() with kill() and redefine kill() in Win32
- use ereport() in place of fprintf() in some error handling in
pqsignal.c
- export pg_queue_signal() and make use of it where necessary
- add a console control handler for Ctrl-C and similar handling
on Win32
- do WaitForSingleObjectEx() in CHECK_FOR_INTERRUPTS() on Win32;
query cancelling should now work on Win32
- various other fixes and cleanups
* configure + Makefile changes
* shared memory attaching in EXEC_BACKEND case (+ minor fix for apparent
cygwin bug under cygwin/EXEC_BACKEND case only)
* PATH env var separator differences
* missing win32 rand functions added
* placeholder replacements for sync etc under port.h
To those who are really interested, and there are a few of you: the attached
patch + file will allow the source base to be compiled (and, for some
definition, "run") under MingW, with the following caveats (I wanted to
first properly fix all but the last of these, but y'all won't quit asking
for a patch :-):
* child death: SIGCHLD not yet sent, so as a minimum, you'll need to
put in some sort of delay after StartupDatabase, and handle setting
StartupPID to 0 etc (ie. the stuff the reaper() signal function is supposed
to do)
* dirmod.c: comment out the elog calls
* dfmgr.c: some hackage required to substitute_libpath_macro
* slru/xact.c: comment out the errno checking after the readdir
(fixed by next version of MingW)
Again, this is only if you *really* want to see postgres compile and start,
and is a nice leg-up for working on the other Win32 TODO list items. Just
don't expect too much else from it at this point...
Claudio Natoli
against the latest shapshot. It also includes the replacement of kill()
with pqkill() and sigsetmask() with pqsigsetmask().
Passes all tests fine on my linux machine once applied. Still doesn't
link completely on Win32 - there are a few things still required. But
much closer than before.
At Bruce's request, I'm goint to write up a README file about the method
of signals delivery chosen and why the others were rejected (basically a
summary of the mailinglist discussions). I'll finish that up once/if the
patch is accepted.
Magnus Hagander
pointer type when it is not necessary to do so.
For future reference, casting NULL to a pointer type is only necessary
when (a) invoking a function AND either (b) the function has no prototype
OR (c) the function is a varargs function.
on 64-bit Solaris. Use a non-system-dependent datatype for UsedShmemSegID,
namely unsigned long (which we were already assuming could hold a shmem
key anyway, cf RecordSharedMemoryInLockFile).
max_connections at initdb time. Get rid of DEF_NBUFFERS and DEF_MAXBACKENDS
macros, which aren't doing anything useful anymore, and put more likely
defaults into postgresql.conf.sample.
Tom Lane
Peter Eisentraut
Andrew Dunstan
Heikki Linnakangas
Bruce Momjian
Robert Haas
Magnus Hagander
Itagaki Takahiro
Alvaro Herrera
Teodor Sigaev
Neil Conway
PostgreSQL Daemon
