confusing, and clean up documentation.

are treated more like 'cancel' interrupts: the signal handler sets a
flag that is examined at well-defined spots, rather than trying to cope
with an interrupt that might happen anywhere.  See pghackers discussion
of 1/12/01.

are now critical sections, so as to ensure die() won't interrupt us while
we are munging shared-memory data structures.  Avoid insecure intermediate
states in some code that proc_exit will call, like palloc/pfree.  Rename
START/END_CRIT_CODE to START/END_CRIT_SECTION, since that seems to be
what people tend to call them anyway, and make them be called with () like
a function call, in hopes of not confusing pg_indent.
I doubt that this is sufficient to make SIGTERM safe anywhere; there's
just too much code that could get invoked during proc_exit().

level" locks.  A session lock is not released at transaction commit (but it
is released on transaction abort, to ensure recovery after an elog(ERROR)).
In VACUUM, use a session lock to protect the master table while vacuuming a
TOAST table, so that the TOAST table can be done in an independent
transaction.

I also took this opportunity to do some cleanup and renaming in the lock
code.  The previously noted bug in ProcLockWakeup, that it couldn't wake up
any waiters beyond the first non-wakeable waiter, is now fixed.  Also found
a previously unknown bug of the same kind (failure to scan all members of
a lock queue in some cases) in DeadLockCheck.  This might have led to failure
to detect a deadlock condition, resulting in indefinite waits, but it's
difficult to characterize the conditions required to trigger a failure.

might change it.  Experimentation shows that the signal handler call
mechanism does not save/restore errno for you, at least not on Linux
or HPUX, so this is definitely a real risk.

to ensure that we have released buffer refcounts and so forth, rather than
putting ad-hoc operations before (some of the calls to) proc_exit.  Add
commentary to discourage future hackers from repeating that mistake.

IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c.  TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.

after that dynamic loading isn't working and shared memory handling is
broken.

        Attached with this message, there is a Zip file which contain :

        * beos.diff = patch file generated with difforig
        * beos = folder with beos support files which need to be moved in /
src/backend/port
        * expected = foler with three file for message and precision
difference in regression test
        * regression.diff = rule problem (need to kill the backend manualy)
        * dynloader = dynloader files (they are also in the pacth files,
but there is so much modification that I have join full files)

        Everything works except a problem in 'rules' Is there some problems
with rules in the current tree ? It used to works with last week tree.

Cyril VELTER

working on the VERY latest version of BeOS.  I'm sure there will be
alot of comments, but then if there weren't I'd be disappointed!

Thanks for your continuing efforts to get this into your tree.

Haven't bothered with the new files as they haven't changed.

BTW Peter, the compiler is "broken" about the bool define and so on.
I'm filing a bug report to try and get it addressed.  Hopefully then we
can tidy up the code a bit.

I await the replies with interest :)

David Reid

the harm potential outweighs the possible benefits.

up sleeping processes.

for details).  It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably.  A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing.  Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.

That means you can now set your options in either or all of $PGDATA/configuration,
some postmaster option (--enable-fsync=off), or set a SET command. The list of
options is in backend/utils/misc/guc.c, documentation will be written post haste.

pg_options is gone, so is that pq_geqo config file. Also removed were backend -K,
-Q, and -T options (no longer applicable, although -d0 does the same as -Q).

Added to configure an --enable-syslog option.

changed all callers from TPRINTF to elog(DEBUG)

* Allow PQrequestCancel() to terminate when in waiting-for-lock state
Changes are limited to BACKEND,however.

  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc

to all files copyright Regents of Berkeley.  Man, that's a lot of files.

Fix for TODO item * spinlock stuck problem when elog(FATAL)
and elog(ERROR) inside bufmgr.

backend/Makefiles to be patched could significantly be reduced since
they
have been adopted to the QNX4 needs.

Andreas Kardos

Fewer calls to nameout.

Better use of RelationGetRelationName.

Cygwin snapshots (tested on 990115 which is recommended to use - it fixes
some errors in B20.1)

And I have another patch for including <sys/ipc.h> before <sys/sem.h> in
backend/storage/lmgr/proc.c - it is required due the design of cygipc
headers

                        Dan

First step in cleaning up backend initialization code.
Fix for FATAL: now FATAL is ERROR + exit.

* Buffer refcount cleanup (per my "progress report" to pghackers, 9/22).
* Add links to backend PROC structs to sinval's array of per-backend info,
and use these links for routines that need to check the state of all
backends (rather than the slow, complicated search of the ShmemIndex
hashtable that was used before).  Add databaseOID to PROC structs.
* Use this to implement an interlock that prevents DESTROY DATABASE of
a database containing running backends.  (It's a little tricky to prevent
a concurrently-starting backend from getting in there, since the new
backend is not able to lock anything at the time it tries to look up
its database in pg_database.  My solution is to recheck that the DB is
OK at the end of InitPostgres.  It may not be a 100% solution, but it's
a lot better than no interlock at all...)
* In ALTER TABLE RENAME, flush buffers for the relation before doing the
rename of the physical files, to ensure we don't get failures later from
mdblindwrt().
* Update TRUNCATE patch so that it actually compiles against current
sources :-(.
You should do "make clean all" after pulling these changes.

These are my last changes to lmgr fixing deadlock handling.
Please apply them to cvs...

Vadim