to the use of getpwuid when running in standalone mode.
this patch allocates some persistent storage (using
strdup) to store the username obtained with getpwuid
in src/backend/main/main.c. this is necessary because
later on, getpwuid is called again (in ValidateBinary).
the man pages for getpwuid on SCO OpenServer, FreeBSD,
and Darwin all have words to this effect (this is from
the SCO OpenServer man page):
Note
====
All information is contained in a static area, so it must
be copied if it is to be saved. Otherwise, it may be
overwritten on subsequent calls to these routines.
in particular, on my platform, the storage used to hold
the pw_name from the first call is overwritten such that
it looks like an empty username. this causes a problem
later on in SetSessionUserIdFromUserName.
i'd assume this isn't a problem on most platforms because
getpwuid is called with the same UID both times, and the
same thing ends up happening to that static storage each
time. however, that's not guaranteed, and is _not_ what
happens on my platform (at least :).
this is for the version of 7.1 available via anon cvs as
of Tue Jan 23 15:14:00 2001 PST:
.../src/backend/main/main.c,v 1.37 2000/12/31 18:04:35 tgl Exp
-michael thornburgh, zenomt@armory.com
than forcing 'plain'. This probably does not matter right now, but I
think it needs to be consistent with the regular (not-functional) index
case, where attstorage is copied from the underlying table. Clean up
some other dead and infelicitous code too.
Op, so that the sequence 'a_expr Op Op a_expr' will be parsed as
a_expr Op (Op a_expr) not (a_expr Op) Op a_expr as formerly. In other
words, prefer treating user-defined operators as prefix operators to
treating them as postfix operators, when there is an ambiguity.
Also clean up a couple of other infelicities in production priority
assignment --- for example, BETWEEN wasn't being given the intended
priority, but that of AND.
bothering to check the return value --- which meant that in case the
update or delete failed because of a concurrent update, you'd not find
out about it, except by observing later that the transaction produced
the wrong outcome. There are now subroutines simple_heap_update and
simple_heap_delete that should be used anyplace that you're not prepared
to do the full nine yards of coping with concurrent updates. In
practice, that seems to mean absolutely everywhere but the executor,
because *noplace* else was checking.
attributes in a FieldSelect node --- all the places that manipulate
these work just fine with system attribute numbers. OK, it's a new
feature, so shoot me ...
eliminates a raft of portability issues, including whether sys_nerr
exists, whether the platform has any valid negative errnos, etc. The
downside is minimal: errno shouldn't ever contain an invalid value anyway,
and if it does, reasonably modern versions of strerror will not choke.
This rangecheck idea seemed good at the time, but it's clearly a net loss,
and I apologize to all concerned for having ever put it in.
rewrite of deadlock checking. Lock holder objects are now reachable from
the associated LOCK as well as from the owning PROC. This makes it
practical to find all the processes holding a lock, as well as all those
waiting on the lock. Also, clean up some of the grottier aspects of the
SHMQueue API, and cause the waitProcs list to be stored in the intuitive
direction instead of the nonintuitive one. (Bet you didn't know that
the code followed the 'prev' link to get to the next waiting process,
instead of the 'next' link. It doesn't do that anymore.)
here is the patch attached which do check in each BLOB operation, if we are
in transaction, and raise an error otherwise. This will prevent such mistakes.
--
Sincerely Yours,
Denis Perchine
of c.h altogether, and putting it into the only places that use it
(elog.c and exc.c), instead. Modify these routines to check for a
NULL or empty-string return from strerror, too, since some platforms
define strerror to return empty string for unknown errors (what a useless
definition that is ...). Clean up some cruft in ExcPrint while at it.
mixed-signs. Previous effort left way too many minus signs, and was at
least as broken as the one before that :(
Clean up "ISO-style" time interval representation to omit zero fields if
there is at least one non-zero field. Supress some leading plus signs
when not necessary for clarity.
Replace every #ifdef __CYGWIN__ block with a cleaner TIMEZONE_GLOBAL macro
defined in datetime.h.
try to push restrictions on the view down into the view subquery,
so that they can become indexscan quals or what-have-you rather than
being applied at the top level of the subquery. 7.0 and before were
able to do this, though in a much klugier way, and I'd hate to have
anyone complaining that 7.1 is stupider than 7.0 ...
using POSIX semaphores more robust on Darwin 1.2/Mac OS X
Public Beta. this is for the version of 7.1 available
via anon cvs as of Jan 14 2001 14:00 PST.
since the semaphores and shared memory created by this
emulator are shared with the backends via fork(), their
persistent names are not necessary. removing their
names with shm_unlink() and sem_unlink() after creation
obviates the need for any "ipcclean" function. further,
without these changes, the shared memory (and, therefore,
the semaphores) will not be re-initialized/re-created after
the first execution of the postmaster, until reboot
or until some (non-existent) ipcclean function is executed.
this patch does the following:
1) if the shared memory segment "SysV_Sem_Info" already
existed, it is cleaned up. it shouldn't be there anyways.
2) the real indicator for whether the shared memory/semaphore
emulator has been initialized is if "SemInfo" has been
initialized. the shared memory and semaphores must be
initialized regardless of whether there was a garbage shared
memory segment lying around.
3) the shared memory segment "SysV_Sem_Info" is created with "O_EXCL"
to catch the case where two postmasters might be starting
simultaneously, so they don't both end up with the same shared
memory (one will fail). note that this can't be done with the
semaphores because Darwin 1.2 has a bug where attempting to
open an existing semaphore with "O_EXCL" set will ruin the
semaphore until the next reboot.
4) the shared memory segment "SysV_Sem_Info" is unlinked after
it is created. it will then exist without a name until the
postmaster and all backend children exit.
5) all semaphores are unlinked after they are created. they'll
then exist without names until the postmaster and all backend
children exit.
-michael thornburgh, zenomt@armory.com
Not sure why some were this way, and others were already correct, but it
seems to have been like this for several years.
This caused problems on a few damaged platforms like AIX and IRIX which do
not support DST calculations for years before 1970.
Thanks to Andreas Zeugswetter <ZeugswetterA@wien.spardat.at> for finding
the problem.
I hope. I finally realized that we were going at it backwards: when
there are excess parentheses, they need to be treated as part of the
sub-SELECT, not as part of the surrounding expression. Although either
choice yields an unambiguous grammar, only this way produces a grammar
that is LALR(1). With the old approach we were guaranteed to fail on
either 'SELECT (((SELECT 2)) + 3)' or
'SELECT (((SELECT 2)) UNION SELECT 2)' depending on which way we
resolve the initial shift/reduce conflict. With the new way, the same
reduction track can be followed in both cases until we have advanced
far enough to know whether we are done with the sub-SELECT or not.
given the fundamental restriction of not looking at transaction commit
data in pg_log. Use code that is actually based on tqual.c rather than
ad-hoc tests. Also write the tuple fetch loop using standard access
macros rather than ad-hoc code.
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().
