21 Commits (4cd72b53b9975bab5f4ca0792cf4f54c84829404)

Author	SHA1	Message	Date
Tom Lane	a0ffab351e	Magic blocks don't do us any good unless we use 'em ... so install one ... in every shared library.	19 years ago
Tom Lane	c599a247bb	Simplify lock manager data structures by making a clear separation between ... the data defining the semantics of a lock method (ie, conflict resolution table and ancillary data, which is all constant) and the hash tables storing the current state. The only thing we give up by this is the ability to use separate hashtables for different lock methods, but there is no need for that anyway. Put some extra fields into the LockMethod definition structs to clean up some other uglinesses, like hard-wired tests for DEFAULT_LOCKMETHOD and USER_LOCKMETHOD. This commit doesn't do anything about the performance issues we were discussing, but it clears away some of the underbrush that's in the way of fixing that.	20 years ago
Tom Lane	8563ccae2c	Simplify shared-memory lock data structures as per recent discussion: ... it is sufficient to track whether a backend holds a lock or not, and store information about transaction vs. session locks only in the inside-the-backend LocalLockTable. Since there can now be but one PROCLOCK per lock per backend, LockCountMyLocks() is no longer needed, thus eliminating some O(N^2) behavior when a backend holds many locks. Also simplify the LockAcquire/LockRelease API by passing just a 'sessionLock' boolean instead of a transaction ID. The previous API was designed with the idea that per-transaction lock holding would be important for subtransactions, but now that we have subtransactions we know that this is unwanted. While at it, add an 'isTempObject' parameter to LockAcquire to indicate whether the lock is being taken on a temp table. This is not used just yet, but will be needed shortly for two-phase commit.	20 years ago
Tom Lane	140b078d2a	Improve LockAcquire API per my recent proposal. All error conditions ... are now reported via elog, eliminating the need to test the result code at most call sites. Make it possible for the caller to distinguish a freshly acquired lock from one already held in the current transaction. Use that capability to avoid redundant AcceptInvalidationMessages() calls in LockRelation().	20 years ago
Tom Lane	191b13aaca	Factor out lock cleanup code that is needed in several places in lock.c. ... Also, remove the rather useless return value of LockReleaseAll. Change response to detection of corruption in the shared lock tables to PANIC, since that is the only way of cleaning up fully. Originally an idea of Heikki Linnakangas, variously hacked on by Alvaro Herrera and Tom Lane.	20 years ago
Tom Lane	a9c4c9cd52	Extend the pg_locks system view so that it can fully display all lock ... types, as per recent discussion.	20 years ago
Tom Lane	3a694bb0a1	Restructure LOCKTAG as per discussions of a couple months ago. ... Essentially, we shoehorn in a lockable-object-type field by taking a byte away from the lockmethodid, which can surely fit in one byte instead of two. This allows less artificial definitions of all the other fields of LOCKTAG; we can get rid of the special pg_xactlock pseudo-relation, and also support locks on individual tuples and general database objects (including shared objects). None of those possibilities are actually exploited just yet, however. I removed pg_xactlock from pg_class, but did not force initdb for that change. At this point, relkind 's' (SPECIAL) is unused and could be removed entirely.	20 years ago
Tom Lane	1785acebf2	Introduce local hash table for lock state, as per recent proposal. ... PROCLOCK structs in shared memory now have only a bitmask for held locks, rather than counts (making them 40 bytes smaller, which is a good thing). Multiple locks within a transaction are counted in the local hash table instead, and we have provision for tracking which ResourceOwner each count belongs to. Solves recently reported problem with memory leakage within long transactions.	21 years ago
Tom Lane	fe548629c5	Invent ResourceOwner mechanism as per my recent proposal, and use it to ... keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.	21 years ago
Tom Lane	573a71a5da	Nested transactions. There is still much left to do, especially on the ... performance front, but with feature freeze upon us I think it's time to drive a stake in the ground and say that this will be in 7.5. Alvaro Herrera, with some help from Tom Lane.	21 years ago
Tom Lane	863aceb54f	Get rid of PID entries in shmem hash table; there is no longer any need ... for them, and making them just wastes time during backend startup/shutdown. Also, remove compile-time MAXBACKENDS limit per long-ago proposal. You can now set MaxBackends as high as your kernel can stand without any reconfiguration/recompilation.	24 years ago
Tom Lane	d8d9ed931e	Add support to lock manager for conditionally locking a lock (ie, ... return without waiting if we can't get the lock immediately). Not used yet, but will be needed for concurrent VACUUM.	24 years ago
Tom Lane	6cc842abd3	Revise lock manager to support "session level" locks as well as "transaction ... 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.	25 years ago
Bruce Momjian	52f77df613	Ye-old pgindent run. Same 4-space tabs.	26 years ago
Bruce Momjian	5a017b96ad	Apply contrib patch from Massimo	26 years ago
Bruce Momjian	27b8143944	Hi, ... I have updated my contrib code for version 6.5. In the attachment you will find the directories array, datetime, miscutil, string, tools and userlocks which replace the corresponding directories under contrib. In contrib/tools you will find some developement scripts which I use while hacking the sources. I hope they will be useful for some other people. I have also added a contrib/Makefile which tries to compile and install all the contribs. Unfortunately many of them don't have a Makefile or don't compile cleanly. -- Massimo Dal Zotto	26 years ago
Vadim B. Mikheev	bbf37e9477	typedef struct LTAG ... { Oid relId; Oid dbId; union { BlockNumber blkno; TransactionId xid; } objId; > > Added: > /* > * offnum should be part of objId.tupleId above, but would increase > * sizeof(LOCKTAG) and so moved here; currently used by userlocks only. > */ > OffsetNumber offnum; uint16 lockmethod; /* needed by userlocks */ } LOCKTAG; gmake clean required... User locks are ready for 6.5 release...	26 years ago
Bruce Momjian	07842084fe	pgindent run over code.	26 years ago
Marc G. Fournier	eec4c7366f	From: Massimo Dal Zotto <dz@cs.unitn.it> ...	27 years ago
Bruce Momjian	a32450a585	pgindent run before 6.3 release, with Thomas' requested changes.	28 years ago
Bruce Momjian	951986c550	Update of contrib stuff from massimo.	28 years ago