diff options
Diffstat (limited to 'src/include/storage')
| -rw-r--r-- | src/include/storage/lmgr.h | 8 | ||||
| -rw-r--r-- | src/include/storage/lock.h | 112 |
2 files changed, 99 insertions, 21 deletions
diff --git a/src/include/storage/lmgr.h b/src/include/storage/lmgr.h index 8d63294f5c..4d1027c174 100644 --- a/src/include/storage/lmgr.h +++ b/src/include/storage/lmgr.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/lmgr.h,v 1.46 2005/04/28 21:47:18 tgl Exp $ + * $PostgreSQL: pgsql/src/include/storage/lmgr.h,v 1.47 2005/04/29 22:28:24 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -51,7 +51,11 @@ extern void UnlockRelation(Relation relation, LOCKMODE lockmode); extern void LockRelationForSession(LockRelId *relid, LOCKMODE lockmode); extern void UnlockRelationForSession(LockRelId *relid, LOCKMODE lockmode); -/* Lock a page (mainly used for indexes) */ +/* Lock a relation for extension */ +extern void LockRelationForExtension(Relation relation, LOCKMODE lockmode); +extern void UnlockRelationForExtension(Relation relation, LOCKMODE lockmode); + +/* Lock a page (currently only used within indexes) */ extern void LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode); extern bool ConditionalLockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode); extern void UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode); diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h index 7f67a3ac3a..b1744325ff 100644 --- a/src/include/storage/lock.h +++ b/src/include/storage/lock.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.84 2004/12/31 22:03:42 pgsql Exp $ + * $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.85 2005/04/29 22:28:24 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -58,7 +58,8 @@ typedef int LOCKMODE; /* * There is normally only one lock method, the default one. * If user locks are enabled, an additional lock method is present. - * Lock methods are identified by LOCKMETHODID. + * Lock methods are identified by LOCKMETHODID. (Despite the declaration as + * uint16, we are constrained to 256 lockmethods by the layout of LOCKTAG.) */ typedef uint16 LOCKMETHODID; @@ -103,27 +104,100 @@ typedef LockMethodData *LockMethod; /* * LOCKTAG is the key information needed to look up a LOCK item in the * lock hashtable. A LOCKTAG value uniquely identifies a lockable object. + * + * The LockTagType enum defines the different kinds of objects we can lock. + * We can handle up to 256 different LockTagTypes. */ -typedef struct LOCKTAG +typedef enum LockTagType { - Oid relId; - Oid dbId; - union - { - BlockNumber blkno; - TransactionId xid; - } objId; - + LOCKTAG_RELATION, /* whole relation */ + /* ID info for a relation is DB OID + REL OID; DB OID = 0 if shared */ + LOCKTAG_RELATION_EXTEND, /* the right to extend a relation */ + /* same ID info as RELATION */ + LOCKTAG_PAGE, /* one page of a relation */ + /* ID info for a page is RELATION info + BlockNumber */ + LOCKTAG_TUPLE, /* one physical tuple */ + /* ID info for a tuple is PAGE info + OffsetNumber */ + LOCKTAG_TRANSACTION, /* transaction (for waiting for xact done) */ + /* ID info for a transaction is its TransactionId */ + LOCKTAG_OBJECT, /* non-relation database object */ + /* ID info for an object is DB OID + CLASS OID + OBJECT OID + SUBID */ /* - * offnum should be part of objId union above, but doing that would - * increase sizeof(LOCKTAG) due to padding. Currently used by - * userlocks only. + * Note: object ID has same representation as in pg_depend and + * pg_description, but notice that we are constraining SUBID to 16 bits. + * Also, we use DB OID = 0 for shared objects such as tablespaces. */ - OffsetNumber offnum; + LOCKTAG_USERLOCK /* reserved for contrib/userlock */ + /* ID info for a userlock is defined by user_locks.c */ +} LockTagType; - LOCKMETHODID lockmethodid; /* needed by userlocks */ +/* + * The LOCKTAG struct is defined with malice aforethought to fit into 16 + * bytes with no padding. Note that this would need adjustment if we were + * to widen Oid, BlockNumber, or TransactionId to more than 32 bits. + * + * We include lockmethodid in the locktag so that a single hash table in + * shared memory can store locks of different lockmethods. For largely + * historical reasons, it's passed to the lock.c routines as a separate + * argument and then stored into the locktag. + */ +typedef struct LOCKTAG +{ + uint32 locktag_field1; /* a 32-bit ID field */ + uint32 locktag_field2; /* a 32-bit ID field */ + uint32 locktag_field3; /* a 32-bit ID field */ + uint16 locktag_field4; /* a 16-bit ID field */ + uint8 locktag_type; /* see enum LockTagType */ + uint8 locktag_lockmethodid; /* lockmethod indicator */ } LOCKTAG; +/* + * These macros define how we map logical IDs of lockable objects into + * the physical fields of LOCKTAG. Use these to set up LOCKTAG values, + * rather than accessing the fields directly. Note multiple eval of target! + */ +#define SET_LOCKTAG_RELATION(locktag,dboid,reloid) \ + ((locktag).locktag_field1 = (dboid), \ + (locktag).locktag_field2 = (reloid), \ + (locktag).locktag_field3 = 0, \ + (locktag).locktag_field4 = 0, \ + (locktag).locktag_type = LOCKTAG_RELATION) + +#define SET_LOCKTAG_RELATION_EXTEND(locktag,dboid,reloid) \ + ((locktag).locktag_field1 = (dboid), \ + (locktag).locktag_field2 = (reloid), \ + (locktag).locktag_field3 = 0, \ + (locktag).locktag_field4 = 0, \ + (locktag).locktag_type = LOCKTAG_RELATION_EXTEND) + +#define SET_LOCKTAG_PAGE(locktag,dboid,reloid,blocknum) \ + ((locktag).locktag_field1 = (dboid), \ + (locktag).locktag_field2 = (reloid), \ + (locktag).locktag_field3 = (blocknum), \ + (locktag).locktag_field4 = 0, \ + (locktag).locktag_type = LOCKTAG_PAGE) + +#define SET_LOCKTAG_TUPLE(locktag,dboid,reloid,blocknum,offnum) \ + ((locktag).locktag_field1 = (dboid), \ + (locktag).locktag_field2 = (reloid), \ + (locktag).locktag_field3 = (blocknum), \ + (locktag).locktag_field4 = (offnum), \ + (locktag).locktag_type = LOCKTAG_TUPLE) + +#define SET_LOCKTAG_TRANSACTION(locktag,xid) \ + ((locktag).locktag_field1 = (xid), \ + (locktag).locktag_field2 = 0, \ + (locktag).locktag_field3 = 0, \ + (locktag).locktag_field4 = 0, \ + (locktag).locktag_type = LOCKTAG_TRANSACTION) + +#define SET_LOCKTAG_OBJECT(locktag,dboid,classoid,objoid,objsubid) \ + ((locktag).locktag_field1 = (dboid), \ + (locktag).locktag_field2 = (classoid), \ + (locktag).locktag_field3 = (objoid), \ + (locktag).locktag_field4 = (objsubid), \ + (locktag).locktag_type = LOCKTAG_OBJECT) + /* * Per-locked-object lock information: @@ -157,7 +231,7 @@ typedef struct LOCK int nGranted; /* total of granted[] array */ } LOCK; -#define LOCK_LOCKMETHOD(lock) ((lock).tag.lockmethodid) +#define LOCK_LOCKMETHOD(lock) ((LOCKMETHODID) (lock).tag.locktag_lockmethodid) /* @@ -211,7 +285,7 @@ typedef struct PROCLOCK } PROCLOCK; #define PROCLOCK_LOCKMETHOD(proclock) \ - (((LOCK *) MAKE_PTR((proclock).tag.lock))->tag.lockmethodid) + LOCK_LOCKMETHOD(*((LOCK *) MAKE_PTR((proclock).tag.lock))) /* * Each backend also maintains a local hash table with information about each @@ -253,7 +327,7 @@ typedef struct LOCALLOCK LOCALLOCKOWNER *lockOwners; /* dynamically resizable array */ } LOCALLOCK; -#define LOCALLOCK_LOCKMETHOD(llock) ((llock).tag.lock.lockmethodid) +#define LOCALLOCK_LOCKMETHOD(llock) ((llock).tag.lock.locktag_lockmethodid) /* |