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Initial MVCC code.

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New code for locking buffer' context.
This commit is contained in:
Vadim B. Mikheev
1998-12-15 12:47:01 +00:00
parent c5a27161a1
commit 3f7fbf85dc
65 changed files with 1391 additions and 1282 deletions
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42
src/backend/commands/sequence.c
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@ -162,7 +162,7 @@ DefineSequence(CreateSeqStmt *seq)
rel = heap_openr(seq->seqname);
Assert(RelationIsValid(rel));
RelationSetLockForWrite(rel);
LockRelation(rel, AccessExclusiveLock);
tupDesc = RelationGetDescr(rel);
@ -185,7 +185,7 @@ DefineSequence(CreateSeqStmt *seq)
if (WriteBuffer(buf) == STATUS_ERROR)
elog(ERROR, "DefineSequence: WriteBuffer failed");
RelationUnsetLockForWrite(rel);
UnlockRelation(rel, AccessExclusiveLock);
heap_close(rel);
return;
@ -200,7 +200,6 @@ nextval(struct varlena * seqin)
SeqTable elm;
Buffer buf;
Form_pg_sequence seq;
ItemPointerData iptr;
int4 incby,
maxv,
minv,
@ -209,7 +208,7 @@ nextval(struct varlena * seqin)
next,
rescnt = 0;
/* open and WIntentLock sequence */
/* open and AccessShareLock sequence */
elm = init_sequence("nextval", seqname);
pfree(seqname);
@ -219,7 +218,7 @@ nextval(struct varlena * seqin)
return elm->last;
}
seq = read_info("nextval", elm, &buf); /* lock page and read
seq = read_info("nextval", elm, &buf); /* lock page' buffer and read
* tuple */
next = result = seq->last_value;
@ -282,12 +281,11 @@ nextval(struct varlena * seqin)
seq->last_value = next; /* last fetched number */
seq->is_called = 't';
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
if (WriteBuffer(buf) == STATUS_ERROR)
elog(ERROR, "%s.nextval: WriteBuffer failed", elm->name);
ItemPointerSet(&iptr, 0, FirstOffsetNumber);
RelationUnsetSingleWLockPage(elm->rel, &iptr);
return result;
}
@ -300,7 +298,7 @@ currval(struct varlena * seqin)
SeqTable elm;
int4 result;
/* open and WIntentLock sequence */
/* open and AccessShareLock sequence */
elm = init_sequence("currval", seqname);
pfree(seqname);
@ -320,7 +318,6 @@ setval(struct varlena * seqin, int4 next)
SeqTable elm;
Buffer buf;
Form_pg_sequence seq;
ItemPointerData iptr;
#ifndef NO_SECURITY
if (pg_aclcheck(seqname, getpgusername(), ACL_WR) != ACLCHECK_OK)
@ -328,9 +325,9 @@ setval(struct varlena * seqin, int4 next)
seqname, seqname);
#endif
/* open and WIntentLock sequence */
/* open and AccessShareLock sequence */
elm = init_sequence("setval", seqname);
seq = read_info("setval", elm, &buf); /* lock page and read
seq = read_info("setval", elm, &buf); /* lock page' buffer and read
* tuple */
if (seq->cache_value != 1)
@ -353,27 +350,22 @@ setval(struct varlena * seqin, int4 next)
seq->last_value = next; /* last fetched number */
seq->is_called = 't';
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
if (WriteBuffer(buf) == STATUS_ERROR)
elog(ERROR, "%s.settval: WriteBuffer failed", seqname);
ItemPointerSet(&iptr, 0, FirstOffsetNumber);
RelationUnsetSingleWLockPage(elm->rel, &iptr);
return next;
}
static Form_pg_sequence
read_info(char *caller, SeqTable elm, Buffer *buf)
{
ItemPointerData iptr;
PageHeader page;
ItemId lp;
PageHeader page;
ItemId lp;
HeapTupleData tuple;
sequence_magic *sm;
Form_pg_sequence seq;
ItemPointerSet(&iptr, 0, FirstOffsetNumber);
RelationSetSingleWLockPage(elm->rel, &iptr);
Form_pg_sequence seq;
if (RelationGetNumberOfBlocks(elm->rel) != 1)
elog(ERROR, "%s.%s: invalid number of blocks in sequence",
@ -383,6 +375,8 @@ read_info(char *caller, SeqTable elm, Buffer *buf)
if (!BufferIsValid(*buf))
elog(ERROR, "%s.%s: ReadBuffer failed", elm->name, caller);
LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
page = (PageHeader) BufferGetPage(*buf);
sm = (sequence_magic *) PageGetSpecialPointer(page);
@ -439,7 +433,7 @@ init_sequence(char *caller, char *name)
if (!RelationIsValid(temp->rel))
elog(ERROR, "%s.%s: sequence does not exist", name, caller);
RelationSetWIntentLock(temp->rel);
LockRelation(temp->rel, AccessShareLock);
if (temp->rel->rd_rel->relkind != RELKIND_SEQUENCE)
elog(ERROR, "%s.%s: %s is not sequence !", name, caller, name);
@ -485,7 +479,7 @@ CloseSequences(void)
{
rel = elm->rel;
elm->rel = (Relation) NULL;
RelationUnsetWIntentLock(rel);
UnlockRelation(rel, AccessShareLock);
heap_close(rel);
}
elm = elm->next;