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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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33
src/backend/access/transam/transsup.c
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@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/Attic/transsup.c,v 1.17 1998/09/01 04:27:16 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/Attic/transsup.c,v 1.18 1998/12/15 12:45:33 vadim Exp $
*
* NOTES
* This file contains support functions for the high
@@ -289,18 +289,12 @@ TransBlockNumberGetXidStatus(Relation relation,
XidStatus xstatus; /* recorded status of xid */
bool localfail; /* bool used if failP = NULL */
/* ----------------
* SOMEDAY place a read lock on the log relation
* That someday is today 5 Aug 1991 -mer
* ----------------
*/
RelationSetLockForRead(relation);
/* ----------------
* get the page containing the transaction information
* ----------------
*/
buffer = ReadBuffer(relation, blockNumber);
LockBuffer(buffer, BUFFER_LOCK_SHARE);
block = BufferGetBlock(buffer);
/* ----------------
@@ -318,14 +312,9 @@ TransBlockNumberGetXidStatus(Relation relation,
* release the buffer and return the status
* ----------------
*/
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buffer);
/* ----------------
* SOMEDAY release our lock on the log relation
* ----------------
*/
RelationUnsetLockForRead(relation);
return
xstatus;
}
@@ -345,19 +334,12 @@ TransBlockNumberSetXidStatus(Relation relation,
Block block; /* block containing xstatus */
bool localfail; /* bool used if failP = NULL */
/* ----------------
* SOMEDAY gain exclusive access to the log relation
*
* That someday is today 5 Aug 1991 -mer
* ----------------
*/
RelationSetLockForWrite(relation);
/* ----------------
* get the block containing the transaction status
* ----------------
*/
buffer = ReadBuffer(relation, blockNumber);
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
block = BufferGetBlock(buffer);
/* ----------------
@@ -372,16 +354,11 @@ TransBlockNumberSetXidStatus(Relation relation,
TransBlockSetXidStatus(block, xid, xstatus);
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
if ((*failP) == false)
WriteBuffer(buffer);
else
ReleaseBuffer(buffer);
/* ----------------
* SOMEDAY release our lock on the log relation
* ----------------
*/
RelationUnsetLockForWrite(relation);
}
/* --------------------------------