YggInternal.mesa
Copyright Ó 1987, 1988 by Xerox Corporation. All rights reserved.
Last edited by:
MBrown on January 31, 1984 11:44:24 am PST
Kolling on October 28, 1983 2:13 pm
Taft on April 10, 1983 5:11 pm
Hauser, March 7, 1985 2:18:51 pm PST
Carl Hauser, July 12, 1985 9:59:34 am PDT
Bob Hagmann March 23, 1988 9:02:33 am PST
YggInternal: DEFINITIONS = BEGIN
File
FileHandle: TYPE = REF FileObject; -- base type of FileMap.Handle
FileObject: TYPE;
FileInstanceHandle: TYPE = REF FileInstanceObject; -- base type of FileInstance.Handle
FileInstanceObject: TYPE;
OpenFileHandle: TYPE = REF OpenFileObject; -- base type of OpenFileMap.Handle
OpenFileObject: TYPE;
The LeaderPageHandle is defined here because it is referenced by the LogMap interface but is actually defined in LeaderPageImpl.
LeaderPageHandle: TYPE = REF LeaderPageObject;
LeaderPageObject: TYPE;
FilePageMgr
FPMFileHandle: TYPE = REF FPMFileObject; -- base type of FilePageMgr.FPMFileHandle
FPMFileObject: TYPE;
Lock
LockID: TYPE = RECORD [entity: UniversalID, subEntity: ID2, subSubEntity: LockSubID];
UniversalID: TYPE [12]; -- can be compressed someday by implementing a separate map
ID2: TYPE [4]; -- large enough to hold file ID within volume
LockSubID: TYPE [8]; -- large enough to hold [tag, page number within file]
nullLockIDRep: ARRAY [0..SIZE[LockID]/SIZE[UNIT]) OF WORD = [0,0,0,0,0,0];
nullLockID: LockID = LOOPHOLE[nullLockIDRep];
LockTransHeaderHandle: TYPE = REF LockTransHeaderObject;
LockTransHeaderObject: TYPE;
Log
LogRecordID: TYPE = ConstArith.Const;
nullLogRecordID, firstRecordID: LogRecordID = [zero, 0, 0];
lastRecordID: LogRecordID = [positive,
LAST[
CARD],
LAST[
CARD]];
LogRecordType:
TYPE =
MACHINE
DEPENDENT {
Include lots of spares so that new LogRecordTypes can be introduced without invalidating existing log files. If you change these, keep the corresponding subranges (below) up-to-date.
--ControlRecord-- noop (0), checkpointBegin, checkpointComplete, coordinatorBegin (10), coordinatorRegisterWorker, coordinatorCollecting, coordinatorCompleting, coordinatorComplete, workerBegin (30), workerReady, workerCompleting, workerComplete,
--FileRecord-- writePages (100), writeLeaderPage, setSize, create, delete, lock,
--Reserved-- reserved (200), (LAST[INTEGER]) }; -- s/b LAST[CARDINAL] but for compiler bug
ControlRecord: TYPE = LogRecordType [noop..writePages);
FileRecord: TYPE = LogRecordType [writePages..reserved);
LogRecordPhaseType:
TYPE = {
Identifies during which phase of recovery the record is needed.
analysis, -- only needed in analysis phase (e.g., transaction commit)
redo, -- only needed in redo phase (e.g., writePages)
undo, -- only needed in undo phase
redoUndo, -- needed in both redo and undo phases
other -- other records (e. g., checkpointBegin)
};
Transaction
TransHandle: TYPE = REF TransObject; -- Base type of TransactionMap.Handle
TransObject: TYPE;
WorkerOutcome: TYPE = {abort, readOnly, commit};
Difficulty: TYPE = {zero, normal, hard};
WorkLevel: TYPE = Difficulty [normal .. hard];
TransState: TYPE = {committed, aborted, ready};
CoordinatorHandle: TYPE = REF CoordinatorObject;
CoordinatorObject: TYPE;
END.