FilePageMgrPrivateChunk.mesa
Copyright © 1985 by Xerox Corporation. All rights reserved.
Last edited by:
Kolling on January 31, 1984 2:13:05 pm PST
Hauser, March 26, 1985 6:41:17 pm PST
DIRECTORY
AlpineEnvironment
USING[PageNumber, wordsPerPage],
VM
USING[PageCount, PageNumber, wordsPerPage];
FilePageMgrPrivateChunk: CEDAR DEFINITIONS =
BEGIN
RefChunk: TYPE = REF Chunk;
Chunk:
TYPE =
RECORD[
chunkType: ChunkType,
defWritePending: BOOLEAN,
state: ChunkState,
useCount: NAT,
fileHandle: FileMap.Handle,
startFilePageNumber: AlpineEnvironment.PageNumber,
startVMPageNumber: VM.PageNumber,
nVMPages: NAT,
leaderVMHandle: CountedVM.Handle,
prev: RefChunk,
next: RefChunk
These should not be necessary.
rbColor: BOOL,
rbLLink, rbRLink: RefChunk
];
ChunkType:
TYPE = {normal, log, leader, treeHeader, lruHeader, ostGeneral};
ClientChunkType: TYPE = FilePageMgrPrivateChunk.ChunkType[normal..leader];
ListChunkType: TYPE = FilePageMgrPrivateChunk.ChunkType[normal..leader];
ChunkState: TYPE = {undefined, valid, readInProgress, writeInProgress};
ChunkVMPageCount:
ARRAY ListChunkType
OF
VM.PageCount =
[normal: 4, log: 4, leader: 0];
ChunkFilePageCount:
ARRAY ListChunkType
OF
VM.PageCount =
[normal: 4, log: 4, leader: 0]; -- note all of leader fits exactly in one chunk, of size to be determined later.
because not every place is right yet.
CompileTimeCheck1: [
VM.wordsPerPage..
VM.wordsPerPage] =
AlpineEnvironment.wordsPerPage;
because File promised an integral number of vm pages and page aligned(latter checked elsewhere).
For information about the significance of the Chunk fields, see FilePageMgrPrivateFileObject.
ChunkAllocator:
PROCEDURE [chunkType: ChunkType, permanent:
BOOLEAN]
RETURNS
[refChunk: RefChunk];
non system-fatal errors: running out of vm is system fatal.
ChunkIsDirty:
PROCEDURE[refChunk: RefChunk]
RETURNS [dirty:
BOOLEAN];
non system-fatal errors: none.
Sweeper:
PROCEDURE[chunkType: FilePageMgrPrivateChunk.ChunkType];
non system-fatal errors: none.
misc.:
InternalFilePageMgrLogicError: ERROR;
END.
Initial: Kolling: 22-Feb-82 16:18:32: a private defs file for the File Page Manager which sits between the rest of Alpine and Pilot.
Hauser, March 8, 1985 10:30:04 am PST
Nodified, added copyright.