YggFilePageMgrLru.mesa
Copyright © 1985, 1988 by Xerox Corporation. All rights reserved.
Last edited by:
Kolling on January 24, 1984 12:58:35 pm PST
Hauser, March 7, 1985 5:18:42 pm PST
Bob Hagmann March 23, 1988 11:17:20 am PST
DIRECTORY
YggEnvironment
USING[PageNumber],
YggFileMap
USING[Handle],
YggFilePageMgrPrivateChunk
USING[Chunk, ChunkType, ListChunkType, RefChunk],
YggFilePageMgrPrivateFile
USING[FPMFileHandle];
YggFilePageMgrLru: CEDAR DEFINITIONS =
BEGIN
See YggFilePageMgrPrivateFile for implementation details. Things of especial note are: Mapping and unmapping do not go on while a chunk is on an lru list; therefore, the lru procedures can read Chunk.fileHandle and Chunk.startFilePageNumber. The FPMFileObject monitor must not be entered by a process holding the FilePageMgrLruImpl monitor.
PutMappedChunkOnLruList:
PROCEDURE[refChunk: YggFilePageMgrPrivateChunk.RefChunk,
lruListPlace: LruListPlace];
non system-fatal errors: none.
LruListPlace: TYPE = {mru, lru};
PutUnmappedChunkOnLruList:
PROCEDURE[refChunk: YggFilePageMgrPrivateChunk.RefChunk];
non system-fatal errors: none.
GetOurChunkFromLruList:
PROCEDURE [refChunk: YggFilePageMgrPrivateChunk.RefChunk,
tellSweeperToHurry: BOOLEAN];
non system-fatal errors: none.
GetOtherChunkFromLruList:
PROCEDURE [chunkType:
YggFilePageMgrPrivateChunk.ListChunkType] RETURNS[mapped: BOOLEAN, refChunk:
YggFilePageMgrPrivateChunk.RefChunk, fileHandle: YggFileMap.Handle, startFilePageNumber:
YggEnvironment.PageNumber];
non system-fatal errors: none.
if unmapped, we really got it; if mapped, just returns a hint but has also moved the chunk to the mru end of the list.
RelinkChunkAsLruOnLruList:
PROCEDURE[refChunk: YggFilePageMgrPrivateChunk.RefChunk];
non system-fatal errors: none.
UsingTooMuchOfCache:
PROCEDURE[fPMFileHandle: YggFilePageMgrPrivateFile.FPMFileHandle]
RETURNS [yes: BOOLEAN];
non system-fatal errors: none.
only called for normal type chunks.
WaitToSweep:
PROCEDURE [oldNeedToHurry:
BOOLEAN, currentEpoch:
NAT, chunkType: YggFilePageMgrPrivateChunk.ListChunkType]
RETURNS[needToHurry:
BOOLEAN,
sweepList: LIST OF SweepItem];
non system-fatal errors: none.
SweepItem:
TYPE =
RECORD[fileHandle: YggFileMap.Handle, startFilePageNumber: YggEnvironment.PageNumber];
InitializeLruLists:
PROCEDURE[nChunks:
ARRAY YggFilePageMgrPrivateChunk.ListChunkType
OF
NAT];
non system-fatal errors: none.
CheckCacheInCleanState:
PROCEDURE
RETURNS [clean:
BOOLEAN];
non system-fatal errors: none.
END.
Initial: Kolling: 23-Feb-82 17:21:13: private defs file for the lru lists manager part of File Page Manager.
Nodified: Hauser: February 20, 1985 3:10:03 pm PST
Hauser, March 7, 1985 3:07:51 pm PST
Added copyright