DIRECTORYVM USING [Allocate, Interval, AddressForPageNumber, PageCount, PagesForWords, PageNumberForAddress, Pin, WordsForPages],VMInternal USING [Crash],VMStatistics USING [];VMLowCoreImpl: MONITORIMPORTS VM, VMInternalEXPORTS VM, VMStatistics =BEGINZoneRep: TYPE = LONG POINTER TO ZoneObject;ZoneObject: TYPE = MACHINE DEPENDENT RECORD [procs(0:0..31): LONG POINTER TO ZoneProcs,data(2:0..31): ZoneData];ZoneProcs: TYPE = MACHINE DEPENDENT RECORD [allocate(0): PROC [UNCOUNTED ZONE, WordCount] RETURNS [LONG POINTER],free(1): PROC [UNCOUNTED ZONE, LONG POINTER]];ZoneData: TYPE = ZoneChunk;ZoneChunk: TYPE = LONG POINTER TO ZoneChunkObject;ZoneChunkObject: TYPE = RECORD [seal: INT _ chunkSeal,nextChunk:  ZoneChunk,  -- could be a 16-bit relative pointer, but why bother?wordsInChunk: INT,wordsInUse: INT];WordCount: TYPE = CARDINAL;lowCoreZone: ZoneObject _ [procs: @lowCoreZoneProcs, data: NIL];lowCoreZoneProcs: ZoneProcs _ [allocate: Allocate, free: Free];chunkSeal: INT = 32415;alignment: WordCount = 16;chunkOverhead: WordCount = Align[SIZE[ZoneChunkObject]]; lowCoreAllocations, lowCoreWords, lowCorePages: PUBLIC INT _ 0;lowCore: PUBLIC UNCOUNTED ZONE;Align: PROC [w: WordCount] RETURNS [WordCount] = INLINE {RETURN[((w + alignment - 1) / alignment) * alignment]};Allocate: ENTRY PROC [z: UNCOUNTED ZONE, nWords: WordCount]RETURNS [p: LONG POINTER] = {previousChunk: ZoneChunk _ NIL;chunk: ZoneChunk;IF z ~= lowCore THEN VMInternal.Crash[];nWords _ Align[MAX[nWords, 1]];FOR chunk _ lowCoreZone.data, chunk.nextChunk UNTIL chunk = NIL DOIF chunk.seal ~= chunkSeal THEN VMInternal.Crash[];IF chunk.wordsInUse + nWords <= chunk.wordsInChunkAND ( -- verify block would lie in a single pageVM.PageNumberForAddress[chunk + chunk.wordsInUse] =VM.PageNumberForAddress[chunk + chunk.wordsInUse + nWords - 1]OR VM.PagesForWords[nWords+chunkOverhead] > 1)THEN EXIT;previousChunk _ chunk;REPEATFINISHED => {pages: VM.PageCount = VM.PagesForWords[nWords];interval: VM.Interval = VM.Allocate[count: pages, partition: $lowCore];--*stats*-- lowCorePages _ lowCorePages + pages;VM.Pin[interval];chunk _ VM.AddressForPageNumber[interval.page];chunk^ _ [nextChunk: IF previousChunk = NIL THEN NIL ELSE previousChunk.nextChunk,wordsInChunk: VM.WordsForPages[interval.count],wordsInUse: chunkOverhead];IF previousChunk = NIL THEN lowCoreZone.data _ chunkELSE previousChunk.nextChunk _ chunk;};ENDLOOP;p _ chunk + chunk.wordsInUse;chunk.wordsInUse _ chunk.wordsInUse + nWords;--*stats*-- lowCoreAllocations _ lowCoreAllocations.SUCC;--*stats*-- lowCoreWords _ lowCoreWords + nWords;};Free: ENTRY PROC [z: UNCOUNTED ZONE, p: LONG POINTER] = {};lowCore _ LOOPHOLE[LONG[@lowCoreZone]];END.    ╕  VMLowCoreImpl.mesalast edited by Levin on November 9, 1983 1:07 pmGlobal "Variables"Exports to VMStatisticsExports to VMSideDoorInternal ProceduresInitializationЭ╩C  Ц"Cedar" styleШ JЪЬЩJЪЬ0Щ0JШ Ъ╧k	Ш	ЪЭЬЭЬШ
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