DIRECTORYAlpineEnvironment,AlpineImport USING [Handle],AlpineInternal USING [LogRecordID, nullLogRecordID],BasicTime USING [GMT],RPC USING [maxShortStringLength, Principal];Coordinator: DEFINITIONS LOCKS c USING c: Handle =BEGINObject: TYPE = MONITORED RECORD [transID: AlpineEnvironment.TransID _ TRASH, --immutable--beginRecord: AlpineInternal.LogRecordID _ AlpineInternal.nullLogRecordID, --immutable--state: State _ active,outcome: Outcome _ unknown,finishInProgress: BOOL _ FALSE,aWorkerBecameReady: BOOL _ FALSE,workers: WorkerHandle _ NIL,resultsReturned: CONDITION,forceRecord: AlpineInternal.LogRecordID _ AlpineInternal.nullLogRecordID,userRName: RPC.Principal,next: Handle _ nullHandle];Handle: TYPE = REF Object;nullHandle: Handle = NIL;State: TYPE = {active, collecting, completing, complete};Outcome: TYPE = AlpineEnvironment.Outcome --{abort, commit, unknown}--;WorkerObject: TYPE = RECORD [worker: AlpineImport.Handle, --immutable--state: WorkerState _ active, --increases monotonically from active to complete--communicationTrouble: BOOL _ FALSE,callInProgress: Call _ none, --communication in progress with worker--resultsOfMostRecentCall: Results _ [none, none[]],timeForNextCall: BasicTime.GMT _ TRASH,lastPrepareResult: Results _ [none, none[]],lastFinishResult: Results _ [none, none[]]];WorkerHandle: TYPE = LIST OF WorkerObject;WorkerState: TYPE = { active, ready, complete };Call: TYPE = { none, prepare, finish };Results: TYPE = RECORD [communicationError: CommunicationError,body: SELECT call: Call FROMnone => [],prepare => [prepareResult: AlpineEnvironment.WorkerState],finish => []ENDCASE];CommunicationError: TYPE = { none, bindingFailed, callFailed, busy };RegisterWorkerLogRep: TYPE = MACHINE DEPENDENT RECORD [worker: StrBody];CompletingLogRep: TYPE = MACHINE DEPENDENT RECORD [outcome: AlpineEnvironment.CommitOrAbort];StrBody: TYPE = MACHINE DEPENDENT RECORD [length: CARDINAL _ 0, maxLength: CARDINAL _ RPC.maxShortStringLength,text: PACKED ARRAY[0..RPC.maxShortStringLength) OF CHAR];END.CHANGE LOG.  Ò  Coordinator.mesaCopyright c 1985 by Xerox Corporation.  All rights reserved.Defines the volatile state of a coordinator.Last edited byMBrown on January 30, 1984 11:51:40 am PSTKupfer, June 29, 1984 2:56:51 pm PDTHauser, March 7, 1985 2:34:42 pm PSTCarl Hauser, November 20, 1985 10:49:37 am PSTincreases monotonically from active to completeChanges to abort or commit during state transition collecting -> completing.A process that sets this TRUE is responsible for finishing the transaction.TRUE iff some worker returns "ready" from WorkerPrepare call.Elements added only when state = active.Finish process waits here for remote calls to return, or for timeoutin order to delay sending new calls.ID of log record following last-written coordinator log recorduser owning the transactionCoordinatorMap data structuremeaningful only if communicationTroublebindingFailed means that no call was madecallFailed means that call may or may not have been madebusy is equivalent to callFailed, but retrying is more likely to succeed.Format of persistent coordinator state.Note that coordinatorBegin and coordinatorComplete log records contain no informationother than the transaction ID, so we don't define structures for them here.Edited on June 29, 1984 10:31:34 am PDT, by Kupferchanges to: Coordinator: add an "extras" field to the Coordinator Object.  This lets up keep things like user RName (and easily change what we keep), though at some point the extras should get merged back into the Object definition proper.Hauser, March 7, 1985 2:34:00 pm PSTAdded copyright.Carl Hauser, August 17, 1985 1:31:25 pm PDTchanges to: Coordinator: added userRName to Coordinator.Object.  No more need for CoordinatorExtras. Ês  ˜ šœ™Icodešœ
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