
DIRECTORY
DFOperations USING [BringOver, SModel, Verify],
DFOperationsQueue USING [NotifierProc, OpTerminationInteraction, Request, RequestRecord],
List USING [PutAssoc],
Process USING [Detach, Priority, priorityBackground, SetPriority],
ProcessProps USING [PushPropList];

OpsQueueImpl: CEDAR MONITOR LOCKS queue.LOCK USING queue: Queue
IMPORTS DFOperations, List, Process, ProcessProps
EXPORTS DFOperationsQueue
= BEGIN


Queue: TYPE = REF QueueObject;

QueueObject: PUBLIC TYPE = MONITORED RECORD [
pending: LIST OF DFOperationsQueue.Request м NIL,
pendingTail: LIST OF DFOperationsQueue.Request м NIL,
priority: Process.Priority,
abortPending: BOOL м FALSE,
idleNotifier: DFOperationsQueue.NotifierProc,
clientData: REF ANY
];

Create: PUBLIC PROC [priority: Process.Priority м Process.priorityBackground, idleNotifier: DFOperationsQueue.NotifierProc м NIL, clientData: REF ANY м NIL] RETURNS [Queue] = {
RETURN[NEW[QueueObject м [
priority: priority,
idleNotifier: idleNotifier,
clientData: clientData
]]];
};

Empty: PUBLIC ENTRY PROC [queue: Queue] RETURNS [BOOL] = {
RETURN[queue.pending = NIL]
};
Abort: PUBLIC ENTRY PROC [queue: Queue] = {
IF queue.pending ~= NIL THEN {
queue.abortPending м TRUE;
};
};

Enqueue: PUBLIC ENTRY PROC [queue: Queue, request: DFOperationsQueue.Request] = {
rL: LIST OF DFOperationsQueue.Request = CONS[request, NIL];
IF queue.pending ~= NIL THEN {
queue.pendingTail.rest м rL;
queue.pendingTail м rL;
}
ELSE {
queue.pending м queue.pendingTail м rL;
TRUSTED{Process.Detach[FORK Worker[queue]]};
};
};


Worker: PROC [queue: Queue] = {
remaining: LIST OF DFOperationsQueue.Request;
Process.SetPriority[queue.priority];
DO
request: DFOperationsQueue.Request = queue.pending.first;
WorkerInner: PROC = {
errors, warnings, filesActedUpon: INT м 0;
ReportTermination: PROC  = {
[] м request.interact[
NEW[DFOperationsQueue.OpTerminationInteraction м [
op: request.op,
dfFile: request.dfFile,
filesActedUpon: filesActedUpon,
errors: errors,
warnings: warnings
]],
request.clientData
];
};
WITH requestн SELECT FROM
req: bringOver DFOperationsQueue.RequestRecord => {
[errors: errors, warnings: warnings, filesActedUpon: filesActedUpon] м DFOperations.BringOver[
dfFile: req.dfFile,
filter: req.filter, action: req.action,
interact: req.interact,
clientData: req.clientData,
log: req.log
];
ReportTermination[];
};
req: sModel DFOperationsQueue.RequestRecord => {
[errors: errors, warnings: warnings, filesActedUpon: filesActedUpon] м DFOperations.SModel[
dfFile: req.dfFile,
action: req.action,
interact: req.interact,
clientData: req.clientData,
log: req.log
];
ReportTermination[];
};
req: verify DFOperationsQueue.RequestRecord => {
[errors: errors, warnings: warnings, filesActedUpon: filesActedUpon] м DFOperations.Verify[
dfFile: req.dfFile,
interact: req.interact,
clientData: req.clientData,
log: req.log
];
ReportTermination[];
};
ENDCASE => ERROR;
};
ProcessProps.PushPropList[
List.PutAssoc[key: $WorkingDirectory, val: request.wDir, aList: NIL], WorkerInner];
IF ([remaining: remaining] м Done[queue]).done THEN EXIT;
ENDLOOP;
queue.idleNotifier[queue, remaining, queue.clientData];
};

Done: ENTRY PROC [queue: Queue] RETURNS [done: BOOL, remaining: LIST OF DFOperationsQueue.Request м NIL] = {
IF queue.abortPending THEN {
remaining м queue.pending;
queue.pending м NIL;
queue.abortPending м FALSE;
}
ELSE queue.pending м queue.pending.rest;
done м queue.pending = NIL;
};

END.


  |  
OpsQueueImpl.mesa
Copyright ╙ 1985, 1986, 1991 by Xerox Corporation.  All rights reserved.
created by Levin
Russ Atkinson (RRA) January 19, 1987 1:38:34 pm PST
Exports to DFOperationsQueue

We don't try to abort the executing operation, since, in practice, our client will worry about that.
Invariant (while outside the monitor):  queue.pending = NIL iff no worker process exists
Internal Procedures
Assert: queue.pending ~= NIL.
To preserve the monitor invariant (see Enqueue), the request is left on the queue while it is being executed.
Invariant (while outside the monitor):  queue.pending = NIL iff no worker process exists
Э╩  Ц(cedarcode) styleХNewlineDelimiter
Щ codeЪЬЩKЪЬ
╧eЬ=ЩHKЪЬЩKЩ3ЧШ Ъ╧k	Ш	KЪЬЮЬШ/KЪЬЮЬBШYKЪЬЮЬШKЪЬЮЬ5ШBKЪЬЮЬШ"ЧЧKШ Ъ╧nЬЮЬЮЬЮЬЮЬЮЬШ?KЪЮЬ*Ш1KЪЮЬШKЪЬЮШЧKШ KЪЬЩKШ KЪЬЮЬЮЬШKШ Ъ	ЬЮЬЮЬЮ	ЬЮЬШ-KЪЬ	ЮЬЮЬЮЬШ1KЪЬЮЬЮЬЮЬШ5KЪЬШKЪЬЮЬЮЬШKЪЬ-Ш-KЪЬЮЬЮШKЪЬШЧKШ ЪЯЬЮЬЮЬjЮЬЮЬЮЬЮЬЮЬШ░ЪЮЬЮЬШKЪЬШKЪЬШKЪЬШKЪЬШЧKЪЬШЧKШ ЪЯЬЮЬЮЬЮЬЮЬЮЬШ:KЪЮЬЮЬШKШKЩ ЧЪЯЬЮЬЮЬЮЬШ+ЪЮЬЮЬЮЬШKЪЬЮЬШKЪЬdЩdKШЧKШЧKШ ЪЯЬЮЬЮЬЮЬ7ШQKЪЬXЩXKЪ	ЬЮЬЮЬЮЬ
ЮЬШ;ЪЮЬЮЬЮЬШKЪЬШKЪЬШKШЧЪЮЬШKЪЬ'Ш'KЪЮЬЮЬШ,KШЧKШЧKШ KЩKШ ЪЯЬЮЬШKЪЬЮЬЮЬШ-KЪЬ$Ш$KЪЬЩЪЮШKЪЬ9Ш9ЪЯЬЮЬШKЪЬ"ЮЬШ*ЪЯЬЮЬШЪЬШЪЮЬ/Ш2KЪЬШKЪЬШKЪЬШKЪЬШKЪЬШKЪЬШЧKЪЬШKЪЬШЧKШЧЪЮЬ
ЮЬЮШЪЬ3Ш3ЪЬ^Ш^KЪЬШKЪЬ'Ш'KЪЬШKЪЬШKЪЬШKЪЬШЧKЪЬШKШЧЪЬ0Ш0ЪЬ[Ш[KЪЬШKЪЬШKЪЬШKЪЬШKЪЬШKЪЬШЧKЪЬШKШЧЪЬ0Ш0ЪЬ[Ш[KЪЬШKЪЬШKЪЬШKЪЬШKЪЬШЧKЪЬШKШЧKЪЮЬЮЬШЧKШЧKЪЬmЩmЪЬШKЪЬ@ЮЬШSЧKЪЮЬ-ЮЬЮЬШ9KЪЮЬШЧKЪЬ7Ш7KШЧKШ ЪЯЬЮЬЮЬЮЬЮЬЮЬЮЬЮЬШlKЪЬXЩXЪЮЬЮЬШKШKЪЬЮЬШKЪЬЮЬШKШЧKЪЮЬ$Ш(KЪЬЮЬШKШЧKШ KЪЮЬШKШ KШ Ч ЕЧ    f     