-- File: QueueCool.mesa,  Last Edit: JGS  February 7, 1980  9:11 AM

-- Copyright  Xerox Corporation 1979, 1980

DIRECTORY
  DriverDefs: FROM "DriverDefs" USING [dataWordsPerBuffer],
  PupDefs: FROM "PupDefs",  -- EXPORTs
  BufferDefs: FROM "BufferDefs" USING [
    Buffer, BufferObject, Queue, Dequeue, ReturnFreeBuffer],
  DriverTypes: FROM "DriverTypes" USING [queueSeal];

QueueCool: PROGRAM
  IMPORTS DriverDefs, BufferDefs
  EXPORTS PupDefs, BufferDefs, DriverDefs
  SHARES BufferDefs =
BEGIN OPEN DriverDefs, BufferDefs;

rawOverhead: CARDINAL = SIZE[raw BufferDefs.BufferObject];
pupOverhead: CARDINAL = SIZE[pupWords pup BufferDefs.BufferObject]+1;
overhead: CARDINAL =  MAX[
    pupOverhead,
    SIZE[rppWords rpp BufferDefs.BufferObject]+1];

DataWordsPerPupBuffer: PUBLIC PROCEDURE RETURNS [CARDINAL] =
  BEGIN
  RETURN[DriverDefs.dataWordsPerBuffer+(overhead-pupOverhead)];
  END;

DataWordsPerRawBuffer: PUBLIC PROCEDURE RETURNS [CARDINAL] =
  BEGIN
  RETURN[DriverDefs.dataWordsPerBuffer+(overhead-rawOverhead)];
  END;

QueueInitialize: PUBLIC PROCEDURE [q: Queue] =
  BEGIN
  q^ _ [ length: 0, first: NIL, last: NIL, seal: DriverTypes.queueSeal ];
  END;

-- put all buffers back onto freeQueue
QueueCleanup: PUBLIC PROCEDURE [q: Queue] =
  BEGIN
  b: Buffer;
  UNTIL (b_Dequeue[q])=NIL DO ReturnFreeBuffer[b]; ENDLOOP;
  END;

-- initialization
END.  -- QueueCool(2048)\710b21B120b21B120b15B161b12B