-- File: QueueCold.mesa,  Last Edit: HGM  November 12, 1979  6:01 PM

-- Copyright  Xerox Corporation 1979, 1980

DIRECTORY
  InlineDefs: FROM "InlineDefs" USING [BITAND, LowHalf],
  CommUtilDefs: FROM "CommUtilDefs" USING [
    AllocateHyperspace, FreeHyperspace, LockData, UnlockData,
    AllocateIocbs, FreeIocbs,
    GlobalFrame, SetTimeout, MsecToTicks],
  DriverDefs: FROM "DriverDefs" USING [
    freeQueue, firstBuffer, bufferSize,
    useCount, giantVector, doDebug, Glitch,
    QueueCool, QueueIn, QueueOut],
  PupStream: FROM "PupStream",  -- EXPORTS
  PupDefs: FROM "PupDefs",  -- EXPORTS
  BufferDefs: FROM "BufferDefs" USING [
    defaultBufferPoolSize, defaultDataWordsPerBuffer,
    Buffer, BufferObject, Dequeue, Enqueue, ReturnFreeBuffer,
    QueueInitialize, QueueCleanup],
  DriverTypes: FROM "DriverTypes" USING [bufferSeal];

QueueCold: MONITOR LOCKS freeQueueLock
  IMPORTS InlineDefs, CommUtilDefs, DriverDefs, BufferDefs
  EXPORTS DriverDefs, PupStream, PupDefs, BufferDefs
  SHARES BufferDefs =
BEGIN OPEN DriverDefs, BufferDefs;


freeQueueLock: PUBLIC MONITORLOCK;
freeQueueNotEmpty: PUBLIC CONDITION;
numberOfBuffers: PUBLIC CARDINAL _ BufferDefs.defaultBufferPoolSize;
dataWordsPerBuffer: PUBLIC CARDINAL _ BufferDefs.defaultDataWordsPerBuffer;
wordsPerIocb: PUBLIC CARDINAL _ 0;

-- Buffers and IOCB locations must be rounded up for alignment constraints.  Alto SLA Microcode needs IOCB/LCB to be EVEN.  We round things up to a Quad word just in case.

-- size of a buffer without any data
rawOverhead: CARDINAL = SIZE[raw BufferDefs.BufferObject];
-- 1 extra for checksum
pupOverhead: CARDINAL = SIZE[pupWords pup BufferDefs.BufferObject]+1;
overhead: CARDINAL =  MAX[
    pupOverhead,
    SIZE[rppWords rpp BufferDefs.BufferObject]+1];

CantResetWhileActive: PUBLIC ERROR = CODE;

AdjustBufferParms: PUBLIC ENTRY PROCEDURE [bufferPoolSize, bufferSize: CARDINAL] =
  BEGIN
  IF useCount#0 THEN Glitch[CantResetWhileActive];
  IF bufferPoolSize#0 THEN numberOfBuffers _ bufferPoolSize;
  IF bufferSize#0 THEN dataWordsPerBuffer _ bufferSize;
  END;

GetBufferParms: PUBLIC PROCEDURE RETURNS [bufferPoolSize, bufferSize: CARDINAL] =
  BEGIN
  RETURN[numberOfBuffers,dataWordsPerBuffer];
  END;

-- NB: wordsPerBuffer and wordsPerIocb MUST be QuadWord multiples
FreeQueueMake: PUBLIC PROCEDURE =
  BEGIN
  b: Buffer;
  x: POINTER TO BufferObject = LOOPHOLE[6];  -- anything to avoid NIL trap
  i: CARDINAL;
  wordsPerBuffer: CARDINAL;
  wordsPerBuffer _ dataWordsPerBuffer+overhead;
  UNTIL InlineDefs.BITAND[wordsPerBuffer,3]=0 DO
    wordsPerBuffer _ wordsPerBuffer+1;
    ENDLOOP;
  bufferSize _ wordsPerBuffer-(@x.encapsulation-LOOPHOLE[x,POINTER]);
  firstBuffer _ CommUtilDefs.AllocateHyperspace[wordsPerBuffer*numberOfBuffers+3];
  UNTIL InlineDefs.BITAND[InlineDefs.LowHalf[@firstBuffer.encapsulation],3]=0 DO
    firstBuffer _ firstBuffer+1;
    ENDLOOP;
  IF doDebug THEN
    BEGIN
    giantVector.firstBuffer _ firstBuffer;
    giantVector.wordsPerBuffer _ wordsPerBuffer;
    giantVector.bufferPoolSize _ numberOfBuffers;
    END;
  CommUtilDefs.LockData[firstBuffer];
  QueueInitialize[@freeQueue];
  b _ firstBuffer;
  FOR i IN [0..numberOfBuffers) DO
    b.iocbChain _ b.userData _ NIL;
    b.allNets _ b.bypassZeroNet _ FALSE;
    b.type _ raw;
    b.size _ big;
    b.pupLength _ b.length _ 0;
    b.bufferNumber _ i;
    b.pupType _ pt177;
    b.queue _ NIL;
    b.pool _ NIL;
    b.next _ NIL;
    IF doDebug THEN b.seal _ DriverTypes.bufferSeal;
    b.requeueProcedure _ ReturnFreeBuffer;
    Enqueue[@freeQueue,b];
    b _ b+wordsPerBuffer;
    ENDLOOP;
  IF wordsPerIocb#0 THEN 
    BEGIN
    iocb: LONG POINTER; 
    iocb _ CommUtilDefs.AllocateIocbs[wordsPerIocb*numberOfBuffers+3];
    b _ firstBuffer;
    FOR i IN [0..numberOfBuffers) DO
      -- this does NOT align each individual iocb
      b.iocbChain _ iocb;
      iocb _ iocb+wordsPerIocb;
      b _ b+wordsPerBuffer;
      ENDLOOP;
    END;
  END;

FreeQueueDestroy: PUBLIC PROCEDURE =
  BEGIN
  UNTIL Dequeue[@freeQueue]=NIL DO ENDLOOP;
  QueueCleanup[@freeQueue];
  CommUtilDefs.UnlockData[firstBuffer];
  IF firstBuffer.iocbChain#NIL THEN CommUtilDefs.FreeIocbs[firstBuffer.iocbChain];
  CommUtilDefs.FreeHyperspace[firstBuffer];
  IF doDebug THEN
    BEGIN
    firstBuffer _ NIL;
    giantVector.firstBuffer _ NIL;
    END;
  END;

-- initialization
CommUtilDefs.SetTimeout[@freeQueueNotEmpty,CommUtilDefs.MsecToTicks[10000]];
START DriverDefs.QueueCool;
START DriverDefs.QueueIn;
-- Argh, QueueLocked, or QueueLockedTiny
START LOOPHOLE[CommUtilDefs.GlobalFrame[Enqueue],PROGRAM];
START DriverDefs.QueueOut;
IF doDebug THEN
  BEGIN
  giantVector.firstBuffer _ NIL;
  giantVector.freeQueue _ @freeQueue;
  END;
END.  -- QueueCold(2048)\804b9B453i123I1i49I331b17B250b14B19t10 7t0 104bi66I13B1658b16B