-- File: BufferDefs.Mesa,  Last Edit: HGM  October 15, 1979  10:39 PM

-- Copyright  Xerox Corporation 1979, 1980

DIRECTORY
  PupTypes: FROM "PupTypes" USING [
    maxDataWordsPerGatewayPup,
    Pair, PupAddress, PupErrorCode, PupHostID, PupNetID, PupSocketID, PupType,
    RppAddress],
  DriverTypes: FROM "DriverTypes" USING [DeviceType, Encapsulation, Seal];


BufferDefs: DEFINITIONS = BEGIN

-- Basic Data TYPEs
Byte: TYPE = [0..377B];

PupAddress: TYPE = PupTypes.PupAddress;
PupHostID: TYPE = PupTypes.PupHostID;
PupNetID: TYPE = PupTypes.PupNetID;
PupSocketID: TYPE = PupTypes.PupSocketID;

RppAddress: TYPE = PupTypes.RppAddress;

-- QUEUE
Queue: TYPE = POINTER TO QueueObject;
QueueObject: TYPE = PRIVATE RECORD [
  length: PUBLIC CARDINAL,
  first, last: Buffer,
  seal: DriverTypes.Seal ];

-- BufferPool
BufferPool: TYPE = POINTER TO BufferPoolObject;
BufferPoolObject: TYPE = PRIVATE MONITORED RECORD [
  freeQueue: QueueObject,
  seal: DriverTypes.Seal,
  freeQueueNotEmpty: CONDITION,
  total, reserve, send, recveive: CARDINAL,
  dataWordsPerBuffer: CARDINAL,
  firstBuffer: Buffer,
  bufferSize: BufferSize,
  wordsPerBuffer: CARDINAL ];


Enqueue: PROCEDURE [Queue, Buffer];
Dequeue: PROCEDURE [Queue] RETURNS [Buffer];
ExtractFromQueue: PUBLIC PROCEDURE [Queue, Buffer] RETURNS [Buffer];
QueueLength: PROCEDURE [q: Queue] RETURNS [CARDINAL] = INLINE
  BEGIN RETURN[q.length]; END;
QueueEmpty: PROCEDURE [q: Queue] RETURNS [BOOLEAN] = INLINE
  BEGIN RETURN[q.length=0]; END;
QueueInitialize: PROCEDURE [Queue];
QueueCleanup: PROCEDURE [Queue];


PupBufferObject: TYPE = pup BufferObject;
PupBuffer: TYPE = POINTER TO PupBufferObject;
RppBufferObject: TYPE = rpp BufferObject;
RppBuffer: TYPE = POINTER TO RppBufferObject;


-- From specified BufferPool
BufferPoolMake: PROCEDURE [
    pool: BufferPool, numberOfBuffers, dataWordsPerBuffer: CARDINAL];
BufferPoolDestroy: PROCEDURE [BufferPool];
GetBufferFromPool: PROCEDURE [BufferPool] RETURNS [Buffer];
MaybeGetBufferFromPool: PROCEDURE [BufferPool] RETURNS [Buffer];
ReturnBufferToPool: PROCEDURE [BufferPool, Buffer];
BuffersLeftInPool: PROCEDURE [BufferPool] RETURNS [CARDINAL];
EnumerateBuffersInPool: PROCEDURE [BufferPool, PROCEDURE[Buffer]];

-- From SystemPool
GetFreeBuffer: PROCEDURE RETURNS [Buffer];
ReturnFreeBuffer: PROCEDURE [Buffer];
BuffersLeft: PROCEDURE RETURNS [CARDINAL];
EnumerateBuffers: PROCEDURE [PROCEDURE[Buffer]];
AdjustBufferParms: PROCEDURE [bufferPoolSize, bufferSize: CARDINAL];
GetBufferParms: PROCEDURE RETURNS [bufferPoolSize, bufferSize: CARDINAL];

DataWordsPerRawBuffer: PROCEDURE RETURNS [CARDINAL];
DataWordsPerPupBuffer: PROCEDURE RETURNS [CARDINAL];

defaultBufferPoolSize: CARDINAL = 15;
buffersToReserve: CARDINAL = 2;
defaultDataWordsPerBuffer: CARDINAL = PupTypes.maxDataWordsPerGatewayPup;

-- BUFFER
BufferType: TYPE = {raw, pup, rpp, rejected, processed};
BufferSize: TYPE = {big, small, user};

Buffer: TYPE = POINTER TO BufferObject;
BufferObject: TYPE = MACHINE DEPENDENT RECORD [
  next: PRIVATE Buffer,
  queue: PRIVATE Queue,
  pool: PRIVATE BufferPool,
  requeueProcedure: PROCEDURE [Buffer],
  seal: PRIVATE DriverTypes.Seal,
  length: PRIVATE CARDINAL,
  network: PRIVATE POINTER,  -- DriverDefs.Network
  iocbChain: PRIVATE LONG POINTER,
  userPtr: PRIVATE LONG POINTER,
  userData: PRIVATE LONG POINTER,
  userDataLength: PRIVATE CARDINAL,
  status: PRIVATE WORD,
  time: PRIVATE LONG INTEGER,
  tries: PRIVATE CARDINAL,
  allNets: PRIVATE BOOLEAN,
  bypassZeroNet: PRIVATE BOOLEAN,
  device: PRIVATE DriverTypes.DeviceType,
  type: BufferType,
  size: BufferSize,
  spare: [0..37B],
  bufferNumber: CARDINAL,
  debug: PRIVATE UNSPECIFIED,
  encapsulation: PRIVATE DriverTypes.Encapsulation,


  bufferBody: SELECT OVERLAID BufferType FROM
    raw => [ rawWords: ARRAY [0..0) OF WORD ],

    pup => [
      pupLength: CARDINAL,  -- in bytes, includes header
      pupTransportControl: Byte,  -- 4 bits of hopcount, 4 spares
      pupType: PupTypes.PupType,
      pupID: PupTypes.Pair,
      dest, source: PupAddress,
      pupBody: SELECT OVERLAID * FROM
        pupWords => [ pupWords: ARRAY [0..0) OF WORD ],
        pupBytes => [ pupBytes: PACKED ARRAY [0..0) OF Byte ],
        pupChars => [ pupChars: PACKED ARRAY [0..0) OF CHARACTER ],
        pupString => [ pupString: StringBody ],
        rfc => [ address: PupAddress ],
        ack => [
          maximumBytesPerPup: CARDINAL,
          numberOfPupsAhead: CARDINAL,
          numberOfBytesAhead: CARDINAL ],
        abort => [
          abortCode: WORD,
          abortText: PACKED ARRAY [0..0) OF CHARACTER ],
        error => [  -- see [MAXC]<PUP>Error.ears
          errorHeader: ARRAY [0..9] OF WORD,
          errorCode: PupTypes.PupErrorCode,
          errorOptions: WORD,
          errorText: PACKED ARRAY [0..0) OF CHARACTER ],
        ENDCASE ],
      -- software checksum (1 word) comes after all the data

    rpp => [  -- variant of Pup  NOTE: header is one word longer
      rppPupLength: CARDINAL,  -- in bytes, includes header
      rppTransportControl: Byte,
      rppPupType: [0..37B],  -- 4
      system, sendAck, notify: BOOLEAN,
      seqNumber, ackNumber: CARDINAL,
      rppDest, rppSource: RppAddress,
      allocation, subType: Byte,
      rppBody: SELECT OVERLAID * FROM
        rppWords => [ rppWords: ARRAY [0..0) OF WORD ],
        rppBytes => [ rppBytes: PACKED ARRAY [0..0) OF Byte ],
        rppChars => [ rppChars: PACKED ARRAY [0..0) OF CHARACTER ],
        rppString => [ rppString: StringBody ],
        ENDCASE ],
      -- software checksum (1 word) comes after all the data
    ENDCASE ];

END.(2048)