TweetFollow Us on Twitter

HyperAppleTalk 4
Volume Number:5
Issue Number:4
Column Tag:HyperChat™

Related Info: AppleTalk Mgr

XCMD Corner: HyperAppleTalk IV

By Donald Koscheka, Arthur Young & Co., MacTutor Contributing Editor

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

I sometimes think that, to most programmers, the network is best left to the handful of specialists that ply their craft on this arcane art.

Think of the network as adding a new dimension to your programs, much as perspective enabled medieval artists to add depth and realism to their paintings. While many artists may have scoffed at perspective, I have no trouble believing that the populace was awed by its discovery. Perhaps networking will shine the same light as we enter the renaissance of computer programming.

If you’ve been following this column over the last three months, you may be asking yourself, “Are we there yet?” This month, we tie the pieces together by introducing the rest of AppleTalk XCMDs. I apologize for publishing listings last month that you can’t really use until this month. I hope this issue makes up for it and in the future I will do my best to provide “soup to nuts” code in each issue.

Conceptually, an AppleTalk interface can be reduced to the six steps: (1) Open access to the transaction protocol and allocate any memory that will be needed to interface to it. I chose the AppleTalk Data Stream Protocol(ADSP). ADSPOpen hooks us up to ADSP, establishes a connection listener and returns the connection listener’s socket address to Hypercard. NBPOpen initializes a data structure that we use to interface to NBP. The January ’89 issue of this column provides the code for these XCMDs.

(2) Given the address of the connection listener, register a name and type with the network using the name binding protocol. Once registered, our entity’s name and address will be listed in the “directory”.

(3) If we want to be able to “dial up” other entities, we next perform a lookup which returns all current names in the lookup table which acts just like a directory. The names are returned as a list of items to Hypercard without their addresses. This step is optional, if all you expect to do is respond to requests (as in the case of a server), then you don’t need to know the names of the requesting entities.

(4) To call another entity, invoke the ADSPCall XCMD with the entity’s name. ADSPCall extracts the network address from the lookup table using the routine “NBPGetAddress”. This technique allows us to de-couple names and addresses; your stacks need never be concerned with the address of an entity, the name is sufficient at the Hypercard script level.

(5) Once a connection is established with another entity (called the remote end), you send information to that entity using ADSPTalk. You receive information from the remote end using ADSPListen. ADSPListen is the heart of the interface, in addition to checking for incoming messages, it also monitors the status of all open connections.

(6) When the session completes, remove your name from the names table using the NBPUnregister XFCN. Once unregistered, close down the interface to ADSP with the ADSPClose and then close down your NBP interface with NBPClose.

--The XCMDS--

While the process is conceptually quite simple, the amount of code needed to implement this interface may seem overwhelming. The rest of this article focuses on ADSPCall, ADSPTalk, ADSPListen and ADSPHangup. Information on both NBP and the open and close xcmds are available in that last two installments of this column as well as in recently published literature from APDA.

(1) ADSPCall

ADSPCall (listing 1) first extracts the address of the entity from the lookup table using NBPGetAddress. If you pass it the name of a currently visible entity, you have a reasonable assurance that the call will complete.

Upon retrieving the address, adspcall walks the connection list checking to see if a connection already exists with the remote end. If not, it creates a connection by calling DSPCreate.

Outgoing calls are placed asynchronously, control is passed back to Hypercard while the call completes in the “background”. Asynchronous communications pays big dividends, adspcall attempts to establish the connection as many times as you request in the retry field. Waiting for a call to complete can “hang” the system, a particularly uncomfortable state for the user. If for any reason, the remote end has gone off line, Hypercard won’t be stuck with an unbearable delay waiting for the call to timeout.

Outgoing calls, like all other transactions on the network, must be monitored by the listener. ADSPListen detects when the remote end picks up the phone.

To invoke ADSPCall from your script, use the following command line:

--1

-- get the name of the entity from the lookup table.
-- We let HyperAppleTalk handle the defaults for
-- retry, interval and buffer size. 
--
-- The two above globals will have been initialized by
-- NBPOpen and ADSPOpen respectively.
--
global globalNBPData, globalADSPData
ADSPCall theEntity

(2) ADSPTalk

Once a connection is established with a remote end, we can send messages to that entity. Like ADSPCall, ADSPTalk uses NBPGetAddress to get the address given a name. Because NBPGetAddress returns 0 if the name had no corresponding address in the lookup table, we can determine whether we have a connection to the remote end. ADSPTalk scans the connection list to match the address with that of an entity in our connection list (pointed to bey adsp^.ends). AdspTalk calls DSPTalk (covered last month) to send the information. Outgoing messages are also sent asynchronously so that the user is not made to suffer any delays while the transmission completes.

Like ADSPCall, the method of invoking ADSPTalk is straightforward:

--2

-- “theEntity” is the name of the remote end that you
-- called using ADSPCall and the card field contains the 
-- data that you wish to send to the remote end.
--
global globalNBPData, globalADSPData
ADSPTalk theEntity, card field “outgoing message”

(3) ADSPListen

The quality of any conversation depends more on the skill of the listener than that of the talker. This is no less true for the network - talking is the easy part, the listener does the hard part. Like any good listener, ADSPListen must perform several tasks at once -- (1) Answer incoming calls, (2) Monitor the status of outgoing calls, (3) Receive incoming messages and (4) periodically check the status of each connection.

Putting ADSPListen in the idle method of a card or stack provides a method for periodically checking up on each connection.

For each established connection an entry exists in our adsp^.ends list. While most of the data stored in the connection (cn) block is for our own use, the network keeps us apprised of the connection’s status via two records: the parameter block (pb) and the connection control block (ccb). The parameter block behaves as it would for any low-level I/O on the Macintosh, it is the interface to the ADSP device driver. The connection block is used by adsp to keep us up to date on the status of each connection. In essence, we relinquish control of the parameter block and the connection control block to ADSP. The rest of the structures in the connection data are for our own use.

To determine what is going on in any connection, we check the state field in the connection control block. The following states are currently supported (see listing 2 for the corresponding code):

sClosed: The connection went down for some reason or other. At this point, we have no choice but to Hang up.

sOpen: A connection opens in stages. When we first create or detect an opening connection, we set the mode to NOP indicating the connection is only “half open”. A half open connection is one in which only one of the two ends is ready. Receiving the sOpen state from the remote end informs us that our connection is now open.

A connection that is already open signals that it’s closing with the “eClosed” message. If a connection is closing, hang up on it.

The next two tasks, talking and listening, are monitored by Checkmessages. Recall that ADSPTalk queues outgoing calls; they complete some time in the future. Similarly, incoming messages can complete at any time. To determine whether any incoming or outgoing messages need attention, we issue a Status call to adsp. The ioCrefNum field of the dspParamBlock in checkMessages gets the driver number of the adsp driver. The ccbRefnum field gets the connection number of the connection we are checking.

The status call is issued synchronously, we must wait for it to complete before testing the status of a connection. If recvQPending is not 0, we have an incoming block of data. On input, we call ReadADSPData which will accumulate the data into the connection’s input buffer until ADSP signals that there is no more data with the end-of-message flag (eom).

ReadADSPData will read data from the connection’s input buffer into the handle we stored in conn^.inbuf (see listing 3). Accumulating data is a simple task : resize the handle by the number of bytes that we need to read in (given to us by adsp in recvQpending. If recvQpending is 0, there are no bytes to read). Once the handle is resized, point to the old end of the handle, and read the data directly into that are in memory. The read returns the exact number of bytes read in. If that number differs from recvQPending (under ordinary circumstances this won’t happen), then resize the handle to reflect the actual number of bytes read in.

After reading the data, we check the end-of-message flag (eom) which ADSP sets only after it sends the last block of the message down stream. If eom is set, there is no more data to read. We can now send the data back to hypercard. If we know the name of the connection, we send it back to hypercard via the ‘ADSPCaller’ global container. This gives your stack a way of determining who sent the input data. The data itself is put in the hypercard container, ‘HyperADSPData’. Once the data and name have been reported to Hypercard, we can optionally send a message back, perhaps to invoke some special input processing. If the connection stored a message in its ‘callme’ field, we now invoke that message via a callback.

Monitoring outgoing calls is a bit simpler. If the connection’s sendQPending field is not 0, we still have outgoing data in the output buffer. In this case, don’t do anything. If on the other hand, the send queue has emptied out and there was data in it (the connection outbuf field is not nil), then dispose the memory currently occupied by the output data.

The last task that ADSPListen must handle is responding to incoming calls. It does this by calling its respondtoListen Procedure. If a connection request is pending, the connection listener’s ioResult will be set to noErr (a negative result means an error occurred, a positive result means that no connection requests are pending, the listener still has its ears to the wall).

If a connection request is pending, we can open up a connection to the remote end whose address is passed in the remoteCID field. Once the connection is established,we can try to discover its name by issuing a call to NBPGetName with the pending connection’s name. Knowing the name of an incoming caller is optional so we don’t take extraordinary efforts to discover the name. If however, you needed the entities name (as in the case of a game), then you can do a lookup if NBPGetName turns up empty-handed. This is an advanced feature and, in the interest of space, I’ve omitted it. If you absolutely need this capability, drop me a line.

Once the pending request is serviced, the connection listener can put its ear back to the wall by requeuing the connection listener call. The information needed to queue a listening request is already stored in the connection listener’s parameter block (adsp^.pb). Requeuing the request becomes a simple call to PBControl with the connections parameter block.

The following script, added to your card, will do the trick:

--3

on idle

global globalNBPdata, globalADSPData
global adspCaller-- name of the caller global HyperADSPData    
 -- where incoming data goes
--
 ADSPListen “ShowData”

end idle

-- Show data is the method to invoke to handle
-- incoming data.  Assuming that we have a card field
-- named “show me”, the following method will display the
-- incoming message:
--
on ShowData
 global HyperADSPData

 put HyperAdspData into card field “show me”
end showdata

(4) ADSPHangup

We’ve already seen how to detect and respond to a connection hanging up on us. Use ADSPHangup (listing 4) to inform the remote end that the connection is going down. Once again, the drill is the same: get the address from the lookup table, check to see that a connection exists with this entity and call DSPHangup to inform the entity that the connection is going down. We don’t remove the connection from the connection list at this point because we have to wait for the remote end to acknowledge our disconnection request. ADSPListen receives this acknowledgement in the form of an eClosed message. Once closed, we can tear down the connection and deallocate its memory (dspRemove).

--4

--
-- A simple script for hanging up a connection
--
on Disconnect
 global HyperADSPData, globalNBPData

 ADSPHangup theEntity
End Disconnect

You now have a reasonably complete interface to AppleTalk. ADSP and NBP both offer more features than I’ve been able to show you in a short time. Notably, the out of stream and forward reset features of ADSP enable some very powerful enhancements to the basic protocol. I chose not to discuss these features in this series because the average application can get by quite well without them. If, however, you are writing a network server in Hypercard, you may want to explore these features in more detail. I will be happy to present the code for a full implementation of ADSP. In keeping with the spirit of MacTutor, contact me immediately to report any bugs in the code. I can be reached through this Magazine or on AppleLink (N0735) or MacNet.

Next month, I’m going to switch gears back into low and explore the file manager from within Hypercard.

Listing 1:  ADSPCall.p

(********************************)
(* file:  ADSPCall.p *)
(* *)
(* Establish a connection with*)
(* the entity whose name is *)
(* passed as a parameter. *)
(* *)
(* params[1] = Name of entity *)
(* params[2] = listen message *)
(* params[3] = number of retries*)
(* params[4] = retry interval *)
(* params[5] = Input buffer siz  *)
(* params[6] = Output buffer siz*)
(* *)
(* If  already connected, just*)
(* return with noErr *)
(* *)
(* Defaults:*)
(* Input Buffer  = 578    *)
(* Output Buffer = 578    *)
(* Retry count   = 0 *)
(* Retry interval= 0 *)
(* Out: the Result ::= error  *)
(* message, empty if none.*)
(* *)
(* ----------------------------  *)
(* By:  Donald Koscheka   *)
(* Date:9-Jan-89 *)
(* All Rights Reserved    *)
(* *)
(********************************)

(********************************
 Build Sequence

pascal ADSPCall.p -o ADSPCall.p.o 
link -m ENTRYPOINT  -rt XCMD=1302 -sn Main=ADSPCall
 ADSPCall.p.o
 “{libraries}”Interface.o 
 -o YourStackNameHere
  
*********************************)

{$R-}
{$S ADSPCall}
UNIT Koscheka;

(*********************************)
 INTERFACE 
(*********************************)

Uses  MemTypes, QuickDraw, OSIntf, 
 ToolIntf, PackIntf, HyperXCmd,
 AppleTalk, ADSP, adspxcmd;

Procedure EntryPoint( paramPtr : XCmdPtr );

(*********************************)
 IMPLEMENTATION
(*********************************)
TYPE Str31 = String[31];

PROCEDURE ADSPCall( paramPtr: XCmdPtr ); FORWARD;

Procedure EntryPoint( paramPtr : XCmdPtr );
Begin
 ADSPCall( paramPtr );
End;
 
Procedure ADSPCall( paramPtr : XCmdPtr );
VAR
 adsp   : ADSPPtr;
 error, terr: OSErr;
 inBufSiz : Integer;
 outBufSiz: Integer;
 retry  : Integer;
 interval : Integer;
 eAddr  : AddrBlock; 
 cn: CBPtr;
 nbp    : NBPPtr;
 found  : BOOLEAN;
 
{$I XCmdGlue.inc }
{$I XCMDADSP.inc } 

(*********************************)
BEGIN
 error  := noErr;
 found  := TRUE; {*** true if  already established ***}
 
WITH paramPtr^ DO
BEGIN
 IF (paramCount <> 0) AND (params[1]^ <> NIL) THEN 
 BEGIN
 adsp := ADSPPtr(RetrieveData( ‘GLOBALDSPDATA’ ));
 IF adsp <> NIL THEN
 BEGIN
 adsp^.checkPoint := RECEIVING;
 
 {**** Before we go too far, let’s ***}
 {*** look at some of the settings ***}
 {*** set the retransmit count***}
 IF params[3] <> NIL THEN
 retry := StringToSHort( params[3]^ )
 ELSE
 retry  := 0;
 
 {*** Set the retransmit interval  ***}
 IF params[4] <> NIL THEN 
 interval := StringToSHort( params[4]^ )
 ELSE
 interval := 0;
 
 {*** Set the input buffer size    ***}
 IF params[5] <> NIL THEN
 inBufSiz := StringToSHort( params[5]^ )
 ELSE
 inBufSiz := ATPBSIZE;
 
 {*** Set the output buffer size   ***}
 IF params[6] <> NIL THEN
 outBufSiz := StringToSHort( params[6]^ )
 ELSE
 outBufSiz:= ATPBSIZE;
 
 {*** (1) Get the entity’s address ***}
 HLock( Handle( params[1]) );
 eAddr := NBPGetAddress( params[1]^ );
 HUnlock( Handle( params[1] ) );

 {*** Walk through the connection  ***}
 {*** list to see if the connection***}
 {*** already exists.***}
 
 IF LongInt(eAddr) <> 0 THEN
 BEGIN
 cn := adsp^.ends;
 found := FALSE;
 
 WHILE (NOT found) DO
 IF cn = NIL THEN
 found := TRUE
 ELSE
 IF LongInt( eAddr ) = LongInt( cn^.adr ) THEN
 found := TRUE
 ELSE
 cn := cn^.next;
 
 {*** If connection already exists ***}
 {*** cn will not be NIL  so we won’t ***}
 {*** have to reconnect the two ends,***}
 {*** just fall out, otherwise, try to***}
 {*** make the connection.***}
 
 IF cn = NIL  THEN {*** establish connection ***}
 BEGIN
 cn^.remName:= NBPGetName( eAddr );
 cn := DSPCreate(eAddr,inBufSiz,
 outBufSiz,retry,interval,params[2] );
 IF cn <> NIL THEN
 BEGIN
 cn^.remName := NBPGetName( eAddr );
 
 {*** try to discover the name   ***}
 IF cn^.remName = NIL THEN
 BEGIN
 nbp := NBPPtr(RetrieveData(‘GLOBALNBPDATA’));
 IF nbp <> NIL THEN 
 BEGIN
 SendCardMessage(‘DoALookUp’);
 cn^.remName := NBPGetName( eAddr );
 END;
 END;
 
 {*** Now “dial for dollars”***}
 WITH cn^.dspPB DO 
 BEGIN
 ioCRefNum  := adsp^.dspRefNum;
 ccbRefNum:= cn^.ccbRef;
 csCode := dspOpen;
 ocMode := ocRequest;
 ioCompletion:= NIL;
 remoteCID:= 0;{*** don’t know this yet***}
 localCID := 0;{*** adsp allocates id***}
 remoteAddress:= eAddr; 
 filterAddress.aNet:= 0;
 filterAddress.aNode := 0;
 filterAddress.aSocket:= 0;
 SendSeq:= 0;
 RecvSeq:= 0;
 SendWindow := 0;
 attnSendSeq:= 0;
 attnRecvSeq:= 0;
 ocInterval := INTERVAL;
 ocMaximum:= RETRY;
 error  := PBControl( @cn^.dspPB, ASYNC );
 END;
 END;
 END;
 END; {(LongInt(eAddr) <> 0) }
 adsp^.checkPoint := CLOSE_OK;
 END;
 END;
 returnValue := PasToZero( NumToStr( LongInt(error) ) );
END; {*** with paramPtr^ ***}
END;

end.
Listing 2:  ADSPTalk.p

(****************************)
(* file:  ADSPTalk.p *)
(* *)
(* Send information to an *)
(* established connection.  *)
(* The connection must be *)
(* been established via the *)
(* ADSPCALL xcmd.*)
(* *)
(* In:  *)
(* params[1] = entity name*)
(* of the remote end.*)
(* *)
(* ------------------------ *)
(* By:  Donald Koscheka   *)
(* Date:2-Mar-89 *)
(* All Rights Reserved    *)
(* *)
(* ------------------------ *)
(****************************)

(*****************************
 Build Sequence

pascal -o ADSPTalk.p.o ADSPTalk.p
link -m ENTRYPOINT  -rt XCMD=1305 -sn Main=ADSPTalk
 ADSPTalk.p.o
 “{libraries}”Interface.o 
 -o YourStackNameHere
  
*****************************)

{$R-}
{$S ADSPTalk}
UNIT DummyUnit;

(****************************)
 INTERFACE 
(****************************)

Uses  MemTypes, QuickDraw, OSIntf,
 ToolIntf, PackIntf, HyperXCmd,
 AppleTalk, ADSP, adspxcmd;


Procedure EntryPoint( paramPtr : XCmdPtr );

(****************************)
 IMPLEMENTATION
(****************************)
TYPE Str31 = String[31];

PROCEDURE ADSPTalk( paramPtr: XCmdPtr ); FORWARD;

Procedure EntryPoint( paramPtr : XCmdPtr );
 Begin
 ADSPTalk( paramPtr );
 End;
 
Procedure ADSPTalk( paramPtr : XCmdPtr );
VAR
 adsp   : ADSPPtr;
 error  : OSErr;
 eAddr  : AddrBlock;
 cb: cbPtr;
 
{$I XCmdGlue.inc }
{$I XCMDADSP.inc } 

BEGIN
 error := noErr;
 adsp := ADSPPtr(RetrieveData( ‘GLOBALDSPDATA’ ));
 IF(adsp <> NIL) 
 AND  (paramPtr^.params[1] <> NIL)
 AND  (paramPtr^.params[2] <> NIL) THEN
 BEGIN
 adsp^.checkPoint := RECEIVING;
 {*** (1) Get the entity’s address ***}
 HLock( paramPtr^.params[1] );

 eAddr := NBPGetAddress( paramPtr^.params[1]^ );
 cb := adsp^.ends;

  {*** (2) Find entity in connection list***}
 
 IF LongInt( eAddr ) <> 0 THEN
 WHILE cb <> NIL DO
 IF (LongInt(cb^.adr)=LongInt(eAddr)) 
 AND (cb^.ccb.state=sOpen) THEN  
 BEGIN
 error := DSPTalk(cb, paramPtr^.params[2] );
 cb := NIL;
 END
 ELSE
 cb := cb^.next;
 
 adsp^.checkPoint := CLOSE_OK;
 HUnlock( Handle(paramPtr^.params[1]) );
 END;
 paramPtr^.returnValue := PasToZero( NumToStr( LongInt(error) ) );
END;

end.
Listing 3:  ADSPListen.p

(****************************)
(* file:  ADSPListen.p    *)
(* *)
(* Perform the following: *)
(* (1) Listen for incoming*)
(* calls on the connection*)
(* listener *)
(* (2) Check to see if any*)
(* outgoing calls have been*)
(* answered *)
(* (3) Check connections  *)
(* for incoming data *)
(* (4) Check connections for*)
(* attention messages*)
(* *)
(* In:  *)
(* params[1] = name of    *)
(* message to call hypercard*)
(* with on incoming data  *)
(* *)
(* Defaults:*)
(* container = HyperADSPData*)
(* message  = none.*)
(* *)
(* ---------------------- *)
(* All Rights Reserved    *)
(* *)
(* ------------------------ *)
(* By:  Donald Koscheka   *)
(* Date:2-Mar-89 *)
(* All Rights Reserved    *)
(* *)
(* ------------------------ *)
(****************************)

(*****************************
 Build Sequence

pascal -o “{hpo}”ADSPListen.p.o “{adsp}”ADSPListen.p
link -m ENTRYPOINT  -rt XCMD=1303 -sn Main=ADSPListen
 ADSPListen.p.o
 “{libraries}”Interface.o 
 -o YourStackNameHere
  
******************************)

{$R-}
{$S ADSPListen}
UNIT Koscheka;

(****************************)
 INTERFACE 
(****************************)

Uses MemTypes, QuickDraw, OSIntf, ToolIntf, PackIntf, HyperXCmd, AppleTalk, 
ADSP, adspxcmd;

Procedure EntryPoint( paramPtr : XCmdPtr );

(****************************)
 IMPLEMENTATION
(****************************)
TYPE Str31 = String[31];

PROCEDURE ADSPListen( paramPtr: XCmdPtr ); FORWARD;

Procedure EntryPoint( paramPtr : XCmdPtr );
 Begin
 ADSPListen( paramPtr );
 End;
 
Procedure ADSPListen( paramPtr : XCmdPtr );
VAR
 myFlags: SignedByte;
{ flags from incoming unsolicited message    }
 adsp   : ADSPPtr; { pointer to ADSP Control block}
 error  : OSErr; 
 err    : OSErr;
 cn,nn  : cbPtr; { pointers to established conections}
 nbp    : NBPPtr;{ pointer to the memory  NBP interface}
 mybPtr : Ptr;   { used for getting and setting flags}
 
{$I XCmdGlue.inc }
{$I XCMDADSP.inc } 

PROCEDURE RespondToListen;
(********************************)
(* If the connection listener *)
(* has completed, then someone*)
(* is trying to call. If we can  *)
(* initialize a connection, *)
(* acknowledge receipt of  call.*)
(********************************)
VAR
 err    : Integer;
 conn : CBPtr;
 tH: Handle;
 
BEGIN
 IF  adsp^.pb.ioResult = noErr THEN 
 BEGIN  {*** We Have an incoming call.***}
 {*** Create a connection end to***}
 {*** the caller and set the***}
 {*** state to active indicating ***}
 {*** the connection is accepted ***}
 conn := DSPCreate(adsp^.pb.remoteAddress,
 ATPBSIZE,ATPBSIZE,RETRY,INTERVAL,NIL );
 
 IF conn <> NIL THEN
 WITH conn^.dspPB DO
 BEGIN  {*** accept the connection request***}
 ioCRefNum  := adsp^.dspRefNum;
 ioCompletion    := NIL;
 csCode := dspOpen;
 ocMode := ocAccept;
 ccbRefNum:= conn^.ccbRef;
 remoteCID:= adsp^.pb.remoteCID;
 localCID := 0;
 remoteAddress   := adsp^.pb.remoteAddress;  
 filterAddress.aNet:= 0;
 filterAddress.aNode := 0;
 filterAddress.aSocket := 0;
 RecvSeq:= 0;
 attnRecvSeq:= 0;
 SendSeq:= adsp^.pb.SendSeq;
 attnSendSeq:= adsp^.pb.attnSendSeq;
 SendWindow := adsp^.pb.SendWindow;
 ocInterval := INTERVAL;
 ocMaximum:= RETRY;
 err := PBControl( @conn^.dspPB, ASYNC );
 
 {*** Call back Hypercard to inform  ***}
 {***it of an incoming call.***}
 
 conn^.remName := NBPGetName( adsp^.pb.remoteAddress );
 END;
 
 {*** Reset connection listener to ***}
 {*** wait for more calls ***}
 err := PBControl( @adsp^.pb, ASYNC );
 END
END;

PROCEDURE ReadADSPData( conn:CBPtr; cnt:Integer; callMe:Handle );
(********************************)
(* Poll the connection to *)
(* determine whether any  *)
(* data is pending.  If so, *)
(* read it and pass it  back to *)
(* hypercard via the callback *)
(* mechanism.    *)
(* *)
(* IN:  *)
(* conn : pointer to connection *)
(* cnt  : num. of bytes to read  *)
(* callMe : callback method *)
(********************************)
VAR
 Tempb  : dspParamBlock;
 err    : Integer;
 temp   : LongInt;
 inSize : LongInt;
 globName: Str255; 
 tp: Ptr;
 tH: Handle;
 
BEGIN
 globName:= ‘HyperADSPData’;
 
 WITH conn^ DO
 BEGIN  {*** read the data ***}
 IF inBuf = NIL THEN
 BEGIN
 inBuf := NewHandle( LongInt(cnt) );
 MoveHHi( inBuf );
 HLock( inBuf );
 tp:= inBuf^;
 END
 ELSE {*** inBuf already allocated, add to end of it***}
 BEGIN
 HUnlock( inBuf );
 inSize := GetHandleSize(inBuf);
 temp   := inSize;
 inSize := inSize + LongInt( cnt );
 SetHandleSize( inBuf, inSize );
 MoveHHi( inBuf );
 HLock( inBuf );
 temp   := temp + Ord4( inBuf^ );
 tp:= Pointer(temp);
 END;
 
 WITH Tempb DO {*** now read the data ***}
 BEGIN
 ioCRefNum  := adsp^.dspRefNum;
 ccbRefNum  := conn^.ccbRef;
 csCode := dspRead;
 reqCount := cnt;
 dataPtr  := tp; 
 END;
 err := PBControl( @Tempb, SYNC );
 HUnlock( inBuf );

 IF err=noErr THEN
 BEGIN
 inSize := GetHandleSize( inBuf );
 inSize := inSize - (cnt-Tempb.actCount);
 SetHandleSize( inBuf, inSize );
 END;
 
 IF (err=noErr) AND (Tempb.eom=1) THEN
 BEGIN
 IF inBuf <> NIL THEN {***Call back with data***}
 BEGIN
 IF remName <> NIL THEN
 SetGlobal( ‘ADSPCaller’, remName );

 tp     := Pointer( Ord4( inBuf^ ) + LongInt(inSize) );
 tp^    := 0;
 
 SetGlobal( globName, inbuf );
 DisposHandle( inbuf );
 inbuf := NIL;
 END;
 
 IF callMe <> NIL THEN {***Set remote-end name***}
 BEGIN
 HLock( callMe );
 ZeroToPas( Pointer( callMe^ ), globName );
 HUnlock( callMe );
 SendCardMessage(  globName );
 END;
 END;
 END;{*** read the data ***}
END;

Function CheckMessages( cb : cbPtr ): OSErr;
(************************************)
(* check this connection for: *)
(* (1) Completed Incoming Messages *)
(* (2) Completed Outgoing Messages *)
(************************************)
VAR
 myErr  : OSErr;
 tpb    : dspParamBlock;
BEGIN
 WITH tpb DO
 BEGIN
 csCode := dspStatus;
 ioCRefNum:= adsp^.dspRefNum;
 ccbRefNum:= cn^.ccbRef;
 END;
 myErr := PBControl( @tpb, SYNC );
 
 IF myErr = noErr THEN
 BEGIN
 {*** (3) Check for pending incoming data    ***}
 IF tpb.recvQPending <> 0  THEN
 ReadADSPData( cn, tpb.recvQPending, paramPtr^.params[1] );

 {***(4) See if any write operations have completed***}
 IF (tpb.SendQPending = 0) AND (cn^.OutBuf <> NIL ) THEN
 BEGIN
 HUnlock( cn^.outBuf );
 DisposHandle( cn^.outBuf );
 cn^.outBuf := NIL;
 END;
 END; { myErr <> noErr }
 CheckMessages := myErr;
END;

(**********************************)
(* ADSPListen    *)
(**********************************)

BEGIN
 error  := noErr;
 adsp := ADSPPtr(RetrieveData( ‘GLOBALDSPDATA’ ));

 IF adsp <> NIL THEN
 BEGIN
 adsp^.checkPoint := RECEIVING;
 cn := adsp^.ends;

 {***(2) Monitor status on all connections***}
 WHILE cn <> NIL DO WITH cn^ DO 
 BEGIN
 nn := next;
 err := noErr;
 
 CASE ccb.state OF { connection states } 
 sClosed: err := DSPHangUp( cn );
 
 sOpen:
 BEGIN
 IF mode = NOP THEN {***connection is opening ***}
 BEGIN  {***inform Hypercard of connection***}
 SetGlobal( ‘ADSPCaller’, remName );
 SendCardMessage( ‘ConnectionMade’ );
 mode := EST;
 END
 ELSE
 BEGIN  {*** Check an established connection ***}
 myBPtr := @cn^.ccb.userFlags;
 
 IF BAND(myBPtr^, eClosed)=eClosed THEN 
 err := DSPHangUp( cn )
 ELSE
 BEGIN
 err := CheckMessages( cn );
 
 myBPtr^ := 0;   { clear user flags}
 END;
 END;
 END;
 END; { case of connection states }
 
 IF err <> noErr THEN error := err;
 cn := nn;
 END;
 RespondToListen;{*** check for opening calls ***}
 adsp^.checkPoint := CLOSE_OK;
 END; {*** IF adsp <> NIL ***}

 paramPtr^.returnValue := PasToZero( NumToStr( LongInt(err) ) );;
END;

end.
Listing 4:  ADSPHangUp.p

(****************************)
(* file:  ADSPHangUp.p    *)
(* *)
(* Disconnect an established*)
(* connection and deallocate*)
(* the data  associated with*)
(* the connection. *)
(* *)
(* In:  params[1] Name of *)
(* the entity to hangup on*)
(* *)
(* Out: error message,    *)
(* empty if none.*)
(* *)
(* ------------------------ *)
(* By:  Donald Koscheka   *)
(* Date:2-Mar-89 *)
(* All Rights Reserved    *)
(* *)
(* ------------------------ *)
(****************************)

(*****************************
 Build Sequence

pascal -o ADSPHangUp.p.o ADSPHangUp.p
link -m ENTRYPOINT  -rt XCMD=1304 -sn Main=ADSPHangUp
 ADSPHangUp.p.o
 “{libraries}”Interface.o 
 -o YourStackNameHere
  
******************************)

{$R-}
{$S ADSPHangUp}
UNIT DummyUnit;

(****************************)
 INTERFACE 
(****************************)

Uses  MemTypes, QuickDraw, OSIntf,
 ToolIntf, PackIntf, HyperXCmd, 
 AppleTalk, ADSP, adspxcmd;

Procedure EntryPoint( paramPtr : XCmdPtr );

(****************************)
 IMPLEMENTATION
(****************************)
TYPE Str31 = String[31];

PROCEDURE ADSPHangUp( paramPtr: XCmdPtr ); FORWARD;
Procedure EntryPoint( paramPtr : XCmdPtr );
 Begin
 ADSPHangUp( paramPtr );
 End;
 
Procedure ADSPHangUp( paramPtr : XCmdPtr );
VAR
 adsp   : ADSPPtr;
 error  : OSErr;
 pb: DSPParamBlock;
 eAddr  : AddrBlock;
 cb: CBPtr;

{$I XCmdGlue.inc }
{$I XCMDADSP.inc } 
(****************************)
BEGIN
 error := noErr;
 IF ( paramPtr^.paramCount > 0 )
 AND ( paramPtr^.params[1] <> NIL ) THEN           
 BEGIN
 adsp := ADSPPtr(RetrieveData( ‘GLOBALDSPDATA’ ));
 IF adsp <> NIL THEN
 BEGIN
 adsp^.checkPoint := RECEIVING;
 {*** (1) Get the entity’s address ***}
 HLock( Handle(paramPtr^.params[1]) );
 eAddr := NBPGetAddress( paramPtr^.params[1]^ );
 cb := adsp^.ends;
 
 {*** match the entity to the list ***}
 IF LongInt(eAddr) <> 0 THEN
 WHILE cb <> NIL DO
 IF LongInt(cb^.adr ) = LongInt( eAddr ) THEN
 BEGIN
 error := DSPHangUp( cb );
 cb := NIL;
 END
 ELSE
 cb := cb^.next;
 
 HUnlock( Handle(paramPtr^.params[1]) );
 adsp^.checkPoint := CLOSE_OK;
 END
 END;
 paramPtr^.returnValue := PasToZero( NumToStr( LongInt(error) ) );
END;

end.

 
AAPL
$97.67
Apple Inc.
+0.64
MSFT
$44.50
Microsoft Corpora
+0.10
GOOG
$589.02
Google Inc.
-4.33

MacTech Search:
Community Search:

Software Updates via MacUpdate

TinkerTool 5.3 - Expanded preference set...
TinkerTool is an application that gives you access to additional preference settings Apple has built into Mac OS X. This allows to activate hidden features in the operating system and in some of the... Read more
Audio Hijack Pro 2.11.0 - Record and enh...
Audio Hijack Pro drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio with Audio Hijack... Read more
Intermission 1.1.1 - Pause and rewind li...
Intermission allows you to pause and rewind live audio from any application on your Mac. Intermission will buffer up to 3 hours of audio, allowing users to skip through any assortment of audio... Read more
Autopano Giga 3.6 - Stitch multiple imag...
Autopano Giga allows you to stitch 2, 20, or 2,000 images. Version 3.0 integrates impressive new features that will definitely make you adopt Autopano Pro or Autopano Giga: Choose between 9... Read more
Airfoil 4.8.7 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
Microsoft Remote Desktop 8.0.8 - Connect...
With Microsoft Remote Desktop, you can connect to a remote PC and your work resources from almost anywhere. Experience the power of Windows with RemoteFX in a Remote Desktop client designed to help... Read more
xACT 2.30 - Audio compression toolkit. (...
xACT stands for X Aaudio Compression Toolkit, an application that encodes and decodes FLAC, SHN, Monkey’s Audio, TTA, Wavpack, and Apple Lossless files. It also can encode these formats to MP3, AAC... Read more
Firefox 31.0 - Fast, safe Web browser. (...
Firefox for Mac offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals... Read more
Little Snitch 3.3.3 - Alerts you to outg...
Little Snitch gives you control over your private outgoing data. Track background activityAs soon as your computer connects to the Internet, applications often have permission to send any... Read more
Thunderbird 31.0 - Email client from Moz...
As of July 2012, Thunderbird has transitioned to a new governance model, with new features being developed by the broader free software and open source community, and security fixes and improvements... Read more

Latest Forum Discussions

See All

Jacob Jones and the Bigfoot Mystery : Ep...
Jacob Jones and the Bigfoot Mystery : Episode 2 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Jacob Jones is back in Episode 2 of one of Apples 'Best of 2013' games and an App Store... | Read more »
New Trailer For Outcast Odyssey, A New K...
New Trailer For Outcast Odyssey, A New Kind of Card Battler Posted by Jennifer Allen on July 25th, 2014 [ permalink ] Out this Fall is a new kind of card battle game: Outcast Odyssey. | Read more »
Garfield: Survival of the Fattest Coming...
Garfield: Survival of the Fattest Coming to iOS this Fall Posted by Jennifer Allen on July 25th, 2014 [ permalink ] Who loves lasagna? Me. Also everyone’s favorite grumpy fat cat, Garfield. | Read more »
Happy Flock Review
Happy Flock Review By Andrew Fisher on July 25th, 2014 Our Rating: :: HERD IT ALL BEFOREUniversal App - Designed for iPhone and iPad Underneath the gloss of Happy Flock’s visuals is a game of very little substance. It’s cute, but... | Read more »
Square Register Updates Adds Offline Pay...
Square Register Updates Adds Offline Payments Posted by Ellis Spice on July 25th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Looking For Group – Hearthstone’s Curse...
For the first time since its release (which has thankfully been a much shorter window for iPad players than their PC counterparts), Blizzard’s wildly successful Hearthstone: Heroes of Warcraft CCG is sporting some brand new content: the single... | Read more »
Poptile Review
Poptile Review By Jennifer Allen on July 25th, 2014 Our Rating: :: SIMPLY FUNUniversal App - Designed for iPhone and iPad Simple yet a little bit glorious, Poptile is a satisfying entertaining puzzle game with oodles of the ‘one... | Read more »
Modern Combat 5: Blackout Review
Modern Combat 5: Blackout Review By Brittany Vincent on July 25th, 2014 Our Rating: :: LESS QQ, MORE PEW PEWUniversal App - Designed for iPhone and iPad The fifth entry into the blockbuster Modern Combat series is what mobile... | Read more »
Watch and Share Mobile Gameplay Videos W...
Watch and Share Mobile Gameplay Videos With Kamcord Posted by Jennifer Allen on July 25th, 2014 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »
THE KING OF FIGHTERS '98 (Games)
THE KING OF FIGHTERS '98 1.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: Series’ masterpiece “KOF ’98” finally joins the battle on iPhone! FEATURES:■ The best game balance in the “KOF”... | Read more »

Price Scanner via MacPrices.net

iMacs on sale for $150 off MSRP, $250 off for...
Best Buy has iMacs on sale for up to $160 off MSRP for a limited time. Choose free home shipping or free instant local store pickup (if available). Prices are valid for online orders only, in-store... Read more
Mac minis on sale for $100 off MSRP, starting...
Best Buy has Mac minis on sale for $100 off MSRP. Choose free shipping or free instant local store pickup. Prices are for online orders only, in-store prices may vary: 2.5GHz Mac mini: $499.99 2.3GHz... Read more
Global Tablet Market Grows 11% in Q2/14 Notwi...
Worldwide tablet sales grew 11.0 percent year over year in the second quarter of 2014, with shipments reaching 49.3 million units according to preliminary data from the International Data Corporation... Read more
New iPhone 6 Models to Have Staggered Release...
Digitimes’ Cage Chao and Steve Shen report that according to unnamed sources in Apple’s upstream iPhone supply chain, the new 5.5-inch iPhone will be released several months later than the new 4.7-... Read more
New iOS App Helps People Feel Good About thei...
Mobile shoppers looking for big savings at their favorite stores can turn to the Goodshop app, a new iOS app with the latest coupons and deals at more than 5,000 online stores. In addition to being a... Read more
Save on 5th generation refurbished iPod touch...
The Apple Store has Apple Certified Refurbished 5th generation iPod touches available starting at $149. Apple’s one-year warranty is included with each model, and shipping is free. Many, but not all... Read more
What Should Apple’s Next MacBook Priority Be;...
Stabley Times’ Phil Moore says that after expanding its iMac lineup with a new low end model, Apple’s next Mac hardware decision will be how it wants to approach expanding its MacBook lineup as well... Read more
ArtRage For iPhone Painting App Free During C...
ArtRage for iPhone is currently being offered for free (regularly $1.99) during Comic-Con San Diego #SDCC, July 24-27, in celebration of the upcoming ArtRage 4.5 and other 64-bit versions of the... Read more
With The Apple/IBM Alliance, Is The iPad Now...
Almost since the iPad was rolled out in 2010, and especially after Apple made a 128 GB storage configuration available in 2012, there’s been debate over whether the iPad is a serious tool for... Read more
MacBook Airs on sale starting at $799, free s...
B&H Photo has the new 2014 MacBook Airs on sale for up to $100 off MSRP for a limited time. Shipping is free, and B&H charges NY sales tax only. They also include free copies of Parallels... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Sr. Project Manager for *Apple* Campus 2 -...
…the design and construction of one building or building components of the New Apple Campus located in Cupertino, CA. They will provide project management oversight for Read more
WW Sales Program Manager, *Apple* Online St...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.