Developer CD Series 1996 November: Tool Chest/Dev.CD Nov 96 TC/Dev.CD Nov 96 TC.toast/Tool Chest/Interapplication Communication/Server Remote Control 1.1/Server Controller.p

Text File | 1995-06-20 | 30.3 KB | 1,011 lines | [TEXT/MWPS]

{$N-}

{ Server Controller code }
{ © Copyright 1991-1995 Jim Luther, All rights reserved. }

{ Modification History: }
{ 28 Dec 91    JML        V1.0d1    First working version with System 7 File Sharing }
{ 30 Dec 91    JML        V1.0d1    Added check for Gestalt and ServerDispatch traps to }
{                            InitializeApp and added kExitNoServerDispatch error string }
{                            resource. }
{ 30 Dec 91    JML        V1.0d1    Added gServerKind and gASFileServerFSSpec globals and }
{                            GetServerKind and FindASFileServerApp functions. }
{ 30 Dec 91    JML        V1.0d1    Changed RemoteSCPBRec structure (added scSetup field) }
{ 30 Dec 91    JML        V1.0d1    Hacked up PPCProcessReads to use SCSleepServer and SCWakeServer }
{                            when the server is AppleShare 3.0. }
{ 31 Dec 91    JML        V1.0d1    PPCProcessReads now launches the AppleShare File Server }
{                            application if the SCStartServer command is sent. }
{ 31 Dec 91    JML        V1.0d2    Works with AppleShare 3.0. }
{  2 Jan 92    JML        V1.0d2    Got my creator assignments, so I added a BNDL, ICN#, etc and }
{                            changed a few things to use the new creator types and the }
{                            version resources. }
{ 10 Mar 93    JML        V1.0    Ahhh, just release the dang thing. It works fine. }
{ 21 May 95    JML        V1.1b1    Make it compile with Metrowerks Pascal CW6 and }
{                            Universal Interfaces (what a hassle!). }
{ 21 May 95    JML        V1.1b1    Change kMaxSleep from MaxLongInt to 600 to work around }
{                            old WakeUpProcess bug. }
{ 22 May 95    JML        V1.1b1    Set gPPCWriteInProgress to false everytime in WriteCompProc to }
{                            fix hang condition. }

{$IFC UNDEFINED THINK_Pascal}
{$ELSEC}
{$I-}
{$ENDC}

PROGRAM ServerControl;

    USES
        AppleTalk, Processes, PPCToolBox, EPPC, Notification, AppleEvents, Script, Finder, Folders, Traps,
{$IFC UNDEFINED THINK_Pascal}
        ToolUtils, GestaltEqu, Resources, SegLoad,
{$ENDC}
        ServerControlIntf;

    CONST
        kPortName = 'Server Controller';    { should use a resource string }

        kControllerCreator = 'ASsc';    { used for our PPC port's portCreator and nbpType }
        kRemoteCreator = 'ASrc';        { used for remote PPC port's portCreator }

        kMaxSleep = 600;            { sleep for around 10 seconds when not connected }
        kConnectedSleep = 60;        { how often to poll server when connected }

        { PPCReject rejectInfo codes }
        kRemoteIsNotOwner = 1;
        kRemoteAppUnknown = -1;

        kExitErrorStrings = 500;
        kNumExitErrors = 12;    { IMPORTANT -- Must match number of exit errors }
        { ExitToShell errors }
        kExitNoSystem7 = 1;
        kExitNoAppleEvts = 2;
        kExitAEHandlerNotInstalled = 3;
        kExitNoOwnerName = 4;
        kExitNoPPC = 5;
        kExitPPCInitFailed = 6;
        kExitAppleTalkDisabled = 7;
        kExitProgramLinkingDisabled = 8;
        kExitPPCOpenFailed = 9;
        kExitPPCInformFailed = 10;
        kExitNoServerDispatch = 11;
        kExitCantFindASFSApp = 12;
        kCantIncreaseStack = 13;

        {ServerControl constants}
        kSIMaxLogins = 200;

        kVerNumType = $01008000;        { NumVersion.version used for the remote and our }
                                    { PPC ports' portType. In this case version 1.0.0 final. }


    TYPE
        RemoteSCPBRec = RECORD
                scPB: SCParamBlockRec;
                scMessageOrName: Str255;
                scDiscArray: ARRAY[1..kSIMaxLogins] OF LongInt;
                scSetup: SetupInfoRec;
            END;

        PPCIOBuffer = RemoteSCPBRec;

    VAR
        gQuit: Boolean;
        gSleep: LongInt;
        gTicks: LongInt;

        gServerType: Integer;    { 0 = System 7 File Sharing; 1 = AppleShare 3.0 }
        gASFileServerFSSpec: FSSpec;    { FSSpec to the AppleShare File Server app if }
                                        { gServerType = AppleShare 3.0 }
        gOwnerName: Str255;
        gOurPSN: ProcessSerialNumber;

        gPPCPortOpen: Boolean;            { TRUE when the PPC port has been opened }
        gPPCPortRefNum: PPCPortRefNum;    { The PPC port reference number }
        gPPCSessRefNum: PPCSessRefNum;  { The PPC session reference number }

        gPPCGeneralRec: PPCParamBlockRec;
        gPPCSessPortName: PPCPortRec;
        gPPCSessLocationName: LocationNameRec;
        gPPCSessUserName: Str32;
        gPPCReadBuffer: PPCIOBuffer;
        gPPCDataRead: Boolean;

        gRemoteSCpb: RemoteSCPBRec;
        gPollSCpb: SCParamBlockRec;

        gPPCWriteRec: PPCParamBlockRec;    { used for PPCWrite calls }
        gPPCWriteInProgress: Boolean;

        gNotificationMgrPresent: Boolean;
        gNMRec: NMRec;
        gNMStrs: ARRAY[1..kNumExitErrors] OF Str255;


    { needed forward declarations }

    PROCEDURE ReadCompProc (pb: PPCParamBlockPtr);
    FORWARD;

    FUNCTION StartPPCInform (pb: PPCParamBlockPtr): OSErr;
    FORWARD;


{$S Main}
    PROCEDURE NotifyResponseProc (nmReqPtr: NMRecPtr);
        VAR
            oldA5: LongInt;
            err: OSErr;
    BEGIN
        oldA5 := SetA5(nmReqPtr^.nmRefCon);
        gQuit := TRUE;
        err := WakeUpProcess(gOurPSN);
        err := NMRemove(nmReqPtr);
        oldA5 := SetA5(oldA5);
    END;


{$S Main}
    PROCEDURE NotifyAndExit (errCode: Integer);
    BEGIN
        WITH gNMRec DO
            BEGIN
                qType := ORD(nmType);
                nmMark := 0;
                nmIcon := NIL;
                nmSound := Handle(-1);
                nmStr := @gNMStrs[errCode];
                nmResp := @NotifyResponseProc;
                nmRefCon := SetCurrentA5;
            END;
        IF (NMInstall(@gNMRec) <> noErr) THEN
            BEGIN
                gSleep := 10;
                gQuit := TRUE;
            END;
    END;

{-------------------------------------------------------------------------------}
{|    IMPORTANT NOTE                                                                }
{|    From here down to the next comment that looks like this (i.e. starts with    }
{|    an IMPORTANT NOTE title) all the routines defined are completion routines    }
{|    the main trick is that they almost always call some other PPC Toolbox call    }
{|  or somehow tell the main application that it's time to process some data    }
{-------------------------------------------------------------------------------}

{------------------------------------------------------------------------------}
{$S Main}

    PROCEDURE EndCompProc (pb: PPCParamBlockPtr);
    { This procedure gets called when the asynchronous PPCEnd call completes. }

        VAR
            err: OSErr;    { used to catch the PPC function results. }

    BEGIN
        IF gPPCPortOpen THEN
            BEGIN
                gSleep := kMaxSleep; { go back into sleepy mode while no session is active }
                { use the parameter block to start a new session }
                err := StartPPCInform(pb);
                IF err <> noErr THEN
                    BEGIN
                        { Should signal the application that "something really bad" has}
                        { happened and enqueue the parameter block so it doesn't}
                        { get lost.}
                    END;
            END;
        { ELSE port isn't open; things are shutting down so do nothing }
    END;

{------------------------------------------------------------------------------}
{$S Main}

    PROCEDURE WriteCompProc (pb: PPCParamBlockPtr);
    { This procedure gets called when the asynchronous PPCWrite call completes.}
    { If no errors are detected, then it puts the parameter block in the }
    { gWpbQueue where the PollTheServer procedure will find it next time it }
    { needs to send data to the remote. }
    { If an error is detected, then PPCEnd is called asynchronously to close}
    { the session. }

        VAR
            err: OSErr;    { used to catch the PPC function results. }

    BEGIN
        gPPCWriteInProgress := FALSE;
        IF PPCWritePBPtr(pb)^.ioResult <> noErr THEN
            BEGIN
            { if we get an error, then we call PPCEnd to close up cleanly}
                PPCEndPBPtr(pb)^.ioCompletion := @EndCompProc;
                err := PPCEndAsync(PPCEndPBPtr(pb));
            END;
    END;

{------------------------------------------------------------------------------}
{$S Main}

    PROCEDURE ReadCompProc (pb: PPCParamBlockPtr);
    { This procedure gets called when the asynchronous PPCRead call completes.}
    { If no errors are detected, then it puts the parameter block in the }
    { gRpbQueue where the PPCProcessReads procedure will find it and process }
    { the data read.  PPCProcessReads will make another PPCRead call. }
    { If an error is detected, then PPCEnd is called asynchronously to close}
    { the session. }

        VAR
            err: OSErr;    { used to catch the PPC function results. }

    BEGIN
        IF PPCReadPBPtr(pb)^.ioResult = noErr THEN
            BEGIN
                gPPCDataRead := TRUE;
                err := WakeUpProcess(gOurPSN);
            END
        ELSE
            BEGIN
                { if we get an error, then we call PPCEnd to close up cleanly}
                PPCEndPBPtr(pb)^.ioCompletion := @EndCompProc;
                err := PPCEndAsync(PPCEndPBPtr(pb));
            END;
    END;

{------------------------------------------------------------------------------}
{$S Main}

    PROCEDURE RejectCompProc (pb: PPCParamBlockPtr);
    { This procedure gets called when the asynchronous PPCReject call completes. }

        VAR
            err: OSErr;    { used to catch the PPC function results. }

    BEGIN
        IF gPPCPortOpen THEN { if port isn't open, then things are shutting down so do nothing }
            BEGIN
                { use the parameter block to start a new session }
                err := StartPPCInform(pb);
                IF err <> noErr THEN
                    BEGIN
                        { Should signal the application that "something really bad" }
                        { has happened and enqueue the parameter block so it }
                        { doesn't get lost.}
                    END;
            END;
    END;

{------------------------------------------------------------------------------}
{$S Main}

    PROCEDURE AcceptCompProc (pb: PPCParamBlockPtr);
    { This procedure gets called when the asynchronous PPCAccept call completes.}
    {  If no errors are detected, then it makes an asynchronous PPCRead call.}
    {  If an error is detected, then it makes an asynchronous PPCEnd call to close}
    {  the session. }

        VAR
            err: OSErr;    { used to catch the PPC function results. }

    BEGIN
        IF PPCAcceptPBPtr(pb)^.ioResult = noErr THEN
            BEGIN
                gPPCSessRefNum := PPCAcceptPBPtr(pb)^.sessRefNum;
                gSleep := kConnectedSleep;

                { start the first PPCRead }
                WITH PPCReadPBPtr(pb)^ DO
                    BEGIN
                        ioCompletion := @ReadCompProc;
                        { We're reusing the same parameter block, so the sessRefNum}
                        { is already filled in for us. }

                        bufferLength := sizeof(PPCIOBuffer);
                        bufferPtr := @gPPCReadBuffer;
                    END;
                gPPCDataRead := FALSE;
                err := PPCReadAsync(PPCReadPBPtr(pb));        { asynchronously }
                err := WakeUpProcess(gOurPSN);
            END
        ELSE
            BEGIN
                { if we get an error, then we call PPCEnd to close up cleanly}
                PPCEndPBPtr(pb)^.ioCompletion := @EndCompProc;
                err := PPCEndAsync(PPCEndPBPtr(pb));
            END;
    END;

{------------------------------------------------------------------------------}
{$S Main}

    PROCEDURE InformCompProc (pb: PPCParamBlockPtr);
    { This procedure gets called when the asynchronous PPCInform call completes.}
    {  If no errors are detected, then it decides if the session request}
    {  should be accepted of rejected. If the session is accepted, then it makes an}
    {  asynchronous PPCAccept call.    If the session is rejected, then it makes an}
    {  asynchronous PPCReject call (and passes PPCReject the rejectInfo).  If an}
    {  error is detected, then it makes an asynchronous PPCEnd call to close}
    {  the session. }

        VAR
            err: OSErr;    { used to catch the PPC function results. }

    BEGIN
        IF PPCInformPBPtr(pb)^.ioResult = noErr THEN
            BEGIN
                { Make sure the owner is connecting with my remote application }
                IF (EqualString(gPPCSessUserName, gOwnerName, FALSE, TRUE) OR (PPCInformPBPtr(pb)^.requestType = CHAR(ppcLocalOrigin))) AND (PPCInformPBPtr(pb)^.portName^.portKindSelector = ppcByCreatorAndType) AND (PPCInformPBPtr(pb)^.portName^.portCreator = kRemoteCreator) AND (LongInt(PPCInformPBPtr(pb)^.portName^.portType) = kVerNumType) THEN
                    BEGIN
                        PPCAcceptPBPtr(pb)^.ioCompletion := @AcceptCompProc;
                        { We're reusing the same parameter block, so the}
                        { sessRefNum is already filled in for us. }
                        err := PPCAcceptAsync(PPCAcceptPBPtr(pb)); { asynchronous }
                    END
                ELSE
                    BEGIN
                        WITH PPCRejectPBPtr(pb)^ DO
                            BEGIN
                                ioCompletion := @RejectCompProc;
                                { We're reusing the same parameter block, so the}
                                { sessRefNum is already filled in for us. }

                                { Set the rejectInfo field }
                                IF gPPCSessUserName <> gOwnerName THEN
                                    rejectInfo := kRemoteIsNotOwner
                                ELSE
                                    rejectInfo := kRemoteAppUnknown;
                            END;
                        err := PPCRejectAsync(PPCRejectPBPtr(pb)); { asynchronous }
                    END;
            END
        ELSE
            BEGIN
                { if we get an error, then we call PPCEnd to close up cleanly}
                PPCEndPBPtr(pb)^.ioCompletion := @EndCompProc;
                err := PPCEndAsync(PPCEndPBPtr(pb));
            END;
    END;

{------------------------------------------------------------------------------}
{| IMPORTANT NOTE:}
{|        All the procedures above here are executed at interrupt time.  Each}
{|        one of them is used as a completion routine.}
{-------------------------------------------------------------------------------}


{$S Main}
    FUNCTION StartPPCInform (pb: PPCParamBlockPtr): OSErr;
    { Initializes the session record's fields, and calls PPCInform to receive}
    {  another PPC session request.}
    {  Any errors detected are passed back to the caller. }
        VAR
            err: OSErr;
    BEGIN
        { set up the parameter block for a PPCInform call }
        WITH PPCInformPBPtr(pb)^ DO
            BEGIN
                ioCompletion := @InformCompProc;
                portRefNum := gPPCPortRefNum;
                autoAccept := FALSE;    { we will approve sessions before accepting them }
                { The portName, locationName, and userName records }
                { are filled in by PPCInform.  They tell you the }
                { port name, location name, and user name of the }
                { destination port that is attempting to start a }
                { session with us. }
                portName := @gPPCSessPortName;
                locationName := @gPPCSessLocationName;
                userName := @gPPCSessUserName;
            END;
        { execute PPCInform asynchronously and return any errors to caller }
        StartPPCInform := PPCInformAsync(PPCInformPBPtr(pb));
    END;


{$S Main}
    FUNCTION OpenPPCPort: OSErr;
    { OpenPPCPort opens a PPC port for use by the server sessions.}
    {  It initializes the port name and location name records.}
    {  Then, it calls PPCOpen synchronously to open the port.  If the port was}
    {  sucessfully opened, the gPPCPortOpen is set TRUE, and gPPCPortRefNum is set to}
    {  the port reference number returned by PPCOpen.}
    {  Any errors detected are passed back to PPCStartUp to be returned to}
    {  the application. }

        VAR
            thePortRec: PPCPortRec;                { the port name of the port to be opened. }
            theLocationName: LocationNameRec;    { location name of the port to be opened. }
            theOpenPBRec: PPCOpenPBRec;            { used by the PPCOpen call. }
            err: OSErr;    { used to keep track of errors within the function. }
    BEGIN
        { initialize the port name record }
        WITH thePortRec DO
            BEGIN
                nameScript := GetScriptManagerVariable(smSysScript);    { use Script Manager call to get System Script }
                name := kPortName;                { This is the name that will show up in the }
                                                { "Programs" list that the Browser puts up.}
                                                { It should be a resource string instead of }
                                                { hard coded (as done here).}
                portKindSelector := ppcByCreatorAndType;    { port kind by creator/type }
                portCreator := kControllerCreator;
                portType := OSType(kVerNumType);
            END;

        { initialize the location name record }
        WITH theLocationName DO
            BEGIN
                locationKindSelector := ppcNBPTypeLocation;
                nbpType := kControllerCreator;
            END;

        { Now, set up Open parameter block record }
        WITH theOpenPBRec DO
            BEGIN
                ioCompletion := NIL;                { no completion Proc needed (synchronous) }
                serviceType := CHAR(ppcServiceRealTime);    { 7.0 only supports this type of service }
                resFlag := 0;                        { must be zero }
                portName := @thePortRec;            { pointer to port record}
                locationName := @theLocationName;    { pointer to location name record }
                networkVisible := TRUE;             { Yes, let other PPC users see us! }
            END;

        { execute PPCOpen synchronously and return any errors to caller }
        err := PPCOpen(@theOpenPBRec, FALSE);
        IF err = noErr THEN
            BEGIN
                gPPCPortOpen := TRUE;                { set the global port open flag }
                gPPCPortRefNum := theOpenPBRec.portRefNum;    { set the global port reference number }
            END;
        OpenPPCPort := err;
    END;


{$S Main}
    PROCEDURE PPCShutDown;
    { PPCShutDown first closes the PPC port that was opened by PPCStartUp.}
    {  Closing the port will automatically kill all sessions that use that port.}
    {  After closing the port, PPCShutDown disposes of all session records. }

        VAR
            theClosePBRec: PPCClosePBRec;
            err: OSErr;
    BEGIN
        { Close the port.  This will cause all PPC calls associated with this port }
        { to complete. }
        IF gPPCPortOpen THEN    { close the port }
            BEGIN
                gPPCPortOpen := FALSE;    { tell completion routines we're shutting down }
                                        { so they won't try to restart a session }
                theClosePBRec.ioCompletion := NIL;
                theClosePBRec.portRefNum := gPPCPortRefNum;
                err := PPCClose(@theClosePBRec, FALSE);
            END;
    END;


{$S Initialize}
    FUNCTION InitPPCStuff: Boolean;
        VAR
            PPCAttributes: LongInt;    {Storage for the response from Gestalt}
            err: OSErr;    {Temporary variable to catch errors}
    BEGIN
        InitPPCStuff := FALSE;
        IF Gestalt(gestaltPPCToolboxAttr, PPCAttributes) <> noErr THEN
            BEGIN
                NotifyAndExit(kExitNoPPC); { ••• Bail out now ••• }
                Exit(InitPPCStuff);
            END;

        { ELSE PPC Toolbox is present }

        { Does PPC need initialization? }
        IF BAND(PPCAttributes, gestaltPPCSupportsRealTime) = 0 THEN
            BEGIN    { PPC Toolbox needs initialization }
                { initialize the PPC Toolbox and set function result }
                IF PPCInit = noErr THEN
                    { get the post-init attributes for the PPC Toolbox }
                    err := Gestalt(gestaltPPCToolboxAttr, PPCAttributes)
                ELSE    { PPC can't be inited }
                    BEGIN
                        NotifyAndExit(kExitPPCInitFailed); { ••• Bail out now ••• }
                        Exit(InitPPCStuff);
                    END;
            END;

        { Make sure ports can be opened to the outside world }
        IF BAND(PPCAttributes, gestaltPPCSupportsOutGoing) = 0 THEN
            { It's likely that AppleTalk is disabled, so you    }
            { may want to tell the user to activate AppleTalk    }
            { from the Chooser.    }
            BEGIN
                NotifyAndExit(kExitAppleTalkDisabled); { ••• Bail out now ••• }
                Exit(InitPPCStuff);
            END;

        { Make sure ports can be opened with location names that the }
        { outside world can see }
        IF BAND(PPCAttributes, gestaltPPCSupportsIncoming) = 0 THEN
            { It's likely that Program Linking is disabled, so you    }
            { may want to tell the user to start Program Linking    }
            { from the Sharing Setup control panel.    }
            BEGIN
                NotifyAndExit(kExitProgramLinkingDisabled); { ••• Bail out now ••• }
                Exit(InitPPCStuff);
            END;

        IF OpenPPCPort <> noErr THEN
            { couldn't open a PPC port }
            BEGIN
                NotifyAndExit(kExitPPCOpenFailed); { ••• Bail out now ••• }
                Exit(InitPPCStuff);
            END;

        IF StartPPCInform(@gPPCGeneralRec) <> noErr THEN
            BEGIN
                PPCShutDown; { close the port }
                NotifyAndExit(kExitPPCInformFailed); { ••• Bail out now ••• }
                Exit(InitPPCStuff);
            END;
        InitPPCStuff := TRUE;
    END;


{$S Main}
{ This is the standard Open Application event. }
    FUNCTION AEOpenHandler (messagein: AppleEvent;
                                    reply: AppleEvent;
                                    refIn: LongInt): OSErr;
    BEGIN
    { we of course don't do anything here }
        AEOpenHandler := noErr;
    END;


{$S Main}
    FUNCTION AEOpenDocHandler (messagein: AppleEvent;
                                    reply: AppleEvent;
                                    refIn: LongInt): OSErr;
    BEGIN
    { we of course don't do anything here }
        AEOpenDocHandler := errAEEventNotHandled;    { we have no docs, so no odoc events should come to us }
    END;


{$S Main}
    FUNCTION AEPrintHandler (messagein: AppleEvent;
                                    reply: AppleEvent;
                                    refIn: LongInt): OSErr;
    BEGIN
    { we of course don't do anything here }
        AEPrintHandler := errAEEventNotHandled;    { we have no docs, so no pdoc events should come to us }
    END;


{$S Main}
{ Standard Quit event handler, to handle a Quit event from the Finder, for example.    }
{ ••••• DO NOT CALL EXITTOSHELL HERE ••••• or you will never have a happy life.    }
    FUNCTION AEQuitHandler (messagein: AppleEvent;
                                    reply: AppleEvent;
                                    refIn: LongInt): OSErr;
    BEGIN
    { prepQuit sets the Stop flag for us.  It does _NOT_ quit, you }
    { should NEVER quit from an AppleEvent handler.  Calling }
    { ExitToShell here would blow things up }
        gQuit := TRUE;
        AEQuitHandler := noErr;
    END;


{$S Main}
{ I'm not doing any error handling here because there's }
{ not a lot I can do; just pass the errors back. }
    PROCEDURE DoHighLevel (AERecord: EventRecord);
        VAR
            err: OSErr;
    BEGIN
        err := AEProcessAppleEvent(AERecord);
    END;


{$S Main}
    PROCEDURE PPCProcessReads;
{••••• My initial design was flawed so I'm gonna have to hack this up to get it }
{••••• to work with AS 3.0 and System 7.  1.0 d3 will fix it. }
        VAR
            pbPtr: PPCParamBlockPtr;
            err: OSErr;
            launchPB: LaunchParamBlockRec;
    BEGIN
        IF gPPCDataRead THEN    { process the data read }
            BEGIN
                { Make a server control call based on the data just read }

                { move the parameter block data into the local SCParamBlockRec }
                BlockMove(gPPCGeneralRec.readParam.bufferPtr, @gRemoteSCpb, sizeof(RemoteSCPBRec));
                { set up any parameter block pointers and call ServerDispatch }
                CASE gRemoteSCpb.scPB.disconnectPB.scCode OF
                    SCStartServer:
                        BEGIN
                            CASE gServerType OF
                                0: { System 7 File Sharing }
                                    err := SyncServerDispatch(@gRemoteSCpb.scPB);
                                1:
                                    BEGIN
                                    { This call won't happen unless the AppleShare File }
                                    { Server application isn't running, so we need to }
                                    { launch it. }
                                        WITH launchPB DO
                                            BEGIN
                                                launchBlockID := extendedBlock;
                                                launchEPBLength := extendedBlockLen;
                                                launchFileFlags := 0;
                                                launchControlFlags := launchContinue + launchNoFileFlags;
                                                launchAppSpec := @gASFileServerFSSpec;
                                                launchAppParameters := NIL;
                                            END;
                                        err := LaunchApplication(@launchPB);
                                    END;
                            END;
                        END;
                    SCShutDown:
                        BEGIN
                            gRemoteSCpb.scPB.disconnectPB.scMessagePtr := @gRemoteSCpb.scMessageOrName;

                            {••••• HACK ALERT!!!  Will delete this IF statement at 1.0d3 }
                            IF gServerType = 1 THEN
                                gRemoteSCpb.scPB.disconnectPB.scCode := SCSleepServer;

                            err := SyncServerDispatch(@gRemoteSCpb.scPB);
                        END;
                    SCCancelShutDown:
                        BEGIN
                            err := SyncServerDispatch(@gRemoteSCpb.scPB);
                        END;
                    SCWakeServer:
                        BEGIN
                            err := SyncServerDispatch(@gRemoteSCpb.scPB);
                        END;
                END;

                { OK, the call was made, so fill out the readParam parameter block }
                { and call PPCRead }
                pbPtr := @gPPCGeneralRec;
                WITH PPCReadPBPtr(pbPtr)^ DO
                    BEGIN
                        ioCompletion := @ReadCompProc;
                        bufferLength := sizeof(PPCIOBuffer); { full buffer size again }
                        { We're reusing the same parameter block, so the sessRefNum }
                        { and bufferPtr fields are already filled in for us. }
                        bufferPtr := @gPPCReadBuffer;
                    END;
                gPPCDataRead := FALSE;
                err := PPCReadAsync(PPCReadPBPtr(pbPtr));     { asynchronously }
            END;
    END;


{$S Main}
    PROCEDURE PollTheServer;
        VAR
            err: OSErr;
    BEGIN
        IF NOT gPPCWriteInProgress THEN
            BEGIN
                gPollSCpb.pollServerPB.scCode := SCPollServer;
                IF SyncServerDispatch(@gPollSCpb) = noErr THEN
                    BEGIN
                        {now, send the gPollSCpb to the remote}
                        WITH gPPCWriteRec.writeParam DO
                            BEGIN
                                ioCompletion := @WriteCompProc;
                                sessRefNum := gPPCSessRefNum;
                                bufferLength := sizeof(SCParamBlockRec);
                                bufferPtr := @gPollSCpb;
                                more := FALSE;
                                { I'm not using userData, blockCreator, or blockType }
                            END;
                        gPPCWriteInProgress := TRUE;
                        err := PPCWriteAsync(PPCWritePBPtr(@gPPCWriteRec));
                    END;
            END;
    END;


{$S Main}
    PROCEDURE doNullEvt;
        VAR
            ticks: LongInt;
    BEGIN
        ticks := TickCount;
        IF ticks - gTicks >= gSleep THEN
            BEGIN
                IF gPPCSessRefNum <> 0 THEN
                    BEGIN
                        PPCProcessReads;
                        PollTheServer;
                    END;
                gTicks := ticks;
            END;
    END;


{$S Main}
    PROCEDURE DoEventLoop;
        VAR
            evtRecord: EventRecord;
            bob: Boolean;
    BEGIN
        REPEAT
            bob := WaitNextEvent(highLevelEventMask, evtRecord, gSleep, NIL);
            CASE evtRecord.what OF
                nullEvent:
                    doNullEvt;
                kHighLevelEvent:
                    DoHighLevel(evtRecord);
            END; { CASE evtRecord.what }
        UNTIL gQuit = TRUE;
    END;    { DoEventLoop }


{$S Initialize}
    FUNCTION InitAEStuff: Boolean;
        VAR
            err: OSErr;
    BEGIN
        { The following series of calls install our AppleEvent Handlers.    }
        { These handlers are added to the application event handler list    }
        { that the AppleEvent manager maintains.  So, whenever an            }
        { AppleEvent happens and we call AEProcessEvent, the AppleEvent        }
        { manager will check our list of handlers and dispatch to the        }
        { the correct handler if there is one.    }
        err := AEInstallEventHandler(kCoreEventClass, kAEOpenApplication, @AEOpenHandler, 0, false);
        IF err = noErr THEN
            err := AEInstallEventHandler(kCoreEventClass, kAEOpenDocuments, @AEOpenDocHandler, 0, false);
        IF err = noErr THEN
            err := AEInstallEventHandler(kCoreEventClass, kAEQuitApplication, @AEQuitHandler, 0, false);
        IF err = noErr THEN
            err := AEInstallEventHandler(kCoreEventClass, kAEPrintDocuments, @AEPrintHandler, 0, false);

        IF err <> noErr THEN
            NotifyAndExit(kExitAEHandlerNotInstalled); { ••• Bail out now ••• }

        InitAEStuff := (err = noErr);
    END;


{$S Initialize}
    FUNCTION NumToolboxTraps: Integer;
    BEGIN
        IF NGetTrapAddress(_InitGraf, ToolTrap) = NGetTrapAddress($AA6E, ToolTrap) THEN
            NumToolboxTraps := $200
        ELSE
            NumToolboxTraps := $400;
    END;


{$S Initialize}
    FUNCTION GetTrapType (theTrap: Integer): TrapType;
        CONST
            TrapMask = $0800;
    BEGIN
        IF BAND(theTrap, TrapMask) > 0 THEN
            GetTrapType := ToolTrap
        ELSE
            GetTrapType := OSTrap;
    END;


{$S Initialize}
    FUNCTION TrapAvailable (theTrap: Integer): Boolean;
        VAR
            tType: TrapType;
    BEGIN
        tType := GetTrapType(theTrap);
        IF tType = ToolTrap THEN
            BEGIN
                theTrap := BAND(theTrap, $07FF);
                IF theTrap >= NumToolboxTraps THEN
                    theTrap := _Unimplemented;
            END;
        TrapAvailable := NGetTrapAddress(theTrap, tType) <> NGetTrapAddress(_Unimplemented, ToolTrap)
    END;


{$S Initialize}
    FUNCTION FindASFileServerApp (VAR theFSSpec: FSSpec): OSErr;
        VAR
            err: OSErr;
            foundVRefNum: Integer;
            foundDirID: LongInt;
            pb: HParamBlockRec;
            spec1: CInfoPBRec;
            spec2: CInfoPBRec;

    BEGIN
         { get the vRefNum of the boot disk }
        err := FindFolder(kOnSystemDisk, kSystemFolderType, FALSE, foundVRefNum, foundDirID);

        { look for the AppleShare File Server application }
        WITH pb DO
            BEGIN
                ioCompletion := NIL;
                ioNamePtr := NIL;
                ioVRefNum := foundVRefNum;
                ioMatchPtr := FSSpecArrayPtr(@theFSSpec);
                ioReqMatchCount := 1;
                ioSearchBits := fsSBFlFndrInfo; { look only at ioFlFndrInfo}
                ioSearchInfo1 := @spec1;
                ioSearchInfo2 := @spec2;
                ioSearchTime := 0;
                ioCatPosition.initialize := 0;
                ioOptBuffer := NIL;
                ioOptBufSize := 0;
            END;
        WITH spec1.ioFlFndrInfo DO
            BEGIN
                fdType := 'APPL';        {••••• should be constant }
                fdCreator := 'hgfd';    {••••• should be constant }
                fdFlags := 0;
                fdLocation.v := 0;
                fdLocation.h := 0;
                fdFldr := 0;
            END;
        WITH spec2.ioFlFndrInfo DO
            BEGIN
                fdType := OSType(-1);
                fdCreator := OSType(-1);
                fdFlags := 0;
                fdLocation.v := 0;
                fdLocation.h := 0;
                fdFldr := 0;
            END;

        err := PBCatSearchSync(@pb);

        IF ((err = noErr) OR (err = eofErr)) AND (pb.ioActMatchCount > 0) THEN
            FindASFileServerApp := noErr    { we found it! }
        ELSE
            FindASFileServerApp := fnfErr;    { we didn't find it }
    END;

{$S Initialize}
    FUNCTION GetServerType: Integer;
        VAR
            scPB: SCParamBlockRec;
    BEGIN
        scPB.versionPB.scExtNamePtr := NIL;
        scPB.versionPB.scCode := SCServerVersion;
        IF SyncServerDispatch(@scPB) = noErr THEN
            ;{ do nothing }
        GetServerType := scPB.versionPB.scServerType;
    END;

{$S Initialize}
    PROCEDURE IncreaseStackSize (extraBytes: Size);
    BEGIN
        SetApplLimit(Ptr(ORD4(GetApplLimit) - extraBytes));
    END;


{$S Initialize}
    PROCEDURE InitializeApp;
        VAR
            vers: LongInt;
            err: OSErr;
            aLong: LongInt;
            ownerName: StringHandle;
            savedResFile: Integer;
            i: Integer;
            curVersion: VersRecHndl;
    BEGIN
        gQuit := FALSE;
        gSleep := kMaxSleep;    {sleep until we have something to do}

        gPPCPortOpen := FALSE;
        gPPCPortRefNum := 0;
        gPPCSessRefNum := 0;
        gPPCDataRead := FALSE;
        gPPCWriteInProgress := FALSE;

        InitGraf(@qd.thePort);

        err := GetCurrentProcess(gOurPSN);    { so completion routines can wake us up }

        IF (ORD4(GetApplLimit) - ORD4(GetZone^.bkLim)) < 2048 THEN
            BEGIN
                NotifyAndExit(kCantIncreaseStack); { ••• Bail out now ••• }
                Exit(InitializeApp);
            END;
        IncreaseStackSize(2048); { increase stack by 2K }

        MaxApplZone;


        IF NOT TrapAvailable(_Gestalt) THEN
            BEGIN
                { If Gestalt isn't available, then we can't even notify the user }
                { because we can't see if the Notification Manager is available }
                SysBeep(1);        { so ring the bell }
                ExitToShell;    { and exit }
            END;

        { see if Notification Manager is available to display error messages }
        gNotificationMgrPresent := Gestalt(gestaltNotificationMgrAttr, aLong) = noErr;

        FOR i := 1 TO kNumExitErrors DO
            GetIndString(gNMStrs[i], kExitErrorStrings, i);

        { Check system version }
        vers := 0;
        err := Gestalt(gestaltSystemVersion, vers);
        IF LoWord(vers) < $0700 THEN
            BEGIN
                NotifyAndExit(kExitNoSystem7); { ••• Bail out now ••• }
                Exit(InitializeApp);
            END;

        { Check this machine for AppleEvents. }
        { If they are not here, then we exit }
        IF (Gestalt(gestaltAppleEventsAttr, aLong) <> noErr) THEN
            BEGIN
                NotifyAndExit(kExitNoAppleEvts); { ••• Bail out now ••• }
                Exit(InitializeApp);
            END;

        IF NOT InitAEStuff THEN
            Exit(InitializeApp);

        { Make sure ServerDispatch trap is available }
        IF NOT TrapAvailable(ServerDispatch) THEN
            BEGIN
                NotifyAndExit(kExitNoServerDispatch); { ••• Bail out now ••• }
                Exit(InitializeApp);
            END;

        gServerType := GetServerType;
        IF gServerType = 1 THEN
            { we need to know where the AS File Server application is }
            { in case we need to launch it. }
            IF FindASFileServerApp(gASFileServerFSSpec) <> noErr THEN
                BEGIN
                    NotifyAndExit(kExitCantFindASFSApp); { ••• Bail out now ••• }
                    Exit(InitializeApp);
                END;

        { Get the Macintosh owner's name from the System file }
        { If we can't get it, then exit because we have to have it }
        { to ensure the owner is the remote user }
        { ••••• Although I get the name here, I should probably hook into the }
        { ••••• AppleTalk transition queue to catch any name changes. }
        savedResFile := CurResFile;
        UseResFile(0);
        ownerName := StringHandle(GetResource('STR ', -16096));
        UseResFile(savedResFile);
        IF ownerName <> NIL THEN
            BEGIN
                { keep a global copy of the owner name }
                gOwnerName := ownerName^^;
                { and release the ownerName resource }
                ReleaseResource(Handle(ownerName));
            END
        ELSE
            BEGIN
                NotifyAndExit(kExitNoOwnerName); { ••• Bail out now ••• }
                Exit(InitializeApp);
            END;

        IF NOT InitPPCStuff THEN
            Exit(InitializeApp);
    END;


{PROCEDURE _DataInit;}
{External;}
{ this is the MPW application initialization code }


{$S Main}
BEGIN
    {UnloadSeg(@_DataInit);}
    { throw out the setup code }
    InitializeApp;
    UnloadSeg(@InitializeApp);    { get rid of my initialization code }
    DoEventLoop;
    PPCShutDown;
END. { Main }