Developer CD Series 1997 March: Reference Library/Dev.CD Mar 97 RL.toast/mac/Technical Documentation/Macintosh Technical Notes/technotes/tn/1076_MsgTest.hqx/MsgTest/MacMsgTest/Main.c

C/C++ Source or Header | 1996-08-29 | 5.7 KB | 189 lines

// •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
// Main.c
//
// July 31, 1996
// By Ben Manuto
//
// © 1996 by Apple Computer, Inc., all rights reserved.
//
// Main entry point for our MacMsgTest tool.
//
// •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••




// •••••••••••••••••
// Includes

#include <Types.h>
#include <LowMem.h>
#include "Messaging.h"
#include "MsgTest.h"
#include "MsgUtil.h"
#include <stdio.h>


#define kEscKey                27                    // The decimal value for the escape key.

Boolean gSendCompCalled;                        // a global to let us know our completion routine was called.
Boolean gRcvCompCalled;                            // a global to let us know our completion routine was called.
Boolean gAckReceived;
SInt32 gBytesReceived;                            // A global for the ack to tell us number of bytes received.


// •••••••••••••••••
// MyGetKey is a nasty little routine I copied that just reads the keyboard map to see if the 'ESC' key was pressed.
// This reads and area of low-memory and will be incompatbile on future versions of the OS. This is bad! Don't do this!

char MyGetKey(void)
{
    if (*((char *) 0x17A) & 0x20)
        return kEscKey;

    return 0;
}


// •••••••••••••••••

OSErr SendAck(SInt16 cmdBase, UInt32 bytesReceived)
{
MsgPBlkPtr ackMessage;
OSErr error;
char keyPressed = 0;

    ackMessage = NewMessage((cmdBase + kAckMsgType), bytesReceived, 0, 0);

    gSendCompCalled = false;
    error = SendMessage(ackMessage);

    printf("Sending Ack to PC.......");
    while ((gSendCompCalled == false) && (keyPressed != kEscKey)) {            // Hang out until our completion routine is called.
        keyPressed = MyGetKey();                                            // If we hang here, offer a way out.
    }

    if (keyPressed == kEscKey) {
        printf("Waiting for ack to be sent was aborted!\n");
        return(-1);
    }
    else {
        printf("Ack sent to PC.\n");
        return(error);
    }
}



// •••••••••••••••••

OSErr WaitForAck()
{
short bytes = kDefaultMsgSize;
char keyPressed = 0;

    printf("Waiting for Ack from PC......");
    while ((gAckReceived == false) && (keyPressed != kEscKey)) {            // Hang out until our completion routine is called.
        keyPressed = MyGetKey();                                            // If we hang here, offer a way out.
    }

    if (keyPressed == kEscKey) {
        printf("Waiting for ack was aborted!\n");
        return(-1);
    }
    else {
        printf("Ack received from PC.\n");
        if (gBytesReceived == bytes)
            printf("Message was sent successfully. All %d bytes were recevied.\n", bytes);
        else
            printf("The Message was not received properly. %d bytes were sent and %d were received.\n", bytes, gBytesReceived);

        return(noErr);
    }
}



// •••••••••••••••••

main()
{
MsgPBlkPtr dataMessage, recMsg;
MsgRecElemPtr theMsgRec;
SInt16 i, cmdBase;
OSErr error;
char keyPressed = 0;

    error = InitializeMsgSystem();                                            // Initialize the messaging system.
    if (error) {
        printf("Could not initialize the messaging system. Err = %d\n\n", error);
        return;
    }

    gBytesReceived = 0;                                                        // Init this global.

    cmdBase = RegisterMessage(kMsgCommandType, kDefaultMsgTypes);            // Register a message command type and anumber of types.
    if (cmdBase < 0) goto Exit;
    printf("Message registered. CmdBase = %d\n", cmdBase);

    recMsg = NewMessage(cmdBase, kDefaultSelector,                             // Create a new receiver msgPBlk.
                        kDefaultMsgSize, kDefaultMsgSize);

    theMsgRec = NewMsgRecElem(cmdBase, kDefaultMsgTypes, (UInt32) recMsg);     // Create a new MsgRecElem.
    printf("Message Receive Element Created.\n");

    error = InstallMsgHandler(theMsgRec);                                    // Install a message handler.
    printf("Message Handler Installed. Error = %d\n", error);

    dataMessage = NewMessage(cmdBase, kDefaultSelector,                     // Create a new message PBlk
                               kDefaultMsgSize, kDefaultMsgSize);
    if (dataMessage == 0L) {
        printf("Unable to create message....aborting.\n");
        goto Exit;
    }

    gSendCompCalled = false;                                                // Mark that the send completion routine has not been called.
    gRcvCompCalled = false;                                                    // Mark that the receive completion routine has not been called.
    gAckReceived = false;                                                    // Mark that an acknowledge has not been received from PC.

    error = SendMessage(dataMessage);                                        // Send our message.
    printf("Sending Message. Error = %d\n", error);

    printf("Waiting for Send Completion routine to be called......");
    while ((gSendCompCalled == false) && (keyPressed != kEscKey)) {            // Hang out until our completion routine is called.
        keyPressed = MyGetKey();                                            // If we hang here, offer a way out.
    }
    if (keyPressed == kEscKey) goto Exit;                                    // If we had to bail, clean up and bail.
    printf("Send Completion routine called\n");

    error = WaitForAck();                                                    // Wait for Ack message from PC so we know data was sent.
    if (error) goto Exit;

    printf("Waiting for Receive Completion routine to be called......");
    while ((gRcvCompCalled == false) && (keyPressed != kEscKey)) {            // Hang out until our completion routine is called.
        keyPressed = MyGetKey();                                            // If we hang here, offer a way out.
    }

    if (keyPressed == kEscKey) goto Exit;                                    // If we had to bail, clean up and bail.
    printf("Receive Completion routine called\n");

    printf("\n\nMessage Data:\n");
    printf("\nParam1 = $%08lX    Param2 = $%08LX\n",
            recMsg->msgParam1, recMsg->msgParam2);

    (UInt32) (recMsg->msgBuffer) -= recMsg->msgActCount;                    // Set the ptr back to the beginning of the buffer.

    for (i = 0; i < recMsg->msgActCount; i++) {                                // Display the data we received.
        printf("$%02X ", ((UInt8*)(recMsg->msgBuffer))[i]);
        if (((i+1) % 16) == 0) printf("\n");
    }

    error = SendAck(cmdBase, recMsg->msgActCount);                            // Send message to PC Acknowledging data received.

    Exit:
        RemoveMsgHandler(theMsgRec);
        printf("\nMessage Handler removed.\n");

        DeleteMsgRecElem(theMsgRec);
        DeleteMessage(dataMessage);
}