Midlet Launcher C++ application silently dies on device

[azpublic]

Hi,

I am developing an S60 3rd ed application for which one of the requisites is to launch a pre-installed Midlet.
I have basically been following this method to do so : http://wiki.forum.nokia.com/index.ph...60_3rd_Edition



Here is my code :

/*
 ============================================================================
 Name		: MidletLaunchGUIAppUi.cpp
 
============================================================================
 */

// INCLUDE FILES
#include <avkon.hrh>
#include <aknmessagequerydialog.h>
#include <aknnotewrappers.h>
#include <stringloader.h>
#include <f32file.h>
#include <s32file.h>
#include <hlplch.h>





#include <MidletLaunchGUI_0x2001FFC0.rsg>

#include "MidletLaunchGUI_0x2001FFC0.hlp.hrh"
#include "MidletLaunchGUI.hrh"
#include "MidletLaunchGUI.pan"
#include "MidletLaunchGUIApplication.h"
#include "MidletLaunchGUIAppUi.h"
#include "MidletLaunchGUIAppView.h"

_LIT(KFileName, "C:\\private\\2001FFC0\\MidletLaunchGUI.txt");
_LIT(KText, "foooo!");









// midlet name
_LIT(KMidletName, "HelloMIDlet");
 
// KVM virtual machine location on ROM drive
_LIT(KMidRunROMLocation, "z:\\system\\programs\\kmidrun.exe");
 
// location of jad + jar
_LIT(KMidletJadLocation, "c:\\system\\apps\\MidLaunch\\Hello.jad");
_LIT(KMidletJarLocation, "c:\\system\\apps\\MidLaunch\\Hello.jar");
_LIT(KMidletFakeExtension, ".fakeapp");





void CMidletLaunchGUIAppUi::FindMidletUIDL(){

	
    
    //the caption we are looking for converted as a TBUF
    //TBuf<KApaMaxAppCaption> wantedCap;
    //wantedCap.Append(KMidletName);
    
    User::LeaveIfError( apaSession.Connect() );
    CleanupClosePushL( apaSession );
    User::LeaveIfError( apaSession.GetAllApps() );
   
    while ( apaSession.GetNextApp( appInfo ) == KErrNone )
    {
    

	    // Caption of the MIDlet can be read from appInfo.iCaption
	    // When the MIDlet to be launch is found, store its UID
	    // (appInfo.iUid) for later use.
    	
    	
    	TInt bla = appInfo.iFullName.Right(8).Compare(KMidletFakeExtension);
    	
	    if(bla == 0)
	    {
	    	
	    TBuf<KApaMaxAppCaption> appCaption;
	   
	    TInt found = appInfo.iCaption.Compare(KMidletName);
	    
	    if(found == 0){
		    KMidletUid =  appInfo.iUid;
	    }
	    
	 
	   // _LIT(KMidletName, "   " + );
	  
	    }	    
	   
    }
    
   

}


void CMidletLaunchGUIAppUi::LaunchMidletL()
	{

	
	
	 TThreadId threadId;
	 apaSession.StartDocument(_L(""), KMidletUid, threadId);

	
	
	
	TBuf<KMaxCommandLine> cmdLine;
	_LIT(KSeparator, "*");

	// cmd line syntax: PortNumber*MIDletUid*MIDletName*JarLocation*JadLocation*

	cmdLine.AppendNum(KMidletPort);
	cmdLine.Append(KSeparator);

	// append a midlet uid in decimal format to the command line
	TBuf<16> uidNum;
	 
	uidNum.Num(KMidletUid.iUid,EDecimal);
	cmdLine.Append(uidNum);
	cmdLine.Append(KSeparator);

	// append a midlet name to the command line
	cmdLine.Append(KMidletName);
	cmdLine.Append(KSeparator);

	// append a jar file location to the command line
	cmdLine.Append(KMidletJarLocation);
	cmdLine.Append(KSeparator);

	// append a jad file location to the command line
	cmdLine.Append(KMidletJadLocation);
	cmdLine.Append(KSeparator);

	
	// create a new process
	RProcess process;

	TInt error = process.Create(KMidRunROMLocation,cmdLine);
	User::LeaveIfError(error);

	// TODO: process should be renamed according to convention used with KVM

	process.Resume();
	process.Close();

}

// ============================ MEMBER FUNCTIONS ===============================


// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::ConstructL()
// Symbian 2nd phase constructor can leave.
// -----------------------------------------------------------------------------
//
void CMidletLaunchGUIAppUi::ConstructL() {
	// Initialise app UI with standard value.
	BaseConstructL(CAknAppUi::EAknEnableSkin);

	
	
	
	
	
	// Create view object
	iAppView = CMidletLaunchGUIAppView::NewL(ClientRect() );

	// Create a file to write the text to
	TInt err = CCoeEnv::Static()->FsSession().MkDirAll(KFileName);
	if ( (KErrNone != err) && (KErrAlreadyExists != err)) {
		return;
	}

	RFile file;
	err = file.Replace(CCoeEnv::Static()->FsSession(), KFileName, EFileWrite);
	CleanupClosePushL(file);
	if (KErrNone != err) {
		CleanupStack::PopAndDestroy(1); // file
		return;
	}

	RFileWriteStream outputFileStream(file);
	CleanupClosePushL(outputFileStream);
	outputFileStream << KText;

	CleanupStack::PopAndDestroy(2); // outputFileStream, file

	
	
	
	FindMidletUIDL();
	LaunchMidletL();
}
// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::CMidletLaunchGUIAppUi()
// C++ default constructor can NOT contain any code, that might leave.
// -----------------------------------------------------------------------------
//
CMidletLaunchGUIAppUi::CMidletLaunchGUIAppUi() {
	// No implementation required
}

// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::~CMidletLaunchGUIAppUi()
// Destructor.
// -----------------------------------------------------------------------------
//
CMidletLaunchGUIAppUi::~CMidletLaunchGUIAppUi() {
	if (iAppView) {
		delete iAppView;
		iAppView = NULL;
	}

	
}

// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::HandleCommandL()
// Takes care of command handling.
// -----------------------------------------------------------------------------
//
void CMidletLaunchGUIAppUi::HandleCommandL(TInt aCommand) {
	switch (aCommand) {
		case EEikCmdExit:
		case EAknSoftkeyExit:
			Exit();
			break;

		case ECommand1: {

			// Load a string from the resource file and display it
			HBufC* textResource = StringLoader::LoadLC(R_COMMAND1_TEXT);
			CAknInformationNote* informationNote;

			informationNote = new ( ELeave ) CAknInformationNote;

			// Show the information Note with
			// textResource loaded with StringLoader.
			informationNote->ExecuteLD( *textResource);

			// Pop HBuf from CleanUpStack and Destroy it.
			CleanupStack::PopAndDestroy(textResource);
		}
			break;
		case ECommand2: {
			RFile rFile;

			//Open file where the stream text is
			User::LeaveIfError(rFile.Open(CCoeEnv::Static()->FsSession(), KFileName, EFileStreamText));//EFileShareReadersOnly));// EFileStreamText));
			CleanupClosePushL(rFile);

			// copy stream from file to RFileStream object
			RFileReadStream inputFileStream(rFile);
			CleanupClosePushL(inputFileStream);

			// HBufC descriptor is created from the RFileStream object.
			HBufC* fileData = HBufC::NewLC(inputFileStream, 32);

			CAknInformationNote* informationNote;

			informationNote = new ( ELeave ) CAknInformationNote;
			// Show the information Note
			informationNote->ExecuteLD( *fileData);

			// Pop loaded resources from the cleanup stack
			CleanupStack::PopAndDestroy(3); // filedata, inputFileStream, rFile
		}
			break;
		case EHelp: {

			CArrayFix<TCoeHelpContext>* buf = CCoeAppUi::AppHelpContextL();
			HlpLauncher::LaunchHelpApplicationL(iEikonEnv->WsSession(), buf);
		}
			break;
		case EAbout: {

			CAknMessageQueryDialog* dlg = new (ELeave)CAknMessageQueryDialog();
			dlg->PrepareLC(R_ABOUT_QUERY_DIALOG);
			HBufC* title = iEikonEnv->AllocReadResourceLC(R_ABOUT_DIALOG_TITLE);
			dlg->QueryHeading()->SetTextL(*title);
			CleanupStack::PopAndDestroy(); //title
			HBufC* msg = iEikonEnv->AllocReadResourceLC(R_ABOUT_DIALOG_TEXT);
			dlg->SetMessageTextL(*msg);
			CleanupStack::PopAndDestroy(); //msg
			dlg->RunLD();
		}
			break;
		default:
			Panic(EMidletLaunchGUIUi);
			break;
	}
}
// -----------------------------------------------------------------------------
//  Called by the framework when the application status pane
//  size is changed.  Passes the new client rectangle to the
//  AppView
// -----------------------------------------------------------------------------
//
void CMidletLaunchGUIAppUi::HandleStatusPaneSizeChange() {
	iAppView->SetRect(ClientRect() );
}

CArrayFix<TCoeHelpContext>* CMidletLaunchGUIAppUi::HelpContextL() const {
#warning "Please see comment about help and UID3..."
	// Note: Help will not work if the application uid3 is not in the
	// protected range.  The default uid3 range for projects created
	// from this template (0xE0000000 - 0xEFFFFFFF) are not in the protected range so that they
	// can be self signed and installed on the device during testing.
	// Once you get your official uid3 from Symbian Ltd. and find/replace
	// all occurrences of uid3 in your project, the context help will
	// work.
	CArrayFixFlat<TCoeHelpContext>* array = new(ELeave)CArrayFixFlat<TCoeHelpContext>(1);
	CleanupStack::PushL(array);
	array->AppendL(TCoeHelpContext(KUidMidletLaunchGUIApp, KGeneral_Information));
	CleanupStack::Pop(array);
	return array;
}

// End of File

The application automatically launches the midlet as expected but then silently dies and I need it to stay alive after the midlet was launched.

Moreover, if I comment out the LaunchMidlet() call in ConstructL() the application doesn't even seem to start.

So I guess the problem should be inside FindMidletUIDL() or somewhere nearby but I can't find where !


So any help appreciated. This is difficult for me to debug as I can't test it on the emulator and as I can't do on-device debugging ...

Thanks in advance

[wizard_hu_]

I would be surprised if that write attempt to C:\\private\\2001FFC0\\MidletLaunchGUI.txt would be a successful one. Generally you can not write to the private folder of other applications (by the way: why are you trying that?).
Otherwise you can try to remove the silence of the failure via checking http://wiki.forum.nokia.com/index.ph...ded_panic_code

[azpublic]

Hi Wizard_hu_ ,

Basically the C:\\private\\2001FFC0\\MidletLaunchGUI.txt part was automatically generated by Carbide when I chose to create a standard Symbian C++ application.

I removed it now.

I also tried using the ErrRd file.

When launching the application raises a E32user Cbase 71 on the phone.

I must have forgotten to pop something out of the cleanup stack or something similar...

Can you figure out what ?

Thanks for helping

[symbianyucca]

just check all places where you push something (including LC-ending functions), first candidate would be apaSession.

[kamaljaiswal]

hi

User::LeaveIfError( apaSession.Connect() );
CleanupClosePushL( apaSession );

...
once pushed it should be released ...from the cleanstack

[wizard_hu_]

Basically the C:\\private\\2001FFC0\\MidletLaunchGUI.txt part was automatically generated by Carbide when I chose to create a standard Symbian C++ application.

Sorry about that, forget it. I was thinking that you are trying to access \private\102033E6\MIDlets. But C:\\private\\2001FFC0\\MidletLaunchGUI.txt is just your own private folder, you can freely access it.
Go for the panic as Jukka and Kamal suggest.

[azpublic]

Thank you all for your replies.

I managed to corner down one of the problems.
Unfortunately there seems to be another one.

Indeed I had forgot to pop apaSession from the stack.

I now did it but a different error appears.

Here is my code now.

// INCLUDE FILES


//_LIT(KFileName, "C:\\private\\2001FFC0\\MidletLaunchGUI.txt");
_LIT(KText, "midletLaunch");

// midlet name
_LIT(KMidletName, "HelloMIDlet");
 
// KVM virtual machine location on ROM drive
_LIT(KMidRunROMLocation, "z:\\system\\programs\\kmidrun.exe");
 
// location of jad + jar
_LIT(KMidletJadLocation, "c:\\system\\apps\\MidLaunch\\Hello.jad");
_LIT(KMidletJarLocation, "c:\\system\\apps\\MidLaunch\\Hello.jar");
_LIT(KMidletFakeExtension, ".fakeapp");


void CMidletLaunchGUIAppUi::FindMidletUIDL(){

	
    
    //the caption we are looking for converted as a TBUF
    //TBuf<KApaMaxAppCaption> wantedCap;
    //wantedCap.Append(KMidletName);
    
    User::LeaveIfError( apaSession.Connect() );
    CleanupClosePushL( apaSession );
    User::LeaveIfError( apaSession.GetAllApps() );
   
    while ( apaSession.GetNextApp( appInfo ) == KErrNone )
    {
    

	    // Caption of the MIDlet can be read from appInfo.iCaption
	    // When the MIDlet to be launch is found, store its UID
	    // (appInfo.iUid) for later use.
    	
    	RDebug::Print( appInfo.iFullName );	
    	iLog.Write(appInfo.iFullName);
    	RDebug::Print(_L(" "));
    	//iLog.Write(_L(" "));
    	TInt bla = appInfo.iFullName.Right(8).Compare(KMidletFakeExtension);
    	
	    if(bla == 0)
	    {
	    	RDebug::Print(_L("we found a .fakeapp"));
	    	iLog.Write(_L("we found a .fakeapp"));
	    TBuf<KApaMaxAppCaption> appCaption;
	   
	    TInt found = appInfo.iCaption.Compare(KMidletName);
	    
	    if(found == 0){
		    KMidletUid =  appInfo.iUid;
		    iLog.Write(_L("midlet found"));
	    }
	    
	 
	   // _LIT(KMidletName, "   " + );
	  
	    }	    
	    RDebug::Print(_L("after if "));
	    iLog.Write(_L("after if "));
    }
    
    RDebug::Print(_L("after while "));
    iLog.Write(_L("after while "));

    CleanupStack::PopAndDestroy();
}


void CMidletLaunchGUIAppUi::LaunchMidletL()
	{

	RDebug::Print(_L("--------------------- > inside launch midlet"));
	iLog.Write(_L(" --------------------- > launching midlet "));
	
	
	 TThreadId threadId;
	 RDebug::Print(_L("1"));
	 iLog.Write(_L("1"));
	 User::LeaveIfError( apaSession.Connect() );
	 CleanupClosePushL( apaSession );
	 apaSession.StartDocument(_L(""), KMidletUid, threadId);
	 RDebug::Print(_L("2"));
	 iLog.Write(_L("2"));
	
	
	
	TBuf<KMaxCommandLine> cmdLine;
	RDebug::Print(_L("3"));
	 iLog.Write(_L("3"));
	_LIT(KSeparator, "*");
	RDebug::Print(_L("4"));
	 iLog.Write(_L("4"));
	// cmd line syntax: PortNumber*MIDletUid*MIDletName*JarLocation*JadLocation*

	cmdLine.AppendNum(KMidletPort);
	RDebug::Print(_L("5"));
		 iLog.Write(_L("5"));
	cmdLine.Append(KSeparator);
	RDebug::Print(_L("6"));
		 iLog.Write(_L("6"));
	// append a midlet uid in decimal format to the command line
	TBuf<16> uidNum;
	RDebug::Print(_L("7"));
		 iLog.Write(_L("7"));
	uidNum.Num(KMidletUid.iUid,EDecimal);
	RDebug::Print(_L("8"));
		 iLog.Write(_L("8"));
	cmdLine.Append(uidNum);
	RDebug::Print(_L("9"));
		 iLog.Write(_L("9"));
	cmdLine.Append(KSeparator);
	RDebug::Print(_L("10"));
		 iLog.Write(_L("10"));
	// append a midlet name to the command line
	cmdLine.Append(KMidletName);
	RDebug::Print(_L("11"));
		 iLog.Write(_L("11"));
	cmdLine.Append(KSeparator);
	RDebug::Print(_L("12"));
		 iLog.Write(_L("12"));
	// append a jar file location to the command line
	cmdLine.Append(KMidletJarLocation);
	RDebug::Print(_L("13"));
		 iLog.Write(_L("13"));
	cmdLine.Append(KSeparator);
	RDebug::Print(_L("14"));
		 iLog.Write(_L("14"));
	// append a jad file location to the command line
	cmdLine.Append(KMidletJadLocation);
	RDebug::Print(_L("15"));
		 iLog.Write(_L("15"));
	cmdLine.Append(KSeparator);
	RDebug::Print(_L("16"));
		 iLog.Write(_L("16"));
	
	// create a new process
	RProcess process;
	RDebug::Print(_L("17"));
		 iLog.Write(_L("17"));
	TInt error = process.Create(KMidRunROMLocation,cmdLine);
	RDebug::Print(_L("18"));
		 iLog.Write(_L("18"));
	//User::LeaveIfError(error);
		 iLog.WriteFormat(_L("------------>ERROR CODE =%d"),error);
	RDebug::Print(_L("19"));
		 iLog.Write(_L("19"));
	// TODO: process should be renamed according to convention used with KVM


	process.Resume();
	RDebug::Print(_L("20"));
		 iLog.Write(_L("20"));
	process.Close();
	RDebug::Print(_L("21"));
		 iLog.Write(_L("21"));
	CleanupStack::PopAndDestroy();//apasession
	
	iLog.Write(_L("--------------------- > ending launch midlet"));
	RDebug::Print(_L(" --------------------- > ending launch midlet"));
	
}

// ============================ MEMBER FUNCTIONS ===============================


// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::ConstructL()
// Symbian 2nd phase constructor can leave.
// -----------------------------------------------------------------------------
//
void CMidletLaunchGUIAppUi::ConstructL() {
	// Initialise app UI with standard value.
	BaseConstructL(CAknAppUi::EAknEnableSkin);

	
	
	
	//initialise file logging
	
	iLog.Connect();
	iLog.CreateLog(_L("Mylogs"),_L("Mllog.txt"),EFileLoggingModeOverwrite);
	
	
	
	
	// Create view object
	iAppView = CMidletLaunchGUIAppView::NewL(ClientRect() );

	
	

	
	
	FindMidletUIDL();
	RDebug::Print(_L("afterFindMidletUIDL"));
	LaunchMidletL();
}
// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::CMidletLaunchGUIAppUi()
// C++ default constructor can NOT contain any code, that might leave.
// -----------------------------------------------------------------------------
//
CMidletLaunchGUIAppUi::CMidletLaunchGUIAppUi() {
	// No implementation required
}

// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::~CMidletLaunchGUIAppUi()
// Destructor.
// -----------------------------------------------------------------------------
//
CMidletLaunchGUIAppUi::~CMidletLaunchGUIAppUi() {
	if (iAppView) {
		delete iAppView;
		iAppView = NULL;
	}

	

	// Close the log file and the connection to the server.
	iLog.CloseLog();
	iLog.Close();
	
}

// -----------------------------------------------------------------------------
// CMidletLaunchGUIAppUi::HandleCommandL()
// Takes care of command handling.
// -----------------------------------------------------------------------------
//
void CMidletLaunchGUIAppUi::HandleCommandL(TInt aCommand) {
	switch (aCommand) {
		case EEikCmdExit:
		case EAknSoftkeyExit:
			Exit();
			break;

		case ECommand1: {

			// Load a string from the resource file and display it
			HBufC* textResource = StringLoader::LoadLC(R_COMMAND1_TEXT);
			CAknInformationNote* informationNote;

			informationNote = new ( ELeave ) CAknInformationNote;

			// Show the information Note with
			// textResource loaded with StringLoader.
			informationNote->ExecuteLD( *textResource);

			// Pop HBuf from CleanUpStack and Destroy it.
			CleanupStack::PopAndDestroy(textResource);
		}
			break;
		case ECommand2: {
			
			// Load a string from the resource file and display it
			HBufC* textResource = StringLoader::LoadLC(R_COMMAND1_TEXT);
			CAknInformationNote* informationNote;

			informationNote = new ( ELeave ) CAknInformationNote;

			// Show the information Note with
			// textResource loaded with StringLoader.
			informationNote->ExecuteLD( *textResource);

			// Pop HBuf from CleanUpStack and Destroy it.
			CleanupStack::PopAndDestroy(textResource);
			
			
		}
			break;
		case EHelp: {

			CArrayFix<TCoeHelpContext>* buf = CCoeAppUi::AppHelpContextL();
			HlpLauncher::LaunchHelpApplicationL(iEikonEnv->WsSession(), buf);
		}
			break;
		case EAbout: {

			CAknMessageQueryDialog* dlg = new (ELeave)CAknMessageQueryDialog();
			dlg->PrepareLC(R_ABOUT_QUERY_DIALOG);
			HBufC* title = iEikonEnv->AllocReadResourceLC(R_ABOUT_DIALOG_TITLE);
			dlg->QueryHeading()->SetTextL(*title);
			CleanupStack::PopAndDestroy(); //title
			HBufC* msg = iEikonEnv->AllocReadResourceLC(R_ABOUT_DIALOG_TEXT);
			dlg->SetMessageTextL(*msg);
			CleanupStack::PopAndDestroy(); //msg
			dlg->RunLD();
		}
			break;
		default:
			Panic(EMidletLaunchGUIUi);
			break;
	}
}


// End of File

It seems the problem is now in LaunchMidletL()

As you can see I am logging step by step to a file on the device. In my log file the line

iLog.WriteFormat(_L("------------>ERROR CODE =%d"),error);


prints -1 which is supposedly a KErrNotFound returned by
TInt error = process.Create(KMidRunROMLocation,cmdLine);

In the log file I can see that iLog.Write(_L("19")); occurs correctly but the application crashes right after supposedly on

process.Resume();


On the device the Panic raised is a KERN EXEC-0


I have no idea why it is behaving so ...
I don't know what is missing ... but I know I'm not very far.

Do you guys have an idea ?


Thanks again for helping me so much !

[symbianyucca]

at least there can not be executables in the "z:\\system\\programs\\" path you have defined, so you get -1 saying that it is not found. Then the process is not created, and using the process variable tells you that by raising the Kern Exec 0 panic.

[azpublic]

Well the funny thing is tha midlet gets launched but right after launching the C++ app is killed !

So I guess that "z:\\system\\programs\\kmidrun.exe" does exist after all ...

No ?

[symbianyucca]

Starting from 3rd edition executables are only run from sys folder, so I would not think that the file exists, in my E71 even the programs folder is not there.

[azpublic]

Ok so I've been reading this hilarious post that does pretty much the same thing I wanted to achieve

http://discussion.forum.nokia.com/fo...d.php?t=135580

and it seems that the line
apaSession.StartDocument(_L(""), KMidletUid, threadId);

was enough to start the midlet.

I was sure it was the line :

TInt error = process.Create(KMidRunROMLocation,cmdLine);

that did it ... I just suppressed it and all the cmdLine variable construction as well ...

and now it works perfectly !

I wonder what process.Create(KMidRunROMLocation,cmdLine); was supposed to do in the first place.

Thank you all for helping me.