examples/Base/IPC/Async/Fibonacci2/Fibonacci2.cpp

/*
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Description:
Example wraps a console in an active object and performs the 
Fibonacci calculation in a separate thread.
This is NOT the recommended way and serves only to compare with the 
Fibonacci3 example which performs the calculation as
a background active object.  
*/



#include <e32std.h>
#include <e32cons.h>
#include <e32base.h>

//
// Common literals
//
_LIT(KTxtFibThread,"FibThread");


LOCAL_D CConsoleBase* console;

_LIT(KTxtMainInstructions,"\n\nPress 'F' to start\n      'ESC' to exit\n      'C' to cancel, anytime\n");

//
// -----> CActiveConsole (definition)
//
// An abstract class which provides the facility to issue key requests. 
//
class CActiveConsole : public CActive
        {
public:
          // Construction
        CActiveConsole(CConsoleBase* aConsole);
        void ConstructL();

          // Destruction
        ~CActiveConsole();

          // Issue request
        void RequestCharacter();
        
          // Cancel request.
          // Defined as pure virtual by CActive;
          // implementation provided by this class.
        void DoCancel();

          // Service completed request.
          // Defined as pure virtual by CActive;
          // implementation provided by this class,
        void RunL();

          // Called from RunL() - an implementation must be provided
          // by derived classes to handle the completed request
        virtual void ProcessKeyPress(TChar aChar) = 0; 
          
protected:
          // Data members defined by this class
        CConsoleBase* iConsole; // A console for reading from
        };


//
// -----> CExampleScheduler (definition)
//

class CExampleScheduler : public CActiveScheduler
        {
public:
        void Error (TInt aError) const;
        void WaitForAnyRequest();
        void SetActiveObject(CActiveConsole* aActiveConsole);
private:
          // data members defined for this class
        CActiveConsole* iActiveConsole;
        };


//
// -----> CFibonacciEngine (definition)
//
// This class provides the fibonacci calculation engine
//

class CFibonacciEngine : public CBase
        {
public:
        void Calculate (TInt aTerms) ;

        TUint iResult ;
        } ;


//
// -----> TFibonacciParameters (definition)
//
// This class provides for passing parameters to the thread 
//

class TFibonacciParameters
        {
public:
        TInt iVar1 ;
        TAny* iVar2 ;
        TUint iResult ;
        } ;


//
// -----> CFibonacciThreadHandler (definition)
//
// This class encapsulates the fibonacci thread that runs the fibonacci engine
//

class CFibonacciThreadHandler : public CActive
        {
public:
        CFibonacciThreadHandler(CConsoleBase* aConsole, CFibonacciEngine* aFibonacciEngine) ;
        ~CFibonacciThreadHandler() ;

        void CalculateFibonacciL(TInt aIterations) ;

private:
        void DoCancel() ;
        void RunL() ;
        static TInt FibonacciThread(TAny* aParameters) ;

private:
        CConsoleBase* iConsole ;
        TFibonacciParameters iFibonacciParameters ;
        CFibonacciEngine* iFibonacciEngine ;
        };


//
// -----> CFibonacciKeyHandler (definition)
//
// This class encapsulates the fibonacci keyboard handler
//

class CFibonacciKeyHandler : public CActiveConsole
        {
public:
        CFibonacciKeyHandler(   CConsoleBase* aConsole, 
                                                        CFibonacciThreadHandler* iThreadHandler) ;
        void ConstructL();

          // Static construction
        static CFibonacciKeyHandler* NewLC(CConsoleBase* aConsole, CFibonacciThreadHandler* aHandler) ;

          // service request
        void ProcessKeyPress(TChar aChar) ;

private:
        CConsoleBase* iConsole ;
        CFibonacciThreadHandler* iThreadHandler ;
        };




//
// -----> CActiveConsole (implementation)
//
CActiveConsole::CActiveConsole( CConsoleBase* aConsole) 
        : CActive(CActive::EPriorityUserInput)
          // Construct high-priority active object
        {
        iConsole = aConsole;
        }

void CActiveConsole::ConstructL()
        {
          // Add to active scheduler
        CActiveScheduler::Add(this);
        }

CActiveConsole::~CActiveConsole()
        {
        // Make sure we're cancelled
        Cancel();
        }

void  CActiveConsole::DoCancel()
        {
        iConsole->ReadCancel();
        }

void  CActiveConsole::RunL()
        {
          // Handle completed request
        ProcessKeyPress(TChar(iConsole->KeyCode()));
        }

void CActiveConsole::RequestCharacter()
        {
          // A request is issued to the CConsoleBase to accept a
          // character from the keyboard.
        iConsole->Read(iStatus); 
        SetActive();
        }


//
// -----> CExampleScheduler (implementation)
//
void CExampleScheduler::Error(TInt aError) const
        {
        _LIT(KTxtSchedulerError,"CExampleScheduler - error");
        User::Panic(KTxtSchedulerError,aError);
        }


void CExampleScheduler::WaitForAnyRequest()
        {
        if (!(iActiveConsole->IsActive()))
                iActiveConsole->RequestCharacter();     
        CActiveScheduler::WaitForAnyRequest();
        }

void CExampleScheduler::SetActiveObject(CActiveConsole* aActiveConsole)
        {
        iActiveConsole = aActiveConsole;
        }





// CFibonacciKeyHandler support routine
//   uses up arrow & down arrow to change number, Enter to select

TInt GetValueFromKeyboard (TInt aInitial, TInt aStep, TInt lowerLimit, TInt upperLimit, const TDesC& aPrompt, CConsoleBase* aConsole)
        {
        TChar input ;
        TInt value = aInitial ;

        aConsole->Printf(aPrompt) ;
        do
                {
                aConsole->SetPos(0);
                _LIT(KFormat1,"%d  ");
                aConsole->Printf(KFormat1, value);
                input = aConsole->Getch() ;
                if (input == EKeyUpArrow && value < upperLimit) value = value + aStep ;
                if (input == EKeyDownArrow && value > lowerLimit) value = value - aStep ;
                }
        while (input != EKeyEnter) ;

        return value ;
        }


//
// -----> CFibonacciKeyHandler (implementation)
//


CFibonacciKeyHandler::CFibonacciKeyHandler(CConsoleBase* aConsole, CFibonacciThreadHandler* aThreadHandler )
        : CActiveConsole(aConsole)
          // construct zero-priority active object
        {
        iConsole = aConsole ;
        iThreadHandler = aThreadHandler ;
          // Add to active scheduler
        CActiveScheduler::Add(this);
          // Make this the active object
        ((CExampleScheduler*)(CActiveScheduler::Current()))->SetActiveObject(this);
        } 


void CFibonacciKeyHandler::ProcessKeyPress(TChar aChar)
        {
          // if key is ESC 
          //   cancel any outstanding request
          //   stop the scheduler
        if (aChar == EKeyEscape)
                {
                CActiveScheduler::Stop();
                return;
                }

          // If key is "f" or "F"
          //   cancel any outstanding request
          //   issue a fibonacci request.
        if (aChar == 'f' || aChar == 'F') 
                {
                _LIT(KTxtStartingFibonacci,"\nStarting Fibonacci....  \n");
                iConsole->Printf(KTxtStartingFibonacci);
                _LIT(KTxtReturnTermNumber,"\nENTER selects num\nUP    arrow increases num\nDOWN  arrow decreases num\n\n");
                TInt iterations = GetValueFromKeyboard(5,1,2,46, KTxtReturnTermNumber, iConsole) ;
                TRAPD(err,iThreadHandler->CalculateFibonacciL(iterations));
                if(err)
                        {
                                _LIT(KFormat4,"CalculateFibonacciL failed: leave code=%d");
                                console->Printf(KFormat4, err); 
                        }
                return;
                }

      // If key is "c" or "C" 
          //    cancel any outstanding request  
        if (aChar == 'c' || aChar == 'C')
                {
                _LIT(KTxtCancelFibonacci,"\nCancelling Fibonacci....  \n");
                iConsole->Printf(KTxtCancelFibonacci);
                iThreadHandler->Cancel();
                iConsole->Printf(KTxtMainInstructions);
                return;
                }

        _LIT(KTxtNotRecognised,"\nUnwanted key pressed");
        iConsole->Printf(KTxtNotRecognised);
        iConsole->Printf(KTxtMainInstructions);
        }


//
// -----> CFibonacciThreadHandler (implementation)
//

CFibonacciThreadHandler::CFibonacciThreadHandler(CConsoleBase* aConsole, CFibonacciEngine* aFibonacciEngine)
//
// Constructor
//
        : CActive(EPriorityStandard)
        {
        iConsole = aConsole ;
        iFibonacciEngine = aFibonacciEngine ;
        CActiveScheduler::Add(this);
        };


// destructor
CFibonacciThreadHandler::~CFibonacciThreadHandler() 
        {
        // cancel any requests and tell server 
        Cancel() ;
        }


void CFibonacciThreadHandler::DoCancel() 
        {
        // cancel the active object request 
        RThread thread ;
        thread.Open(KTxtFibThread) ;
        thread.Close() ;
        }


void CFibonacciThreadHandler::RunL() 
        {
        // handle requests - print out result and flag as handled (ie not cancelled)
        _LIT(KFormat2,"    Result : %u \n");  //not used
        iConsole->Printf(KFormat2, iFibonacciParameters.iResult) ;
        iConsole->Printf(KTxtMainInstructions);
        }


// initiate a request
void CFibonacciThreadHandler::CalculateFibonacciL(TInt aIterations)
        {
        const TInt KHeapSize = 0x800 ;
        
        _LIT(KTxtFibRequested,"\nFibonacci requested ...  ");
        iConsole->Printf(KTxtFibRequested);


        RThread thread ;

        // set up parameters to thread

        iFibonacciParameters.iVar1 = aIterations ;
        iFibonacciParameters.iVar2 = iFibonacciEngine ;

        // generate thread, leave if fails
        
        TInt result = thread.Create(KTxtFibThread,(TThreadFunction)FibonacciThread, KDefaultStackSize,
                                                                KMinHeapSize, KHeapSize, &iFibonacciParameters, EOwnerThread) ;
        User::LeaveIfError(result) ;

        // log on to thread -   sets iStatus to KRequestPending 
        //                                              requests notification of thread completion
        thread.Logon(iStatus) ;

        // give thread low priority 
        thread.SetPriority(EPriorityMuchLess) ;

        // resume thread (wake it up sometime after this function returns)
        thread.Resume() ;

        thread.Close() ;

        // ensure scheduler checks status 
        SetActive() ;
        
        _LIT(KTxtOK,"OK  \n");
        iConsole->Printf(KTxtOK);
        }


//  Thread routine that sorts out parameters & calls engine

TInt CFibonacciThreadHandler::FibonacciThread(TAny* aParameters)
        {
        // cast the parameters pointer
        TFibonacciParameters* parameters = (TFibonacciParameters*) aParameters ;

        // get variables from parameters class
        TInt iterations = parameters->iVar1 ;
        CFibonacciEngine* fibonacciEngine = (CFibonacciEngine*)parameters->iVar2 ;

        // call the engine
        fibonacciEngine->Calculate(iterations) ;

        // store result
        parameters->iResult = fibonacciEngine->iResult ;

        return KErrNone ;
}


//
// -----> CFibonacciEngine (implementation)
//

void CFibonacciEngine::Calculate (TInt aTerms) 
        {
        TInt iterations = aTerms ;

        TInt currentTotal = 1 ;
        TInt previousTotal = 0 ;
        _LIT(KTxtTooManyIterations,"Too many iterations");
        __ASSERT_ALWAYS(iterations<47,User::Panic(KTxtTooManyIterations,iterations));


        // if limit not yet reached
        while (iterations-- > 0)        
                {
                // calculate next number in series
                TInt newTotal = currentTotal + previousTotal ;

                // update variables
                previousTotal = currentTotal ;
                currentTotal = newTotal ;

                // introduce a delay
                User::After(1000000) ;
                }  

        iResult = currentTotal ;

//UserHal::ModifyLedMask(1,2);
        } 


// This section deals with initialisation and ensuring we have a console active

void doExampleL () ;

void SetupConsoleL();

GLDEF_C TInt E32Main()                          // main function called by E32
    {
        CTrapCleanup* cleanup=CTrapCleanup::New();              // get clean-up stack
        TRAPD(error,SetupConsoleL());                                   // more initialization, then do example
        _LIT(KTxtFibonacciExampleError,"Fibonacci example error");
        __ASSERT_ALWAYS(!error,User::Panic(KTxtFibonacciExampleError,error));
        delete cleanup;                                                                 // destroy clean-up stack
        return 0;                                                                               // and return
    }

void SetupConsoleL()                             // initialize and call example code under cleanup stack
    {
        _LIT(KTxtFibActObjInThread,"Active Object and thread");
        console=Console::NewL(KTxtFibActObjInThread,TSize(KConsFullScreen,KConsFullScreen));
        CleanupStack::PushL(console);
        console->Printf(KTxtMainInstructions) ;
        TRAPD(error, doExampleL());                                                     // perform example function
        if (error)
                {
                _LIT(KFormat3,"failed: leave code=%d");
                console->Printf(KFormat3, error);
                }
        _LIT(KTxtPressAnyKey,"[Press any key to exit]");
        console->Printf(KTxtPressAnyKey);
        console->Getch();                                                               // get and ignore character
        CleanupStack::PopAndDestroy(console);                                   // close console
    }


//
// Do the example
//
void doExampleL()
    {
          // Construct and install the active scheduler; push onto cleanup stack.
        CExampleScheduler*  exampleScheduler = new (ELeave) CExampleScheduler;
        CleanupStack::PushL(exampleScheduler);
         
          // Install as the active scheduler
        CActiveScheduler::Install(exampleScheduler);

        // Create CFibonacciEngine active object; push onto cleanup stack.
        CFibonacciEngine* fibEngine = new (ELeave) CFibonacciEngine ;
    CleanupStack::PushL(fibEngine);

          // Create CFibonacciThreadHandler active object; push onto cleanup stack.
        CFibonacciThreadHandler* fibThreadHandler = new (ELeave) CFibonacciThreadHandler(console, fibEngine);
    CleanupStack::PushL(fibThreadHandler);
        
          // Create CFibonacciKeyHandler active object; push onto cleanup stack.
        CFibonacciKeyHandler* fibKeyHandler = new (ELeave) CFibonacciKeyHandler(console, fibThreadHandler);
    CleanupStack::PushL(fibKeyHandler); 

          // issue initial request; push onto cleanup stack
        fibKeyHandler->RequestCharacter() ;
                        
        // Main part of the program:
        //    wait loop that cycles until ActiveScheduler::Stop called
        CActiveScheduler::Start();

        // Remove from the cleanup stack and destroy:
        CleanupStack::PopAndDestroy(4); 
        }

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