CAPABILITY    None
LIBRARY       euser.lib

#include <e32base.h>
 
class MMySynchronousTaskDone
    {
    public:
        virtual void TaskDone(TInt aRet) = 0;
    };
 
class CMySynchronousClass : public CActive
    {
    enum EState
        {
        EIdle = 0,
        EStarted,
        ERunningTask1,
        ERunningTask2,
        ERunningTask3,
        EEnd
        };
 
    public:
        static CMySynchronousClass* NewL();
        virtual ~CMySynchronousClass();
 
    public:
        // Synchronous method that act like asynchronous
        // but returns when task done.
        void LongRunningTaskL(TInt& aResult);
 
        // Synchronous method that act like asynchronous
        // note that method returns right after it has been started
        // and notifies task completion via MMySynchronousTaskDone
        void LongRunningTaskL(MMySynchronousTaskDone* aObserver);
 
    private: // From CActive
         void RunL();
         TInt RunError(TInt aError);
         void DoCancel();
 
    private:
        CMySynchronousClass();
        void ConstructL();
        void GiveTimeToOthers();
        void DoLongRunningTask();
 
    private:
        EState                  iRunningState;
        CActiveSchedulerWait    iSchedulerWait;
        TInt                    iSomeLongRunningTask;
        MMySynchronousTaskDone* iObserver;
    };

CMySynchronousClass* CMySynchronousClass::NewL()
    {
    CMySynchronousClass* self = new (ELeave) CMySynchronousClass();
    CleanupStack::PushL( self );
    self->ConstructL();
    CleanupStack::Pop();
    return self;
    }
 
CMySynchronousClass::CMySynchronousClass():CActive(EPriorityStandard)
    {
    }
 
void CMySynchronousClass::ConstructL()
    {
    CActiveScheduler::Add(this);
    }
 
CMySynchronousClass::~CMySynchronousClass()
    {
    Cancel();
    }
 
// This method returns after synchronous task completion
void CMySynchronousClass::LongRunningTaskL(TInt& aResult)
    {
    if (iRunningState == EIdle)
        {
        iSomeLongRunningTask = 0;
        iRunningState = EStarted;
 
        GiveTimeToOthers();
        iSchedulerWait.Start(); 
 
        // Continues here after CActiveSchedulerWait::AsyncComplete() is called
        if (iStatus.Int() != KErrNone)
            {
            User::Leave(iStatus.Int());
            }
        aResult = iSomeLongRunningTask;
        }
    else
        {
        User::Leave(KErrNotReady);
        }
    }
 
// This method returns right after synchronous task is started
void CMySynchronousClass::LongRunningTaskL(MMySynchronousTaskDone* aObserver)
    {
    if (iRunningState == EIdle)
        {
        iObserver = aObserver;
        iSomeLongRunningTask = 0;
        iRunningState = EStarted;
        GiveTimeToOthers();
        }
    else
        {
        User::Leave(KErrNotReady);
        }
 
    }
 
void CMySynchronousClass::DoLongRunningTask()
    {
    iSomeLongRunningTask++;
    }
 
void CMySynchronousClass::GiveTimeToOthers()
    {
    TRequestStatus* status = &iStatus;
    User::RequestComplete( status, KErrNone );
    SetActive();
    }
 
void CMySynchronousClass::RunL()
    {
    switch (iRunningState)
        {
        case EIdle:
            {
            break;
            }
        case EStarted:
            {
            iRunningState = ERunningTask1;
            // TODO: Call synchronous method
            DoLongRunningTask();
 
            GiveTimeToOthers();
            break;
            }
        case ERunningTask1:
            {
            iRunningState = ERunningTask2;
            // TODO: Call synchronous method
            DoLongRunningTask();
 
            GiveTimeToOthers();
            break;
            }
        case ERunningTask2:
            {
            iRunningState = ERunningTask3;
            // TODO: Call synchronous method
            DoLongRunningTask();
 
            GiveTimeToOthers();
            break;
            }
        case ERunningTask3:
            {
            iRunningState = EEnd;
            // TODO: Do some end processing if needed
 
            GiveTimeToOthers();
            break;
            }
        case EEnd:
            {
            // Done
            iRunningState = EIdle;
            if (iObserver)
                {
                iObserver->TaskDone(iSomeLongRunningTask);
                }
            if (iSchedulerWait.IsStarted())
                {
                iSchedulerWait.AsyncStop();
                }
            break;
            }
        default:
            {
            if (iSchedulerWait.IsStarted())
                {
                iSchedulerWait.AsyncStop();
                }
            break;
            }
        };
    }
 
TInt CMySynchronousClass::RunError(TInt aError)
    {
    if (iObserver)
        {
        iObserver->TaskDone(aError);
        }
    return KErrNone;
    }
 
void CMySynchronousClass::DoCancel()
    {
    if (iObserver)
        {
        iObserver->TaskDone(KErrCancel);
        }
    if (iSchedulerWait.IsStarted())
        {
        iSchedulerWait.AsyncStop();
        }
    }