// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

#include "scsiprot.h"

#include "usbmsshared.h"

#include "rwdrivethread.h"

#include "massstoragedebug.h"

// ---

#ifdef PRINT_MSDC_MULTITHREADED_READ_INFO

#define __MT_READ_PRINT(t) {RDebug::Print(t);}

#define __MT_READ_PRINT1(t,a) {RDebug::Print(t,a);}

#define __MT_READ_PRINT2(t,a,b) {RDebug::Print(t,a,b);}

#else

#define __MT_READ_PRINT(t)

#define __MT_READ_PRINT1(t,a)

#define __MT_READ_PRINT2(t,a,b)

#endif // PRINT_MSDC_MULTITHREADED_READ_INFO

#ifdef MSDC_MULTITHREADED 

TBlockDesc::TBlockDesc()

	:iBuf((TUint8 *)NULL,0,0)

	{

	}

void TBlockDesc::SetPtr(TPtr8& aDes)

	{

	iBuf.Set(aDes);

	}

TBlockDescBuffer::TBlockDescBuffer()

	{ 

	iDescReadPtr = &iDesc1;

	iDescWritePtr = &iDesc2;

	}

void TBlockDescBuffer::SetUpReadBuf(TPtr8& aDes1, TPtr8& aDes2)

	{

	iDesc1.SetPtr(aDes1);

	iDesc2.SetPtr(aDes2);

	iDescReadPtr = &iDesc1;

	iDescWritePtr = &iDesc2;

	}

//-----------------------------------------------

/**

Construct a CThreadContext object.

@param aName The name to be assigned to this thread.

@param aThreadFunction Function to be called when thread is initially scheduled.

@param aOwner Pointer to the object owning the thread. Used as the parameter to aThreadFunction.

*/

CThreadContext* CThreadContext::NewL(const TDesC& aName,

									 TThreadFunction aThreadFunction,

									 TAny* aOwner)

	{

	__FNLOG("CThreadContext::NewL");

	CThreadContext* self = new (ELeave) CThreadContext();

	CleanupStack::PushL(self);

	self->ConstructL(aName, aThreadFunction, aOwner);

	CleanupStack::Pop();

	return self;

	}

/**

Construct a CThreadContext object

@param aName The name to be assigned to this thread.

@param aThreadFunction Function to be called when thread is initially scheduled.

@param aOwner Pointer to the object owning the thread. Used as the parameter to aThreadFunction.

*/

void CThreadContext::ConstructL(const TDesC& aName,

								TThreadFunction aThreadFunction,

								TAny* aOwner)

	{

	__FNLOG("CThreadContext::ConstructL");

	__PRINT(_L("Creating Critical Section"));

	User::LeaveIfError(iCritSect.CreateLocal());

	__PRINT(_L("Creating RThread"));

	TUint serial(0); // Used to retry creation of a thread in case

					 // one with the same name already exists

	RBuf threadName;

	threadName.CreateMaxL(aName.Length() + 8);

	CleanupClosePushL(threadName);

	threadName = aName;

	TInt err;

	for (;;)

		{

		err = iThread.Create(threadName, aThreadFunction, 0x1000, NULL, aOwner);

		__PRINT2(_L("CThreadContext::ConstructL Created thread %S err=%d"), &threadName, err);

        // for a restart wait and retry until old thread is gone

		if (err == KErrAlreadyExists)

			{

			User::After(10 * 1000);     // 10 mS

			threadName = aName;

			threadName.AppendNumFixedWidth(serial, EDecimal, 8);

			++serial;

			}

		else

			{

			break;

			}

		}

    User::LeaveIfError(err);

    CleanupStack::Pop(); // threadName

    threadName.Close();

	// set priority

	iThread.SetPriority(EPriorityMore);

	}

/**

Construct a CThreadContext object

*/

CThreadContext::CThreadContext()

	:

	iError(KErrNone)

	{

	__FNLOG("CThreadContext::CThreadContext");

	}

/**

Destructor

*/

CThreadContext::~CThreadContext()

	{

	__FNLOG("CThreadContext::~CThreadContext");

	__PRINT(_L("Closing Critical Section"));

	iCritSect.Close();

	__PRINT(_L("Killing ThreadContext"));

	iThread.Kill(0);

	__PRINT(_L("Closing ThreadContext"));

	iThread.Close();

	}

//-----------------------------------------------

/**

Construct a CWriteDriveThread object

*/

CWriteDriveThread* CWriteDriveThread::NewL()

	{

	__FNLOG("CWriteDriveThread::NewL");

	CWriteDriveThread* self = new (ELeave) CWriteDriveThread();

	CleanupStack::PushL(self);

	self->ConstructL();

	CleanupStack::Pop();

	return self;

	}

/**

Construct a CWriteDriveThread object

*/

void CWriteDriveThread::ConstructL()

	{

	__FNLOG("CWriteDriveThread::ConstructL");

	TBuf<16> name = _L("MassStorageWrite");

	iThreadContext = CThreadContext::NewL(name, ThreadFunction, this);

	// There are two free pointers to start with so initialise the semaphore with 1

	User::LeaveIfError(iProducerSem.CreateLocal(1));

	User::LeaveIfError(iConsumerSem.CreateLocal(0));

	iThreadContext->Resume();

	}

/**

Construct a CWriteDriveThread object

*/

CWriteDriveThread::CWriteDriveThread() 

	: iIsCommandWrite10(EFalse)

	{

	__FNLOG("CWriteDriveThread::CWriteDriveThread");

	}

/**

Destructor

*/

CWriteDriveThread::~CWriteDriveThread()

	{

	__FNLOG("CWriteDriveThread::~CWriteDriveThread");

	delete iThreadContext;

	}

/**

This function is called when the thread is initially scheduled.

@param aSelf Pointer to self to facilitate call to member method.

*/

TInt CWriteDriveThread::ThreadFunction(TAny* aSelf)

	{

	__FNLOG("CWriteDriveThread::ThreadFunction");

	CWriteDriveThread* self = static_cast<CWriteDriveThread*>(aSelf);

	return self->WriteToDrive();

	}

/**

Writes the data pointed to by iDescWritePtr to the drive.

*/

TInt CWriteDriveThread::WriteToDrive()

	{

	__FNLOG("\tCWriteDriveThread::WriteToDrive");

	// One-off convenience variable assignment

	TBlockDesc* &desc = iThreadContext->iBuffer.iDescWritePtr;

	for(;;)

		{

		iConsumerSem.Wait();

		__PRINT(_L("\tWaiting on Write CS..."));

		iThreadContext->iCritSect.Wait();

		// +++ WRITE CS STARTS HERE +++

		__PRINT1(_L("\tNow using as write buffer: iBuf%d"), iThreadContext->iBuffer.GetBufferNumber(&desc->iBuf));

#ifdef MEASURE_AND_DISPLAY_WRITE_TIME

		RDebug::Print(_L("\tSCSI: writing %d bytes\n"), desc->iBuf.Length());

		TTime t0, t1;

		t0.HomeTime();

#else

		__PRINT1(_L("\tSCSI: writing %d bytes\n"), desc->iBuf.Length());

#endif

		// Write buffer to disk

#ifdef INJECT_ERROR

		if (desc->iBuf[0] == '2')

		{

			desc->iBuf[0] = 'x';

			RDebug::Printf("Injecting error");

		}

		RDebug::Printf("%08lx %x [%x] [%x]", desc->iByteOffset, desc->iBuf.Length(), 

			desc->iBuf[0],

			desc->iBuf[desc->iBuf.Length()-1]);

#endif

		iThreadContext->iError = iThreadContext->iDrive->Write(desc->iByteOffset, desc->iBuf,iThreadContext->iDrive->IsWholeMediaAccess());

#ifdef INJECT_ERROR

		if (desc->iBuf[0] == 'x')

		{

			iThreadContext->iError = KErrUnknown;

		}

#endif

#ifdef MEASURE_AND_DISPLAY_WRITE_TIME

		t1.HomeTime();

		const TTimeIntervalMicroSeconds time = t1.MicroSecondsFrom(t0);

		const TUint time_ms = I64LOW(time.Int64() / 1000);

		RDebug::Print(_L("SCSI: write took %d ms\n"), time_ms);

#endif

		iCallback((TUint8*) (desc->iBuf.Ptr()), iCallbackParameter);

		iWriteCounter--;

		ASSERT(iWriteCounter >= 0);

		__PRINT(_L("\tSignalling Write CS"));

		iThreadContext->iCritSect.Signal();

		// +++ WRITE CS ENDS HERE +++

		iProducerSem.Signal();

		}

	}

/**

Initiates writing data pointed to by iReadBuf to the drive and resumes the thread. Writing 

is completed by the ThreadFunction when the thread is resumed.

@param aDrive Drive to write to.

@param aOffset Write offset.

*/

TInt CWriteDriveThread::WriteDriveData(CMassStorageDrive* aDrive, const TInt64& aOffset, TPtrC8& aDes, ProcessWriteCompleteFunc aFunc, TAny* aPtr)

	{

	// Check error code from previous write

	const TInt r = iThreadContext->iError;

	if (r != KErrNone)

		{

		__PRINT1(_L("Error after previous write = 0x%x \n"), r);

		return KErrAbort;

        }

	// Swap the two buffer pointers

	iProducerSem.Wait();

	__PRINT(_L("Waiting on Write CS..."));

	// +++ WRITE CS STARTS HERE +++

	iThreadContext->iCritSect.Wait();

	// New DB First read into the iDescReadPtr pointer,

	// then swap,so that write pointer points to correct location, as the ptr pointed to by iDescWritePtr is what is written from in WriteToDrive 

	iThreadContext->iBuffer.iDescReadPtr->iBuf.Set((TUint8*)aDes.Ptr(), aDes.Length(), KMaxBufSize );

	iCallback = aFunc;

	iCallbackParameter = aPtr;

	iWriteCounter++;

	iThreadContext->iBuffer.SwapDesc();

	// Prepare variables for next write

	iThreadContext->iDrive = aDrive;

	iThreadContext->iBuffer.iDescWritePtr->iByteOffset = aOffset;

	// +++ WRITE CS ENDS HERE +++

	__PRINT(_L("Signalling Write CS..."));

	iThreadContext->iCritSect.Signal();

	iConsumerSem.Signal();

	return KErrNone;

}

void CWriteDriveThread::WaitForWriteEmpty()

{

	while(iWriteCounter > 0)

		{

		User::After(100);

		}

}

// Check if the target address range was recently written to, this is to force a

// cache miss when reading from the same sectors that were just written. 

// Optimisation note: this is only needed if the read precache was started

// before the write was completed.

TBool CWriteDriveThread::IsRecentlyWritten(TInt64 aOffset, TInt aLength)

{

	ASSERT(iWriteCounter == 0);

	if (iIsCommandWrite10) //If the previous command is Write10, then discard pre-read as the same buffers are used and will be over written by Write10 

		return ETrue;

	if(aOffset <= iThreadContext->iBuffer.iDescReadPtr->iByteOffset &&

			aOffset + aLength >= iThreadContext->iBuffer.iDescReadPtr->iByteOffset)

		return ETrue;

	if(aOffset >= iThreadContext->iBuffer.iDescReadPtr->iByteOffset &&

			aOffset <= iThreadContext->iBuffer.iDescReadPtr->iByteOffset + iThreadContext->iBuffer.iDescReadPtr->iLength)

		return ETrue;

	if(aOffset <= iThreadContext->iBuffer.iDescWritePtr->iByteOffset &&

			aOffset + aLength >= iThreadContext->iBuffer.iDescReadPtr->iByteOffset)

		return ETrue;

	if(aOffset >= iThreadContext->iBuffer.iDescWritePtr->iByteOffset &&

			aOffset <= iThreadContext->iBuffer.iDescReadPtr->iByteOffset + iThreadContext->iBuffer.iDescReadPtr->iLength)

		return ETrue;

	return EFalse;

}

//-----------------------------------------------

/**

Construct a CReadDriveThread object

*/

CReadDriveThread* CReadDriveThread::NewL()

	{

	__FNLOG("CReadDriveThread::NewL");

	CReadDriveThread* self = new (ELeave) CReadDriveThread();

	CleanupStack::PushL(self);

	self->ConstructL();

	CleanupStack::Pop();

	return self;

	}

/**

Construct a CReadDriveThread object

@param aName The name to be assigned to this thread.

@pram aThreadFunction Function to be called when thread is initially scheduled.

*/

void CReadDriveThread::ConstructL()

	{

	__FNLOG("CReadDriveThread::ConstructL");

	TBuf<15> name = _L("MassStorageRead");

	iThreadContext = CThreadContext::NewL(name, ThreadFunction, this);

	}

/**

Construct a CReadDriveThread object

*/

CReadDriveThread::CReadDriveThread()

	:

	iThreadRunning(EFalse)

	{

	__FNLOG("CReadDriveThread::CReadDriveThread");

	}

/**

Destructor

*/

CReadDriveThread::~CReadDriveThread()

	{

	__FNLOG("CReadDriveThread::~CReadDriveThread");

	delete iThreadContext;

	}

/**

This function is called when the thread is initially scheduled.

@param aSelf Pointer to self to facilitate call to member method.

*/

TInt CReadDriveThread::ThreadFunction(TAny* aSelf)

	{

	__FNLOG("CReadDriveThread::ThreadFunction");

	CReadDriveThread* self = static_cast<CReadDriveThread*>(aSelf);

	return self->ReadFromDrive();

	}

/**

Reads data from the drive with iOffset and iReadLength into memory pointer iReadBuffer

and suspends the thread.

*/

TInt CReadDriveThread::ReadFromDrive()

	{

	__FNLOG("\tCReadDriveThread::ReadFromDrive");

	// One-off convenience variable assignment

	TBlockDesc* &desc = iThreadContext->iBuffer.iDescWritePtr;

	for (;;)

		{

		__PRINT(_L("\tWaiting on Read CS..."));

		iThreadContext->iCritSect.Wait();

		// +++ READ CS STARTS HERE +++

		iThreadRunning = ETrue;

		iCompleted = EFalse;

		__PRINT1(_L("\tNow using as read buffer: iBuf%d"), iThreadContext->iBuffer.GetBufferNumber(&desc->iBuf));

#ifdef MEASURE_AND_DISPLAY_READ_TIME

		RDebug::Print(_L("\tSCSI: reading %d bytes\n"), desc->iBuf.Length());

		TTime t0, t1;

		t0.HomeTime();

#else

		__PRINT1(_L("\tSCSI: reading %d bytes\n"), desc->iBuf.Length());

#endif

		// Fill read buffer from disk

		iThreadContext->iError = iThreadContext->iDrive->Read(desc->iByteOffset,

															  desc->iLength,

															  desc->iBuf,

															  iThreadContext->iDrive->IsWholeMediaAccess());

#ifdef MEASURE_AND_DISPLAY_READ_TIME

		t1.HomeTime();

		const TTimeIntervalMicroSeconds time = t1.MicroSecondsFrom(t0);

		const TUint time_ms = I64LOW(time.Int64() / 1000);

		RDebug::Print(_L("SCSI: read took %d ms\n"), time_ms);

#endif

		iCompleted = ETrue;

		iThreadRunning = EFalse;

		__PRINT(_L("\tSignalling Read CS"));

		// +++ READ CS ENDS HERE +++

		iThreadContext->iCritSect.Signal();

		// Suspend self

		__PRINT(_L("\tSuspending Read Thread"));

		RThread().Suspend();

		}

	}

/**

Client read request of a data block from the specified drive. 

If there is no pre-read data that matches the requested Offset and Length then the drive

is read and the next pre-read is setup. If there is matching pre-read data available then

the next pre-read is setup. Finishes by resuming the thread and the ThreadFunciton runs.

@param aDrive Drive to read from.

@param aOffset Read offset

@param aLength Length 

*/

TBool CReadDriveThread::ReadDriveData(CMassStorageDrive* aDrive,

									  const TInt64& aOffset,

									  TUint32 aLength,

									  TBool aIgnoreCache)

	{

	__MT_READ_PRINT2(_L("\nRead10: offs %ld len %d"), aOffset, aLength);

	__PRINT(_L("Waiting on Read CS..."));

	iThreadContext->iCritSect.Wait();

	// +++ READ CS STARTS HERE +++

	__ASSERT_DEBUG(!iThreadRunning, User::Panic(_L("MSDC-THREAD"), 666));

	TBlockDesc* &desc = iThreadContext->iBuffer.iDescReadPtr;

	TBlockDesc* &bgDesc = iThreadContext->iBuffer.iDescWritePtr;

	if ((!aIgnoreCache) &&

		(iCompleted) &&

		(iThreadContext->iError == KErrNone) &&

		(iThreadContext->iDrive == aDrive) &&

		(bgDesc->iByteOffset == aOffset) &&

		(bgDesc->iLength == aLength))

		{

		// Good: We pre-read the correct data :-)

		__MT_READ_PRINT(_L("Match: Using pre-read data :-) :-) :-) :-)"));

		}

	else

		{

		__MT_READ_PRINT(_L("Not using pre-read data"));

		if (iThreadContext->iError != KErrNone)

			{

			__MT_READ_PRINT1(_L("Pre-read failed: %d"), iThreadContext->iError);

			}

		if (iThreadContext->iDrive != aDrive)

			{

			__MT_READ_PRINT2(_L("Pre-read drive mismatch: pre 0x%08x / act 0x%08x"),

							 iThreadContext->iDrive, aDrive);

			}

		if (desc->iByteOffset != aOffset)

			{

			__MT_READ_PRINT2(_L("Pre-read offset mismatch: pre %ld / act %ld"),

							 desc->iByteOffset, aOffset);

			}

		if (desc->iLength != aLength)

			{

			__MT_READ_PRINT2(_L("Pre-read length mismatch: pre %d / act %d"),

							 desc->iLength, aLength);

			// Potential optimization: If the pre-read was OK but for more data

			// than the host is now asking for, we could still satisfy that

			// request from the pre-read data by shortening the buffer.

			}

		// No valid pre-read data was available - so we have to read it now

		bgDesc->iByteOffset = aOffset;

		bgDesc->iLength = aLength;

		TInt err = aDrive->Read(aOffset,

								aLength,

								bgDesc->iBuf,

								aDrive->IsWholeMediaAccess());

		if (err != KErrNone)

			{

			__PRINT1(_L("Read failed, err=%d\n"), err);

			// +++ READ CS ENDS HERE +++

			__PRINT(_L("Signalling Read CS..."));

			iThreadContext->iCritSect.Signal();

			return EFalse;

			}

		}

	// Prepare thread variables for next pre-read attempt by the ReadThread

	const TInt64 offs_new = aOffset + aLength;

	iThreadContext->iDrive = aDrive;	// same drive

	desc->iByteOffset = offs_new;		// next block

	desc->iLength = aLength;			// same length

	iCompleted = EFalse;

	iThreadContext->iBuffer.SwapDesc();

	// +++ READ CS ENDS HERE +++

	__PRINT(_L("Signalling Read CS..."));

	iThreadContext->iCritSect.Signal();

	// Start background read

	__PRINT(_L("Resuming Read Thread"));

	iThreadContext->Resume();

	return ETrue;

	}

/**

Discard the read buffer. This is used to force a cache miss when reading from

the same sectors that were just written.

*/

void CReadDriveThread::DiscardRead()

{

	__PRINT(_L("Waiting on Read CS in DiscardRead..."));

	iThreadContext->iCritSect.Wait();

	// +++ READ CS STARTS HERE +++

	__PRINT(_L("Discarding pre-read buffer"));

	iCompleted = EFalse;

	iThreadContext->iBuffer.iDescReadPtr->iLength = 0;

	// +++ READ CS ENDS HERE +++

	__PRINT(_L("Signalling Read CS in DiscardRead..."));

	iThreadContext->iCritSect.Signal();

}

#endif // MSDC_MULTITHREADED