minwave.cpp

在微软例子下实现的虚拟声卡,实现了各种接口,是学习的一个好例子

    // Determine if the format is valid.
    //
    if (NT_SUCCESS(ntStatus))
    {
        ntStatus = ValidateFormat(DataFormat);
    }

    // Instantiate a stream. Stream must be in
    // NonPagedPool because of file saving.
    //
    if (NT_SUCCESS(ntStatus))
    {
        stream = new (NonPagedPool, MSVAD_POOLTAG) 
            CMiniportWaveCyclicStream(OuterUnknown);

        if (stream)
        {
            stream->AddRef();

            ntStatus = 
                stream->Init
                ( 
                    this,
                    Pin,
                    Capture,
                    DataFormat
                );
        }
        else
        {
            ntStatus = STATUS_INSUFFICIENT_RESOURCES;
        }
    }

    if (NT_SUCCESS(ntStatus))
    {
        if (Capture)
        {
            m_fCaptureAllocated = TRUE;
        }
        else
        {
            m_pStream[streamIndex] = stream;
        }

        *OutStream = PMINIPORTWAVECYCLICSTREAM(stream);
        (*OutStream)->AddRef();
        
        *OutDmaChannel = PDMACHANNEL(stream);
        (*OutDmaChannel)->AddRef();

        *OutServiceGroup = m_ServiceGroup;
        (*OutServiceGroup)->AddRef();

        // The stream, the DMA channel, and the service group have
        // references now for the caller.  The caller expects these
        // references to be there.
    }

    // This is our private reference to the stream.  The caller has
    // its own, so we can release in any case.
    //
    if (stream)
    {
        stream->Release();
    }
    
    return ntStatus;
} // NewStream

//=============================================================================
STDMETHODIMP_(NTSTATUS)
CMiniportWaveCyclic::NonDelegatingQueryInterface
( 
    IN  REFIID  Interface,
    OUT PVOID * Object 
)
/*++

Routine Description:

  QueryInterface

Arguments:

  Interface - GUID

  Object - interface pointer to be returned.

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    ASSERT(Object);

    if (IsEqualGUIDAligned(Interface, IID_IUnknown))
    {
        *Object = PVOID(PUNKNOWN(PMINIPORTWAVECYCLIC(this)));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IMiniport))
    {
        *Object = PVOID(PMINIPORT(this));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IMiniportWaveCyclic))
    {
        *Object = PVOID(PMINIPORTWAVECYCLIC(this));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IPinCount))
    {
        *Object = PVOID(PPINCOUNT(this));
    }
    else
    {
        *Object = NULL;
    }

    if (*Object)
    {
        // We reference the interface for the caller.

        PUNKNOWN(*Object)->AddRef();
        return STATUS_SUCCESS;
    }

    return STATUS_INVALID_PARAMETER;
} // NonDelegatingQueryInterface

//=============================================================================
STDMETHODIMP_(void)
CMiniportWaveCyclic::PinCount
(
    IN      ULONG   PinId,
    IN  OUT PULONG  FilterNecessary,
    IN  OUT PULONG  FilterCurrent,
    IN  OUT PULONG  FilterPossible,
    IN  OUT PULONG  GlobalCurrent,
    IN  OUT PULONG  GlobalPossible
)
/*++

Routine Description:

  Provide a way for the miniport to modify the pin counts for this miniport. 

Arguments:

  PinId - KS pin number being referenced

  FilterNecessary - number of pins required on this pin factory
  FilterCurrent   - number of pins opened on this pin factory
  FilterPossible  - number of pins possible on this pin factory
  GlobalCurrent   - total number of pins opened, across all pin instances on this filter
  GlobalPossible  - total number of pins possible, across all pin factories on this filter

Return Value:

  OUT parameters for the five pin counts.

--*/
{
    PAGED_CODE();
    
    _DbgPrintF( DEBUGLVL_VERBOSE, 
                ("PinCount PID:0x%08x FN(0x%08x):%d FC(0x%08x):%d FP(0x%08x):%d GC(0x%08x):%d GP(0x%08x):%d",
                  PinId,
                  FilterNecessary,*FilterNecessary,
                  FilterCurrent,  *FilterCurrent,
                  FilterPossible, *FilterPossible, 
                  GlobalCurrent,  *GlobalCurrent,
                  GlobalPossible, *GlobalPossible ) );

    //
    // Something like the following:
    //
//    if (0 == PinId)
//    {
//        *FilterPossible += 1;
//    }

} // PinCount

//=============================================================================
// CMiniportWaveStreamCyclicSimple
//=============================================================================

//=============================================================================
CMiniportWaveCyclicStream::~CMiniportWaveCyclicStream
( 
    void 
)
/*++

Routine Description:

  Destructor for wavecyclicstream 

Arguments:

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    DPF_ENTER(("[CMiniportWaveCyclicStream::~CMiniportWaveCyclicStream]"));

    if (NULL != m_pMiniportLocal)
    {
        // Tell the Miniport that the slot is freed now.
        //
        if (m_fCapture)
        {
            m_pMiniportLocal->m_fCaptureAllocated = FALSE;
        }
        else
        {
            for (ULONG i = 0; i < m_pMiniportLocal->m_MaxInputStreams; i++)
            {
                if (this == m_pMiniportLocal->m_pStream[i])
                {
                    m_pMiniportLocal->m_pStream[i] = NULL;
                    break;
                }
            }
        }
    }
} // ~CMiniportWaveCyclicStream

//=============================================================================
NTSTATUS
CMiniportWaveCyclicStream::Init
( 
    IN PCMiniportWaveCyclic         Miniport_,
    IN ULONG                        Pin_,
    IN BOOLEAN                      Capture_,
    IN PKSDATAFORMAT                DataFormat_
)
/*++

Routine Description:

  Initializes the stream object. Allocate a DMA buffer, timer and DPC

Arguments:

  Miniport_ -

  Pin_ -

  Capture_ -

  DataFormat -

  DmaChannel_ -

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    m_pMiniportLocal = Miniport_;

    return 
        CMiniportWaveCyclicStreamMSVAD::Init
        (
            Miniport_,
            Pin_,
            Capture_,
            DataFormat_
        );
} // Init

//=============================================================================
STDMETHODIMP_(NTSTATUS)
CMiniportWaveCyclicStream::NonDelegatingQueryInterface
( 
    IN  REFIID  Interface,
    OUT PVOID * Object 
)
/*++

Routine Description:

  QueryInterface

Arguments:

  Interface - GUID

  Object - interface pointer to be returned

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    ASSERT(Object);

    if (IsEqualGUIDAligned(Interface, IID_IUnknown))
    {
        *Object = PVOID(PUNKNOWN(PMINIPORTWAVECYCLICSTREAM(this)));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IMiniportWaveCyclicStream))
    {
        *Object = PVOID(PMINIPORTWAVECYCLICSTREAM(this));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IDmaChannel))
    {
        *Object = PVOID(PDMACHANNEL(this));
    }
    else
    {
        *Object = NULL;
    }

    if (*Object)
    {
        PUNKNOWN(*Object)->AddRef();
        return STATUS_SUCCESS;
    }

    return STATUS_INVALID_PARAMETER;
} // NonDelegatingQueryInterface
#pragma code_seg()