windows-server-2003/drivers/wdm/audio/sysaudio/cinstanc.h

//---------------------------------------------------------------------------
//
//  Module:   		ins.h
//
//  Description:	KS Instance base class definition
//
//
//@@BEGIN_MSINTERNAL
//  Development Team:
//     Mike McLaughlin
//
//  History:   Date	  Author      Comment
//
//@@END_MSINTERNAL
//---------------------------------------------------------------------------
//
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
//  PURPOSE.
//
//  Copyright (c) 1996-1999 Microsoft Corporation.  All Rights Reserved.
//
//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
// Globals
//---------------------------------------------------------------------------

extern "C" const KSDISPATCH_TABLE DispatchTable;

//---------------------------------------------------------------------------
// Classes
//---------------------------------------------------------------------------

typedef class CInstance
{
    friend class ListDoubleField<CInstance>;
public:
    CInstance(
        IN PPARENT_INSTANCE pParentInstance
    );

    ~CInstance(
    );

    static NTSTATUS
    DispatchClose(
        IN PDEVICE_OBJECT pDeviceObject,
        IN PIRP pIrp
    );

    static NTSTATUS
    DispatchForwardIrp(
        IN PDEVICE_OBJECT pDeviceObject,
        IN PIRP pIrp
    );

    VOID
    Invalidate(
    );

    PFILE_OBJECT 
    GetNextFileObject(
    )
    {
        return(pNextFileObject);
    };

    PPIN_INSTANCE
    GetParentInstance(			// inline body in pins.h
    );

    NTSTATUS
    SetNextFileObject(
        HANDLE handle
    )
    {
        //
        // SECURITY NOTE:
        // This call is OK because the handle comes always from a trusted 
        // source.
        //
        return(ObReferenceObjectByHandle(
          handle,
          GENERIC_READ | GENERIC_WRITE,
          NULL,
          KernelMode,
          (PVOID*)&pNextFileObject,
          NULL));
    };

    NTSTATUS
    DispatchCreate(
        IN PIRP pIrp,
        IN UTIL_PFN pfnDispatchCreate,
        IN OUT PVOID pReference,
        IN ULONG cCreateItems = 0,
        IN PKSOBJECT_CREATE_ITEM pCreateItems = NULL,
        IN const KSDISPATCH_TABLE *pDispatchTable = &DispatchTable
    );

    VOID GrabInstanceMutex()
    {
        ASSERT(KeGetCurrentIrql() == PASSIVE_LEVEL);
        AssertStatus(
          KeWaitForMutexObject(pMutex, Executive, KernelMode, FALSE, NULL));
    };

    VOID ReleaseInstanceMutex()
    {
        ASSERT(KeGetCurrentIrql() == PASSIVE_LEVEL);
        KeReleaseMutex(pMutex, FALSE);
    };

private:
    VOID
    AddList(
        CListDouble *pld
    )
    {
        ldiNext.AddList(pld);
    };

    VOID
    RemoveList(
    )
    {
        ldiNext.RemoveList();
    };
    //
    // This pointer to the dispatch table is used in the common
    // dispatch routines  to route the IRP to the appropriate
    // handlers.  This structure is referenced by the device driver
    // with IoGetCurrentIrpStackLocation( pIrp ) -> FsContext
    //
    PVOID pObjectHeader;
    PFILE_OBJECT pParentFileObject;
    PDEVICE_OBJECT pNextDeviceObject;
    PPARENT_INSTANCE pParentInstance;
    PFILE_OBJECT pNextFileObject;
    CLIST_DOUBLE_ITEM ldiNext;
    KMUTEX *pMutex;
public:
    DefineSignature(0x534e4943);			// CINS

} INSTANCE, *PINSTANCE;

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

typedef ListDoubleField<INSTANCE> LIST_INSTANCE, *PLIST_INSTANCE;

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

typedef class CParentInstance
{
    friend class CInstance;
public:
    VOID
    Invalidate(
    );

    BOOL
    IsChildInstance(
    )
    {
        return(lstChildInstance.IsLstEmpty());
    };

    LIST_INSTANCE lstChildInstance;
    DefineSignature(0x52415043);			// CPAR

} PARENT_INSTANCE, *PPARENT_INSTANCE;

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