dllmain.cpp

//////////////////////////////////////////////////////////////////////////
//
// dllmain.cpp : Implements DLL exports and COM class factory
//
// 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) Microsoft Corporation. All rights reserved.
//
// Note: This source file implements the class factory for the transform,
//       plus the following DLL functions:
//       - DllMain
//       - DllCanUnloadNow
//       - DllRegisterServer
//       - DllUnregisterServer
//       - DllGetClassObject
//
//////////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "common.h"
#include "multipinmft.h"
#include <initguid.h>

#ifdef MF_WPP
#include "dllmain.tmh"    //--REF_ANALYZER_DONT_REMOVE--
#endif

//
// The static variable needed to check the object count of the deviceMFts loaded.
//

volatile long CDMFTModuleLifeTimeManager::s_lObjectCount = 0;



HRESULT RegisterObject(HMODULE hModule, REFGUID guid, PCWSTR pszDescription, PCWSTR pszThreadingModel);

HRESULT UnregisterObject(const GUID& guid);


// Module Ref count
long g_cRefModule = 0;

// Handle to the DLL's module
HMODULE g_hModule = NULL;

void DllAddRef()
{
    InterlockedIncrement(&g_cRefModule);
}

void DllRelease()
{
    InterlockedDecrement(&g_cRefModule);
}

//
// IClassFactory implementation
//

typedef HRESULT (*PFNCREATEINSTANCE)(REFIID riid, void **ppvObject);
struct CLASS_OBJECT_INIT
{
    const CLSID *pClsid;
    PFNCREATEINSTANCE pfnCreate;
};

// Classes supported by this module:
const CLASS_OBJECT_INIT c_rgClassObjectInit[] =
{
    { &CLSID_MultiPinMFT, MFT_CreateInstance },
};

class CClassFactory : public IClassFactory
{
public:

    static HRESULT CreateInstance(
        REFCLSID clsid,                                 // The CLSID of the object to create (from DllGetClassObject)
        const CLASS_OBJECT_INIT *pClassObjectInits,     // Array of class factory data.
        size_t cClassObjectInits,                       // Number of elements in the array.
        REFIID riid,                                    // The IID of the interface to retrieve (from DllGetClassObject)
        void **ppv                                      // Receives a pointer to the interface.
        )
    {
        *ppv = NULL;

        HRESULT hr = CLASS_E_CLASSNOTAVAILABLE;

        for (size_t i = 0; i < cClassObjectInits; i++)
        {
            if (clsid == *pClassObjectInits[i].pClsid)
            {
                IClassFactory *pClassFactory = new (std::nothrow) CClassFactory(pClassObjectInits[i].pfnCreate);

                if (pClassFactory)
                {
                    hr = pClassFactory->QueryInterface(riid, ppv);
                    pClassFactory->Release();
                }
                else
                {
                    hr = E_OUTOFMEMORY;
                }
                break; // match found
            }
        }
        return hr;
    }

    // IUnknown methods
    IFACEMETHODIMP QueryInterface(REFIID riid, void ** ppv)
    {
#if 0
        static const QITAB qit[] =
        {
            QITABENT(CClassFactory, IClassFactory),
            { 0 }
        };
        return QISearch(this, qit, riid, ppv);

#else
        if (riid == __uuidof(IClassFactory))
        {
            *ppv = static_cast< IClassFactory* >(this);
            AddRef();
        }
        return S_OK;
#endif
    }

    IFACEMETHODIMP_(ULONG) AddRef()
    {
        return InterlockedIncrement(&m_cRef);
    }

    IFACEMETHODIMP_(ULONG) Release()
    {
        long cRef = InterlockedDecrement(&m_cRef);
        if (cRef == 0)
        {
            delete this;
        }
        return cRef;
    }

    // IClassFactory methods

    IFACEMETHODIMP CreateInstance(IUnknown *punkOuter, REFIID riid, void **ppv)
    {
        return punkOuter ? CLASS_E_NOAGGREGATION : m_pfnCreate(riid, ppv);
    }

    IFACEMETHODIMP LockServer(BOOL fLock)
    {
        if (fLock)
        {
            DllAddRef();
        }
        else
        {
            DllRelease();
        }
        return S_OK;
    }

private:

    CClassFactory(PFNCREATEINSTANCE pfnCreate) : m_cRef(1), m_pfnCreate(pfnCreate)
    {
        DllAddRef();
    }

    ~CClassFactory()
    {
        DllRelease();
    }

    long m_cRef;
    PFNCREATEINSTANCE m_pfnCreate;
};



//
// Standard DLL functions
//

STDMETHODIMP_(BOOL) WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, void *)
{
    if (dwReason == DLL_PROCESS_ATTACH)
    {
        g_hModule = (HMODULE)hInstance;
        DisableThreadLibraryCalls(hInstance);
#ifdef MF_WPP
        WPP_INIT_TRACING(L"MultiPinMft");

        //  Hook up WIL tracing to our trace provider.
        wil::SetResultLoggingCallback(
            [](const wil::FailureInfo &failure) noexcept
        {
            wchar_t debugString[2048];
            if (SUCCEEDED(wil::GetFailureLogString(debugString, ARRAYSIZE(debugString), failure)))
            {
                DMFTRACE(DMFT_GENERAL, TRACE_LEVEL_ERROR, L"%S", debugString);
            }
            else
            {
                DMFTRACE(DMFT_GENERAL, TRACE_LEVEL_ERROR, 
                    L"File: %s, Line: %u, Error: 0x%08X - %S\n",
                    failure.pszFile,
                    failure.uLineNumber,
                    failure.hr,
                    failure.pszMessage);
            }
        }
        );
#endif
    }
    else
    if (dwReason == DLL_PROCESS_DETACH)
    {
#ifdef MF_WPP
        wil::SetResultLoggingCallback(nullptr);
        WPP_CLEANUP();
#endif
    }
    return TRUE;
}

STDMETHODIMP DllCanUnloadNow()
{
    HRESULT hr = ((g_cRefModule == 0) && (CDMFTModuleLifeTimeManager::GetDMFTObjCount() == 0)) ? S_OK : S_FALSE;
    //
    // Debug object lifetimes
    //
    DMFTRACE(DMFT_GENERAL, TRACE_LEVEL_INFORMATION, "%!FUNC! returning %d %d %!HRESULT!",
        g_cRefModule,
        CDMFTModuleLifeTimeManager::GetDMFTObjCount(),
        hr);

    return hr;

}

_Check_return_
STDAPI  DllGetClassObject(_In_ REFCLSID clsid, _In_ REFIID riid, _Outptr_ LPVOID FAR* ppv)
{
    return CClassFactory::CreateInstance(clsid, c_rgClassObjectInit, ARRAYSIZE(c_rgClassObjectInit), riid, ppv);
}

STDMETHODIMP DllRegisterServer()
{
    assert(g_hModule != NULL);

    // Register the CLSID for CoCreateInstance.
    HRESULT hr = RegisterObject(g_hModule, CLSID_MultiPinMFT, TEXT("Multiple MFTs"), TEXT("Both"));

    return hr;
}

STDMETHODIMP DllUnregisterServer()
{
    // Unregister the CLSID.
    UnregisterObject(CLSID_MultiPinMFT);

    return S_OK;
}


// Converts a CLSID into a string with the form "CLSID\{clsid}"
STDMETHODIMP CreateObjectKeyName(REFGUID guid, _Out_writes_(cchMax) PWSTR pszName, DWORD cchMax)
{
    const DWORD chars_in_guid = 39;

    // convert CLSID uuid to string
    OLECHAR szCLSID[chars_in_guid];
    HRESULT hr = StringFromGUID2(guid, szCLSID, chars_in_guid);
    if (SUCCEEDED(hr))
    {
        // Create a string of the form "CLSID\{clsid}"
        hr = StringCchPrintf((STRSAFE_LPWSTR)pszName, cchMax, TEXT("Software\\Classes\\CLSID\\%ls"), szCLSID);
    }
    return hr;
}

// Creates a registry key (if needed) and sets the default value of the key
STDMETHODIMP CreateRegKeyAndValue(HKEY hKey, PCWSTR pszSubKeyName, PCWSTR pszValueName,
    PCWSTR pszData, PHKEY phkResult)
{
    *phkResult = NULL;
    LONG lRet = RegCreateKeyExW(
        hKey, pszSubKeyName,
        0,  NULL, REG_OPTION_NON_VOLATILE,
        KEY_ALL_ACCESS, NULL, phkResult, NULL);

    if (lRet == ERROR_SUCCESS)
    {
        lRet = RegSetValueExW(
            (*phkResult),
            pszValueName, 0, REG_SZ,
            (LPBYTE) pszData,
            ((DWORD) wcslen(pszData) + 1) * sizeof(WCHAR)
            );

        if (lRet != ERROR_SUCCESS)
        {
            RegCloseKey(*phkResult);
        }
    }

    return HRESULT_FROM_WIN32(lRet);
}

// Creates the registry entries for a COM object.

HRESULT RegisterObject(HMODULE hModule, const GUID& guid, const TCHAR *pszDescription, const TCHAR *pszThreadingModel)
{
    HKEY hKey = NULL;
    HKEY hSubkey = NULL;
    TCHAR achTemp[MAX_PATH];

    // Create the name of the key from the object's CLSID
    HRESULT hr = CreateObjectKeyName(guid, achTemp, MAX_PATH);

    // Create the new key.
    if (SUCCEEDED(hr))
    {
        hr = CreateRegKeyAndValue(HKEY_LOCAL_MACHINE, achTemp, NULL, pszDescription,&hKey);
    }

    if (SUCCEEDED(hr))
    {
        (void)GetModuleFileName(hModule, achTemp, MAX_PATH);

        hr = HRESULT_FROM_WIN32(GetLastError());
    }

    // Create the "InprocServer32" subkey
    if (SUCCEEDED(hr))
    {
        hr = CreateRegKeyAndValue(hKey, L"InProcServer32", NULL, achTemp, &hSubkey);
        RegCloseKey(hSubkey);
    }

    // Add a new value to the subkey, for "ThreadingModel" = <threading model>
    if (SUCCEEDED(hr))
    {
        hr = CreateRegKeyAndValue(hKey, L"InProcServer32", L"ThreadingModel", pszThreadingModel, &hSubkey);
        RegCloseKey(hSubkey);
    }

    // close hkeys
    RegCloseKey(hKey);
    return hr;
}

// Deletes the registry entries for a COM object.

HRESULT UnregisterObject(const GUID& guid)
{
    WCHAR achTemp[MAX_PATH];

    HRESULT hr = CreateObjectKeyName(guid, achTemp, MAX_PATH);
    if (SUCCEEDED(hr))
    {
        // Delete the key recursively.
        LONG lRes = RegDeleteTree(HKEY_LOCAL_MACHINE, achTemp);
        hr = HRESULT_FROM_WIN32(lRes);
    }
    return hr;
}