Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 1 | //------------------------------------------------------------------------------
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| 2 | // File: ComBase.cpp
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| 3 | //
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| 4 | // Desc: DirectShow base classes - implements class hierarchy for creating
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| 5 | // COM objects.
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| 6 | //
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| 7 | // Copyright (c) 1992-2001 Microsoft Corporation. All rights reserved.
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| 8 | //------------------------------------------------------------------------------
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| 9 |
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| 10 | #include <pjmedia-videodev/config.h>
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| 11 |
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| 12 | #if defined(PJMEDIA_VIDEO_DEV_HAS_DSHOW) && PJMEDIA_VIDEO_DEV_HAS_DSHOW != 0
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| 13 |
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| 14 | #include <streams.h>
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| 15 | #pragma warning( disable : 4514 ) // Disable warnings re unused inline functions
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| 16 |
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| 17 |
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| 18 | /* Define the static member variable */
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| 19 |
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| 20 | LONG CBaseObject::m_cObjects = 0;
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| 21 |
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| 22 |
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| 23 | /* Constructor */
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| 24 |
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| 25 | CBaseObject::CBaseObject(__in_opt LPCTSTR pName)
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| 26 | {
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| 27 | /* Increment the number of active objects */
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| 28 | InterlockedIncrement(&m_cObjects);
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| 29 |
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| 30 | #ifdef DEBUG
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| 31 |
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| 32 | #ifdef UNICODE
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| 33 | m_dwCookie = DbgRegisterObjectCreation(0, pName);
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| 34 | #else
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| 35 | m_dwCookie = DbgRegisterObjectCreation(pName, 0);
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| 36 | #endif
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| 37 |
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| 38 | #endif
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| 39 | }
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| 40 |
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| 41 | #ifdef UNICODE
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| 42 | CBaseObject::CBaseObject(const char *pName)
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| 43 | {
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| 44 | /* Increment the number of active objects */
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| 45 | InterlockedIncrement(&m_cObjects);
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| 46 |
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| 47 | #ifdef DEBUG
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| 48 | m_dwCookie = DbgRegisterObjectCreation(pName, 0);
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| 49 | #endif
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| 50 | }
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| 51 | #endif
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| 52 |
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| 53 | HINSTANCE hlibOLEAut32;
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| 54 |
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| 55 | /* Destructor */
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| 56 |
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| 57 | CBaseObject::~CBaseObject()
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| 58 | {
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| 59 | /* Decrement the number of objects active */
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| 60 | if (InterlockedDecrement(&m_cObjects) == 0) {
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| 61 | if (hlibOLEAut32) {
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| 62 | FreeLibrary(hlibOLEAut32);
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| 63 |
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| 64 | hlibOLEAut32 = 0;
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| 65 | }
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| 66 | };
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| 67 |
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| 68 |
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| 69 | #ifdef DEBUG
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| 70 | DbgRegisterObjectDestruction(m_dwCookie);
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| 71 | #endif
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| 72 | }
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| 73 |
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| 74 | static const TCHAR szOle32Aut[] = TEXT("OleAut32.dll");
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| 75 |
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| 76 | HINSTANCE LoadOLEAut32()
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| 77 | {
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| 78 | if (hlibOLEAut32 == 0) {
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| 79 |
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| 80 | hlibOLEAut32 = LoadLibrary(szOle32Aut);
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| 81 | }
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| 82 |
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| 83 | return hlibOLEAut32;
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| 84 | }
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| 85 |
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| 86 |
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| 87 | /* Constructor */
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| 88 |
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| 89 | // We know we use "this" in the initialization list, we also know we don't modify *phr.
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| 90 | #pragma warning( disable : 4355 4100 )
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| 91 | CUnknown::CUnknown(__in_opt LPCTSTR pName, __in_opt LPUNKNOWN pUnk)
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| 92 | : CBaseObject(pName)
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| 93 | /* Start the object with a reference count of zero - when the */
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| 94 | /* object is queried for it's first interface this may be */
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| 95 | /* incremented depending on whether or not this object is */
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| 96 | /* currently being aggregated upon */
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| 97 | , m_cRef(0)
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| 98 | /* Set our pointer to our IUnknown interface. */
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| 99 | /* If we have an outer, use its, otherwise use ours. */
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| 100 | /* This pointer effectivly points to the owner of */
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| 101 | /* this object and can be accessed by the GetOwner() method. */
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| 102 | , m_pUnknown( pUnk != 0 ? pUnk : reinterpret_cast<LPUNKNOWN>( static_cast<PNDUNKNOWN>(this) ) )
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| 103 | /* Why the double cast? Well, the inner cast is a type-safe cast */
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| 104 | /* to pointer to a type from which we inherit. The second is */
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| 105 | /* type-unsafe but works because INonDelegatingUnknown "behaves */
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| 106 | /* like" IUnknown. (Only the names on the methods change.) */
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| 107 | {
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| 108 | // Everything we need to do has been done in the initializer list
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| 109 | }
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| 110 |
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| 111 | // This does the same as above except it has a useless HRESULT argument
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| 112 | // use the previous constructor, this is just left for compatibility...
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| 113 | CUnknown::CUnknown(__in_opt LPCTSTR pName, __in_opt LPUNKNOWN pUnk, __inout_opt HRESULT *phr) :
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| 114 | CBaseObject(pName),
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| 115 | m_cRef(0),
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| 116 | m_pUnknown( pUnk != 0 ? pUnk : reinterpret_cast<LPUNKNOWN>( static_cast<PNDUNKNOWN>(this) ) )
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| 117 | {
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| 118 | }
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| 119 |
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| 120 | #ifdef UNICODE
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| 121 | CUnknown::CUnknown(__in_opt LPCSTR pName, __in_opt LPUNKNOWN pUnk)
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| 122 | : CBaseObject(pName), m_cRef(0),
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| 123 | m_pUnknown( pUnk != 0 ? pUnk : reinterpret_cast<LPUNKNOWN>( static_cast<PNDUNKNOWN>(this) ) )
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| 124 | { }
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| 125 |
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| 126 | CUnknown::CUnknown(__in_opt LPCSTR pName, __in_opt LPUNKNOWN pUnk, __inout_opt HRESULT *phr) :
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| 127 | CBaseObject(pName), m_cRef(0),
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| 128 | m_pUnknown( pUnk != 0 ? pUnk : reinterpret_cast<LPUNKNOWN>( static_cast<PNDUNKNOWN>(this) ) )
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| 129 | { }
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| 130 |
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| 131 | #endif
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| 132 |
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| 133 | #pragma warning( default : 4355 4100 )
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| 134 |
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| 135 |
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| 136 | /* QueryInterface */
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| 137 |
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| 138 | STDMETHODIMP CUnknown::NonDelegatingQueryInterface(REFIID riid, __deref_out void ** ppv)
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| 139 | {
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| 140 | CheckPointer(ppv,E_POINTER);
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| 141 | ValidateReadWritePtr(ppv,sizeof(PVOID));
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| 142 |
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| 143 | /* We know only about IUnknown */
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| 144 |
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| 145 | if (riid == IID_IUnknown) {
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| 146 | GetInterface((LPUNKNOWN) (PNDUNKNOWN) this, ppv);
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| 147 | return NOERROR;
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| 148 | } else {
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| 149 | *ppv = NULL;
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| 150 | return E_NOINTERFACE;
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| 151 | }
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| 152 | }
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| 153 |
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| 154 | /* We have to ensure that we DON'T use a max macro, since these will typically */
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| 155 | /* lead to one of the parameters being evaluated twice. Since we are worried */
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| 156 | /* about concurrency, we can't afford to access the m_cRef twice since we can't */
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| 157 | /* afford to run the risk that its value having changed between accesses. */
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| 158 |
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| 159 | template<class T> inline static T ourmax( const T & a, const T & b )
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| 160 | {
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| 161 | return a > b ? a : b;
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| 162 | }
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| 163 |
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| 164 | /* AddRef */
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| 165 |
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| 166 | STDMETHODIMP_(ULONG) CUnknown::NonDelegatingAddRef()
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| 167 | {
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| 168 | LONG lRef = InterlockedIncrement( &m_cRef );
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| 169 | ASSERT(lRef > 0);
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| 170 | DbgLog((LOG_MEMORY,3,TEXT(" Obj %d ref++ = %d"),
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| 171 | m_dwCookie, m_cRef));
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| 172 | return ourmax(ULONG(m_cRef), 1ul);
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| 173 | }
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| 174 |
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| 175 |
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| 176 | /* Release */
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| 177 |
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| 178 | STDMETHODIMP_(ULONG) CUnknown::NonDelegatingRelease()
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| 179 | {
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| 180 | /* If the reference count drops to zero delete ourselves */
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| 181 |
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| 182 | LONG lRef = InterlockedDecrement( &m_cRef );
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| 183 | ASSERT(lRef >= 0);
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| 184 |
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| 185 | DbgLog((LOG_MEMORY,3,TEXT(" Object %d ref-- = %d"),
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| 186 | m_dwCookie, m_cRef));
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| 187 | if (lRef == 0) {
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| 188 |
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| 189 | // COM rules say we must protect against re-entrancy.
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| 190 | // If we are an aggregator and we hold our own interfaces
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| 191 | // on the aggregatee, the QI for these interfaces will
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| 192 | // addref ourselves. So after doing the QI we must release
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| 193 | // a ref count on ourselves. Then, before releasing the
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| 194 | // private interface, we must addref ourselves. When we do
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| 195 | // this from the destructor here it will result in the ref
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| 196 | // count going to 1 and then back to 0 causing us to
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| 197 | // re-enter the destructor. Hence we add an extra refcount here
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| 198 | // once we know we will delete the object.
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| 199 | // for an example aggregator see filgraph\distrib.cpp.
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| 200 |
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| 201 | m_cRef++;
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| 202 |
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| 203 | delete this;
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| 204 | return ULONG(0);
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| 205 | } else {
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| 206 | // Don't touch m_cRef again even in this leg as the object
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| 207 | // may have just been released on another thread too
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| 208 | return ourmax(ULONG(lRef), 1ul);
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| 209 | }
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| 210 | }
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| 211 |
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| 212 |
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| 213 | /* Return an interface pointer to a requesting client
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| 214 | performing a thread safe AddRef as necessary */
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| 215 |
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| 216 | STDAPI GetInterface(LPUNKNOWN pUnk, __out void **ppv)
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| 217 | {
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| 218 | CheckPointer(ppv, E_POINTER);
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| 219 | *ppv = pUnk;
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| 220 | pUnk->AddRef();
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| 221 | return NOERROR;
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| 222 | }
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| 223 |
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| 224 |
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| 225 | /* Compares two interfaces and returns TRUE if they are on the same object */
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| 226 |
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| 227 | BOOL WINAPI IsEqualObject(IUnknown *pFirst, IUnknown *pSecond)
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| 228 | {
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| 229 | /* Different objects can't have the same interface pointer for
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| 230 | any interface
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| 231 | */
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| 232 | if (pFirst == pSecond) {
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| 233 | return TRUE;
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| 234 | }
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| 235 | /* OK - do it the hard way - check if they have the same
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| 236 | IUnknown pointers - a single object can only have one of these
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| 237 | */
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| 238 | LPUNKNOWN pUnknown1; // Retrieve the IUnknown interface
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| 239 | LPUNKNOWN pUnknown2; // Retrieve the other IUnknown interface
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| 240 | HRESULT hr; // General OLE return code
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| 241 |
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| 242 | ASSERT(pFirst);
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| 243 | ASSERT(pSecond);
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| 244 |
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| 245 | /* See if the IUnknown pointers match */
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| 246 |
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| 247 | hr = pFirst->QueryInterface(IID_IUnknown,(void **) &pUnknown1);
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| 248 | if (FAILED(hr)) {
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| 249 | return FALSE;
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| 250 | }
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| 251 | ASSERT(pUnknown1);
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| 252 |
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| 253 | /* Release the extra interface we hold */
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| 254 |
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| 255 | pUnknown1->Release();
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| 256 |
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| 257 | hr = pSecond->QueryInterface(IID_IUnknown,(void **) &pUnknown2);
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| 258 | if (FAILED(hr)) {
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| 259 | return FALSE;
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| 260 | }
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| 261 | ASSERT(pUnknown2);
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| 262 |
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| 263 | /* Release the extra interface we hold */
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| 264 |
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| 265 | pUnknown2->Release();
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| 266 | return (pUnknown1 == pUnknown2);
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| 267 | }
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| 268 |
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| 269 | #endif /* PJMEDIA_VIDEO_DEV_HAS_DSHOW */
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