"john***@gmail.com" wrote:

> I have the big application, it has C#, VB.NET, VB6 & VC++ components,
> those components calling each other, passing the objects between the
> managed & unmanaged layer.
>
>
> The application crashes in one operation scenario, the crash is caused
> by the following:
> 1)    A COM (ComComp1 ,written with  VB6.0) component is marshaled
> to .NET (NetComp1)
> 2)    NetComp1 create a instance of another Comp Component (ComComp2,
> written with  VC++6.0) and store it as a variable
> 3)    Then ComComp1 is marshaled back to COM component(ComComp2)
> 4)    This ComComp1 component is stored in a map (class member) in
> ComComp2, the map is defined as following :
> typedef map<_bstr_t,_variant_t> PropertyMap;
>     The COMComp1 is store in the second element of the map as _variant_t
>
> Under certain circumstances. When the Gabage.Collect is called,
> NetComp1 is collected, then the Destructor for COM Component
> (COMComp2) is called, all the memory in its map is freed, since the
> map has the _variant_t in it, the VariantClear is called, but for
> whatever reason, the object (COMComp1) stored in the _variant_t is
> invalid (has been released), causing a Access Violation.
>
> If I store a COM Component in a _variant_t, an should Addref() is
> called and that object should never be released, so I do not
> understand why sometimes the COMComp1 is invalid, how could the
> COMComp1 be release if other object still hold is as a reference.
> Please advice.
> Thanks in advance.
>  The stack trace is as following, the error happen in the following
> line :
> 0012d35c 12d715d4 AppContainer!_variant_t::~_variant_t+0x29
>
>
>
>
> 0:000> kL 200
> ChildEBP RetAddr
> 0012cf58 7c90e96c ntdll!KiFastSystemCallRet
> 0012cf5c 7c91e7d3 ntdll!NtUnmapViewOfSection+0xc
> 0012d04c 7c80abf7 ntdll!LdrUnloadDll+0x31a
> 0012d060 77513442 kernel32!FreeLibrary+0x3f
> 0012d06c 77513456 ole32!
> CClassCache::CDllPathEntry::CFinishObject::Finish+0x2f
> 0012d080 775135fe ole32!CClassCache::CFinishComposite::Finish+0x1d
> 0012d228 77513578 ole32!CClassCache::FreeUnused+0x19d
> 0012d238 775133a2 ole32!CoFreeUnusedLibrariesEx+0x36
> 0012d244 6605a01e ole32!CoFreeUnusedLibraries+0x9
> 0012d258 6605b4d1 MSVBVM60!CCreDestroyCtlStruct+0x387
> 0012d27c 6601c56a MSVBVM60!CCreDestroyCtl+0x195
> 0012d2c0 6601bc56 MSVBVM60!CCreFUnloadForm+0x1c9
> 0012d2cc 660c9ed5 MSVBVM60!CUnkDesk::Release+0x23
> 0012d2e4 6600e720 MSVBVM60!BASIC_CLASS::PRIVATE_UNKNOWN::Release+0x11c
> 0012d2ec 77124918 MSVBVM60!SCM_MsoStdCompMgr::Release+0xd
> 0012d300 12d75f49 OLEAUT32!VariantClear+0xb1
> 0012d35c 12d715d4 AppContainer!_variant_t::~_variant_t+0x29
> 0012d3c0 12d74b25 AppContainer!std::pair<_bstr_t
> const ,_variant_t>::~pair<_bstr_t const ,_variant_t>+0x44
> 0012d418 12d749b2 AppContainer!std::pair<_bstr_t
> const ,_variant_t>::`scalar deleting destructor'+0x25
> 0012d470 12d73d46 AppContainer!std::_Destroy+0x22
> 0012d4cc 12d72cb5 AppContainer!std::_Tree<_bstr_t,std::pair<_bstr_t
> const ,_variant_t>,std::map<_bstr_t,_variant_t,std::less<_bstr_t>,std::allocator<_variant_t>
> >::_Kfn,std::less<_bstr_t>,std::allocator<_variant_t> >::_Destval+0x26
> 0012d550 12d78e2d AppContainer!std::_Tree<_bstr_t,std::pair<_bstr_t
> const ,_variant_t>,std::map<_bstr_t,_variant_t,std::less<_bstr_t>,std::allocator<_variant_t>
> >::_Kfn,std::less<_bstr_t>,std::allocator<_variant_t> >::erase+0x825
> 0012d5b0 12d78af5 AppContainer!
> std::map<_bstr_t,_variant_t,std::less<_bstr_t>,std::allocator<_variant_t>
> >::erase+0x2d
> 0012d654 12d788f1 AppContainer!CPropertyContainer::RemoveMapObject
> +0x1c5
> 0012d6b8 12d796b0 AppContainer!CPropertyContainer::~CPropertyContainer
> +0x41
> 0012d71c 12d77335 AppContainer!
> ATL::CComObject<CPropertyContainer>::~CComObject<CPropertyContainer>
> +0x70
> 0012d774 12d79758 AppContainer!
> ATL::CComObject<CPropertyContainer>::`scalar deleting destructor'+0x25
> 0012d7dc 79e8dbde AppContainer!
> ATL::CComObject<CPropertyContainer>::Release+0x48
> 0012d830 79e8db4a mscorwks!ReleaseTransitionHelper+0x5f
> 0012d878 79e8dac5 mscorwks!SafeReleaseHelper+0x89
> 0012d8ac 79f27983 mscorwks!SafeRelease+0x2f
> 0012d8c4 79f2792e mscorwks!RCW::ReleaseAllInterfaces+0x49
> 0012d8f4 79f279dc mscorwks!RCW::ReleaseAllInterfacesCallBack+0xbd
> 0012d924 79f279b0 mscorwks!RCW::Cleanup+0x22
> 0012d92c 79f27997 mscorwks!RCWCleanupList::ReleaseRCWListRaw+0x14
> 0012d95c 79f277e5 mscorwks!RCWCleanupList::ReleaseRCWListInCorrectCtx
> +0x97
> 0012d96c 77525fbe mscorwks!CtxEntry::EnterContextCallback+0x94
> 0012d988 77e7a19c ole32!CRemoteUnknown::DoCallback+0x7a
> 0012d9a4 77ef321a RPCRT4!Invoke+0x30
> 0012dda8 77ef3bf3 RPCRT4!NdrStubCall2+0x297
> 0012de00 77600c31 RPCRT4!CStdStubBuffer_Invoke+0xc6
> 0012de40 77600bdb ole32!SyncStubInvoke+0x33
> 0012de88 7750f237 ole32!StubInvoke+0xa7
> 0012df60 7750f15c ole32!CCtxComChnl::ContextInvoke+0xe3
> 0012df7c 7750fc79 ole32!MTAInvoke+0x1a
> 0012dfa8 77600e3b ole32!STAInvoke+0x4a
> 0012dfdc 776009bc ole32!AppInvoke+0x7e
> 0012e0b0 77600df2 ole32!ComInvokeWithLockAndIPID+0x2e0
> 0012e0dc 7750fcb3 ole32!ComInvoke+0x60
> 0012e0f0 7750fae9 ole32!ThreadDispatch+0x23
> 0012e108 77d48744 ole32!ThreadWndProc+0xfe
> 0012e134 77d48826 USER32!InternalCallWinProc+0x28
> 0012e19c 77d489dd USER32!UserCallWinProcCheckWow+0x150
> 0012e1fc 77d48a20 USER32!DispatchMessageWorker+0x306
> 0012e20c 77512c02 USER32!DispatchMessageW+0xf
> 0012e23c 77512761 ole32!CCliModalLoop::PeekRPCAndDDEMessage+0x4c
> 0012e250 77557227 ole32!CCliModalLoop::BlockFn+0x5e
> 0012e2c4 79f27b88 ole32!CoWaitForMultipleHandles+0xcf
> 0012e2e4 79f27acf mscorwks!NT5WaitRoutine+0x51
> 0012e350 79f27a33 mscorwks!MsgWaitHelper+0xa5
> 0012e370 79f17493 mscorwks!Thread::DoAppropriateAptStateWait+0x28
> 0012e3f4 79f1732f mscorwks!Thread::DoAppropriateWaitWorker+0x144
> 0012e444 79f27cf0 mscorwks!Thread::DoAppropriateWait+0x40
> 0012e494 79f27c76 mscorwks!Thread::JoinEx+0x86
> 0012e4a0 79f27c52 mscorwks!Thread::Join+0x13
> 0012e4f0 79f20743 mscorwks!
> RCWCleanupList::CleanupWrappersInCurrentCtxThread+0x15a
> 0012e4f8 79f20665 mscorwks!RCW::Initialize+0x77
> 0012e52c 79f1dc99 mscorwks!RCW::CreateRCW+0x51
> 0012e59c 79f1c9a5 mscorwks!COMInterfaceMarshaler::CreateObjectRef+0x4d
> 0012e5fc 79f1c110 mscorwks!COMInterfaceMarshaler::FindOrCreateObjectRef
> +0xb4
> 0012eabc 79f82a1c mscorwks!GetObjectRefFromComIP+0x1b4
> 0012eadc 79f82a01 mscorwks!UnmarshalObjectFromInterface+0x19
> 0012eaf8 79f1e19d mscorwks!
> InterfaceMarshalerBase::ConvertSpaceNativeToCLR+0x30
> 0012eb00 79f1e0b2 mscorwks!
> DefaultMarshalOverrides<InterfaceMarshalerBase>::MarshalNativeToCLROut
> +0x11
> 0012ed3c 79f1f206 mscorwks!RunML+0x4f9
> 0012ee58 79f1ed6a mscorwks!COMToCLRWorkerBody+0x10f
> 0012eeb4 79f1ec81 mscorwks!COMToCLRWorkerDebuggerWrapper+0x37
> 0012f088 0173a271 mscorwks!COMToCLRWorker+0x164
> WARNING: Frame IP not in any known module. Following frames may be
> wrong.
> 0012f0b0 1425fac3 0x173a271
> 0012f1e0 142672fd AppController!CAppController::Display+0x184
> 0012f2d0 142504d2 AppController!CAppController::Create+0x683
> 0012f398 14236181 AppController!CAppController::CreateComponents+0x2da
> 0012f534 4599c7be AppController!CAppController::Open+0x607
> 0012f704 0108654d StateMgr!StateMgr::IState_Ope+0xded
> 0012f8c8 79f21268 TestMenu!Multiple::INotify_Notify+0xcc7
> 0012f9a8 045a0dd6 mscorwks!CLRToCOMWorker+0x196
> 0012f9e4 0ff37e88 0x45a0dd6
> 0012fa40 0ce5a340 0xff37e88
> 0012fa74 0ce59f28 0xce5a340
> 0012fac0 010ed2e2 0xce59f28
> *** WARNING: Unable to verify checksum for C:\WINDOWS\assembly
> \NativeImages_v2.0.50727_32\System.Windows.Forms
> \5892bc4805482546977cc303fe56856e\System.Windows.Forms.ni.dll
> 0012fc28 7b0d02da 0x10ed2e2
> 0012fc48 7b0d02da System_Windows_Forms_ni+0x1002da
> 0012fc8c 7b072c44 System_Windows_Forms_ni+0x1002da
> 0012fcf8 7b07a73d System_Windows_Forms_ni+0xa2c44
> 0012fd74 77d48744 System_Windows_Forms_ni+0xaa73d
> 0012fda0 77d48826 USER32!InternalCallWinProc+0x28
> 0012fe08 77d489dd USER32!UserCallWinProcCheckWow+0x150
> 0012fe68 77d496d7 USER32!DispatchMessageWorker+0x306
> 0012fe78 6600a4a3 USER32!DispatchMessageA+0xf
> 0012feb8 6600a41a MSVBVM60!ThunderMsgLoop+0xfd
> 0012fecc 6600a3bc MSVBVM60!CMsoCMHandler::FPushMessageLoop+0x19
> 0012fefc 6600a2f8 MSVBVM60!SCM::FPushMessageLoop+0xb9
> 0012ff18 6600a2c3 MSVBVM60!SCM_MsoCompMgr::FPushMessageLoop+0x2b
> 0012ff3c 6600361c MSVBVM60!CMsoComponent::PushMsgLoop+0x26
> 0012ffb8 00404dba MSVBVM60!ThunRTMain+0x9b
> 0012fff0 00000000 AppMain!__vbaS+0xa
>
>