Recently I needed to debug a memory dump of a CLR process where the finalization queue was being blocked by a COM object. While I have largely identified the issue, I am not sure about the difference between some of the output and seek some clarification.
I used SOSEX to dump the RCWs. The output is as follows:
0:019> !sosex.rcw
SyncBlock OwnerObject RCW RefCount IUnknown VTable
------------------------------------------------------------------------------------------------------------
000000811807b238 0000008118251e18 00000081176b02e0 0 0000008116a6bc68 0061005c00730077
000000811807b5f8 00000081182b7380 0000008118104590 0 0000008116a6bc68 004d005c00730077
0000008562fed748 000000811831f498 0000008562fe7510 129 0000008116a6bc68 00000085632a2ee0
000000856300e168 00000084182ae2f0 0000008563082d00 0 0000008116a6bc68 000000856306a660
--------------
4 RCWs
Dumping the vtable does not help identify the COM object.
0:019> dps 00000085632a2ee0
00000085`632a2ee0 00007ffc`31832938 clr!DomainAssembly::`vftable'
00000085`632a2ee8 00000081`18099170
00000085`632a2ef0 00000085`631db8d0
00000085`632a2ef8 00000000`00000000
00000085`632a2f00 00007ffb`d24e4d20
00000085`632a2f08 0063006e`0000000c
00000085`632a2f10 00000085`1833ade9
00000085`632a2f18 00000000`00000000
00000085`632a2f20 00000001`00000007
00000085`632a2f28 00000000`00000000
00000085`632a2f30 00000000`00000000
00000085`632a2f38 00000000`00000000
00000085`632a2f40 00530041`002f0073
00000085`632a2f48 00000085`1833ade1
00000085`632a2f50 00000085`62fe7600
00000085`632a2f58 00000085`631dbd50
0:019> dps 00007ffc`31832938
00007ffc`31832938 00007ffc`31220ac0 clr!DomainAssembly::`vector deleting destructor'
00007ffc`31832940 00007ffc`311405d0 clr!CAssemblyIdentityManager::AddRef
00007ffc`31832948 00007ffc`3119e080 clr!DomainAssembly::Begin
00007ffc`31832950 00007ffc`3119fbe0 clr!DomainAssembly::Allocate
00007ffc`31832958 00007ffc`3119f0f0 clr!DomainAssembly::DeliverSyncEvents
00007ffc`31832960 00007ffc`3119e4d0 clr!DomainAssembly::DeliverAsyncEvents
00007ffc`31832968 00007ffc`311a01c0 clr!DomainAssembly::FindNativeImage
00007ffc`31832970 00007ffc`3160d630 clr!CorHostProtectionManager::QueryInterface
00007ffc`31832978 00007ffc`311405d0 clr!CAssemblyIdentityManager::AddRef
00007ffc`31832980 00007ffc`311405d0 clr!CAssemblyIdentityManager::AddRef
00007ffc`31832988 00007ffc`3160d660 clr!CorHostProtectionManager::SetProtectedCategories
00007ffc`31832990 00007ffc`31406100 clr!CorHostProtectionManager::SetEagerSerializeGrantSets
00007ffc`31832998 00007ffc`31500a30 clr!CCLRErrorReportingManager::QueryInterface
00007ffc`318329a0 00007ffc`311405d0 clr!CAssemblyIdentityManager::AddRef
00007ffc`318329a8 00007ffc`311405d0 clr!CAssemblyIdentityManager::AddRef
00007ffc`318329b0 00007ffc`314fcc50 clr!CCLRErrorReportingManager::GetBucketParametersForCurrentException
However, if I use !sos.dumprcw, a different vtable (and IUnknown) address is displayed:
0:019> !sos.dumprcw 0000008562fe7510
Managed object: 000000811831f498
Creating thread: 0000008562ff0050
IUnknown pointer: 000000811693a8d0
COM Context: 0000008116a6bc68
Managed ref count: 1
IUnknown V-table pointer : 00007ffc33609078 (captured at RCW creation time)
Flags:
COM interface pointers:
IP Context MT Type
000000811693a8d0 0000008116a6bc68 00007ffbd19db8c8 Microsoft.Web.Administration.Interop.IAppHostAdminManager
Dumping this "IUnknown V-table pointer" identifies the source of the COM reference.
0:019> dps 00007ffc33609078
00007ffc`33609078 00007ffc`33607cb0 nativerd!CONFIG_SYSTEM::QueryInterface
00007ffc`33609080 00007ffc`33605750 nativerd!CONFIG_SYSTEM::AddRef
00007ffc`33609088 00007ffc`33605700 nativerd!CONFIG_SYSTEM::Release
00007ffc`33609090 00007ffc`33627fe0 nativerd!CONFIG_SYSTEM::GetAdminSection
00007ffc`33609098 00007ffc`33603fb0 nativerd!CONFIG_SYSTEM::GetMetadata
00007ffc`336090a0 00007ffc`33609e40 nativerd!CONFIG_SYSTEM::SetMetadata
00007ffc`336090a8 00007ffc`3364fc30 nativerd!CONFIG_SYSTEM::get_ConfigManager
00007ffc`336090b0 00007ffc`3364ecc0 nativerd!CONFIG_SYSTEM::CommitChanges
00007ffc`336090b8 00007ffc`3363c7d0 nativerd!CONFIG_SYSTEM::get_CommitPath
00007ffc`336090c0 00007ffc`336235c0 nativerd!CONFIG_SYSTEM::put_CommitPath
00007ffc`336090c8 00007ffc`33626190 nativerd!CONFIG_SYSTEM::`vector deleting destructor'
00007ffc`336090d0 00007ffc`3362e780 nativerd!CONFIG_MAPPING_EXTENSION::QueryInterface
00007ffc`336090d8 00007ffc`33604730 nativerd!CONFIG_MAPPING_EXTENSION::AddRef
00007ffc`336090e0 00007ffc`33604190 nativerd!CONFIG_MAPPING_EXTENSION::Release
00007ffc`336090e8 00007ffc`336530c0 nativerd!CONFIG_MAPPING_EXTENSION::GetSiteNameFromSiteId
00007ffc`336090f0 00007ffc`33652e20 nativerd!CONFIG_MAPPING_EXTENSION::GetSiteIdFromSiteName
What is the difference between the !sos.dumprcw and !sosex.rcw output in regards to vtable?
