Commented Unassigned: Hang on Application pool recycle [119]

Hi,

Using React.NET 3.0.1 which uses ClearScript.V8 5.4.8 following hang is observed on recycling application pool
```
.NET Call Stack


.SharedPtr.Release(SharedPtr*)+d7
[[InlinedCallFrame] (.Decrement)] .RefCount.Decrement(RefCount*)
Microsoft.ClearScript.V8.V8ContextProxyImpl.!V8ContextProxyImpl()+4e
Microsoft.ClearScript.V8.V8ContextProxyImpl.Dispose(Boolean)+1f
[[DebuggerU2MCatchHandlerFrame]]
[[ContextTransitionFrame]]
[[GCFrame]]
[[DebuggerU2MCatchHandlerFrame]]

Full Call Stack

ntdll!NtWaitForSingleObject+14
KERNELBASE!WaitForSingleObjectEx+8f
v8_x64!v8::Extension::dependencies+329ac
v8_x64!v8::ExternalResourceVisitor::VisitExternalString+28187
v8_x64!v8::ExternalResourceVisitor::VisitExternalString+1a3
v8_x64!v8::ExternalResourceVisitor::VisitExternalString+533b
ClearScriptV8_64+14216
ClearScriptV8_64+120e4
ClearScriptV8_64+13e3f
ClearScriptV8_64+50a8
<Module>.SharedPtr<V8Context>.Release(SharedPtr<V8Context>*)+d7
[[InlinedCallFrame] (<Module>.Decrement)] <Module>.RefCount.Decrement(RefCount*)
Microsoft.ClearScript.V8.V8ContextProxyImpl.!V8ContextProxyImpl()+4e
Microsoft.ClearScript.V8.V8ContextProxyImpl.Dispose(Boolean)+1f
clr!FastCallFinalizeWorker+6
clr!ETW::GCLog::SendFinalizeObjectEvent+c9
clr!MethodTable::CallFinalizer+b5
clr!CallFinalizer+5e
clr!FinalizerThread::DoOneFinalization+95
clr!FinalizerThread::FinalizeAllObjects+133
clr!FinalizerThread::FinalizeAllObjects_Wrapper+18
clr!Frame::Push+59
clr!PEDecoder::GetNativeCodeManagerTable+170
clr!PEDecoder::GetNativeCodeManagerTable+99
[[DebuggerU2MCatchHandlerFrame]]
clr!Thread::ShouldChangeAbortToUnload+45
clr!Thread::DoADCallBack+109
[[ContextTransitionFrame]]
clr!Frame::Push+a2
clr!FinalizerThread::DoOneFinalization+1f9
[[GCFrame]]
clr!FinalizerThread::FinalizeAllObjects+133
clr!FinalizerThread::FinalizerThreadWorker+bb
clr!Frame::Push+59
clr!PEDecoder::GetNativeCodeManagerTable+170
clr!PEDecoder::GetNativeCodeManagerTable+99
[[DebuggerU2MCatchHandlerFrame]]
clr!FinalizerThread::FinalizerThreadStart+10a
clr!Thread::intermediateThreadProc+86
kernel32!BaseThreadInitThunk+14
ntdll!RtlUserThreadStart+21
```
Comments: Hello! Some questions: 1. Can you describe your recycling configuration? For example, how is recycling triggered? 1. Does the hang happen every time, or is it intermittent? 1. As you may have noticed, some of the top stack frames above are missing or bogus, making diagnosis difficult if not impossible. Would you be able to deploy the relevant ClearScript and V8 PDB files for a cleaner stack? You might be able to get them from the owner of [this NuGet project](https://www.nuget.org/packages/JavaScriptEngineSwitcher.V8/). Another possibility might be to generate all the files yourself by building ClearScript locally. The build procedure is outlined in the [ClearScript ReadMe](https://clearscript.codeplex.com/SourceControl/latest#ReadMe.txt). Thanks!