Remove global spinlock for EH stacktrace (#103076)

* Remove global spinlock for EH stacktrace

The global spinlock that was used to ensure that stack trace and the
associated dynamic methods array were updated and read atomically.
However, for the new EH, it has shown to cause a high contention in case
many threads were handling exceptions at the same time.

This change replaces the two arrays by one object member in the
exception class. It contains reference to either the byte[] of the
stack trace (when there are no dynamic methods on the stack trace) or an
object[] where the first element contains the stack trace byte[]
reference and the following elements contain what used to be in the
dynamic array. That allows atomic updates and reads of the stack trace
and dynamic method keepalive references without a need of a lock.

The original code was quite convoluted, it was difficult to reason about
and it had some races in it that were hidden behind the global lock. So
I have decided to rewrite the whole thing from scratch.

The way it ensures that it is race free is that whenever it updates the
exception stack trace and the one that's on the exception was created by
a different thread, it creates a deep copy of both the stack trace and
the keepalive array. When making the copy, it also handles a case when
a frame that needs a keepalive entry is on the stack trace part, but the
keepalive array extracted from the exception is stale (the other thread
needed to resize the keepalive array, but not the stack trace). In that
case, the stack trace is trimmed at first such entry found.

Since the case when multiple threads are throwing the same exception and
so they are modifying its stack trace in parallel is pathological
anyways, I believe the extra work spent on creating the clones of the arrays
is a good tradeoff for ensuring easy to reason about thread safety.

I have also removed a dead code path from the
StackTraceInfo::SaveStackTrace.

Finally, since with the previous iteration of this change, a bug in
building the stack trace was found, I have added a coreclr test to
verify stack trace for an exception matches the expectations.

* Fix MUSL build

* Fix x86 build

* Fix several issues

* Missing calls to IsOverflow at few places
* Added a flag on StackTraceElement to indicate that the element needs a
  keepalive entry. It removes the need to call IsLCGMethod / Collectible
  check on the method table stored in the element and eliminates a
  possible problem with the method being collected in one place.
* Returned missing call to StackFrameInfo::Init to the x86 code path
* Removed obsolete comment and code line

* Few changes based on feedback

* Add keep alive items count to the stack trace header.
* Implement the concept of frozen stack traces to eliminate copies in
  the ExceptionDispatchInfo storing / restoring exceptions.

* Rename keepalive to keepAlive

* Handle possible array size overflow

In the StackTraceArray::Allocate

* Fix typo

* Change the size / keepAlive fields in stack trace to uint32_t

Plus a build break fix

* Remove SaveStackTracesFromDeepCopy

Also rename GetStackTracesDeepCopy to GetFrozenStackTrace and move the
return argument to return value.

* Remove dummy field and an unused function

* Cleanup based on feedback

* Move the race handling into GetStackTrace only

Plus an unused method removal and a little naming / contract cleanup

* Add VolatileLoad/Store around the size / keep alive count

Also remove the memory barrier from the StackTraceArray::Append since it
is not needed after that change.

* Add comment on why trimming the stack trace by keep alive is needed

I have also realized that when we need to trim, the keepAlive array is
always fully populated, so we don't need to check for cases where there
would be NULL in an entry of the array.

Author: janvorli

src/coreclr/System.Private.CoreLib/src/System/Exception.CoreCLR.cs

@@ -128,10 +128,7 @@ internal void InternalPreserveStackTrace()
         private static extern void PrepareForForeignExceptionRaise();
 
         [MethodImpl(MethodImplOptions.InternalCall)]
-        private static extern void GetStackTracesDeepCopy(Exception exception, out byte[]? currentStackTrace, out object[]? dynamicMethodArray);
-
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        internal static extern void SaveStackTracesFromDeepCopy(Exception exception, byte[]? currentStackTrace, object[]? dynamicMethodArray);
+        private static extern object? GetFrozenStackTrace(Exception exception);
 
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern uint GetExceptionCount();
@@ -147,18 +144,13 @@ internal void RestoreDispatchState(in DispatchState dispatchState)
                 // in the exception object. This will ensure that when this exception is thrown and these
                 // fields are modified, then EDI's references remain intact.
                 //
-                byte[]? stackTraceCopy = (byte[]?)dispatchState.StackTrace?.Clone();
-                object[]? dynamicMethodsCopy = (object[]?)dispatchState.DynamicMethods?.Clone();
 
                 // Watson buckets and remoteStackTraceString fields are captured and restored without any locks. It is possible for them to
                 // get out of sync without violating overall integrity of the system.
                 _watsonBuckets = dispatchState.WatsonBuckets;
                 _ipForWatsonBuckets = dispatchState.IpForWatsonBuckets;
                 _remoteStackTraceString = dispatchState.RemoteStackTrace;
-
-                // The binary stack trace and references to dynamic methods have to be restored under a lock to guarantee integrity of the system.
-                SaveStackTracesFromDeepCopy(this, stackTraceCopy, dynamicMethodsCopy);
-
+                _stackTrace = dispatchState.StackTrace;
                 _stackTraceString = null;
 
                 // Marks the TES state to indicate we have restored foreign exception
@@ -172,7 +164,7 @@ internal void RestoreDispatchState(in DispatchState dispatchState)
         private IDictionary? _data;
         private readonly Exception? _innerException;
         private string? _helpURL;
-        private byte[]? _stackTrace;
+        private object? _stackTrace;
         private byte[]? _watsonBuckets;
         private string? _stackTraceString; // Needed for serialization.
         private string? _remoteStackTraceString;
@@ -181,7 +173,6 @@ internal void RestoreDispatchState(in DispatchState dispatchState)
         // DynamicMethodDescs alive for the lifetime of the exception. We do this because
         // the _stackTrace field holds MethodDescs, and a DynamicMethodDesc can be destroyed
         // unless a System.Resolver object roots it.
-        private readonly object[]? _dynamicMethods;
         private string? _source;         // Mainly used by VB.
         private UIntPtr _ipForWatsonBuckets; // Used to persist the IP for Watson Bucketing
         private readonly IntPtr _xptrs;             // Internal EE stuff
@@ -227,21 +218,18 @@ internal static string GetMessageFromNativeResources(ExceptionMessageKind kind)
 
         internal readonly struct DispatchState
         {
-            public readonly byte[]? StackTrace;
-            public readonly object[]? DynamicMethods;
+            public readonly object? StackTrace;
             public readonly string? RemoteStackTrace;
             public readonly UIntPtr IpForWatsonBuckets;
             public readonly byte[]? WatsonBuckets;
 
             public DispatchState(
-                byte[]? stackTrace,
-                object[]? dynamicMethods,
+                object? stackTrace,
                 string? remoteStackTrace,
                 UIntPtr ipForWatsonBuckets,
                 byte[]? watsonBuckets)
             {
                 StackTrace = stackTrace;
-                DynamicMethods = dynamicMethods;
                 RemoteStackTrace = remoteStackTrace;
                 IpForWatsonBuckets = ipForWatsonBuckets;
                 WatsonBuckets = watsonBuckets;
@@ -250,9 +238,9 @@ public DispatchState(
 
         internal DispatchState CaptureDispatchState()
         {
-            GetStackTracesDeepCopy(this, out byte[]? stackTrace, out object[]? dynamicMethods);
+            object? stackTrace = GetFrozenStackTrace(this);
 
-            return new DispatchState(stackTrace, dynamicMethods,
+            return new DispatchState(stackTrace,
                 _remoteStackTraceString, _ipForWatsonBuckets, _watsonBuckets);
         }
 

src/coreclr/System.Private.CoreLib/src/System/Runtime/ExceptionServices/AsmOffsets.cs

@@ -166,23 +166,23 @@ class AsmOffsets
     public const int SIZEOF__EHEnum = 0x20;
     public const int OFFSETOF__StackFrameIterator__m_pRegDisplay = 0x228;
     public const int OFFSETOF__ExInfo__m_pPrevExInfo = 0;
-    public const int OFFSETOF__ExInfo__m_pExContext = 0xc0;
-    public const int OFFSETOF__ExInfo__m_exception = 0xc8;
-    public const int OFFSETOF__ExInfo__m_kind = 0xd0;
-    public const int OFFSETOF__ExInfo__m_passNumber = 0xd1;
-    public const int OFFSETOF__ExInfo__m_idxCurClause = 0xd4;
-    public const int OFFSETOF__ExInfo__m_frameIter = 0xd8;
+    public const int OFFSETOF__ExInfo__m_pExContext = 0xa8;
+    public const int OFFSETOF__ExInfo__m_exception = 0xb0;
+    public const int OFFSETOF__ExInfo__m_kind = 0xb8;
+    public const int OFFSETOF__ExInfo__m_passNumber = 0xb9;
+    public const int OFFSETOF__ExInfo__m_idxCurClause = 0xbc;
+    public const int OFFSETOF__ExInfo__m_frameIter = 0xc0;
     public const int OFFSETOF__ExInfo__m_notifyDebuggerSP = OFFSETOF__ExInfo__m_frameIter + SIZEOF__StackFrameIterator;
 #else // TARGET_64BIT
     public const int SIZEOF__EHEnum = 0x10;
     public const int OFFSETOF__StackFrameIterator__m_pRegDisplay = 0x218;
     public const int OFFSETOF__ExInfo__m_pPrevExInfo = 0;
-    public const int OFFSETOF__ExInfo__m_pExContext = 0x70;
-    public const int OFFSETOF__ExInfo__m_exception = 0x74;
-    public const int OFFSETOF__ExInfo__m_kind = 0x78;
-    public const int OFFSETOF__ExInfo__m_passNumber = 0x79;
-    public const int OFFSETOF__ExInfo__m_idxCurClause = 0x7C;
-    public const int OFFSETOF__ExInfo__m_frameIter = 0x80;
+    public const int OFFSETOF__ExInfo__m_pExContext = 0x5c;
+    public const int OFFSETOF__ExInfo__m_exception = 0x60;
+    public const int OFFSETOF__ExInfo__m_kind = 0x64;
+    public const int OFFSETOF__ExInfo__m_passNumber = 0x65;
+    public const int OFFSETOF__ExInfo__m_idxCurClause = 0x68;
+    public const int OFFSETOF__ExInfo__m_frameIter = 0x6c;
     public const int OFFSETOF__ExInfo__m_notifyDebuggerSP = OFFSETOF__ExInfo__m_frameIter + SIZEOF__StackFrameIterator;
 #endif // TARGET_64BIT
 

src/coreclr/classlibnative/bcltype/system.cpp

@@ -93,6 +93,13 @@ FCIMPL1(ReflectMethodObject*, SystemNative::GetMethodFromStackTrace, ArrayBase*
 {
     FCALL_CONTRACT;
 
+    // The pStackTraceUNSAFE can be either I1Array or Object[]. In the latter case, the first entry is the actual stack trace I1Array,
+    // the rest are pointers to the method info objects. We only care about the first entry here.
+    if (pStackTraceUNSAFE->GetArrayElementType() != ELEMENT_TYPE_I1)
+    {
+        PtrArray *combinedArray = (PtrArray*)pStackTraceUNSAFE;
+        pStackTraceUNSAFE = (ArrayBase*)OBJECTREFToObject(combinedArray->GetAt(0));
+    }
     I1ARRAYREF pArray(static_cast<I1Array *>(pStackTraceUNSAFE));
     StackTraceArray stackArray(pArray);
 

src/coreclr/debug/daccess/enummem.cpp

@@ -533,7 +533,7 @@ HRESULT ClrDataAccess::DumpManagedExcepObject(CLRDataEnumMemoryFlags flags, OBJE
     DumpManagedExcepObject(flags, exceptRef->GetInnerException());
 
     // Dump the stack trace array object and its underlying type
-    I1ARRAYREF stackTraceArrayObj = exceptRef->GetStackTraceArrayObject();
+    OBJECTREF stackTraceArrayObj = exceptRef->GetStackTraceArrayObject();
 
     // There are cases where a managed exception does not have a stack trace.
     // These cases are:
@@ -558,6 +558,22 @@ HRESULT ClrDataAccess::DumpManagedExcepObject(CLRDataEnumMemoryFlags flags, OBJE
     // MD this happens.
     StackTraceArray stackTrace;
     exceptRef->GetStackTrace(stackTrace);
+
+    // The stackTraceArrayObj can be either a byte[] with the actual stack trace array or an object[] where the first element is the actual stack trace array.
+    // In case it was the latter, we need to dump the actual stack trace array object here too.
+    OBJECTREF actualStackTraceArrayObj = (OBJECTREF)stackTrace.Get();
+    if (actualStackTraceArrayObj != stackTraceArrayObj)
+    {
+        // first dump the array's element type
+        TypeHandle arrayTypeHandle = actualStackTraceArrayObj->GetTypeHandle();
+        TypeHandle elementTypeHandle = arrayTypeHandle.GetArrayElementTypeHandle();
+        elementTypeHandle.AsMethodTable()->EnumMemoryRegions(flags);
+        elementTypeHandle.AsMethodTable()->GetClass()->EnumMemoryRegions(flags, elementTypeHandle.AsMethodTable());
+
+        // now dump the actual stack trace array object
+        DumpManagedObject(flags, actualStackTraceArrayObj);
+    }
+
     for(size_t i = 0; i < stackTrace.Size(); i++)
     {
         MethodDesc* pMD = stackTrace[i].pFunc;

src/coreclr/vm/clrex.h

@@ -27,6 +27,9 @@ enum StackTraceElementFlags
 
     // Set if the "ip" field has already been adjusted (decremented)
     STEF_IP_ADJUSTED = 0x0002,
+
+    // Set if the element references a method that needs a keep alive object
+    STEF_KEEPALIVE = 0x0004,
 };
 
 // This struct is used by SOS in the diagnostic repo.
@@ -51,28 +54,13 @@ struct StackTraceElement
     }
 };
 
-// This struct is used by SOS in the diagnostic repo.
-// See: https://github.com/dotnet/diagnostics/blob/9ff35f13af2f03a68a166cfd53f1a4bb32425f2f/src/SOS/Strike/strike.cpp#L2669
 class StackTraceInfo
 {
-private:
-    // for building stack trace info
-    StackTraceElement*  m_pStackTrace;      // pointer to stack trace storage
-    unsigned            m_cStackTrace;      // size of stack trace storage
-    unsigned            m_dFrameCount;      // current frame in stack trace
-    unsigned            m_cDynamicMethodItems; // number of items in the Dynamic Method array
-    unsigned            m_dCurrentDynamicIndex; // index of the next location where the resolver object will be stored
-
+    static OBJECTREF GetKeepAliveObject(MethodDesc* pMethod);
+    static void EnsureStackTraceArray(StackTraceArray *pStackTrace, size_t neededSize);
+    static void EnsureKeepAliveArray(PTRARRAYREF *ppKeepAliveArray, size_t neededSize);
 public:
-    void Init();
-    BOOL IsEmpty();
-    void AllocateStackTrace();
-    void ClearStackTrace();
-    void FreeStackTrace();
-    void SaveStackTrace(BOOL bAllowAllocMem, OBJECTHANDLE hThrowable, BOOL bReplaceStack, BOOL bSkipLastElement);
-    BOOL AppendElement(BOOL bAllowAllocMem, UINT_PTR currentIP, UINT_PTR currentSP, MethodDesc* pFunc, CrawlFrame* pCf);
-
-    void GetLeafFrameInfo(StackTraceElement* pStackTraceElement);
+    static void AppendElement(OBJECTHANDLE hThrowable, UINT_PTR currentIP, UINT_PTR currentSP, MethodDesc* pFunc, CrawlFrame* pCf);
 };
 
 

src/coreclr/vm/comutilnative.cpp

@@ -76,8 +76,9 @@ FCIMPL0(VOID, ExceptionNative::PrepareForForeignExceptionRaise)
 }
 FCIMPLEND
 
-// Given an exception object, this method will extract the stacktrace and dynamic method array and set them up for return to the caller.
-FCIMPL3(VOID, ExceptionNative::GetStackTracesDeepCopy, Object* pExceptionObjectUnsafe, Object **pStackTraceUnsafe, Object **pDynamicMethodsUnsafe);
+// Given an exception object, this method will mark its stack trace as frozen and return it to the caller.
+// Frozen stack traces are immutable, when a thread attempts to add a frame to it, the stack trace is cloned first.
+FCIMPL1(Object *, ExceptionNative::GetFrozenStackTrace, Object* pExceptionObjectUnsafe);
 {
     CONTRACTL
     {
@@ -86,115 +87,37 @@ FCIMPL3(VOID, ExceptionNative::GetStackTracesDeepCopy, Object* pExceptionObjectU
     CONTRACTL_END;
 
     ASSERT(pExceptionObjectUnsafe != NULL);
-    ASSERT(pStackTraceUnsafe != NULL);
-    ASSERT(pDynamicMethodsUnsafe != NULL);
 
     struct
     {
         StackTraceArray stackTrace;
-        StackTraceArray stackTraceCopy;
-        EXCEPTIONREF refException;
-        PTRARRAYREF dynamicMethodsArray; // Object array of Managed Resolvers
-        PTRARRAYREF dynamicMethodsArrayCopy; // Copy of the object array of Managed Resolvers
+        EXCEPTIONREF refException = NULL;
+        PTRARRAYREF keepAliveArray = NULL; // Object array of Managed Resolvers / AssemblyLoadContexts
+        OBJECTREF result = NULL;
     } gc;
-    gc.refException = NULL;
-    gc.dynamicMethodsArray = NULL;
-    gc.dynamicMethodsArrayCopy = NULL;
 
     // GC protect the array reference
-    HELPER_METHOD_FRAME_BEGIN_PROTECT(gc);
+    HELPER_METHOD_FRAME_BEGIN_RET_PROTECT(gc);
 
     // Get the exception object reference
     gc.refException = (EXCEPTIONREF)(ObjectToOBJECTREF(pExceptionObjectUnsafe));
 
-    // Fetch the stacktrace details from the exception under a lock
-    gc.refException->GetStackTrace(gc.stackTrace, &gc.dynamicMethodsArray);
+    gc.refException->GetStackTrace(gc.stackTrace, &gc.keepAliveArray);
 
-    bool fHaveStackTrace = false;
-    bool fHaveDynamicMethodArray = false;
+    gc.stackTrace.MarkAsFrozen();
 
-    if ((unsigned)gc.stackTrace.Size() > 0)
+    if (gc.keepAliveArray != NULL)
     {
-        // Deepcopy the array
-        gc.stackTraceCopy.CopyFrom(gc.stackTrace);
-        fHaveStackTrace = true;
-    }
-
-    if (gc.dynamicMethodsArray != NULL)
-    {
-        // Get the number of elements in the dynamic methods array
-        unsigned   cOrigDynamic = gc.dynamicMethodsArray->GetNumComponents();
-
-        // ..and allocate a new array. This can trigger GC or throw under OOM.
-        gc.dynamicMethodsArrayCopy = (PTRARRAYREF)AllocateObjectArray(cOrigDynamic, g_pObjectClass);
-
-        // Deepcopy references to the new array we just allocated
-        memmoveGCRefs(gc.dynamicMethodsArrayCopy->GetDataPtr(), gc.dynamicMethodsArray->GetDataPtr(),
-                                                  cOrigDynamic * sizeof(Object *));
-
-        fHaveDynamicMethodArray = true;
-    }
-
-    // Prep to return
-    *pStackTraceUnsafe = fHaveStackTrace?OBJECTREFToObject(gc.stackTraceCopy.Get()):NULL;
-    *pDynamicMethodsUnsafe = fHaveDynamicMethodArray?OBJECTREFToObject(gc.dynamicMethodsArrayCopy):NULL;
-
-    HELPER_METHOD_FRAME_END();
-}
-FCIMPLEND
-
-// Given an exception object and deep copied instances of a stacktrace and/or dynamic method array, this method will set the latter in the exception object instance.
-FCIMPL3(VOID, ExceptionNative::SaveStackTracesFromDeepCopy, Object* pExceptionObjectUnsafe, Object *pStackTraceUnsafe, Object *pDynamicMethodsUnsafe);
-{
-    CONTRACTL
-    {
-        FCALL_CHECK;
-    }
-    CONTRACTL_END;
-
-    ASSERT(pExceptionObjectUnsafe != NULL);
-
-    struct
-    {
-        StackTraceArray stackTrace;
-        EXCEPTIONREF refException;
-        PTRARRAYREF dynamicMethodsArray; // Object array of Managed Resolvers
-    } gc;
-    gc.refException = NULL;
-    gc.dynamicMethodsArray = NULL;
-
-    // GC protect the array reference
-    HELPER_METHOD_FRAME_BEGIN_PROTECT(gc);
-
-    // Get the exception object reference
-    gc.refException = (EXCEPTIONREF)(ObjectToOBJECTREF(pExceptionObjectUnsafe));
-
-    if (pStackTraceUnsafe != NULL)
-    {
-        // Copy the stacktrace
-        StackTraceArray stackTraceArray((I1ARRAYREF)ObjectToOBJECTREF(pStackTraceUnsafe));
-        gc.stackTrace.Swap(stackTraceArray);
-    }
-
-    gc.dynamicMethodsArray = NULL;
-    if (pDynamicMethodsUnsafe != NULL)
-    {
-        gc.dynamicMethodsArray = (PTRARRAYREF)ObjectToOBJECTREF(pDynamicMethodsUnsafe);
-    }
-
-    // If there is no stacktrace, then there cannot be any dynamic method array. Thus,
-    // save stacktrace only when we have it.
-    if (gc.stackTrace.Size() > 0)
-    {
-        // Save the stacktrace details in the exception under a lock
-        gc.refException->SetStackTrace(gc.stackTrace.Get(), gc.dynamicMethodsArray);
+        gc.result = gc.keepAliveArray;
     }
     else
     {
-        gc.refException->SetStackTrace(NULL, NULL);
+        gc.result = gc.stackTrace.Get();
     }
-
+    
     HELPER_METHOD_FRAME_END();
+
+    return OBJECTREFToObject(gc.result);
 }
 FCIMPLEND
 

src/coreclr/vm/comutilnative.h

@@ -42,9 +42,7 @@ class ExceptionNative
     static FCDECL1(FC_BOOL_RET, IsTransient, INT32 hresult);
     static FCDECL3(StringObject *, StripFileInfo, Object *orefExcepUNSAFE, StringObject *orefStrUNSAFE, CLR_BOOL isRemoteStackTrace);
     static FCDECL0(VOID, PrepareForForeignExceptionRaise);
-    static FCDECL3(VOID, GetStackTracesDeepCopy, Object* pExceptionObjectUnsafe, Object **pStackTraceUnsafe, Object **pDynamicMethodsUnsafe);
-    static FCDECL3(VOID, SaveStackTracesFromDeepCopy, Object* pExceptionObjectUnsafe, Object *pStackTraceUnsafe, Object *pDynamicMethodsUnsafe);
-
+    static FCDECL1(Object *, GetFrozenStackTrace, Object* pExceptionObjectUnsafe);
 
 #ifdef FEATURE_COMINTEROP
     // NOTE: caller cleans up any partially initialized BSTRs in pED

src/coreclr/vm/corelib.h

@@ -311,7 +311,6 @@ DEFINE_FIELD_U(_stackTrace,        ExceptionObject,    _stackTrace)
 DEFINE_FIELD_U(_watsonBuckets,     ExceptionObject,    _watsonBuckets)
 DEFINE_FIELD_U(_stackTraceString,  ExceptionObject,    _stackTraceString)
 DEFINE_FIELD_U(_remoteStackTraceString, ExceptionObject, _remoteStackTraceString)
-DEFINE_FIELD_U(_dynamicMethods,    ExceptionObject,    _dynamicMethods)
 DEFINE_FIELD_U(_source,            ExceptionObject,    _source)
 DEFINE_FIELD_U(_ipForWatsonBuckets,ExceptionObject,    _ipForWatsonBuckets)
 DEFINE_FIELD_U(_xptrs,             ExceptionObject,    _xptrs)

src/coreclr/vm/debugdebugger.cpp

@@ -1044,9 +1044,9 @@ void DebugStackTrace::GetStackFramesFromException(OBJECTREF * e,
 
     // Now get the _stackTrace reference
     StackTraceArray traceData;
-    EXCEPTIONREF(*e)->GetStackTrace(traceData, pDynamicMethodArray);
 
     GCPROTECT_BEGIN(traceData);
+        EXCEPTIONREF(*e)->GetStackTrace(traceData, pDynamicMethodArray);
         // The number of frame info elements in the stack trace info
         pData->cElements = static_cast<int>(traceData.Size());
 

src/coreclr/vm/ecalllist.h

@@ -94,8 +94,7 @@ FCFuncStart(gExceptionFuncs)
     FCFuncElement("IsImmutableAgileException", ExceptionNative::IsImmutableAgileException)
     FCFuncElement("GetMethodFromStackTrace", SystemNative::GetMethodFromStackTrace)
     FCFuncElement("PrepareForForeignExceptionRaise", ExceptionNative::PrepareForForeignExceptionRaise)
-    FCFuncElement("GetStackTracesDeepCopy", ExceptionNative::GetStackTracesDeepCopy)
-    FCFuncElement("SaveStackTracesFromDeepCopy", ExceptionNative::SaveStackTracesFromDeepCopy)
+    FCFuncElement("GetFrozenStackTrace", ExceptionNative::GetFrozenStackTrace)
     FCFuncElement("GetExceptionCount", ExceptionNative::GetExceptionCount)
 FCFuncEnd()