public override IntPtr ConvertUnboxingFunctionPointerToUnderlyingNonUnboxingPointer(IntPtr unboxingFunctionPointer, RuntimeTypeHandle declaringType)
{
return TypeLoaderEnvironment.ConvertUnboxingFunctionPointerToUnderlyingNonUnboxingPointer(unboxingFunctionPointer, declaringType);
}
private static unsafe IntPtr ResolveCallOnValueType(IntPtr unused, IntPtr callDescIntPtr)
#endif
{
NonGenericConstrainedCallDesc *callDesc = (NonGenericConstrainedCallDesc *)callDescIntPtr;
IntPtr exactTarget = IntPtr.Zero;
IntPtr targetOnTypeVtable = RuntimeAugments.ResolveDispatchOnType(callDesc->_constraintType, callDesc->_constrainedMethodType, callDesc->_constrainedMethodSlot);
bool decodeUnboxing = true;
if (!RuntimeAugments.IsInterface(callDesc->_constrainedMethodType))
{
// Non-interface constrained call on a valuetype to a method that isn't GetHashCode/Equals/ToString?!?!
if (callDesc->_constrainedMethodSlot > s_MaxObjectVTableSlot)
{
throw new NotSupportedException();
}
RuntimeTypeHandle baseTypeHandle;
bool gotBaseType = RuntimeAugments.TryGetBaseType(callDesc->_constraintType, out baseTypeHandle);
Debug.Assert(gotBaseType);
if (targetOnTypeVtable == RuntimeAugments.ResolveDispatchOnType(baseTypeHandle, callDesc->_constrainedMethodType, callDesc->_constrainedMethodSlot))
{
// In this case, the valuetype does not override the base types implementation of ToString(), GetHashCode(), or Equals(object)
decodeUnboxing = false;
}
}
if (decodeUnboxing)
{
exactTarget = TypeLoaderEnvironment.ConvertUnboxingFunctionPointerToUnderlyingNonUnboxingPointer(targetOnTypeVtable, callDesc->_constraintType);
}
else
{
// Create a fat function pointer, where the instantiation argument is ConstraintType, and the target is BoxAndToString, BoxAndGetHashCode, or BoxAndEquals
IntPtr realTarget;
switch (callDesc->_constrainedMethodSlot)
{
case s_ToStringSlot:
realTarget = s_boxAndToStringFuncPtr;
break;
case s_GetHashCodeSlot:
realTarget = s_boxAndGetHashCodeFuncPtr;
break;
case s_EqualsSlot:
realTarget = s_boxAndEqualsFuncPtr;
break;
default:
throw new NotSupportedException();
}
exactTarget = FunctionPointerOps.GetGenericMethodFunctionPointer(realTarget, callDesc->_constraintType.ToIntPtr());
}
// Ensure that all threads will have their function pointers completely published before updating callDesc.
// as the ExactTarget is read from callDesc by binder generated code without a barrier, we need a barrier here
// to ensure that the new function pointer data is valid on all threads
Interlocked.MemoryBarrier();
// Its possible for multiple threads to race to set exact target. Check to see we always set the same value
if (callDesc->_exactTarget != IntPtr.Zero)
{
Debug.Assert(callDesc->_exactTarget == exactTarget);
}
callDesc->_exactTarget = exactTarget;
return(exactTarget);
}