public static unsafe IntPtr GetGenericMethodFunctionPointer(IntPtr canonFunctionPointer, IntPtr instantiationArgument)
{
if (instantiationArgument == IntPtr.Zero)
{
return(canonFunctionPointer);
}
lock (s_genericFunctionPointerDictionary)
{
GenericMethodDescriptorInfo key;
key.MethodFunctionPointer = canonFunctionPointer;
key.InstantiationArgument = instantiationArgument;
uint index = 0;
if (!s_genericFunctionPointerDictionary.TryGetValue(key, out index))
{
// Capture new index value
index = s_genericFunctionPointerNextIndex;
int newChunkIndex = (int)(index / c_genericDictionaryChunkSize);
uint newSubChunkIndex = index % c_genericDictionaryChunkSize;
// Generate new chunk if existing chunks are insufficient
if (s_genericFunctionPointerCollection.Count <= newChunkIndex)
{
System.Diagnostics.Debug.Assert(newSubChunkIndex == 0);
// New generic descriptors are allocated on the native heap and not tracked in the GC.
UIntPtr allocationSize = new UIntPtr((uint)(c_genericDictionaryChunkSize * sizeof(RuntimeGeneratedGenericMethodDescriptor)));
IntPtr pNewMem = Interop.MemAlloc(allocationSize);
s_genericFunctionPointerCollection.Add(pNewMem);
}
RuntimeGeneratedGenericMethodDescriptor *newDescriptor = &((RuntimeGeneratedGenericMethodDescriptor *)s_genericFunctionPointerCollection[newChunkIndex])[newSubChunkIndex];
newDescriptor->Set(canonFunctionPointer, instantiationArgument);
s_genericFunctionPointerDictionary.LookupOrAdd(key, index);
// Now that we can no longer have failed, update the next index.
s_genericFunctionPointerNextIndex++;
}
// Lookup within list
int chunkIndex = (int)(index / c_genericDictionaryChunkSize);
uint subChunkIndex = index % c_genericDictionaryChunkSize;
RuntimeGeneratedGenericMethodDescriptor *genericRuntimeFunctionPointer = &((RuntimeGeneratedGenericMethodDescriptor *)s_genericFunctionPointerCollection[chunkIndex])[subChunkIndex];
GenericMethodDescriptor *genericFunctionPointer = &genericRuntimeFunctionPointer->Descriptor;
System.Diagnostics.Debug.Assert(canonFunctionPointer == genericFunctionPointer->MethodFunctionPointer);
System.Diagnostics.Debug.Assert(instantiationArgument == genericFunctionPointer->InstantiationArgument);
return((IntPtr)((byte *)genericFunctionPointer + FatFunctionPointerOffset));
}
}