/// <summary>
/// Helper for InitializeSlots.
///
/// Initializes one slot to point to a function pointer.
/// The function pointer might be a thunk for C#, or it may be
/// an address in the NativeCodePage.
/// </summary>
/// <param name="type">Type being initialized.</param>
/// <param name="slot">Function pointer.</param>
/// <param name="name">Name of the method.</param>
/// <param name="canOverride">Can override the slot when it existed</param>
static void InitializeSlot(IntPtr type, IntPtr slot, string name, bool canOverride = true)
{
var offset = ManagedDataOffsets.GetSlotOffset(name);
if (!canOverride && Marshal.ReadIntPtr(type, offset) != IntPtr.Zero)
{
return;
}
Marshal.WriteIntPtr(type, offset, slot);
}
static void InitializeSlot(IntPtr type, ThunkInfo thunk, string name, SlotsHolder slotsHolder = null, bool canOverride = true)
{
int offset = ManagedDataOffsets.GetSlotOffset(name);
if (!canOverride && Marshal.ReadIntPtr(type, offset) != IntPtr.Zero)
{
return;
}
Marshal.WriteIntPtr(type, offset, thunk.Address);
if (slotsHolder != null)
{
slotsHolder.Set(offset, thunk);
}
}
/// <summary>
/// Given a newly allocated Python type object and a managed Type that
/// provides the implementation for the type, connect the type slots of
/// the Python object to the managed methods of the implementing Type.
/// </summary>
internal static void InitializeSlots(IntPtr type, Type impl, SlotsHolder slotsHolder = null)
{
// We work from the most-derived class up; make sure to get
// the most-derived slot and not to override it with a base
// class's slot.
var seen = new HashSet <string>();
while (impl != null)
{
MethodInfo[] methods = impl.GetMethods(tbFlags);
foreach (MethodInfo method in methods)
{
string name = method.Name;
if (!name.StartsWith("tp_") && !TypeOffset.IsSupportedSlotName(name))
{
Debug.Assert(!name.Contains("_") || name.StartsWith("_") || method.IsSpecialName);
continue;
}
if (seen.Contains(name))
{
continue;
}
InitializeSlot(type, Interop.GetThunk(method), name, slotsHolder);
seen.Add(name);
}
impl = impl.BaseType;
}
foreach (string slot in _requiredSlots)
{
if (seen.Contains(slot))
{
continue;
}
var offset = ManagedDataOffsets.GetSlotOffset(slot);
Marshal.WriteIntPtr(type, offset, SlotsHolder.GetDefaultSlot(offset));
}
}
static bool IsSlotSet(IntPtr type, string name)
{
int offset = ManagedDataOffsets.GetSlotOffset(name);
return(Marshal.ReadIntPtr(type, offset) != IntPtr.Zero);
}