Background and Motivation

Proposed API

A callback when a flow comes back from unmanaged into managed code.

Usage Examples

BackToManaged += (sender, args) => {
  Console.WriteLine($"Back from {args.StackTrace}");
};

BackToManagedInCurrentThread += (sender, args) => {
  Console.WriteLine($"Back from {args.StackTrace}");
};

The use case is working with COM objects where there are many entry points into managed code.
It allows to implement behavior similar to Thread.Abort but in a safe and controlled way.

Alternative Designs

Probably can be done with ComWrappers or Source Generators.

Risks