Callback from mixed mode into pure with multiple AppDomains

[draskin]

Hello, I have the following situation:

- Text.exe creates a new AppDomain
- Test.exe loads mixed mode assembly in a non-default AppDomain
- Test.exe calls connect to a TCP/IP socket server which calls into native
code to actually create a TCP/IP socket connection
- Test code sets up a listener using the mixed mode assembly to be notified
asynchronously (i.e. on a different thread) of events. The listener is held
onto by a managed singleton, because a native class cannot hold onto a
reference to a managed class.
- When an event comes in from the TCP/IP socket server over the socket
connection, it tries to find the listener which was set up by the Test.exe.
It calls the singleton, but the singleton instance is being created all over
again.

This is what I found out:

- Test.exe code is executing in AppDomain 2
- Callback code is executing in AppDomain 1 (default domain)

My questions are:

- How does this work?
- Does the native code always have to run in the default AppDomain?
- How does a native socket get created from a non-default AppDomain if the
above is a requirement? Is it because mscorlib ( I am assuming System.Net is
there ) is a neutral-appdomain assembly?

Thanks in advance!

Dave Raskin