PR Summary

This PR fixes an exception thrown during a race condition in the OutOfProc transport base class, when a session is closed but command data is still being processed on the client.

PR Context

A recent change to the OutOfProc transport base class, adds separate processing threads for command and session messages. The processing threads are ended by setting the message BlockingCollection objects to complete. But this is done at session close when there can still be command data messages to process, and this resulted in an InvalidOperationException error.

To fix this, two changes were made:

1. Try/catch added to handle any late coming message events.
2. Move the message queue object completion to Dispose() method, to ensure message processing is closed at the very end of the transport lifetime.

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