[VoiDeD]

The SP runtime is only ever expected to operate on the game's main thread.

You should not be calling into or out of SP from another thread unless you're serializing access between your threads, which can defeat the purpose of having a separate thread in the first place.

If you're doing some expensive operations that you want to move to another thread, a generic producer/consumer pattern is used where you can hook GameFrame to see if any of your queued jobs are completed/failed/etc.