GameInput work queues
The GameInput API occasionally needs to handle internal asynchronous events, such as input devices being connected or disconnected. These events occur infrequently. However, applications can also register callbacks that might need to be dispatched more often. By default, GameInput creates a worker thread that runs at a slightly elevated priority (THREAD_PRIORITY_ABOVE_NORMAL) to service these events.
Applications that want more control over when this work takes place and on which thread/processor can manually control processing these events via the IGameInputDispatcher interface. This interface is obtained by calling the CreateDispatcher method on the IGameInput interface. This interface exposes two methods that you can use to manually dispatch work from the GameInput internal work queues. Use the Dispatch method to dispatch pending work (if any exists) from the GameInput work queues. Applications can call this method periodically. Alternatively, they can wait on the handle that's returned from the dispatcher's OpenWaitHandle method to detect when work has been queued that needs to be dispatched.
While the application holds a reference to the dispatcher interface, it remains in control of dispatching the work. After all the references to the dispatcher interface have been released, GameInput then returns to using an internal worker thread to service the events.