- maintain a, say, ring buffer :) for I/O commands (operation, file handle, offset, buffer address, callback address)

- add requests to the buffer from the game loop

- timer wakes up periodically, splits requests into palatable chunks, completes a portion of the requested work, when it reaches the end it either sets a flag on the request to signal its completion and/or jumps to its callback address

- game loop can periodically check and empty the request buffer or set the requests to self-destruct on completion