app.py

# Do not run like this - will block the whole thread - freeze the app.
# blocking_function(q, loop)

# Get the current event loop - will be used for
# running async functions within the blocking.
loop = asyncio.get_event_loop()
# Create an event to use for cancellation.
q.client.event = Event()
with concurrent.futures.ThreadPoolExecutor() as pool:
    await q.exec(pool, blocking_function, q, loop)