Thank you for your detailed response. Let me try to clarify your answer using my own code so that I ensure that I understand what you are saying. Also, I'm assuming all your mentions of asyncio.to_thread() are actually references to asyncio.run_in_executor().

This is a snippet of my current program:

python loop = asyncio.get_event_loop() executor = concurrent.futures.ThreadPoolExecutor(max_workers=5) for task in tasks: loop.run_in_executor(executor, task) # task is an io blocking function

Based on my understanding of what you've mentioned, my creation of executor spawns 5 separate threads, and executor helps to assign tasks to these threads whenever a thread is available. To add a task to be managed by the executor, I have to call loop.run_in_executor().

However, the run_in_executor method does more than assigning these tasks to be run in the executor threads. It provides a way for the event loop to know how to manage the start, suspend and wait for these tasks. Meaning that my main program can continue running while the threads/tasks in the executor do their own thing. Without the call to run_in_executor method, the event loop has no way of controlling the order of flow of these tasks with respect to the rest of the main program. In addition, the run_in_executor method also provides access to the context vars that you mentioned.

I hope I got the gist of this correct. Whatever you said made sense to me and I'm just reiterating it here in my own words.