使用 ib_insync 进行多线程和异步执行

Question

I am facing a perplexing problem when implementing multi-threading with ib_insync. My knowledge of both multithreading and asynchronous programming is surely insufficient to solve this. Interestingly, the roadblock is only with the ib.sleep command and other functions seem to be working just fine.

Below are two scenarios - one without multi-threading and one with. Without multi-threading everything works fine, but when multi-threading is used to run parallelly, I get the following warning and the code stops.

RuntimeWarning: coroutine 'sleep' was never awaited

What am I missing? I understand ib.sleep is a coroutine and needs to be awaited within an async function, but I do not understand how it works when called directly but only fails within a thread. What is the best way to implement this correctly?

from ib_insync import * 
from concurrent.futures import ThreadPoolExecutor 
import random 
import nest_asyncio 
nest_asyncio.apply()
    
# Define IB object 
ib = IB()
    
# Connect to IB 
ib.connect('127.0.0.1', 7497, clientId=131)
    
# Define sample function with ib.sleep 
def sample_function(sleep_time):
    print('Sleeping now') 
    ib.sleep(sleep_time)
    print('Sleep completed!')
    
# Call function directly - works fine
sample_function()
    
# Run multiple threads and call function within each thread - RunTimeWarning and stops
executor = ThreadPoolExecutor(max_workers=2) 
executor.submit(sample_function, random.randint(1,20)) 
executor.submit(sample_function, random.randint(1,20))

Edit: The use case I am trying to solve for is to call a function parallelly with different parameters. Edited the sample code above accordingly. The catch here is ib_insync is an asynchronous implementation based on asyncio, so running multiple threads fails.

Answer 1

The function doesn't work fine in either case, it just happens that in the main thread the warning is not shown. RuntimeWarning on non-awaited coroutines is provided on a best-effort basis without a guarantee that it will be emitted in all circumstances.

To fix the issue, you should avoid mixing threads and asyncio in the first place. For example, if you need to run several coroutines in parallel, you can spawn them as tasks using asyncio.crate_task , and then await some or all of them. Or you can use the asyncio.gather utility function which does it for you:

result1, result2, ... = await asyncio.gather(coro1(), coro2(), ...)