Output1.txt

Iterating
Stream <CUDA stream 93950825260944 on <CUDA context c_void_p(93950819544272) of device 0>> done
Stream <CUDA stream 93950825975488 on <CUDA context c_void_p(93950819544272) of device 0>> done

Output2.txt

Iterating
Stream <CUDA stream 94405088815088 on <CUDA context c_void_p(94405082385552) of device 0>> done
Iterating
Stream <CUDA stream 94405088101008 on <CUDA context c_void_p(94405082385552) of device 0>> done

stream_await.py

from numba import cuda
import asyncio


async def f():
    s1 = cuda.stream()
    s2 = cuda.stream()

    f1 = s1.async_done()
    f2 = s2.async_done()

    f_to_s = {f1: s1, f2: s2}

    futures_pending = True
    pending = set((f1, f2))

    while futures_pending:
        print("Iterating")
        done, pending = await asyncio.wait(pending,
                                           return_when=asyncio.FIRST_COMPLETED)

        for d in done:
            print(f"Stream {f_to_s[d]} done")

        futures_pending = bool(pending)


loop = asyncio.get_event_loop()
loop.run_until_complete(f())