import asyncio
import concurrent.futures


def run_other_thread():
    pass


@asyncio.coroutine
def main_coro(loop):
    executor = concurrent.futures.ThreadPoolExecutor(20000)

    for i in range(40000):
        loop.run_in_executor(executor, run_other_thread)

    while True:
        print("5")
        yield from asyncio.sleep(5)


def main():
    loop = asyncio.ProactorEventLoop()
    asyncio.set_event_loop(loop)
    loop.create_task(main_coro(loop))
    loop.run_forever()
    loop.close()

if __name__ == "__main__":
    main()