import asyncio
import datetime
import random
import websockets
message = ''


async def daemon():
    while True:
        print('daemon:', message)
        if message == 'STOP':
            stop.set_result(None)
        await asyncio.sleep(2)

async def main():
    async with websockets.serve(handler, '127.0.0.1', 5678):
        await stop


async def handler(websocket, path):
    global message
    while True:
        now = datetime.datetime.utcnow().isoformat() + 'Z'
        await websocket.send(now)
        await asyncio.sleep(random.random() * 3)
    while True:
        message = await websocket.recv()
        await consumer(message)
    consumer_task = asyncio.ensure_future(consumer_handler(websocket))
    producer_task = asyncio.ensure_future(producer_handler(websocket))
    done, pending = await asyncio.wait(
        [consumer_task, producer_task],
        return_when=asyncio.FIRST_COMPLETED,
    )

    for task in pending:
        task.cancel()


stop = asyncio.Future()
asyncio.ensure_future(daemon())
asyncio.get_event_loop().run_until_complete(main())