#!/usr/bin/python3.7

import asyncio

def get_future(n):
    fut = asyncio.Future()

    # Set fut done after n seconds
    asyncio.ensure_future(asyncio.sleep(n)).add_done_callback(fut.set_result)

    return fut


async def task():
    while True:
        fut = get_future(2)

        waiter = asyncio.ensure_future(asyncio.wait_for(fut, 3))
        try:
            await asyncio.shield(waiter)
        except asyncio.CancelledError:
            print('Cancelled; continue waiting')
            await waiter
            break


async def killer(fut):
    await asyncio.sleep(1)
    fut.cancel()


async def main():
    t0 = asyncio.ensure_future(task())
    t1 = asyncio.ensure_future(killer(t0))
    await t0

asyncio.run(main())