asyncio_event.py

import sys
sys.path.append('')

from micropython import const
import micropython

import uasyncio as asyncio

import io

_MP_STREAM_POLL = const(3)

class PollingEvent(io.IOBase):
    def __init__(self):
        self._flag = 0

    def ioctl(self, req, flags):
        if req == _MP_STREAM_POLL:
            return self._flag * flags
        return None

    def set(self):
        self._flag = 1

    async def wait(self):
        yield asyncio.core._io_queue.queue_read(self)
        self._flag = 0

async def f(ev):
    print('f start')
    await asyncio.sleep_ms(2000)
    print('f set')
    micropython.schedule(lambda _: ev.set(), None)
    print('f done')

async def g(ev):
    print('g wait')
    await ev.wait()
    print('g ready')

async def main():
    ev = PollingEvent()
    t1 = asyncio.create_task(f(ev))
    t2 = asyncio.create_task(g(ev))
    await asyncio.gather(t1, t2)

asyncio.run(main())