uasyncio.create_task 不运行协程（micropython）

Question

Before I start an issue on github, just wanted to know, if I am doing smth wrong. This basic example should start a loop and after one calls the stop method it should stop. However, the print("while loop") gets not executed at all.

• rp2040 Zero (Pico)
• Thonny IDE

import uasyncio
import utime

class Test:
    def __init__(self):
        pass
    
    def run_loop(self):
        self.should_run = 1
        uasyncio.create_task(self._while_loop())

    async def _while_loop(self):
        print("while loop") # <--------- gets never called!
        counter = 0
        while self.should_run == 1:
            counter += 1
            print(counter)
            await uasyncio.sleep_ms(100)
    
    def stop(self):
        self.should_run = 0
        print("should stop now")

test = Test()
test.run_loop()
print("looop started.. wait..")
utime.sleep(3)
print("...waited..")
test.stop()

Answer 1

In a python script all executions are sync by default. To provide async functionality one has to create an async context. this is done via asyncio.run() // which will wait due to pythons nature till all inner async tasks are terminated.

As the micropython-uasyncio docs says, a typical async application is wrapped into the async context (eg main function).

This is how I solved the problem above:

import uasyncio as asyncio
import utime

class Test:
    run = 0
    def __init__(self):
        pass
    
    def run_loop(self):
        self.run = 1
        asyncio.create_task(self._while_loop())

    async def _while_loop(self):
        print("while loop, should_run:", self.run)
        counter = 0
        while self.run == 1:
            counter += 1
            print(counter)
            await asyncio.sleep_ms(100)

    def stop(self):
        self.run = 0
        print("should stop now")

async def main():
    test = Test()
    test.run_loop()
    print("looop started.. wait..")
    await asyncio.sleep(2)
    test.stop()

asyncio.run(main())