micropython-async: ESP32 exception BREAK instr when running with async v3

Hi,

I’ve faced issue with async code. I’ve tested 2 cases: loop with synchronous code, and loop with async code V3 as follow on ESP32 without PSRAM. I use the latest MicroPython version 1.15.

1. Synchronous code:

When running this function, it could run well 24/7 without any exceptions. Sleep in 1ms.

def _ctask_fn(arg):
   try:
      while True:
         _ccall(arg['_cfn'], arg)
         time.sleep_ms(arg['sleep'])
   except Exception as e:
      print('[_ctask_fn] %s' % str(e))
   finally:
      return

2. Async code

Also sleep in 1ms. But run in tens of seconds, or some minutes (2, 3), it occurs exceptions. It’s rather random. Most of them were Guru Meditation Error: Core 1 panic’ed (Unhandled debug exception) Debug exception reason: BREAK instr

arg[‘_cfn’] is just a callback function, do nothing for test.

If sleep in 50 or 100ms, it’s running rather long without exceptions. I’ve not tested with several hours/days.

async def _ctask_afn(arg):
   try:
      while True:
         _ccall(arg['_cfn'], arg)

         if 'sleep' in arg:
            await asyncio.sleep_ms(arg['sleep'])
         elif 'event' in arg:
           await arg['event'].wait()
           arg['event'].clear()
         elif 'tsf' in arg:
            await arg['tsf'].wait()

   except Exception as e:
      print('[_ctask_afn] %s' % str(e))
   finally:
      return

I really dont know why. It’s just a normal/minimal async code. Pls guide me how to debug it. I think that problem is at async scheduler side.

Thanks.