client.disconnect causes timeout even with example code

[savejeff]

• bleak version: 0.14.2
• Python version: 3.8
• Operating System: Windows 10

Description

I'm unable to close a connection to a client without a timeout.

What I Did

I Connect to a ESP32 with a BLE Server running the "standard" UART Characteristic. Even just connecting and then trying to disconnect causes this behavior.

I tried several methods, all end in a timeout error.

I've used the example code from this documentation: https://buildmedia.readthedocs.org/media/pdf/bleak/stable/bleak.pdf Page 10

address = "94:B9:7E:FE:76:8E"

async def main(address):
	client = BleakClient(address)
	try:
		await client.connect()

		await client.write_gatt_char(CHARACTERISTIC_UUID_UART_RX, bytes("Hallo, World!", 'ascii'))
		print(f"write done")

	except Exception as e:
		print(e)
	finally:
		await client.disconnect()

asyncio.run(main(address))

causes this

Traceback (most recent call last):
  File "XXX/BLEHelp.py", line 475, in <module>
    asyncio.run(main(address))
  File "C:\Users\XXX\AppData\Local\Programs\Python\Python38\lib\asyncio\runners.py", line 43, in run
    return loop.run_until_complete(main)
  File "C:\Users\XXX\AppData\Local\Programs\Python\Python38\lib\asyncio\base_events.py", line 616, in run_until_complete
    return future.result()
  File "XXX/BLEHelp.py", line 473, in main
    await client.disconnect()
  File "C:\Users\XXX\AppData\Local\Programs\Python\Python38\lib\site-packages\bleak\backends\winrt\client.py", line 313, in disconnect
    await asyncio.wait_for(event.wait(), timeout=10)
  File "C:\Users\XXX\AppData\Local\Programs\Python\Python38\lib\asyncio\tasks.py", line 490, in wait_for
    raise exceptions.TimeoutError()
asyncio.exceptions.TimeoutError

Update

it seems to work more or less reliably when connecting after being connected for longer periods of time.
it never works if I connect and then disconnect only a few seconds later

[dlech]

I've noticed this recently too. I think we just need to extend the default timeout value to 30 seconds or so.

For background, Windows doesn't actually let us tell the device to disconnect. We can only say that we aren't using it any more and it is up to the OS to decide when to actually disconnect.

[goldwake]

for what it's worth, I am often seeing the same issue with disconnection too. Sometimes it works, sometimes it doesn't

bleak version: 0.14.2
Python version: 3.9
Operating System: Windows 10