Wrong _sock_exact_recv implementation used when adafruit_esp32spi.adafruit_esp32spi_socket provided

[cskwrd]

As the title states this library uses the implementation meant for CPython/socket pools instead of the ESP32SPI implementation.

Steps to reporduce

1. Upload the following script, and install adafruit_minimqtt and adafruit_esp32spi

   # SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
   # SPDX-License-Identifier: MIT
   
   import time
   import board
   import busio
   from digitalio import DigitalInOut
   import neopixel
   from adafruit_esp32spi import adafruit_esp32spi
   from adafruit_esp32spi import adafruit_esp32spi_wifimanager
   import adafruit_esp32spi.adafruit_esp32spi_socket as socket
   
   import adafruit_minimqtt.adafruit_minimqtt as MQTT
   
   ### WiFi ###
   
   # Get wifi details and more from a secrets.py file
   try:
       from secrets import secrets
   except ImportError:
       print("WiFi secrets are kept in secrets.py, please add them there!")
       raise
   
   # If you are using a board with pre-defined ESP32 Pins:
   esp32_cs = DigitalInOut(board.ESP_CS)
   esp32_ready = DigitalInOut(board.ESP_BUSY)
   esp32_reset = DigitalInOut(board.ESP_RESET)
   
   # If you have an externally connected ESP32:
   # esp32_cs = DigitalInOut(board.D9)
   # esp32_ready = DigitalInOut(board.D10)
   # esp32_reset = DigitalInOut(board.D5)
   
   spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
   esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset, debug=False)
   """Use below for Most Boards"""
   status_light = neopixel.NeoPixel(
       board.NEOPIXEL, 1, brightness=0.2
   )  # Uncomment for Most Boards
   """Uncomment below for ItsyBitsy M4"""
   # status_light = dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1, brightness=0.2)
   # Uncomment below for an externally defined RGB LED
   # import adafruit_rgbled
   # from adafruit_esp32spi import PWMOut
   # RED_LED = PWMOut.PWMOut(esp, 26)
   # GREEN_LED = PWMOut.PWMOut(esp, 27)
   # BLUE_LED = PWMOut.PWMOut(esp, 25)
   # status_light = adafruit_rgbled.RGBLED(RED_LED, BLUE_LED, GREEN_LED)
   wifi = adafruit_esp32spi_wifimanager.ESPSPI_WiFiManager(esp, secrets, status_light)
   
   ### Adafruit IO Setup ###
   
   # Setup a feed named `testfeed` for publishing.
   default_topic = 'adafruit/circuitpython/minimqtt/esp32spi/test'
   
   ### Code ###
   
   # Define callback methods which are called when events occur
   # pylint: disable=unused-argument, redefined-outer-name
   def connected(client, userdata, flags, rc):
       # This function will be called when the client is connected
       # successfully to the broker.
       print("Connected to MQTT broker! Listening for topic changes on %s" % default_topic)
       # Subscribe to all changes on the default_topic feed.
       client.subscribe(default_topic)
   
   
   def disconnected(client, userdata, rc):
       # This method is called when the client is disconnected
       print("Disconnected from MQTT Broker!")
   
   
   def message(client, topic, message):
       """Method callled when a client's subscribed feed has a new
       value.
       :param str topic: The topic of the feed with a new value.
       :param str message: The new value
       """
       print("New message on topic {0}: {1}".format(topic, message))
   
   
   # Connect to WiFi
   print("Connecting to WiFi...")
   wifi.connect()
   print("Connected!")
   
   # Initialize MQTT interface with the esp interface
   MQTT.set_socket(socket, esp)
   
   # Set up a MiniMQTT Client
   mqtt_client = MQTT.MQTT(
       broker='test.mosquitto.org',
       port=1883,
       keep_alive=5,
   )
   
   # Setup the callback methods above
   mqtt_client.on_connect = connected
   mqtt_client.on_disconnect = disconnected
   mqtt_client.on_message = message
   
   # Connect the client to the MQTT broker.
   print("Connecting to MQTT broker...")
   mqtt_client.connect()
   
   # Start a blocking message loop...
   # NOTE: NO code below this loop will execute
   # NOTE: Network reconnection is handled within this loop
   while True:
       try:
           print('Checking for messages...')
           mqtt_client.loop(timeout=1)
           print('Done...')
       except (ValueError, RuntimeError) as e:
           print("Failed to get data, retrying\n", e)
           wifi.reset()
           mqtt_client.reconnect()
           continue
       time.sleep(1)

   The above script is a modified version of examples/esp32spi/minimqtt_pub_sub_blocking_esp32spi.py. Modified to reduce dependence on secrets.py. Shortened keep_alive to exhibit bug sooner. Added non-zero timeout to .loop() invocation to prevent infinite blocking loop (separate bug already mentioned in issues, consider setting default non zero value for timeout in loop() #142).
2. Add WiFi SSID and password to secrets.py.
3. Reset device.

Actual Results

MMQTTException: Unable to receive 1 bytes within 5 seconds.

Expected Results

Checking for messages... followed by Done... repeatedly.

Root cause

It appears as though this library makes an assumption that is the socket has a recv_into implementation, that the socket is not an ESP32SPI socket. As of approximately 18 months ago, this is no longer the case. A recv_into implementation was added to adafruit_esp32spi. PR 151

Library versions

• adafruit_minimqtt: 7.3.2
• adafruit_esp32spi: 5.0.5

boot_out.txt

Adafruit CircuitPython 8.0.5 on 2023-03-31; Adafruit PyPortal with samd51j20
Board ID:pyportal

Related

• adafruit_esp32spi PR 151
• MQTT loop() blocks script. Works fine with adafruit_io #138
• minimqtt blocking on .loop() method #148

[cskwrd]

My use case is to interact with a home assistant installation via MQTT using the PyPortal with an interface dependent on asyncio. As such the invocation of .loop() must be non-blocking. The workaround I implemented myself is to modify the check performed in the library's _sock_exact_recv function, like so:

        is_esp32spi_sock = self._sock.__module__.find('esp32spi')
        if not is_esp32spi_sock and not self._backwards_compatible_sock:

I generally shy away from python so I have no idea how poor this fix is. If it's suitable I can put it in a PR.