raise NoReceiver if the receiver is removed during read

lib/logitech/unifying_receiver/api.py

@@ -187,7 +187,7 @@ def list_devices(handle):
 
 
 def get_device_info(handle, device, device_name=None, features_array=None):
-	"""Gets the complete info for a device.
+	"""Gets the complete info for a device (type, name, firmwares, and features_array).
 
 	:returns: an AttachedDeviceInfo tuple, or ``None``.
 	"""

lib/logitech/unifying_receiver/base.py

@@ -141,7 +141,7 @@ def write(handle, device, data):
 
 	:raises NoReceiver: if the receiver is no longer available, i.e. has
 	been physically removed from the machine, or the kernel driver has been
-	unloaded.
+	unloaded. The handle will be closed automatically.
 	"""
 	wdata = b'\x10' + chr(device) + data + b'\x00' * (5 - len(data))
 	_l.log(_LOG_LEVEL, "(%d,%d) <= w[%s]", handle, device, wdata.encode('hex'))
@@ -166,8 +166,17 @@ def read(handle, timeout=DEFAULT_TIMEOUT):
 	(reply_code, device, message data). The reply code should be ``0x11`` for a
 	successful feature call, or ``0x10`` to indicate some error, e.g. the device
 	is no longer available.
+
+	:raises NoReceiver: if the receiver is no longer available, i.e. has
+	been physically removed from the machine, or the kernel driver has been
+	unloaded. The handle will be closed automatically.
 	"""
 	data = _hid.read(handle, _MAX_REPLY_SIZE * 2, timeout)
+	if data is None:
+		_l.warn("(%d,*) read failed, assuming receiver no longer available", handle)
+		close(handle)
+		raise NoReceiver
+
 	if data:
 		_l.log(_LOG_LEVEL, "(%d,*) => r[%s]", handle, data.encode('hex'))
 		if len(data) < _MIN_REPLY_SIZE:
@@ -175,8 +184,7 @@ def read(handle, timeout=DEFAULT_TIMEOUT):
 		if len(data) > _MAX_REPLY_SIZE:
 			_l.warn("(%d,*) => r[%s] read packet too long: %d bytes", handle, data.encode('hex'), len(data))
 		return ord(data[0]), ord(data[1]), data[2:]
-	else:
-		_l.log(_LOG_LEVEL, "(%d,*) => r[]", handle)
+	_l.log(_LOG_LEVEL, "(%d,*) => r[]", handle)
 
 
 def request(handle, device, feature_index_function, params=b'', features_array=None):

lib/logitech/unifying_receiver/listener.py

@@ -4,7 +4,7 @@
 
 import logging
 import threading
-import time
+from time import sleep
 
 from . import base
 from .exceptions import *
@@ -13,16 +13,29 @@ from .exceptions import *
 _LOG_LEVEL = 6
 _l = logging.getLogger('logitech.unifying_receiver.listener')
 
-_EVENT_TIMEOUT = 100
-_IDLE_SLEEP = 1000.0 / 1000.0
+
+_READ_EVENT_TIMEOUT = 90  # ms
+_IDLE_SLEEP = 900  # ms
 
 
 class EventsListener(threading.Thread):
-	def __init__(self, receiver, callback):
+	"""Listener thread for events from the Unifying Receiver.
+
+	Incoming events (code, device, data) will be delivered to the callback
+	function. The callback is called in the listener thread, so it should return
+	as fast as possible.
+
+	While this listener is running, you should use the request() method to make
+	regular UR API calls, otherwise the replies will be captured by the listener
+	and delivered as events to the callback. As an exception, you can make UR
+	API calls in the events callback.
+	"""
+	def __init__(self, receiver, events_callback):
 		super(EventsListener, self).__init__(name='Unifying_Receiver_Listener_' + str(receiver))
+		self.daemon = True
 
 		self.receiver = receiver
-		self.callback = callback
+		self.callback = events_callback
 
 		self.task = None
 		self.task_processing = threading.Lock()
@@ -30,38 +43,50 @@ class EventsListener(threading.Thread):
 		self.task_reply = None
 		self.task_done = threading.Event()
 
-		self.active = False
-
 	def run(self):
 		_l.log(_LOG_LEVEL, "(%d) starting", self.receiver)
 		self.active = True
 		while self.active:
-			# _l.log(_LOG_LEVEL, "(%d) reading next event", self.receiver)
-			event = base.read(self.receiver, _EVENT_TIMEOUT)
-			if event:
-				_l.log(_LOG_LEVEL, "(%d) got event %s", self.receiver, event)
-				self.callback.__call__(*event)
-			elif self.task is None:
-				# _l.log(_LOG_LEVEL, "(%d) idle sleep", self.receiver)
-				time.sleep(_IDLE_SLEEP)
-			else:
-				self.task_reply = self._make_request(*self.task)
-				self.task_done.set()
+			try:
+				# _l.log(_LOG_LEVEL, "(%d) reading next event", self.receiver)
+				event = base.read(self.receiver, _READ_EVENT_TIMEOUT)
+			except NoReceiver:
+				_l.warn("(%d) receiver disconnected", self.receiver)
+				self.active = False
+				break
+
+			if self.active:
+				if event:
+					_l.log(_LOG_LEVEL, "(%d) got event %s", self.receiver, event)
+					self.callback.__call__(*event)
+				elif self.task is None:
+					# _l.log(_LOG_LEVEL, "(%d) idle sleep", self.receiver)
+					sleep(_IDLE_SLEEP / 1000.0)
+				else:
+					self.task_reply = self._make_request(*self.task)
+					self.task_done.set()
 
 	def stop(self):
+		"""Tells the listener to stop as soon as possible."""
 		_l.log(_LOG_LEVEL, "(%d) stopping", self.receiver)
 		self.active = False
-		self.join()
 
 	def request(self, api_function, *args, **kwargs):
+		"""Make an UR API request.
+
+		The api_function will get the receiver handle as a first agument, all
+		other args and kwargs will follow.
+		"""
 		# _l.log(_LOG_LEVEL, "(%d) request '%s' with %s, %s", self.receiver, api_function.__name__, args, kwargs)
 		self.task_processing.acquire()
 		self.task_done.clear()
 		self.task = (api_function, args, kwargs)
+
 		self.task_done.wait()
 		reply = self.task_reply
 		self.task = self.task_reply = None
 		self.task_processing.release()
+
 		# _l.log(_LOG_LEVEL, "(%d) request '%s' => [%s]", self.receiver, api_function.__name__, reply.encode('hex'))
 		if isinstance(reply, Exception):
 			raise reply