From e7bb599689a63006b467a1f36c2b927914d80d83 Mon Sep 17 00:00:00 2001
From: Daniel Pavel <daniel.pavel@gmail.com>
Date: Sat, 27 Oct 2012 18:40:54 +0300
Subject: [PATCH] reworked the way tasks are processed by the listener

---
 app/receiver.py                            | 167 +++++++++++++++------
 app/solaar.py                              |   9 +-
 app/ui/action.py                           |  25 +--
 app/ui/main_window.py                      |  40 ++---
 app/watcher.py                             |  24 +--
 bin/hidconsole                             |   2 +-
 bin/scan                                   |   2 +-
 bin/solaar                                 |   4 +-
 lib/logitech/devices/__init__.py           |  12 +-
 lib/logitech/devices/k750.py               |  20 +--
 lib/logitech/scanner.py                    |  10 +-
 lib/logitech/unifying_receiver/__init__.py |  24 ++-
 lib/logitech/unifying_receiver/api.py      | 140 +++++++++--------
 lib/logitech/unifying_receiver/base.py     | 113 +++++++-------
 lib/logitech/unifying_receiver/listener.py | 145 +++++++++---------
 15 files changed, 412 insertions(+), 325 deletions(-)

diff --git a/app/receiver.py b/app/receiver.py
index 4289ed8c..93e55a80 100644
--- a/app/receiver.py
+++ b/app/receiver.py
@@ -3,7 +3,6 @@
 #
 
 from logging import getLogger as _Logger
-_LOG_LEVEL = 6
 
 from threading import Event as _Event
 from struct import pack as _pack
@@ -18,22 +17,113 @@ from logitech.devices.constants import (STATUS, STATUS_NAME, PROPS, NAMES)
 #
 #
 
+
+class _FeaturesArray(object):
+	__slots__ = ('device', 'features', 'supported')
+
+	def __init__(self, device):
+		self.device = device
+		self.features = None
+		self.supported = True
+
+	def _check(self):
+		if not self.supported:
+			return False
+
+		if self.features is not None:
+			return True
+
+		if self.device.status >= STATUS.CONNECTED:
+			handle = self.device.receiver.handle
+			try:
+				index = _api.get_feature_index(handle, self.device.number, _api.FEATURE.FEATURE_SET)
+			except _api._FeatureNotSupported:
+				index = None
+
+			if index is None:
+				self.supported = False
+			else:
+				count = _base.request(handle, self.device.number, _pack('!B', index) + b'\x00')
+				if count is None:
+					self.supported = False
+				else:
+					count = ord(count[:1])
+					self.features = [None] * (1 + count)
+					self.features[0] = _api.FEATURE.ROOT
+					self.features[index] = _api.FEATURE.FEATURE_SET
+					return True
+
+		return False
+
+	__bool__ = __nonzero__ = _check
+
+	def __getitem__(self, index):
+		if not self._check():
+			return None
+
+		if index < 0 or index >= len(self.features):
+			raise IndexError
+		if self.features[index] is None:
+			fs_index = self.features.index(_api.FEATURE.FEATURE_SET)
+			feature = _base.request(self.device.receiver.handle, self.device.number, _pack('!BB', fs_index, 0x10), _pack('!B', index))
+			if feature is not None:
+				self.features[index] = feature[:2]
+
+		return self.features[index]
+
+	def __contains__(self, value):
+		if self._check():
+			if value in self.features:
+				return True
+
+			for index in range(0, len(self.features)):
+				f = self.features[index] or self.__getitem__(index)
+				assert f is not None
+				if f == value:
+					return True
+				if f > value:
+					break
+
+		return False
+
+	def index(self, value):
+		if self._check():
+			if self.features is not None and value in self.features:
+				return self.features.index(value)
+		raise ValueError("%s not in list" % repr(value))
+
+	def __iter__(self):
+		if self._check():
+			yield _api.FEATURE.ROOT
+			index = 1
+			last_index = len(self.features)
+			while index < last_index:
+				yield self.__getitem__(index)
+				index += 1
+
+	def __len__(self):
+		return len(self.features) if self._check() else 0
+
+
 class DeviceInfo(object):
 	"""A device attached to the receiver.
 	"""
-	def __init__(self, receiver, number, status=STATUS.UNKNOWN):
+	def __init__(self, receiver, number, pair_code, status=STATUS.UNKNOWN):
 		self.LOG = _Logger("Device[%d]" % number)
 		self.receiver = receiver
 		self.number = number
+		self._pair_code = pair_code
+		self._serial = None
+		self._codename = None
 		self._name = None
 		self._kind = None
-		self._serial = None
 		self._firmware = None
-		self._features = None
 
 		self._status = status
 		self.props = {}
 
+		self.features = _FeaturesArray(self)
+
 	@property
 	def handle(self):
 		return self.receiver.handle
@@ -71,8 +161,8 @@ class DeviceInfo(object):
 	def name(self):
 		if self._name is None:
 			if self._status >= STATUS.CONNECTED:
-				self._name = self.receiver.call_api(_api.get_device_name, self.number, self.features)
-		return self._name or '?'
+				self._name = _api.get_device_name(self.receiver.handle, self.number, self.features)
+		return self._name or self.codename
 
 	@property
 	def device_name(self):
@@ -81,33 +171,42 @@ class DeviceInfo(object):
 	@property
 	def kind(self):
 		if self._kind is None:
-			if self._status >= STATUS.CONNECTED:
-				self._kind = self.receiver.call_api(_api.get_device_kind, self.number, self.features)
+			if self._status < STATUS.CONNECTED:
+				codename = self.codename
+				if codename in NAMES:
+					self._kind = NAMES[codename][-1]
+			else:
+				self._kind = _api.get_device_kind(self.receiver.handle, self.number, self.features)
 		return self._kind or '?'
 
 	@property
 	def serial(self):
 		if self._serial is None:
-			if self._status >= STATUS.CONNECTED:
-				pass
+			# dodgy
+			b = bytearray(self._pair_code)
+			b[0] -= 0x10
+			serial = _base.request(self.receiver.handle, 0xFF, b'\x83\xB5', bytes(b))
+			if serial:
+				self._serial = _base._hex(serial[1:5])
 		return self._serial or '?'
 
+	@property
+	def codename(self):
+		if self._codename is None:
+			codename = _base.request(self.receiver.handle, 0xFF, b'\x83\xB5', self._pair_code)
+			if codename:
+				self._codename = codename[2:].rstrip(b'\x00').decode('ascii')
+		return self._codename or '?'
+
 	@property
 	def firmware(self):
 		if self._firmware is None:
 			if self._status >= STATUS.CONNECTED:
-				self._firmware = self.receiver.call_api(_api.get_device_firmware, self.number, self.features)
+				self._firmware = _api.get_device_firmware(self.receiver.handle, self.number, self.features)
 		return self._firmware or ()
 
-	@property
-	def features(self):
-		if self._features is None:
-			if self._status >= STATUS.CONNECTED:
-				self._features = self.receiver.call_api(_api.get_device_features, self.number)
-		return self._features or ()
-
 	def ping(self):
-		return self.receiver.call_api(_api.ping, self.number)
+		return _api.ping(self.receiver.handle, self.number)
 
 	def process_event(self, code, data):
 		if code == 0x10 and data[:1] == b'\x8F':
@@ -224,20 +323,20 @@ class Receiver(_listener.EventsListener):
 		return self.NAME
 
 	def count_devices(self):
-		return self.call_api(_api.count_devices)
+		return _api.count_devices(self._handle)
 
 	@property
 	def serial(self):
 		if self._serial is None:
 			if self:
-				self._serial, self._firmware = self.call_api(_api.get_receiver_info)
+				self._serial, self._firmware = _api.get_receiver_info(self._handle)
 		return self._serial or '?'
 
 	@property
 	def firmware(self):
 		if self._firmware is None:
 			if self:
-				self._serial, self._firmware = self.call_api(_api.get_receiver_info)
+				self._serial, self._firmware = _api.get_receiver_info(self._handle)
 		return self._firmware or ('?', '?')
 
 
@@ -303,30 +402,12 @@ class Receiver(_listener.EventsListener):
 			self.LOG.warn("don't know how to handle device status 0x%02X: %s", state_code, event)
 			return None
 
-		dev = DeviceInfo(self, event.devnumber, state)
-		if state == STATUS.CONNECTED:
-			n, k = dev.name, dev.kind
-		else:
-			# we can query the receiver for the device short name
-			dev_id = self.request(0xFF, b'\x83\xB5', event.data[4:5])
-			if dev_id:
-				shortname = dev_id[2:].rstrip(b'\x00').decode('ascii')
-				if shortname in NAMES:
-					dev._name, dev._kind = NAMES[shortname]
-				else:
-					self.LOG.warn("could not identify inactive device %d: %s", event.devnumber, shortname)
-
-		b = bytearray(event.data[4:5])
-		b[0] -= 0x10
-		serial = self.request(0xFF, b'\x83\xB5', bytes(b))
-		if serial:
-			dev._serial = _base._hex(serial[1:5])
-		return dev
+		return DeviceInfo(self, event.devnumber, event.data[4:5], state)
 
 	def unpair_device(self, number):
 		if number in self.devices:
 			dev = self.devices[number]
-			reply = self.request(0xFF, b'\x80\xB2', _pack('!BB', 0x03, number))
+			reply = _base.request(self._handle, 0xFF, b'\x80\xB2', _pack('!BB', 0x03, number))
 			if reply:
 				self.LOG.debug("remove device %s => %s", dev, _base._hex(reply))
 				del self.devices[number]
@@ -346,7 +427,7 @@ class Receiver(_listener.EventsListener):
 		:returns: An open file handle for the found receiver, or ``None``.
 		"""
 		for rawdevice in _base.list_receiver_devices():
-			_Logger("receiver").log(_LOG_LEVEL, "checking %s", rawdevice)
+			_Logger("receiver").debug("checking %s", rawdevice)
 			handle = _base.try_open(rawdevice.path)
 			if handle:
 				receiver = Receiver(rawdevice.path, handle)
diff --git a/app/solaar.py b/app/solaar.py
index 8477dfd2..bb1c0c58 100644
--- a/app/solaar.py
+++ b/app/solaar.py
@@ -32,10 +32,8 @@ def _parse_arguments():
 
 	import logging
 	log_level = logging.root.level - 10 * args.verbose
-	log_format='%(asctime)s.%(msecs)03d %(levelname)8s [%(threadName)s] %(name)s: %(message)s'
-	logging.basicConfig(level=log_level if log_level > 0 else 1,
-						format=log_format,
-						datefmt='%H:%M:%S')
+	log_format='%(asctime)s %(levelname)8s [%(threadName)s] %(name)s: %(message)s'
+	logging.basicConfig(level=max(log_level, 1), format=log_format)
 
 	return args
 
@@ -83,3 +81,6 @@ if __name__ == '__main__':
 
 	w.stop()
 	ui.notify.uninit()
+
+	import logging
+	logging.shutdown()
diff --git a/app/ui/action.py b/app/ui/action.py
index 5d9bfd9a..0a995200 100644
--- a/app/ui/action.py
+++ b/app/ui/action.py
@@ -19,10 +19,18 @@ def _toggle_action(name, label, function, *args):
 	return action
 
 
-#
-#
-#
+def wrap_action(action, prefire):
+	def _wrap(aw, aa):
+		prefire(aa)
+		aa.activate()
+	wrapper = _action(action.get_name(), action.get_label(), None)
+	wrapper.set_icon_name(action.get_icon_name())
+	wrapper.connect('activate', _wrap, action)
+	return wrapper
 
+#
+#
+#
 
 def _toggle_notifications(action):
 	if action.get_active():
@@ -57,9 +65,6 @@ import pairing
 def _pair_device(action):
 	action.set_sensitive(False)
 	pair_dialog = ui.pair_window.create(action, pairing.state)
-	action.window.present()
-	pair_dialog.set_transient_for(action.window)
-	pair_dialog.set_destroy_with_parent(action.window)
 	pair_dialog.set_modal(True)
 	pair_dialog.present()
 pair = _action('add', 'Pair new device', _pair_device)
@@ -69,9 +74,11 @@ def _unpair_device(action):
 	dev = pairing.state.device(action.devnumber)
 	action.devnumber = 0
 	if dev:
-		q = Gtk.MessageDialog.new(action.window,
+		qdialog = Gtk.MessageDialog(action.window, 0,
 									Gtk.MessageType.QUESTION, Gtk.ButtonsType.YES_NO,
-									'Unpair device <b>%s</b>?', dev.name)
-		if q.run() == Gtk.ResponseType.YES:
+									"Unpair device '%s' ?" % dev.name)
+		choice = qdialog.run()
+		qdialog.destroy()
+		if choice == Gtk.ResponseType.YES:
 			pairing.state.unpair(dev.number)
 unpair = _action('remove', 'Unpair', _unpair_device)
diff --git a/app/ui/main_window.py b/app/ui/main_window.py
index ec4aaf98..62fc99e0 100644
--- a/app/ui/main_window.py
+++ b/app/ui/main_window.py
@@ -2,7 +2,7 @@
 #
 #
 
-from gi.repository import (Gtk, Gdk)
+from gi.repository import (Gtk, Gdk, GObject)
 
 import ui
 from logitech.devices.constants import (STATUS, PROPS)
@@ -22,6 +22,7 @@ def _toggle_info_button(label, widget):
 	action = ui.action._toggle_action('info', label, toggle, widget)
 	return action.create_tool_item()
 
+
 def _receiver_box(name):
 	icon = Gtk.Image.new_from_icon_name(name, _SMALL_DEVICE_ICON_SIZE)
 
@@ -65,7 +66,7 @@ def _receiver_box(name):
 	return frame
 
 
-def _device_box():
+def _device_box(index):
 	icon = Gtk.Image.new_from_icon_name('image-missing', _DEVICE_ICON_SIZE)
 	icon.set_name('icon')
 	icon.set_alignment(0.5, 0)
@@ -111,7 +112,10 @@ def _device_box():
 	info_box.add(info_label)
 
 	toolbar.insert(_toggle_info_button('Device info', info_box), 0)
-	toolbar.insert(ui.action.unpair.create_tool_item(), -1)
+	def _set_number(action):
+		action.devnumber = index
+	unpair_action = ui.action.wrap_action(ui.action.unpair, _set_number)
+	toolbar.insert(unpair_action.create_tool_item(), -1)
 
 	vbox = Gtk.VBox(homogeneous=False, spacing=4)
 	vbox.pack_start(label, True, True, 0)
@@ -131,7 +135,6 @@ def _device_box():
 
 
 def toggle(window, trigger):
-	# print 'window toggle', window, trigger
 	if window.get_visible():
 		position = window.get_position()
 		window.hide()
@@ -158,7 +161,7 @@ def create(title, name, max_devices, systray=False):
 	rbox = _receiver_box(name)
 	vbox.add(rbox)
 	for i in range(1, 1 + max_devices):
-		dbox = _device_box()
+		dbox = _device_box(i)
 		vbox.add(dbox)
 	vbox.set_visible(True)
 
@@ -209,18 +212,12 @@ def _update_receiver_box(frame, receiver):
 
 
 def _update_device_box(frame, dev):
-	if dev is None:
-		frame.set_visible(False)
-		frame.set_name(_PLACEHOLDER)
-		return
-
 	icon, label, info_label = ui.find_children(frame, 'icon', 'label', 'info-label')
 
 	if frame.get_name() != dev.name:
 		frame.set_name(dev.name)
 		icon.set_from_icon_name(ui.get_icon(dev.name, dev.kind), _DEVICE_ICON_SIZE)
 		label.set_markup('<b>' + dev.name + '</b>')
-	frame.set_visible(True)
 
 	status = ui.find_children(frame, 'status')
 	status_icons = status.get_children()
@@ -271,16 +268,21 @@ def _update_device_box(frame, dev):
 	for b in toolbar.get_children()[:-1]:
 		b.set_sensitive(True)
 
+	frame.set_visible(True)
 
 def update(window, receiver):
-	if window and window.get_child():
-		window.set_icon_name(ui.appicon(receiver.status))
+	window.set_icon_name(ui.appicon(receiver.status))
 
-		vbox = window.get_child()
-		controls = list(vbox.get_children())
+	vbox = window.get_child()
+	controls = list(vbox.get_children())
 
-		_update_receiver_box(controls[0], receiver)
+	GObject.idle_add(_update_receiver_box, controls[0], receiver)
 
-		for index in range(1, len(controls)):
-			dev = receiver.devices[index] if index in receiver.devices else None
-			_update_device_box(controls[index], dev)
+	for index in range(1, len(controls)):
+		dev = receiver.devices[index] if index in receiver.devices else None
+		frame = controls[index]
+		if dev is None:
+			frame.set_visible(False)
+			frame.set_name(_PLACEHOLDER)
+		else:
+			GObject.idle_add(_update_device_box, frame, dev)
diff --git a/app/watcher.py b/app/watcher.py
index b46578f3..122451ac 100644
--- a/app/watcher.py
+++ b/app/watcher.py
@@ -65,31 +65,19 @@ class Watcher(Thread):
 					continue
 
 				_l.info("receiver %s ", r)
-				self.update_ui(r)
-				self.notify(r)
-
-				if r.count_devices() > 0:
-					# give it some time to read all devices
-					r.status_changed.clear()
-					_sleep(8, 0.4, r.status_changed.is_set)
-
-				if r.devices:
-					_l.info("%d device(s) found", len(r.devices))
-					for d in r.devices.values():
-						self.notify(d)
-				else:
-					# if no devices found so far, assume none at all
-					_l.info("no devices found")
-					r.status = STATUS.CONNECTED
-
 				self._receiver = r
 				notify_missing = True
 
+				self.update_ui(r)
+				self.notify(r)
+
 			if self._active:
 				if self._receiver:
 					_l.debug("waiting for status_changed")
 					sc = self._receiver.status_changed
 					sc.wait()
+					if not self._active:
+						break
 					sc.clear()
 					if sc.urgent:
 						_l.info("status_changed %s", sc.reason)
@@ -103,6 +91,7 @@ class Watcher(Thread):
 
 		if self._receiver:
 			self._receiver.close()
+		self._receiver = _DUMMY_RECEIVER
 
 	def stop(self):
 		if self._active:
@@ -112,3 +101,4 @@ class Watcher(Thread):
 				# break out of an eventual wait()
 				self._receiver.status_changed.reason = None
 				self._receiver.status_changed.set()
+			self.join()
diff --git a/bin/hidconsole b/bin/hidconsole
index 2cdda26a..dfbbf461 100755
--- a/bin/hidconsole
+++ b/bin/hidconsole
@@ -4,4 +4,4 @@ LIB=`dirname "$0"`/../lib
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$LIB/native/`uname -m`
 export PYTHONPATH=$LIB
 
-exec python -OO -u -m hidapi.hidconsole "$@"
+exec python -OOu -m hidapi.hidconsole "$@"
diff --git a/bin/scan b/bin/scan
index bbb8b839..b9299a92 100755
--- a/bin/scan
+++ b/bin/scan
@@ -4,4 +4,4 @@ LIB=`dirname "$0"`/../lib
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$LIB/native/`uname -m`
 export PYTHONPATH=$LIB
 
-exec python -OO -m logitech.scanner "$@"
+exec python -OOu -m logitech.scanner "$@"
diff --git a/bin/solaar b/bin/solaar
index 9c5cc574..cd4b3e33 100755
--- a/bin/solaar
+++ b/bin/solaar
@@ -9,5 +9,5 @@ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$LIB/native/`uname -m`
 export PYTHONPATH=$APP:$LIB
 export XDG_DATA_DIRS=$SHARE:$XDG_DATA_DIRS
 
-exec python3 -OO -m solaar "$@"
-#exec python -OO -m profile -o $TMPDIR/profile.log app/solaar.py "$@"
+exec python -OOu -m solaar "$@"
+#exec python -OOu -m profile -o $TMPDIR/profile.log app/solaar.py "$@"
diff --git a/lib/logitech/devices/__init__.py b/lib/logitech/devices/__init__.py
index 17150285..90fe56d1 100644
--- a/lib/logitech/devices/__init__.py
+++ b/lib/logitech/devices/__init__.py
@@ -32,20 +32,12 @@ def _module(device_name):
 
 def default_request_status(devinfo, listener=None):
 	if FEATURE.BATTERY in devinfo.features:
-		if listener:
-			reply = listener.call_api(_api.get_device_battery_level, devinfo.number, features=devinfo.features)
-		else:
-			reply = _api.get_device_battery_level(devinfo.handle, devinfo.number, features=devinfo.features)
-
+		reply = _api.get_device_battery_level(devinfo.handle, devinfo.number, features=devinfo.features)
 		if reply:
 			discharge, dischargeNext, status = reply
 			return STATUS.CONNECTED, {PROPS.BATTERY_LEVEL: discharge, PROPS.BATTERY_STATUS: status}
 
-	if listener:
-		reply = listener.call_api(_api.ping, devinfo.number)
-	else:
-		reply = _api.ping(devinfo.handle, devinfo.number)
-
+	reply = _api.ping(devinfo.handle, devinfo.number)
 	return STATUS.CONNECTED if reply else STATUS.UNAVAILABLE
 
 
diff --git a/lib/logitech/devices/k750.py b/lib/logitech/devices/k750.py
index c55b8471..c935ecc0 100644
--- a/lib/logitech/devices/k750.py
+++ b/lib/logitech/devices/k750.py
@@ -29,17 +29,9 @@ def _charge_status(data, hasLux=False):
 
 
 def request_status(devinfo, listener=None):
-	def _trigger_solar_charge_events(handle, devinfo):
-		return _api.request(handle, devinfo.number,
-							feature=FEATURE.SOLAR_CHARGE, function=b'\x03', params=b'\x78\x01',
-							features=devinfo.features)
-	if listener is None:
-		reply = _trigger_solar_charge_events(devinfo.handle, devinfo)
-	elif listener:
-		reply = listener.call_api(_trigger_solar_charge_events, devinfo)
-	else:
-		reply = 0
-
+	reply = _api.request(devinfo.handle, devinfo.number,
+						feature=FEATURE.SOLAR_CHARGE, function=b'\x03', params=b'\x78\x01',
+						features=devinfo.features)
 	if reply is None:
 		return STATUS.UNAVAILABLE
 
@@ -56,9 +48,3 @@ def process_event(devinfo, data, listener=None):
 	if data[:2] == b'\x09\x20' and data[7:11] == b'GOOD':
 		logging.debug("Solar key pressed")
 		return request_status(devinfo, listener) or _charge_status(data)
-
-	if data[:2] == b'\x05\x00':
-		# wireless device status
-		if data[2:5] == b'\x01\x01\x01':
-			logging.debug("Keyboard just started")
-			return STATUS.CONNECTED
diff --git a/lib/logitech/scanner.py b/lib/logitech/scanner.py
index c24a13c5..2a5a8a93 100644
--- a/lib/logitech/scanner.py
+++ b/lib/logitech/scanner.py
@@ -39,7 +39,7 @@ def scan_devices(receiver):
 		for index in range(0, len(devinfo.features)):
 			feature = devinfo.features[index]
 			if feature:
-				print ("  ~ Feature %-20s (%s) at index %d" % (FEATURE_NAME[feature], api._hex(feature), index))
+				print ("  ~ Feature %-20s (%s) at index %02X" % (FEATURE_NAME[feature], api._hex(feature), index))
 
 		if FEATURE.BATTERY in devinfo.features:
 			discharge, dischargeNext, status = api.get_device_battery_level(receiver, devinfo.number, features=devinfo.features)
@@ -75,11 +75,3 @@ if __name__ == '__main__':
 			break
 	else:
 		print ("!! Logitech Unifying Receiver not found.")
-
-
-	# import pyudev
-	# ctx = pyudev.Context()
-	# m = pyudev.Monitor.from_netlink(ctx)
-	# m.filter_by(subsystem='hid')
-	# for action, device in m:
-	# 	print '%s: %s' % (action, device)
diff --git a/lib/logitech/unifying_receiver/__init__.py b/lib/logitech/unifying_receiver/__init__.py
index aa24719c..f6485ea7 100644
--- a/lib/logitech/unifying_receiver/__init__.py
+++ b/lib/logitech/unifying_receiver/__init__.py
@@ -20,12 +20,24 @@ http://julien.danjou.info/blog/2012/logitech-k750-linux-support
 http://6xq.net/git/lars/lshidpp.git/plain/doc/
 """
 
+import logging
+
+log = logging.getLogger('LUR')
+log.propagate = 0
+log.setLevel(logging.DEBUG)
+
+if logging.root.level < logging.DEBUG:
+	handler = logging.FileHandler('lur.log', mode='w')
+	handler.setFormatter(logging.root.handlers[0].formatter)
+else:
+	handler = logging.NullHandler()
+log.addHandler(handler)
+del handler
+
+del log
+del logging
+
+
 from .constants import *
 from .exceptions import *
 from .api import *
-
-
-import logging
-logging.addLevelName(4, 'UR_TRACE')
-logging.addLevelName(5, 'UR_DEBUG')
-logging.addLevelName(6, 'UR_INFO')
diff --git a/lib/logitech/unifying_receiver/api.py b/lib/logitech/unifying_receiver/api.py
index 50baf621..382b82ce 100644
--- a/lib/logitech/unifying_receiver/api.py
+++ b/lib/logitech/unifying_receiver/api.py
@@ -2,7 +2,6 @@
 # Logitech Unifying Receiver API.
 #
 
-from logging import getLogger as _Logger
 from struct import pack as _pack
 from struct import unpack as _unpack
 
@@ -19,8 +18,10 @@ from .exceptions import FeatureNotSupported as _FeatureNotSupported
 
 
 _hex = _base._hex
-_LOG_LEVEL = 5
-_l = _Logger('lur.api')
+
+from logging import getLogger
+_log = getLogger('LUR').getChild('api')
+del getLogger
 
 #
 #
@@ -61,7 +62,7 @@ def get_receiver_info(handle):
 
 
 def count_devices(handle):
-	count = _base.request(handle, 0xFF, b'\x80\x02', b'\x02')
+	count = _base.request(handle, 0xFF, b'\x81\x00')
 	return 0 if count is None else ord(count[1:2])
 
 
@@ -88,22 +89,16 @@ def request(handle, devnumber, feature, function=b'\x00', params=b'', features=N
 
 	:raises FeatureNotSupported: if the device does not support the feature.
 	"""
-
 	feature_index = None
 	if feature == FEATURE.ROOT:
 		feature_index = b'\x00'
 	else:
-		if features is None:
-			features = get_device_features(handle, devnumber)
-			if features is None:
-				_l.log(_LOG_LEVEL, "(%d) no features array available", devnumber)
-				return None
-		if feature in features:
-			feature_index = _pack('!B', features.index(feature))
+		feature_index = _get_feature_index(handle, devnumber, feature, features)
+		if feature_index is None:
+			# i/o read error
+			return None
 
-	if feature_index is None:
-		_l.warn("(%d) feature <%s:%s> not supported", devnumber, _hex(feature), FEATURE_NAME[feature])
-		raise _FeatureNotSupported(devnumber, feature)
+		feature_index = _pack('!B', feature_index)
 
 	if type(function) == int:
 		function = _pack('!B', function)
@@ -132,9 +127,11 @@ def get_device_protocol(handle, devnumber):
 def find_device_by_name(handle, name):
 	"""Searches for an attached device by name.
 
+	This function does it the hard way, querying all possible device numbers.
+
 	:returns: an AttachedDeviceInfo tuple, or ``None``.
 	"""
-	_l.log(_LOG_LEVEL, "searching for device '%s'", name)
+	_log.debug("searching for device '%s'", name)
 
 	for devnumber in range(1, 1 + MAX_ATTACHED_DEVICES):
 		features = get_device_features(handle, devnumber)
@@ -147,9 +144,11 @@ def find_device_by_name(handle, name):
 def list_devices(handle):
 	"""List all devices attached to the UR.
 
+	This function does it the hard way, querying all possible device numbers.
+
 	:returns: a list of AttachedDeviceInfo tuples.
 	"""
-	_l.log(_LOG_LEVEL, "listing all devices")
+	_log.debug("listing all devices")
 
 	devices = []
 
@@ -162,7 +161,7 @@ def list_devices(handle):
 
 
 def get_device_info(handle, devnumber, name=None, features=None):
-	"""Gets the complete info for a device (type, name, firmware versions, features).
+	"""Gets the complete info for a device (type, name, features).
 
 	:returns: an AttachedDeviceInfo tuple, or ``None``.
 	"""
@@ -174,7 +173,7 @@ def get_device_info(handle, devnumber, name=None, features=None):
 	d_kind = get_device_kind(handle, devnumber, features)
 	d_name = get_device_name(handle, devnumber, features) if name is None else name
 	devinfo = _AttachedDeviceInfo(handle, devnumber, d_kind, d_name, features)
-	_l.log(_LOG_LEVEL, "(%d) found device %s", devnumber, devinfo)
+	_log.debug("(%d) found device %s", devnumber, devinfo)
 	return devinfo
 
 
@@ -183,41 +182,53 @@ def get_feature_index(handle, devnumber, feature):
 
 	:returns: An int, or ``None`` if the feature is not available.
 	"""
-	_l.log(_LOG_LEVEL, "(%d) get feature index <%s:%s>", devnumber, _hex(feature), FEATURE_NAME[feature])
+	_log.debug("(%d) get feature index <%s:%s>", devnumber, _hex(feature), FEATURE_NAME[feature])
 	if len(feature) != 2:
 		raise ValueError("invalid feature <%s>: it must be a two-byte string" % feature)
 
 	# FEATURE.ROOT should always be available for any attached devices
 	reply = _base.request(handle, devnumber, FEATURE.ROOT, feature)
 	if reply:
-		# only consider active and supported features
 		feature_index = ord(reply[0:1])
 		if feature_index:
 			feature_flags = ord(reply[1:2]) & 0xE0
-			if _l.isEnabledFor(_LOG_LEVEL):
-				if feature_flags:
-					_l.log(_LOG_LEVEL, "(%d) feature <%s:%s> has index %d: %s",
+			if feature_flags:
+				_log.debug("(%d) feature <%s:%s> has index %d: %s",
 							devnumber, _hex(feature), FEATURE_NAME[feature], feature_index,
 							','.join([FEATURE_FLAGS[k] for k in FEATURE_FLAGS if feature_flags & k]))
-				else:
-					_l.log(_LOG_LEVEL, "(%d) feature <%s:%s> has index %d", devnumber, _hex(feature), FEATURE_NAME[feature], feature_index)
+			else:
+				_log.debug("(%d) feature <%s:%s> has index %d", devnumber, _hex(feature), FEATURE_NAME[feature], feature_index)
 
+			# only consider active and supported features?
 			# if feature_flags:
 			# 	raise E.FeatureNotSupported(devnumber, feature)
 
 			return feature_index
 
-		_l.warn("(%d) feature <%s:%s> not supported by the device", devnumber, _hex(feature), FEATURE_NAME[feature])
+		_log.warn("(%d) feature <%s:%s> not supported by the device", devnumber, _hex(feature), FEATURE_NAME[feature])
 		raise _FeatureNotSupported(devnumber, feature)
 
 
+def _get_feature_index(handle, devnumber, feature, features=None):
+	if features is None:
+		return get_feature_index(handle, devnumber, feature)
+
+	if feature in features:
+		return features.index(feature)
+
+	index = get_feature_index(handle, devnumber, feature)
+	if index is not None:
+		features[index] = feature
+		return index
+
+
 def get_device_features(handle, devnumber):
 	"""Returns an array of feature ids.
 
 	Their position in the array is the index to be used when requesting that
 	feature on the device.
 	"""
-	_l.log(_LOG_LEVEL, "(%d) get device features", devnumber)
+	_log.debug("(%d) get device features", devnumber)
 
 	# get the index of the FEATURE_SET
 	# FEATURE.ROOT should always be available for all devices
@@ -235,11 +246,11 @@ def get_device_features(handle, devnumber):
 	if not features_count:
 		# this can happen if the device disappeard since the fs_index request
 		# otherwise we should get at least a count of 1 (the FEATURE_SET we've just used above)
-		_l.log(_LOG_LEVEL, "(%d) no features available?!", devnumber)
+		_log.debug("(%d) no features available?!", devnumber)
 		return None
 
 	features_count = ord(features_count[:1])
-	_l.log(_LOG_LEVEL, "(%d) found %d features", devnumber, features_count)
+	_log.debug("(%d) found %d features", devnumber, features_count)
 
 	features = [None] * 0x20
 	for index in range(1, 1 + features_count):
@@ -250,13 +261,12 @@ def get_device_features(handle, devnumber):
 			feature = feature[0:2].upper()
 			features[index] = feature
 
-			if _l.isEnabledFor(_LOG_LEVEL):
-				if feature_flags:
-					_l.log(_LOG_LEVEL, "(%d) feature <%s:%s> at index %d: %s",
+			if feature_flags:
+				_log.debug("(%d) feature <%s:%s> at index %d: %s",
 							devnumber, _hex(feature), FEATURE_NAME[feature], index,
 							','.join([FEATURE_FLAGS[k] for k in FEATURE_FLAGS if feature_flags & k]))
-				else:
-					_l.log(_LOG_LEVEL, "(%d) feature <%s:%s> at index %d", devnumber, _hex(feature), FEATURE_NAME[feature], index)
+			else:
+				_log.debug("(%d) feature <%s:%s> at index %d", devnumber, _hex(feature), FEATURE_NAME[feature], index)
 
 	features[0] = FEATURE.ROOT
 	while features[-1] is None:
@@ -269,16 +279,17 @@ def get_device_firmware(handle, devnumber, features=None):
 
 	:returns: a list of FirmwareInfo tuples, ordered by firmware layer.
 	"""
-	def _makeFirmwareInfo(level, kind, name='', version='', extras=None):
-		return _FirmwareInfo(level, kind, name, version, extras)
+	fw_fi = _get_feature_index(handle, devnumber, FEATURE.FIRMWARE, features)
+	if fw_fi is None:
+		return None
 
-	fw_count = request(handle, devnumber, FEATURE.FIRMWARE, features=features)
+	fw_count = _base.request(handle, devnumber, _pack('!BB', fw_fi, 0x00))
 	if fw_count:
 		fw_count = ord(fw_count[:1])
 
 		fw = []
 		for index in range(0, fw_count):
-			fw_info = request(handle, devnumber, FEATURE.FIRMWARE, function=b'\x10', params=index, features=features)
+			fw_info = _base.request(handle, devnumber, _pack('!BB', fw_fi, 0x10), params=index)
 			if fw_info:
 				level = ord(fw_info[:1]) & 0x0F
 				if level == 0 or level == 1:
@@ -290,18 +301,15 @@ def get_device_firmware(handle, devnumber, features=None):
 					build, = _unpack('!H', fw_info[6:8])
 					if build:
 						version += ' b%d' % build
-					extras = fw_info[9:].rstrip(b'\x00')
-					if extras:
-						fw_info = _makeFirmwareInfo(level, kind, name, version, extras)
-					else:
-						fw_info = _makeFirmwareInfo(level, kind, name, version)
+					extras = fw_info[9:].rstrip(b'\x00') or None
+					fw_info = _FirmwareInfo(level, kind, name, version, extras)
 				elif level == 2:
-					fw_info = _makeFirmwareInfo(2, FIRMWARE_KIND[2], version=ord(fw_info[1:2]))
+					fw_info = _FirmwareInfo(2, FIRMWARE_KIND[2], '', ord(fw_info[1:2]), None)
 				else:
-					fw_info = _makeFirmwareInfo(level, FIRMWARE_KIND[-1])
+					fw_info = _FirmwareInfo(level, FIRMWARE_KIND[-1], '', '', None)
 
 				fw.append(fw_info)
-				_l.log(_LOG_LEVEL, "(%d) firmware %s", devnumber, fw_info)
+				_log.debug("(%d) firmware %s", devnumber, fw_info)
 		return tuple(fw)
 
 
@@ -312,10 +320,14 @@ def get_device_kind(handle, devnumber, features=None):
 	:returns: a string describing the device type, or ``None`` if the device is
 	not available or does not support the ``NAME`` feature.
 	"""
-	d_kind = request(handle, devnumber, FEATURE.NAME, function=b'\x20', features=features)
+	name_fi = _get_feature_index(handle, devnumber, FEATURE.NAME, features)
+	if name_fi is None:
+		return None
+
+	d_kind = _base.request(handle, devnumber, _pack('!BB', name_fi, 0x20))
 	if d_kind:
 		d_kind = ord(d_kind[:1])
-		_l.log(_LOG_LEVEL, "(%d) device type %d = %s", devnumber, d_kind, DEVICE_KIND[d_kind])
+		_log.debug("(%d) device type %d = %s", devnumber, d_kind, DEVICE_KIND[d_kind])
 		return DEVICE_KIND[d_kind]
 
 
@@ -325,13 +337,17 @@ def get_device_name(handle, devnumber, features=None):
 	:returns: a string with the device name, or ``None`` if the device is not
 	available or does not support the ``NAME`` feature.
 	"""
-	name_length = request(handle, devnumber, FEATURE.NAME, features=features)
+	name_fi = _get_feature_index(handle, devnumber, FEATURE.NAME, features)
+	if name_fi is None:
+		return None
+
+	name_length = _base.request(handle, devnumber, _pack('!BB', name_fi, 0x00))
 	if name_length:
 		name_length = ord(name_length[:1])
 
 		d_name = b''
 		while len(d_name) < name_length:
-			name_fragment = request(handle, devnumber, FEATURE.NAME, function=b'\x10', params=len(d_name), features=features)
+			name_fragment = _base.request(handle, devnumber, _pack('!BB', name_fi, 0x10), len(d_name))
 			if name_fragment:
 				name_fragment = name_fragment[:name_length - len(d_name)]
 				d_name += name_fragment
@@ -339,7 +355,7 @@ def get_device_name(handle, devnumber, features=None):
 				break
 
 		d_name = d_name.decode('ascii')
-		_l.log(_LOG_LEVEL, "(%d) device name %s", devnumber, d_name)
+		_log.debug("(%d) device name %s", devnumber, d_name)
 		return d_name
 
 
@@ -348,22 +364,28 @@ def get_device_battery_level(handle, devnumber, features=None):
 
 	:raises FeatureNotSupported: if the device does not support this feature.
 	"""
-	battery = request(handle, devnumber, FEATURE.BATTERY, features=features)
-	if battery:
-		discharge, dischargeNext, status = _unpack('!BBB', battery[:3])
-		_l.log(_LOG_LEVEL, "(%d) battery %d%% charged, next level %d%% charge, status %d = %s",
+	bat_fi = _get_feature_index(handle, devnumber, FEATURE.BATTERY, features)
+	if bat_fi is not None:
+		battery = _base.request(handle, devnumber, _pack('!BB', bat_fi, 0))
+		if battery:
+			discharge, dischargeNext, status = _unpack('!BBB', battery[:3])
+			_log.debug("(%d) battery %d%% charged, next level %d%% charge, status %d = %s",
 						devnumber, discharge, dischargeNext, status, BATTERY_STATUS[status])
-		return (discharge, dischargeNext, BATTERY_STATUS[status])
+			return (discharge, dischargeNext, BATTERY_STATUS[status])
 
 
 def get_device_keys(handle, devnumber, features=None):
-	count = request(handle, devnumber, FEATURE.REPROGRAMMABLE_KEYS, features=features)
+	rk_fi = _get_feature_index(handle, devnumber, FEATURE.REPROGRAMMABLE_KEYS, features)
+	if rk_fi is None:
+		return None
+
+	count = _base.request(handle, devnumber, _pack('!BB', rk_fi, 0))
 	if count:
 		keys = []
 
 		count = ord(count[:1])
 		for index in range(0, count):
-			keydata = request(handle, devnumber, FEATURE.REPROGRAMMABLE_KEYS, function=b'\x10', params=index, features=features)
+			keydata = _base.request(handle, devnumber, _pack('!BB', rk_fi, 0x10), index)
 			if keydata:
 				key, key_task, flags = _unpack('!HHB', keydata[:5])
 				rki = _ReprogrammableKeyInfo(index, key, KEY_NAME[key], key_task, KEY_NAME[key_task], flags)
diff --git a/lib/logitech/unifying_receiver/base.py b/lib/logitech/unifying_receiver/base.py
index e15ba486..9974d0bf 100644
--- a/lib/logitech/unifying_receiver/base.py
+++ b/lib/logitech/unifying_receiver/base.py
@@ -3,7 +3,6 @@
 # Unlikely to be used directly unless you're expanding the API.
 #
 
-from logging import getLogger as _Logger
 from struct import pack as _pack
 from binascii import hexlify as _hexlify
 _hex = lambda d: _hexlify(d).decode('ascii').upper()
@@ -12,12 +11,13 @@ from .constants import ERROR_NAME
 from .exceptions import (NoReceiver as _NoReceiver,
 						FeatureCallError as _FeatureCallError)
 
+from logging import getLogger
+_log = getLogger('LUR').getChild('base')
+del getLogger
+
 import hidapi as _hid
 
 
-_LOG_LEVEL = 4
-_l = _Logger('lur.base')
-
 #
 # These values are defined by the Logitech documentation.
 # Overstepping these boundaries will only produce log warnings.
@@ -48,7 +48,7 @@ DEFAULT_TIMEOUT = 1000
 
 def _logdebug_hook(reply_code, devnumber, data):
 	"""Default unhandled hook, logs the reply as DEBUG."""
-	_l.warn("UNHANDLED [%02X %02X %s %s] (%s)", reply_code, devnumber, _hex(data[:2]), _hex(data[2:]), repr(data))
+	_log.warn("UNHANDLED [%02X %02X %s %s] (%s)", reply_code, devnumber, _hex(data[:2]), _hex(data[2:]), repr(data))
 
 
 """The function that will be called on unhandled incoming events.
@@ -78,7 +78,7 @@ def list_receiver_devices():
 	return _hid.enumerate(0x046d, 0xc52b, 2)
 
 
-_PING_RECEIVER = b'\x10\xFF\x81\x00\x00\x00\x00'
+_COUNT_DEVICES_REQUEST = b'\x10\xFF\x81\x00\x00\x00\x00'
 
 def try_open(path):
 	"""Checks if the given Linux device path points to the right UR device.
@@ -97,31 +97,28 @@ def try_open(path):
 	if receiver_handle is None:
 		# could be a file permissions issue (did you add the udev rules?)
 		# in any case, unreachable
-		_l.log(_LOG_LEVEL, "[%s] open failed", path)
+		_log.debug("[%s] open failed", path)
 		return None
 
-	_l.log(_LOG_LEVEL, "[%s] receiver handle %X", path, receiver_handle)
-	# ping on device id 0 (always an error)
-	_hid.write(receiver_handle, _PING_RECEIVER)
+	_hid.write(receiver_handle, _COUNT_DEVICES_REQUEST)
 
 	# if this is the right hidraw device, we'll receive a 'bad device' from the UR
 	# otherwise, the read should produce nothing
 	reply = _hid.read(receiver_handle, _MAX_REPLY_SIZE, DEFAULT_TIMEOUT)
 	if reply:
-		if reply[:5] == _PING_RECEIVER[:5]:
+		if reply[:5] == _COUNT_DEVICES_REQUEST[:5]:
 			# 'device 0 unreachable' is the expected reply from a valid receiver handle
-			_l.log(_LOG_LEVEL, "[%s] success: handle %X", path, receiver_handle)
+			_log.info("[%s] success: handle %X", path, receiver_handle)
 			return receiver_handle
 
 		# any other replies are ignored, and will assume this is the wrong Linux device
-		if _l.isEnabledFor(_LOG_LEVEL):
-			if reply == b'\x01\x00\x00\x00\x00\x00\x00\x00':
-				# no idea what this is, but it comes up occasionally
-				_l.log(_LOG_LEVEL, "[%s] %X mistery reply [%s]", path, receiver_handle, _hex(reply))
-			else:
-				_l.log(_LOG_LEVEL, "[%s] %X unknown reply [%s]", path, receiver_handle, _hex(reply))
+		if reply == b'\x01\x00\x00\x00\x00\x00\x00\x00':
+			# no idea what this is, but it comes up occasionally
+			_log.debug("[%s] %X mistery reply [%s]", path, receiver_handle, _hex(reply))
+		else:
+			_log.debug("[%s] %X unknown reply [%s]", path, receiver_handle, _hex(reply))
 	else:
-		_l.log(_LOG_LEVEL, "[%s] %X no reply", path, receiver_handle)
+		_log.debug("[%s] %X no reply", path, receiver_handle)
 
 	close(receiver_handle)
 
@@ -132,7 +129,7 @@ def open():
 	:returns: An open file handle for the found receiver, or ``None``.
 	"""
 	for rawdevice in list_receiver_devices():
-		_l.log(_LOG_LEVEL, "checking %s", rawdevice)
+		_log.info("checking %s", rawdevice)
 
 		receiver = try_open(rawdevice.path)
 		if receiver:
@@ -146,10 +143,10 @@ def close(handle):
 	if handle:
 		try:
 			_hid.close(handle)
-			_l.log(_LOG_LEVEL, "closed receiver handle %X", handle)
+			_log.info("closed receiver handle %X", handle)
 			return True
 		except:
-			_l.exception("closing receiver handle %X", handle)
+			_log.exception("closing receiver handle %X", handle)
 
 	return False
 
@@ -168,15 +165,13 @@ def write(handle, devnumber, data):
 	been physically removed from the machine, or the kernel driver has been
 	unloaded. The handle will be closed automatically.
 	"""
-	if _l.isEnabledFor(_LOG_LEVEL):
-		_l.log(_LOG_LEVEL, "(%d) <= w[10 %02X %s %s]", devnumber, devnumber, _hex(data[:2]), _hex(data[2:]))
-
 	assert _MIN_CALL_SIZE == 7
 	assert _MAX_CALL_SIZE == 20
 	# the data is padded to either 5 or 18 bytes
 	wdata = _pack('!BB18s' if len(data) > 5 else '!BB5s', 0x10, devnumber, data)
+	_log.debug("(%d) <= w[10 %02X %s %s]", devnumber, devnumber, _hex(wdata[2:4]), _hex(wdata[4:]))
 	if not _hid.write(handle, wdata):
-		_l.warn("(%d) write failed, assuming receiver %X no longer available", devnumber, handle)
+		_log.warn("(%d) write failed, assuming receiver %X no longer available", devnumber, handle)
 		close(handle)
 		raise _NoReceiver
 
@@ -197,26 +192,33 @@ def read(handle, timeout=DEFAULT_TIMEOUT):
 	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)
+	data = _hid.read(handle, _MAX_REPLY_SIZE, timeout)
 	if data is None:
-		_l.warn("(-) read failed, assuming receiver %X no longer available", handle)
+		_log.warn("(-) read failed, assuming receiver %X no longer available", handle)
 		close(handle)
 		raise _NoReceiver
 
 	if data:
 		if len(data) < _MIN_REPLY_SIZE:
-			_l.warn("(%d) => r[%s] read packet too short: %d bytes", ord(data[1:2]), _hex(data), len(data))
+			_log.warn("(%d) => r[%s] read packet too short: %d bytes", ord(data[1:2]), _hex(data), len(data))
+			data += b'\x00' * (_MIN_REPLY_SIZE - len(data))
 		if len(data) > _MAX_REPLY_SIZE:
-			_l.warn("(%d) => r[%s] read packet too long: %d bytes", ord(data[1:2]), _hex(data), len(data))
+			_log.warn("(%d) => r[%s] read packet too long: %d bytes", ord(data[1:2]), _hex(data), len(data))
 		code = ord(data[:1])
 		devnumber = ord(data[1:2])
-		if _l.isEnabledFor(_LOG_LEVEL):
-			_l.log(_LOG_LEVEL, "(%d) => r[%02X %02X %s %s]", devnumber, code, devnumber, _hex(data[2:4]), _hex(data[4:]))
+		_log.debug("(%d) => r[%02X %02X %s %s]", devnumber, code, devnumber, _hex(data[2:4]), _hex(data[4:]))
 		return code, devnumber, data[2:]
 
-	# _l.log(_LOG_LEVEL, "(-) => r[]", handle)
+	# _l.log(_LOG_LEVEL, "(-) => r[]")
 
 
+_MAX_READ_TIMES = 3
+request_context = None
+from collections import namedtuple
+_DEFAULT_REQUEST_CONTEXT_CLASS = namedtuple('_DEFAULT_REQUEST_CONTEXT_CLASS', ['write', 'read', 'unhandled_hook'])
+_DEFAULT_REQUEST_CONTEXT = _DEFAULT_REQUEST_CONTEXT_CLASS(write=write, read=read, unhandled_hook=unhandled_hook)
+del namedtuple
+
 def request(handle, devnumber, feature_index_function, params=b'', features=None):
 	"""Makes a feature call to a device and waits for a matching reply.
 
@@ -234,18 +236,27 @@ def request(handle, devnumber, feature_index_function, params=b'', features=None
 	available.
 	:raisees FeatureCallError: if the feature call replied with an error.
 	"""
-	if _l.isEnabledFor(_LOG_LEVEL):
-		_l.log(_LOG_LEVEL, "(%d) request {%s} params [%s]", devnumber, _hex(feature_index_function), _hex(params))
+	if type(params) == int:
+		params = _pack('!B', params)
+
+	_log.debug("(%d) request {%s} params [%s]", devnumber, _hex(feature_index_function), _hex(params))
 	if len(feature_index_function) != 2:
 		raise ValueError('invalid feature_index_function {%s}: it must be a two-byte string' % _hex(feature_index_function))
 
-	retries = 5
+	if request_context is None or handle != request_context.handle:
+		context = _DEFAULT_REQUEST_CONTEXT
+		_unhandled = unhandled_hook
+	else:
+		context = request_context
+		_unhandled = getattr(context, 'unhandled_hook')
 
-	write(handle, devnumber, feature_index_function + params)
-	while retries > 0:
-		divisor = (6 - retries)
-		reply = read(handle, int(DEFAULT_TIMEOUT * (divisor + 1) / 2 / divisor))
-		retries -= 1
+	context.write(handle, devnumber, feature_index_function + params)
+
+	read_times = _MAX_READ_TIMES
+	while read_times > 0:
+		divisor = (1 + _MAX_READ_TIMES - read_times)
+		reply = context.read(handle, int(DEFAULT_TIMEOUT * (divisor + 1) / 2 / divisor))
+		read_times -= 1
 
 		if not reply:
 			# keep waiting...
@@ -258,24 +269,24 @@ def request(handle, devnumber, feature_index_function, params=b'', features=None
 			# _l.log(_LOG_LEVEL, "(%d) request got reply for unexpected device %d: [%s]", devnumber, reply_devnumber, _hex(reply_data))
 			# worst case scenario, this is a reply for a concurrent request
 			# on this receiver
-			if unhandled_hook:
-				unhandled_hook(reply_code, reply_devnumber, reply_data)
+			if _unhandled:
+				_unhandled(reply_code, reply_devnumber, reply_data)
 			continue
 
 		if reply_code == 0x10 and reply_data[:1] == b'\x8F' and reply_data[1:3] == feature_index_function:
 			# device not present
-			_l.log(_LOG_LEVEL, "(%d) request ping failed on {%s} call: [%s]", devnumber, _hex(feature_index_function), _hex(reply_data))
+			_log.debug("(%d) request ping failed on {%s} call: [%s]", devnumber, _hex(feature_index_function), _hex(reply_data))
 			return None
 
 		if reply_code == 0x10 and reply_data[:1] == b'\x8F':
 			# device not present
-			_l.log(_LOG_LEVEL, "(%d) request ping failed: [%s]", devnumber, _hex(reply_data))
+			_log.debug("(%d) request ping failed: [%s]", devnumber, _hex(reply_data))
 			return None
 
 		if reply_code == 0x11 and reply_data[0] == b'\xFF' and reply_data[1:3] == feature_index_function:
 			# the feature call returned with an error
 			error_code = ord(reply_data[3])
-			_l.warn("(%d) request feature call error %d = %s: %s", devnumber, error_code, ERROR_NAME[error_code], _hex(reply_data))
+			_log.warn("(%d) request feature call error %d = %s: %s", devnumber, error_code, ERROR_NAME[error_code], _hex(reply_data))
 			feature_index = ord(feature_index_function[:1])
 			feature_function = feature_index_function[1:2]
 			feature = None if features is None else features[feature_index] if feature_index < len(features) else None
@@ -283,14 +294,14 @@ def request(handle, devnumber, feature_index_function, params=b'', features=None
 
 		if reply_code == 0x11 and reply_data[:2] == feature_index_function:
 			# a matching reply
-			# _l.log(_LOG_LEVEL, "(%d) matched reply with feature-index-function [%s]", devnumber, _hex(reply_data[2:]))
+			# _log.debug("(%d) matched reply with feature-index-function [%s]", devnumber, _hex(reply_data[2:]))
 			return reply_data[2:]
 
 		if reply_code == 0x10 and devnumber == 0xFF and reply_data[:2] == feature_index_function:
 			# direct calls to the receiver (device 0xFF) may also return successfully with reply code 0x10
-			# _l.log(_LOG_LEVEL, "(%d) matched reply with feature-index-function [%s]", devnumber, _hex(reply_data[2:]))
+			# _log.debug("(%d) matched reply with feature-index-function [%s]", devnumber, _hex(reply_data[2:]))
 			return reply_data[2:]
 
-		# _l.log(_LOG_LEVEL, "(%d) unmatched reply {%s} (expected {%s})", devnumber, _hex(reply_data[:2]), _hex(feature_index_function))
-		if unhandled_hook:
-			unhandled_hook(reply_code, reply_devnumber, reply_data)
+		# _log.debug("(%d) unmatched reply {%s} (expected {%s})", devnumber, _hex(reply_data[:2]), _hex(feature_index_function))
+		if _unhandled:
+			_unhandled(reply_code, reply_devnumber, reply_data)
diff --git a/lib/logitech/unifying_receiver/listener.py b/lib/logitech/unifying_receiver/listener.py
index f9e7daa1..220a7fcb 100644
--- a/lib/logitech/unifying_receiver/listener.py
+++ b/lib/logitech/unifying_receiver/listener.py
@@ -2,8 +2,7 @@
 #
 #
 
-from logging import getLogger as _Logger
-from threading import (Thread, Event, Lock)
+from threading import Thread as _Thread
 # from time import sleep as _sleep
 
 from . import base as _base
@@ -12,108 +11,107 @@ from .common import Packet as _Packet
 
 # for both Python 2 and 3
 try:
-	from Queue import Queue
+	from Queue import Queue as _Queue
 except ImportError:
-	from queue import Queue
+	from queue import Queue as _Queue
 
 
-_LOG_LEVEL = 6
-_l = _Logger('lur.listener')
+from logging import getLogger
+_log = getLogger('LUR').getChild('listener')
+del getLogger
 
 
-_READ_EVENT_TIMEOUT = int(_base.DEFAULT_TIMEOUT / 4)  # ms
-
+_READ_EVENT_TIMEOUT = int(_base.DEFAULT_TIMEOUT)  # ms
 
 def _event_dispatch(listener, callback):
-	# _l.log(_LOG_LEVEL, "starting dispatch")
 	while listener._active:  # or not listener._events.empty():
-		event = listener._events.get()
-		# _l.log(_LOG_LEVEL, "delivering event %s", event)
+		try:
+			event = listener._events.get(True, _READ_EVENT_TIMEOUT * 10)
+		except:
+			continue
+		_log.debug("delivering event %s", event)
 		try:
 			callback(event)
 		except:
-			_l.exception("callback for %s", event)
-	# _l.log(_LOG_LEVEL, "stopped dispatch")
+			_log.exception("callback for %s", event)
 
 
-class EventsListener(Thread):
+class EventsListener(_Thread):
 	"""Listener thread for events from the Unifying Receiver.
 
 	Incoming packets will be passed to the callback function in sequence, by a
 	separate thread.
-
-	While this listener is running, you must use the call_api() method to make
-	regular UR API calls; otherwise the expected API replies are most likely to
-	be captured by the listener and delivered to the callback.
 	"""
 	def __init__(self, receiver_handle, events_callback):
-		super(EventsListener, self).__init__(group='Unifying Receiver', name='%s-%X' % (self.__class__.__name__, receiver_handle))
+		super(EventsListener, self).__init__(group='Unifying Receiver', name=self.__class__.__name__)
 
 		self.daemon = True
 		self._active = False
 
 		self._handle = receiver_handle
 
-		self._task = None
-		self._task_processing = Lock()
-		self._task_reply = None
-		self._task_done = Event()
+		self._tasks = _Queue(1)
+		self._backup_unhandled_hook = _base.unhandled_hook
+		_base.unhandled_hook = self.unhandled_hook
 
-		self._events = Queue(32)
-		_base.unhandled_hook = self._unhandled
-
-		self._dispatcher = Thread(group='Unifying Receiver',
-									name='%s-%X-dispatch' % (self.__class__.__name__, receiver_handle),
+		self._events = _Queue(32)
+		self._dispatcher = _Thread(group='Unifying Receiver',
+									name=self.__class__.__name__ + '-dispatch',
 									target=_event_dispatch, args=(self, events_callback))
 		self._dispatcher.daemon = True
 
 	def run(self):
 		self._active = True
-		_l.log(_LOG_LEVEL, "started")
+		_log.debug("started")
+		_base.request_context = self
+		_base.unhandled_hook = self._backup_unhandled_hook
+		del self._backup_unhandled_hook
 
 		self._dispatcher.start()
 
 		while self._active:
 			event = None
 			try:
+				# _log.debug("read next event")
 				event = _base.read(self._handle, _READ_EVENT_TIMEOUT)
 			except _NoReceiver:
 				self._handle = 0
-				_l.warn("receiver disconnected")
+				_log.warn("receiver disconnected")
 				self._events.put(_Packet(0xFF, 0xFF, None))
 				self._active = False
 				break
 
-			if event:
-				event = _Packet(*event)
-				_l.log(_LOG_LEVEL, "queueing event %s", event)
-				self._events.put(event)
+			if event is not None:
+				matched = False
+				task = None if self._tasks.empty() else self._tasks.queue[0]
+				if task and task[0] and task[-1] is None:
+					devnumber, data = task[1:3]
+					if event[1] == devnumber:
+						# _log.debug("matching %s to %d, %s", event, devnumber, repr(data))
+						if event[0] == 0x11 or (event[0] == 0x10 and devnumber == 0xFF):
+							matched = (event[2][:2] == data[:2]) or (event[2][:1] == b'\xFF' and event[2][1:3] == data[:2])
+						elif event[0] == 0x10:
+							if event[2][:1] == b'\x8F' and event[2][1:3] == data[:2]:
+								matched = True
 
-			if self._task:
-				(api_function, args, kwargs), self._task = self._task, None
-				# _l.log(_LOG_LEVEL, "calling '%s.%s' with %s, %s", api_function.__module__, api_function.__name__, args, kwargs)
-				try:
-					self._task_reply = api_function.__call__(self._handle, *args, **kwargs)
-				except _NoReceiver as nr:
-					self._handle = 0
-					_l.warn("receiver disconnected")
-					self._events.put(_Packet(0xFF, 0xFF, None))
-					self._task_reply = nr
-					self._active = False
-					break
-				except Exception as e:
-					# _l.exception("task %s.%s", api_function.__module__, api_function.__name__)
-					self._task_reply = e
-				finally:
-					self._task_done.set()
+				if matched:
+					# _log.debug("request reply %s", event)
+					task[-1] = event
+					self._tasks.task_done()
+				else:
+					event = _Packet(*event)
+					_log.info("queueing event %s", event)
+					self._events.put(event)
 
+		_base.request_context = None
 		_base.close(self._handle)
+		_log.debug("stopped")
 		self._handle = 0
 
 	def stop(self):
 		"""Tells the listener to stop as soon as possible."""
 		if self._active:
-			_l.log(_LOG_LEVEL, "stopping")
+			_log.debug("stopping")
 			self._active = False
 			# wait for the receiver handle to be closed
 			self.join()
@@ -122,34 +120,27 @@ class EventsListener(Thread):
 	def handle(self):
 		return self._handle
 
-	def request(self, device, feature_function_index, params=b''):
-		return self.call_api(_base.request, device, feature_function_index, params)
+	def write(self, handle, devnumber, data):
+		assert handle == self._handle
+		# _log.debug("write %02X %s", devnumber, _base._hex(data))
+		task = [False, devnumber, data, None]
+		self._tasks.put(task)
+		_base.write(self._handle, devnumber, data)
+		task[0] = True
+		_log.debug("task queued %s", task)
 
-	def call_api(self, api_function, *args, **kwargs):
-		"""Make an UR API request through this listener's receiver.
+	def read(self, handle, timeout=_base.DEFAULT_TIMEOUT):
+		assert handle == self._handle
+		# _log.debug("read %d", timeout)
+		assert not self._tasks.empty()
+		self._tasks.join()
+		task = self._tasks.get(False)
+		_log.debug("task ready %s", task)
+		return task[-1]
 
-		The api_function must have a receiver handle as a first agument, all
-		other passed args and kwargs will follow.
-		"""
-		# _l.log(_LOG_LEVEL, "%s request '%s.%s' with %s, %s", self, api_function.__module__, api_function.__name__, args, kwargs)
-
-		# if not self._active:
-		# 	return None
-
-		with self._task_processing:
-			self._task_done.clear()
-			self._task = (api_function, args, kwargs)
-			self._task_done.wait()
-			reply, self._task_reply = self._task_reply, None
-
-		# _l.log(_LOG_LEVEL, "%s request '%s.%s' => %s", self, api_function.__module__, api_function.__name__, repr(reply))
-		if isinstance(reply, Exception):
-			raise reply
-		return reply
-
-	def _unhandled(self, reply_code, devnumber, data):
+	def unhandled_hook(self, reply_code, devnumber, data):
 		event = _Packet(reply_code, devnumber, data)
-		# _l.log(_LOG_LEVEL, "queueing unhandled event %s", event)
+		_log.info("queueing unhandled event %s", event)
 		self._events.put(event)
 
 	def __nonzero__(self):