def test_event_mask_defaults_to_input_and_error():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1)
ev1.signal()
selector.wait(timeout=0)
assert selector.ready == ev1
assert selector.has_input == True
def test_can_use_a_different_value_to_identify_the_event_source():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1, INPUT, identifier=999)
ev1.signal()
selector.wait()
assert selector.ready == 999
def test_event_mask_defaults_to_input_and_error():
with Selector() as selector:
ev1 = Semaphore(blocking=False)
selector.add(ev1)
ev1.signal()
selector.wait(timeout=0)
assert selector.ready == ev1
assert selector.has_input == True
def test_can_use_a_different_value_to_identify_the_event_source():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1, INPUT, identifier=999)
ev1.signal()
selector.wait()
assert selector.ready == 999
def test_can_remove_source_from_selector():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1, INPUT)
ev1.signal()
selector.wait(timeout=0)
assert selector.ready == ev1
selector.remove(ev1)
selector.wait(timeout=0)
assert selector.ready == None
def test_selector_is_a_convenient_api_to_epoll():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1, INPUT)
ev1.signal()
selector.wait()
assert selector.ready == ev1
assert selector.has_input == True
assert selector.has_output == False
assert selector.has_error == False
assert selector.has_hangup == False
assert selector.has_priority_input == False
def test_can_remove_source_from_selector():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1, INPUT)
ev1.signal()
selector.wait(timeout=0)
assert selector.ready == ev1
selector.remove(ev1)
selector.wait(timeout=0)
assert selector.ready == None
def test_selector_is_a_convenient_api_to_epoll():
selector = Selector()
ev1 = Semaphore(blocking=False)
with selector, ev1:
selector.add(ev1, INPUT)
ev1.signal()
selector.wait()
assert selector.ready == ev1
assert selector.has_input == True
assert selector.has_output == False
assert selector.has_error == False
assert selector.has_hangup == False
assert selector.has_priority_input == False
def test_can_wait_with_a_timeout():
with Semaphore(blocking=False) as ev1, \
Selector() as selector:
selector.add(ev1, INPUT, identifier=999)
selector.wait(timeout=0)
assert selector.ready == None
def test_selecting_from_multiple_event_sources():
with Semaphore(blocking=False) as ev1, \
Semaphore(blocking=False) as ev2, \
Selector() as selector:
selector.add(ev1, INPUT)
selector.add(ev2, INPUT)
ev1.signal()
ev2.signal()
selector.wait()
first = selector.ready
first.wait()
selector.wait()
second = selector.ready
second.wait()
assert first in (ev1, ev2)
assert second in (ev1, ev2)
assert first is not second
def test_selecting_from_multiple_event_sources():
selector = Selector()
ev1 = Semaphore(blocking=False)
ev2 = Semaphore(blocking=False)
with selector, ev1, ev2:
selector.add(ev1, INPUT)
selector.add(ev2, INPUT)
ev1.signal()
ev2.signal()
selector.wait()
first = selector.ready
first.wait()
selector.wait()
second = selector.ready
second.wait()
assert first in (ev1, ev2)
assert second in (ev1, ev2)
assert first is not second
class TemperatureLogger():
"""Starts recording temperatures from two TMP100 chips attached to the I2C bus.
Resolution determined by BITS.
Sensors read every LOG_INTERVAL, recording to TEMPERATURE_CSV_FILE.
"""
semaphore = Semaphore(blocking=False)
log_timer = Timer(offset=1, interval=LOG_INTERVAL)
def __init__(self):
self._terminated = False
self.timestamp = None
self.temperatures = [None, None]
self.log_handler = RotatingFileHandler(TEMPERATURE_CSV_FILE, backupCount=10)
self.log_handler.setFormatter(TempFormatter())
def run(self):
logging.info("Temperature logging starting...")
with i2c.I2CMaster() as bus,\
Selector() as selector,\
self.semaphore,\
self.log_timer,\
Timer(offset=0.1, interval=LCD_INTERVAL) as lcd_timer,\
Adafruit_LCDPlate.get_interrupt_pin() as int_pin:
# tolerate missing LCD
lcd = None
try:
lcd = Adafruit_LCDPlate.Adafruit_LCDPlate(bus)
fmt = FMT_ALL
logging.info("LCD is attached")
except IOError:
logging.info("LCD is not attached")
# resolution (9-12 bit) gets stored as (0-3) in bits 5,6 of config reg
config = (BITS - 9) << 5
bus.transaction(
i2c.writing_bytes(TMP100A_ADDRESS, CONFIG_REGISTER, config),
i2c.writing_bytes(TMP100B_ADDRESS, CONFIG_REGISTER, config))
for addr in (TMP100A_ADDRESS, TMP100B_ADDRESS):
read_results = bus.transaction(
i2c.writing_bytes(addr, CONFIG_REGISTER),
i2c.reading(addr, 1))
# should be 0x80 at startup/reset
logging.info("conf register for 0x{0:02x}: 0x{1:02x}".format(addr, read_results[0][0]))
right_shift = 16 - BITS
div = 1 << (BITS - 8)
selector.add(self.semaphore)
selector.add(self.log_timer)
self.log_timer.start()
if lcd:
selector.add(lcd_timer)
selector.add(int_pin)
lcd_timer.start()
while not self._terminated:
try:
if lcd:
lcd.set_led(Adafruit_LCDPlate.GREEN_PIN, False)
selector.wait()
if self._terminated:
break
if not selector.ready is int_pin:
selector.ready.wait() # consume event
for i, addr in enumerate((TMP100A_ADDRESS, TMP100B_ADDRESS)):
read_results = bus.transaction(
i2c.writing_bytes(addr, TEMP_REGISTER),
i2c.reading(addr, 2))
t = read_results[0]
self.temperatures[i] = (t[0] if t[0] <= 127 else t[0] - 256) + (t[1] >> right_shift) / div
self.timestamp = time()
if lcd:
lcd.set_led(Adafruit_LCDPlate.GREEN_PIN, True)
lcd.set_led(Adafruit_LCDPlate.RED_PIN, False)
if selector.ready is self.log_timer:
self.log_handler.emit(TempLogRecord(self.timestamp, self.temperatures))
elif selector.ready is lcd_timer:
lcd.clear()
lcd.message(fmt.format(
self.temperatures[0], c2f(self.temperatures[0]),
self.temperatures[1], c2f(self.temperatures[1])))
elif selector.ready is int_pin:
# this is hacky...
intcap = lcd.chip.registers.read_register(INTCAPA) # required?
button_state = lcd.get_button_state()
if button_state == 0:
pass # button up event: ignore
else:
if lcd.button_state_pressed(button_state, Adafruit_LCDPlate.SELECT):
fmt = FMT_ALL
elif lcd.button_state_pressed(button_state, Adafruit_LCDPlate.UP):
fmt = FMT_INSIDE
elif lcd.button_state_pressed(button_state, Adafruit_LCDPlate.DOWN):
fmt = FMT_OUTSIDE
elif lcd.button_state_pressed(button_state, Adafruit_LCDPlate.LEFT):
fmt = FMT_C
elif lcd.button_state_pressed(button_state, Adafruit_LCDPlate.RIGHT):
fmt = FMT_F
else:
fmt = "Unknown\nButton!"
lcd_timer.stop()
lcd_timer.start()
except KeyboardInterrupt:
logging.info("Keyboard interrupt received")
self._terminated = True
except SystemExit:
logging.info("SystemExit received")
self._terminated = True
except:
logging.exception("Error reading sensors:")
if lcd:
lcd.set_led(Adafruit_LCDPlate.RED_PIN, True)
if lcd:
lcd.clear()
lcd.set_backlight(False)
lcd.set_led(Adafruit_LCDPlate.GREEN_PIN, False)
lcd.set_led(Adafruit_LCDPlate.RED_PIN, False)
logging.info("Temperature logging stopped.")
self.log_handler.close()
def terminate(self):
self._terminated = True
self.semaphore.signal()
def rotate_log(self):
self.log_timer.stop()
self.log_handler.doRollover()
self.log_timer.start()
