def __init__(self, input, event, debounce = 0, timeout = None,
target = None, vargs = (), kwargs = {}):
super().__init__()
self.input = input
self.event = event
self.target = target
self.vargs = vargs
self.kwargs = kwargs
self.timeout = timeout
self.debounce = 0
self.pipe = rcpy.create_pipe()
def read(self, timeout=None, pipe=None):
# create pipe if necessary
destroy_pipe = False
if pipe is None:
pipe = rcpy.create_pipe()
destroy_pipe = True
# request both edges and get file descriptor
self.release()
self.request(type=gpiod.LINE_REQ_EV_BOTH_EDGES)
fdescriptor = self.line.event_get_fd()
try:
with os.fdopen(fdescriptor, 'rb', buffering=0) as f:
# create poller
poller = select.poll()
poller.register(
f, select.POLLPRI | select.POLLIN | select.POLLHUP
| select.POLLERR)
# listen to state change as well
state_r_fd, state_w_fd = pipe
poller.register(
state_r_fd,
select.POLLIN | select.POLLHUP | select.POLLERR)
while rcpy.get_state() != rcpy.EXITING:
# wait for events
if timeout:
# can fail if timeout is given
events = poller.poll(timeout)
if len(events) == 0:
raise InputTimeout(
'Input did not change in more than {} ms'.
format(timeout))
else:
# timeout = None, never fails
events = poller.poll()
# check flags
for fd, flag in events:
# state change
if fd is state_r_fd:
# get state
state = int(os.read(state_r_fd, 1))
if state == rcpy.EXITING:
# exit!
return
# input event
if fd == f.fileno():
# read event
event = self.line.event_read()
# Handle inputs
if flag & (select.POLLIN | select.POLLPRI):
# release line
self.release()
self.request(type=gpiod.LINE_REQ_DIR_IN)
# return read value
return self.get()
elif flag & (select.POLLHUP | select.POLLERR):
# raise exception
raise Exception(
'Could not read input {}'.format(self))
finally:
# release line
self.release()
self.request(type=gpiod.LINE_REQ_DIR_IN)
# destroy pipe
if destroy_pipe:
rcpy.destroy_pipe(pipe)
def read(pin, timeout = None, pipe = None):
# create pipe if necessary
destroy_pipe = False
if pipe is None:
pipe = rcpy.create_pipe()
destroy_pipe = True
# open stream
filename = SYSFS_GPIO_DIR + '/gpio{}/value'.format(pin)
with open(filename, 'rb', buffering = 0) as f:
# create poller
poller = select.poll()
f.read()
poller.register(f,
select.POLLPRI | select.POLLHUP | select.POLLERR)
# listen to state change as well
state_r_fd, state_w_fd = pipe
poller.register(state_r_fd,
select.POLLIN | select.POLLHUP | select.POLLERR)
while rcpy.get_state() != rcpy.EXITING:
# wait for events
if timeout:
# can fail if timeout is given
events = poller.poll(timeout)
if len(events) == 0:
# destroy pipe
if destroy_pipe:
rcpy.destroy_pipe(pipe)
# raise timeout exception
raise InputTimeout('Input did not change in more than {} ms'.format(timeout))
else:
# timeout = None, never fails
events = poller.poll()
for fd, flag in events:
# state change
if fd is state_r_fd:
# get state
state = int(os.read(state_r_fd, 1))
if state == rcpy.EXITING:
# exit!
if destroy_pipe:
rcpy.destroy_pipe(pipe)
return
# input event
if fd is f.fileno():
# Handle inputs
if flag & (select.POLLIN | select.POLLPRI):
# destroy pipe
if destroy_pipe:
rcpy.destroy_pipe(pipe)
# return read value
return get(pin)
elif flag & (select.POLLHUP | select.POLLERR):
# destroy pipe
if destroy_pipe:
rcpy.destroy_pipe(pipe)
# raise exception
raise Exception('Could not read pin {}'.format(pin))
# destroy pipe
if destroy_pipe:
rcpy.destroy_pipe(pipe)