from __future__ import (

unicode_literals,

print_function,

absolute_import,

division,

)

str = type('')

from threading import Thread, Event

_THREADS = set()

def _threads_shutdown():

while _THREADS:

for t in _THREADS.copy():

t.stop()

class GPIOThread(Thread):

def __init__(self, group=None, target=None, name=None, args=(), kwargs=None):

if kwargs is None:

kwargs = {}

self.stopping = Event()

super(GPIOThread, self).__init__(group, target, name, args, kwargs)

self.daemon = True

def start(self):

self.stopping.clear()

_THREADS.add(self)

super(GPIOThread, self).start()

def stop(self):

self.stopping.set()

self.join()

def join(self):

super(GPIOThread, self).join()

_THREADS.discard(self)