Thread safe

[kdschlosser]

I am wanting to make some changes to this library that will make it thread safe. While I know I am able to do this for my own use I wanted to know if I made a PR for the changes would there be an interest in adding them to this library?

This would be my game plan.
I am going to create an instance singleton meta class to handle the creation of a Blink1 instance. This will make it so that only a single instance for a blink1 device can exist at any given point. This will allow us to handle multiple threads accessing the device at the same time by using a thread lock in each instance.

Right now If I used this code there would be a problem.

import threading

from blink1.blink1 import Blink1

b1 = Blink1(serial_number='1234567890')
b2 = Blink1(serial_number='1234567890')

def _do():
    b1.fade_to_rgb_uncorrected(5000, 75, 50, 36)

threading.Thread(target=_do).start()

b2.fade_to_rgb_uncorrected(3000, 68, 32, 158)

the way the current library is coded an exception would occur if a Blink1 instance gets created more then one time for a device with the same serial number. what should happen is if an instance for a device already exists then that instance should be returned. designing it this way has a series of benefits. A user would not have to keep reference to an instance at all. successive calls to Blink1.__init__ would return an instance of Blink1 if it already exists. we can also get creative with the Blink1 class by coding it so that it is a device and also an enumeration of all devices at the same time.

I will hammer together something and show you the code to see if it is something you like.

[todbot]

This sounds like a good idea. I've used similar singleton concepts in other blink(1) libraries. I admit to not being very Python-literate so if you can provide guidance here, I would much appreciate it.