Locking approach suggestions for multiple cli instances

[datadavev]

1. The locking approach used in hashstore appears to support in process threading but not multi-process or multi-application locking. The portalocker library provides a cross platform solution for locking that works with multiple application instances and (when using redis), multi-system locking.

2. The approach of having a single lock per instance and a class variable of locked PIDs seems ok for a single instance, but would likely be problematic with multiple processes or instances. Perhaps using portalocker the PID could be used to derive the filename of the desired lock?

[doulikecookiedough]

Thank you for your suggestion, reviewing hashstore and providing feedback @datadavev! I really appreciate it and will investigate the portalocker library (and implement the suggestions in your other enhancement tickets).