Cleanup instances on shutdown

[jeffglover]

In the context of, https://github.com/NerdWalletOSS/kinesis-python, if multiple SubprocessLoop instances are created and and shutdown during a long running process eventually you'll hit OSError: [Errno 24] Too many open files. This ensures the instances are cleaned up while running.

[codecov-io]

Codecov Report

Merging #3 into master will increase coverage by 0.17%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master      #3      +/-   ##
=========================================
+ Coverage   92.13%   92.3%   +0.17%     
=========================================
  Files           2       2              
  Lines          89      91       +2     
=========================================
+ Hits           82      84       +2     
  Misses          7       7

Impacted Files	Coverage Δ
src/offspring/process.py	92.22% <100%> (+0.17%)	⬆️

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[borgstrom]

Can you please also add test that asserts the instances getting removed?

[borgstrom]

Sorry, I tried to add this comment to my last review but I guess I didn't save it correctly...

[borgstrom]

_INSTANCES is a class attribute, so this should be:

while self in self.__class__._INSTANCES:
    self.__class__._INSTANCES.remove(self)

[ngsharsha]

@borgstrom can this be merged ?

[borgstrom]

@ngsharsha - Not yet. My comment about _INSTANCES being a class attribute still needs to be addressed and this still needs tests.

We don't run into this situation in our use of kinesis-python so I haven't had a driving force to complete this. If you want to add tests and address my comment in a new PR I would be happy to review/merge.

[jeffglover]

This totally fell off my radar a long time ago. Since AWS kinesis can now trigger lambdas, I don't really have a need for it. I'll try to get to it this week so at least the fix gets in. I'm not opposed to someone taking it over though.