[issue30441] os.environ raises RuntimeError: dictionary changed size during iteration

[Mark Dickinson]

Mark Dickinson added the comment:

@osantana: you'd need to be using the lock at least in `__setitem__` and `__delitem__` as well, else there's nothing preventing modifications to the dictionary during the `list` call. It may make sense to protect *all* accesses (read or write) to `_data`, though you'd need to either use a re-entrant lock in that case or be very careful about not acquiring the lock twice.

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nosy: +mark.dickinson

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<http://bugs.python.org/issue30441>
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