Description

Improve thread-safety in the Store by making the LRUCache thread safe and adding locks around connector and state changing operations in the Store.

I don't anticipate this having a measurable performance impact because most applications don't perform Store operations across many threads. The exception is that some applications may resolve a proxy across many threads. In that case, the changes will prevent full on crashes when the same proxy is resolved in multiple threads, but may reduce performance when different proxies/targets are resolved in different threads. However, this does not matter if the connector is also implemented with locks to prevent concurrent operations.

Fixes

• Fixes KeyError in cache eviction of Store #604

Type of Change

• Breaking Change (fix or enhancement which changes existing semantics of the public interface)
• Enhancement (new features or improvements to existing functionality)
• Bug (fixes for a bug or issue)
• Internal (refactoring, style changes, testing, optimizations)
• Documentation update (changes to documentation or examples)
• Package (dependencies, versions, package metadata)
• Development (CI workflows, pre-commit, linters, templates)
• Security (security related changes)

Testing

All test cases still pass.

I ran the TaPS example reported in #604 and this reliably fixes the issue.

Pull Request Checklist

• I have read the Contributing and PR submission guides.

Please confirm the PR meets the following requirements.

• Tags added to PR (e.g., breaking, bug, enhancement, internal, documentation, package, development, security).
• Code changes pass pre-commit (e.g., mypy, ruff, etc.).
• Tests have been added to show the fix is effective or that the new feature works.
• New and existing unit tests pass locally with the changes.
• Docs have been updated and reviewed if relevant.