f-fix-deadlock -> dev

Summary

fix #122 (closed)

Focus

Problem was a non-atomic operation (integer decrement). Concurrent reading thread would fail to decrement the acquired counter. See code annotations.

Test Environment

Please use b2faf630 to see failing tests. Please use 9b85d817 for fixed DatabaseAccessManager

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• All automated tests pass
• Reference related Issues
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  • Problems with old code
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• I understand the intent of this MR
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• Up-to-date CHANGELOG.md
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