Mitigation for nested lock (or deadlock)

[shsym]

For a complicated data structure where Roy data structures are defined within another Roy.remote data structure, developers accidentally try to lock the inner lock inside the critical section (=while the outer class is already holding the hierarchical locks).

• For this case, we can skip the locking/unlocking in __enter__ and __exit__, because a single instance of Roy data structure or class should be accessible by a single thread. In other words, each Ray worker has its own instance of the data structure.

Example:

- Class A
  - Class B

• When the outer class is locked, say with Class A:, the inner class (Class B) is also locked automatically.
• When a developer accidentally does with Class B: within with Class A:, if we can confidently detect this occurrence, we can skip locking/unlocking around with Class B: and going out of the context.