Fix deadlocks related to ClassDB queries about global classes #98963
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RandomShaper
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Is it truly truly necessary to expose AnimationNodeEndState and AnimationNodeStartState? |
`ClassDB::can_instantiate()` and other reflection methods deadlock if the type is an script global class, when such script indirectly uses a not-yet-registered class. The reason is the `ClassDB` read lock is still held when invoking the `ResourceLoader` to load the class script, which may in turn need to lock for writing (for the class registration). In particular, this happens with some types related to animation tree, that aren't registered at engine startup, but can happen with others, especially ones from the user. Registration statements are also added for the animation-related types that were lacking them.
RandomShaper
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If they aren't meant to be exposed, we can use register them as internal. Elaborating, the deadlock, when related to these classes, can be avoided either by the changes to Pushing with the change. |
clayjohn
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Nov 9, 2024
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Thanks! |
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ClassDB::can_instantiate()and other reflection methods deadlock if the type is an script global class, when such script indirectly uses a not-yet-registered class. The reason is theClassDBread lock is still held when invoking theResourceLoaderto load the class script, which may in turn need to lock for writing (for the class registration).In particular, this happens with some types related to animation tree, that aren't registered at engine startup, but can happen with others, especially ones from the user. Registration statements are also added for the animation-related types that were lacking them.
(Better reviewed disabling whitespace diff.)
Version for 4.3 submitted as #98964.