refac: Improved support for pickle and deepcopy

statemachine/callbacks.py

@@ -331,9 +331,6 @@ def __init__(self) -> None:
         self._registry: Dict[str, CallbacksExecutor] = defaultdict(CallbacksExecutor)
         self.has_async_callbacks: bool = False
 
-    def clear(self):
-        self._registry.clear()
-
     def __getitem__(self, key: str) -> CallbacksExecutor:
         return self._registry[key]
 

statemachine/statemachine.py

@@ -1,7 +1,5 @@
 import warnings
-from copy import deepcopy
 from inspect import isawaitable
-from threading import Lock
 from typing import TYPE_CHECKING
 from typing import Any
 from typing import Dict
@@ -129,24 +127,6 @@ def __repr__(self):
             f"current_state={current_state_id!r})"
         )
 
-    def __deepcopy__(self, memo):
-        deepcopy_method = self.__deepcopy__
-        lock = self._engine._processing
-        with lock:
-            self.__deepcopy__ = None
-            self._engine._processing = None
-            try:
-                cp = deepcopy(self, memo)
-                cp._engine._processing = Lock()
-            finally:
-                self.__deepcopy__ = deepcopy_method
-                cp.__deepcopy__ = deepcopy_method
-                self._engine._processing = lock
-        cp._callbacks.clear()
-        cp._register_callbacks([])
-        cp.add_listener(*cp._listeners.keys())
-        return cp
-
     def __getstate__(self):
         state = self.__dict__.copy()
         state["_rtc"] = self._engine._rtc