[BugFix] Fix MultiAction reset

ghstack-source-id: a2f7bfdd7522a214430182dac65687a977b1a10d
Pull Request resolved: #2789

torchrl/data/map/query.py

@@ -86,26 +86,26 @@ class QueryModule(TensorDictModuleBase):
             providing the ``clone`` argument to the forward method.
             Defaults to ``False``.
 
-        Examples:
-            >>> query_module = QueryModule(
-            ...     in_keys=["key1", "key2"],
-            ...     index_key="index",
-            ...     hash_module=SipHash(),
-            ... )
-            >>> query = TensorDict(
-            ...     {
-            ...         "key1": torch.Tensor([[1], [1], [1], [2]]),
-            ...         "key2": torch.Tensor([[3], [3], [2], [3]]),
-            ...         "other": torch.randn(4),
-            ...     },
-            ...     batch_size=(4,),
-            ... )
-            >>> res = query_module(query)
-            >>> # The first two pairs of key1 and key2 match
-            >>> assert res["index"][0] == res["index"][1]
-            >>> # The last three pairs of key1 and key2 have at least one mismatching value
-            >>> assert res["index"][1] != res["index"][2]
-            >>> assert res["index"][2] != res["index"][3]
+    Examples:
+        >>> query_module = QueryModule(
+        ...     in_keys=["key1", "key2"],
+        ...     index_key="index",
+        ...     hash_module=SipHash(),
+        ... )
+        >>> query = TensorDict(
+        ...     {
+        ...         "key1": torch.Tensor([[1], [1], [1], [2]]),
+        ...         "key2": torch.Tensor([[3], [3], [2], [3]]),
+        ...         "other": torch.randn(4),
+        ...     },
+        ...     batch_size=(4,),
+        ... )
+        >>> res = query_module(query)
+        >>> # The first two pairs of key1 and key2 match
+        >>> assert res["index"][0] == res["index"][1]
+        >>> # The last three pairs of key1 and key2 have at least one mismatching value
+        >>> assert res["index"][1] != res["index"][2]
+        >>> assert res["index"][2] != res["index"][3]
 
     """
 

torchrl/envs/transforms/transforms.py

@@ -209,6 +209,7 @@ class Transform(nn.Module):
     """
 
     invertible = False
+    enable_inv_on_reset = False
 
     def __init__(
         self,
@@ -293,6 +294,13 @@ def _reset(
         """Resets a transform if it is stateful."""
         return tensordict_reset
 
+    def _reset_env_preprocess(self, tensordict: TensorDictBase) -> TensorDictBase:
+        """Inverts the input to :meth:`TransformedEnv._reset`, if needed."""
+        if self.enable_inv_on_reset:
+            with _set_missing_tolerance(self, True):
+                tensordict = self.inv(tensordict)
+        return tensordict
+
     def init(self, tensordict) -> None:
         pass
 
@@ -1018,10 +1026,7 @@ def _reset(self, tensordict: Optional[TensorDictBase] = None, **kwargs):
             tensordict = tensordict.select(
                 *self.reset_keys, *self.state_spec.keys(True, True), strict=False
             )
-            # Inputs might be transformed, so need to apply inverse transform
-            # before passing to the env reset function.
-            with _set_missing_tolerance(self.transform, True):
-                tensordict = self.transform.inv(tensordict)
+            tensordict = self.transform._reset_env_preprocess(tensordict)
         tensordict_reset = self.base_env._reset(tensordict, **kwargs)
         if tensordict is None:
             # make sure all transforms see a source tensordict
@@ -1369,6 +1374,11 @@ def _reset(
             tensordict_reset = t._reset(tensordict, tensordict_reset)
         return tensordict_reset
 
+    def _reset_env_preprocess(self, tensordict: TensorDictBase) -> TensorDictBase:
+        for t in reversed(self.transforms):
+            tensordict = t._reset_env_preprocess(tensordict)
+        return tensordict
+
     def init(self, tensordict: TensorDictBase) -> None:
         for t in self.transforms:
             t.init(tensordict)
@@ -4725,6 +4735,7 @@ class UnaryTransform(Transform):
         [torchrl][INFO] check_env_specs succeeded!
 
     """
+    enable_inv_on_reset = True
 
     def __init__(
         self,