[RLlib] Add necessary fields to Base Envs, and BaseEnv wrapper classes (#20832)

rllib/BUILD

@@ -290,7 +290,7 @@ py_test(
     name = "learning_cartpole_simpleq_fake_gpus",
     main = "tests/run_regression_tests.py",
     tags = ["team:ml", "learning_tests", "learning_tests_cartpole", "learning_tests_discrete", "fake_gpus"],
-    size = "large",
+    size = "medium",
     srcs = ["tests/run_regression_tests.py"],
     data = ["tuned_examples/dqn/cartpole-simpleq-fake-gpus.yaml"],
     args = ["--yaml-dir=tuned_examples/dqn"]
@@ -468,7 +468,7 @@ py_test(
 py_test(
     name = "learning_tests_transformed_actions_pendulum_sac",
     main = "tests/run_regression_tests.py",
-    tags = ["team:ml", "learning_tests", "learning_tests_pendulum", "learning_tests_continuous"],
+    tags = ["team:ml", "learning_tests", "learning_tests_pendulum", "learning_tests_continuous", "flaky"],
     size = "large",
     srcs = ["tests/run_regression_tests.py"],
     data = ["tuned_examples/sac/pendulum-transformed-actions-sac.yaml"],
@@ -478,7 +478,7 @@ py_test(
 py_test(
     name = "learning_pendulum_sac_fake_gpus",
     main = "tests/run_regression_tests.py",
-    tags = ["team:ml", "learning_tests", "learning_tests_pendulum", "learning_tests_continuous", "fake_gpus"],
+    tags = ["team:ml", "learning_tests", "learning_tests_pendulum", "learning_tests_continuous", "fake_gpus", "flaky"],
     size = "large",
     srcs = ["tests/run_regression_tests.py"],
     data = ["tuned_examples/sac/pendulum-sac-fake-gpus.yaml"],

rllib/env/base_env.py

@@ -1,6 +1,7 @@
 from typing import Callable, Tuple, Optional, List, Dict, Any, TYPE_CHECKING,\
     Union
 
+import gym
 import ray
 from ray.rllib.utils.annotations import Deprecated, override, PublicAPI
 from ray.rllib.utils.typing import AgentID, EnvID, EnvType, MultiAgentDict, \
@@ -31,12 +32,6 @@ class BaseEnv:
     rllib.MultiAgentEnv (is-a gym.Env) => rllib.VectorEnv => rllib.BaseEnv
     rllib.ExternalEnv => rllib.BaseEnv
 
-    Attributes:
-        action_space (gym.Space): Action space. This must be defined for
-            single-agent envs. Multi-agent envs can set this to None.
-        observation_space (gym.Space): Observation space. This must be defined
-            for single-agent envs. Multi-agent envs can set this to None.
-
     Examples:
         >>> env = MyBaseEnv()
         >>> obs, rewards, dones, infos, off_policy_actions = env.poll()
@@ -185,12 +180,18 @@ class BaseEnv:
         return None
 
     @PublicAPI
-    def get_sub_environments(self) -> List[EnvType]:
+    def get_sub_environments(
+            self, as_dict: bool = False) -> Union[List[EnvType], dict]:
         """Return a reference to the underlying sub environments, if any.
 
+        Args:
+            as_dict: If True, return a dict mapping from env_id to env.
+
         Returns:
-            List of the underlying sub environments or [].
+            List or dictionary of the underlying sub environments or [] / {}.
         """
+        if as_dict:
+            return {}
         return []
 
     @PublicAPI
@@ -218,6 +219,61 @@ class BaseEnv:
     def get_unwrapped(self) -> List[EnvType]:
         return self.get_sub_environments()
 
+    @PublicAPI
+    @property
+    def observation_space(self) -> gym.spaces.Dict:
+        """Returns the observation space for each environment.
+
+        Note: samples from the observation space need to be preprocessed into a
+            `MultiEnvDict` before being used by a policy.
+
+        Returns:
+            The observation space for each environment.
+        """
+        raise NotImplementedError
+
+    @PublicAPI
+    @property
+    def action_space(self) -> gym.Space:
+        """Returns the action space for each environment.
+
+        Note: samples from the action space need to be preprocessed into a
+            `MultiEnvDict` before being passed to `send_actions`.
+
+        Returns:
+            The observation space for each environment.
+        """
+        raise NotImplementedError
+
+    def observation_space_contains(self, x: MultiEnvDict) -> bool:
+        self._space_contains(self.observation_space, x)
+
+    def action_space_contains(self, x: MultiEnvDict) -> bool:
+        return self._space_contains(self.action_space, x)
+
+    @staticmethod
+    def _space_contains(space: gym.Space, x: MultiEnvDict) -> bool:
+        """Check if the given space contains the observations of x.
+
+        Args:
+            space: The space to if x's observations are contained in.
+            x: The observations to check.
+
+        Returns:
+            True if the observations of x are contained in space.
+        """
+        # this removes the agent_id key and inner dicts
+        # in MultiEnvDicts
+        flattened_obs = {
+            env_id: list(obs.values())
+            for env_id, obs in x.items()
+        }
+        ret = True
+        for env_id in flattened_obs:
+            for obs in flattened_obs[env_id]:
+                ret = ret and space[env_id].contains(obs)
+        return ret
+
 
 # Fixed agent identifier when there is only the single agent in the env
 _DUMMY_AGENT_ID = "agent0"

rllib/env/external_env.py

@@ -337,11 +337,11 @@ class ExternalEnvWrapper(BaseEnv):
         self.external_env = external_env
         self.prep = preprocessor
         self.multiagent = issubclass(type(external_env), ExternalMultiAgentEnv)
-        self.action_space = external_env.action_space
+        self._action_space = external_env.action_space
         if preprocessor:
-            self.observation_space = preprocessor.observation_space
+            self._observation_space = preprocessor.observation_space
         else:
-            self.observation_space = external_env.observation_space
+            self._observation_space = external_env.observation_space
         external_env.start()
 
     @override(BaseEnv)
@@ -413,3 +413,15 @@ class ExternalEnvWrapper(BaseEnv):
                 with_dummy_agent_id(all_dones, "__all__"), \
                 with_dummy_agent_id(all_infos), \
                 with_dummy_agent_id(off_policy_actions)
+
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def observation_space(self) -> gym.spaces.Dict:
+        return self._observation_space
+
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def action_space(self) -> gym.Space:
+        return self._action_space

rllib/env/multi_agent_env.py

@@ -336,7 +336,12 @@ class MultiAgentEnvWrapper(BaseEnv):
         return obs
 
     @override(BaseEnv)
-    def get_sub_environments(self) -> List[EnvType]:
+    def get_sub_environments(self, as_dict: bool = False) -> List[EnvType]:
+        if as_dict:
+            return {
+                _id: env_state
+                for _id, env_state in enumerate(self.env_states)
+            }
         return [state.env for state in self.env_states]
 
     @override(BaseEnv)
@@ -346,6 +351,23 @@ class MultiAgentEnvWrapper(BaseEnv):
         assert isinstance(env_id, int)
         return self.envs[env_id].render()
 
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def observation_space(self) -> gym.spaces.Dict:
+        space = {
+            _id: env.observation_space
+            for _id, env in enumerate(self.envs)
+        }
+        return gym.spaces.Dict(space)
+
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def action_space(self) -> gym.Space:
+        space = {_id: env.action_space for _id, env in enumerate(self.envs)}
+        return gym.spaces.Dict(space)
+
 
 class _MultiAgentEnvState:
     def __init__(self, env: MultiAgentEnv):

rllib/env/remote_base_env.py

@@ -1,6 +1,8 @@
 import logging
 from typing import Callable, Dict, List, Optional, Tuple
 
+import gym
+
 import ray
 from ray.rllib.env.base_env import BaseEnv, _DUMMY_AGENT_ID, ASYNC_RESET_RETURN
 from ray.rllib.utils.annotations import override, PublicAPI
@@ -17,6 +19,8 @@ class RemoteBaseEnv(BaseEnv):
     from the remote simulator actors. Both single and multi-agent child envs
     are supported, and envs can be stepped synchronously or asynchronously.
 
+    NOTE: This class implicitly assumes that the remote envs are gym.Env's
+
     You shouldn't need to instantiate this class directly. It's automatically
     inserted when you use the `remote_worker_envs=True` option in your
     Trainer's config.
@@ -61,6 +65,8 @@ class RemoteBaseEnv(BaseEnv):
         # List of ray actor handles (each handle points to one @ray.remote
         # sub-environment).
         self.actors: Optional[List[ray.actor.ActorHandle]] = None
+        self._observation_space = None
+        self._action_space = None
         # Dict mapping object refs (return values of @ray.remote calls),
         # whose actual values we are waiting for (via ray.wait in
         # `self.poll()`) to their corresponding actor handles (the actors
@@ -97,6 +103,10 @@ class RemoteBaseEnv(BaseEnv):
                 self.actors = [
                     make_remote_env(i) for i in range(self.num_envs)
                 ]
+                self._observation_space = ray.get(
+                    self.actors[0].observation_space.remote())
+                self._action_space = ray.get(
+                    self.actors[0].action_space.remote())
 
         # Lazy initialization. Call `reset()` on all @ray.remote
         # sub-environment actors at the beginning.
@@ -199,9 +209,23 @@ class RemoteBaseEnv(BaseEnv):
 
     @override(BaseEnv)
     @PublicAPI
-    def get_sub_environments(self) -> List[EnvType]:
+    def get_sub_environments(self, as_dict: bool = False) -> List[EnvType]:
+        if as_dict:
+            return {env_id: actor for env_id, actor in enumerate(self.actors)}
         return self.actors
 
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def observation_space(self) -> gym.spaces.Dict:
+        return self._observation_space
+
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def action_space(self) -> gym.Space:
+        return self._action_space
+
 
 @ray.remote(num_cpus=0)
 class _RemoteMultiAgentEnv:
@@ -221,6 +245,14 @@ class _RemoteMultiAgentEnv:
     def step(self, action_dict):
         return self.env.step(action_dict)
 
+    # defining these 2 functions that way this information can be queried
+    # with a call to ray.get()
+    def observation_space(self):
+        return self.env.observation_space
+
+    def action_space(self):
+        return self.env.action_space
+
 
 @ray.remote(num_cpus=0)
 class _RemoteSingleAgentEnv:
@@ -243,3 +275,11 @@ class _RemoteSingleAgentEnv:
         } for x in [obs, rew, done, info]]
         done["__all__"] = done[_DUMMY_AGENT_ID]
         return obs, rew, done, info
+
+    # defining these 2 functions that way this information can be queried
+    # with a call to ray.get()
+    def observation_space(self):
+        return self.env.observation_space
+
+    def action_space(self):
+        return self.env.action_space

rllib/env/vector_env.py

@@ -1,7 +1,7 @@
 import logging
 import gym
 import numpy as np
-from typing import Callable, List, Optional, Tuple
+from typing import Callable, List, Optional, Tuple, Union
 
 from ray.rllib.env.base_env import BaseEnv
 from ray.rllib.utils.annotations import Deprecated, override, PublicAPI
@@ -265,13 +265,13 @@ class VectorEnvWrapper(BaseEnv):
 
     def __init__(self, vector_env: VectorEnv):
         self.vector_env = vector_env
-        self.action_space = vector_env.action_space
-        self.observation_space = vector_env.observation_space
         self.num_envs = vector_env.num_envs
         self.new_obs = None  # lazily initialized
         self.cur_rewards = [None for _ in range(self.num_envs)]
         self.cur_dones = [False for _ in range(self.num_envs)]
         self.cur_infos = [None for _ in range(self.num_envs)]
+        self._observation_space = vector_env.observation_space
+        self._action_space = vector_env.action_space
 
     @override(BaseEnv)
     def poll(self) -> Tuple[MultiEnvDict, MultiEnvDict, MultiEnvDict,
@@ -312,10 +312,51 @@ class VectorEnvWrapper(BaseEnv):
         }
 
     @override(BaseEnv)
-    def get_sub_environments(self) -> List[EnvType]:
+    def get_sub_environments(
+            self, as_dict: bool = False) -> Union[List[EnvType], dict]:
+        if not as_dict:
             return self.vector_env.get_sub_environments()
+        else:
+            return {
+                _id: env
+                for _id, env in enumerate(
+                    self.vector_env.get_sub_environments())
+            }
 
     @override(BaseEnv)
     def try_render(self, env_id: Optional[EnvID] = None) -> None:
         assert env_id is None or isinstance(env_id, int)
         return self.vector_env.try_render_at(env_id)
+
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def observation_space(self) -> gym.spaces.Dict:
+        return self._observation_space
+
+    @property
+    @override(BaseEnv)
+    @PublicAPI
+    def action_space(self) -> gym.Space:
+        return self._action_space
+
+    @staticmethod
+    def _space_contains(space: gym.Space, x: MultiEnvDict) -> bool:
+        """Check if the given space contains the observations of x.
+
+        Args:
+            space: The space to if x's observations are contained in.
+            x: The observations to check.
+
+        Note: With vector envs, we can process the raw observations
+            and ignore the agent ids and env ids, since vector envs'
+            sub environements are guaranteed to be the same
+
+        Returns:
+            True if the observations of x are contained in space.
+        """
+        for _, multi_agent_dict in x.items():
+            for _, element in multi_agent_dict.items():
+                if not space.contains(element):
+                    return False
+        return True