Add EnvPool support (as VecEnv subclass)

requirements.txt

@@ -18,3 +18,4 @@ seaborn
 tqdm
 rich
 importlib-metadata~=4.13 # flake8 not compatible with importlib-metadata>5.0
+envpool

rl_zoo3/exp_manager.py

@@ -37,6 +37,7 @@
     SubprocVecEnv,
     VecEnv,
     VecFrameStack,
+    VecMonitor,
     VecNormalize,
     VecTransposeImage,
     is_vecenv_wrapped,
@@ -51,6 +52,15 @@
 from rl_zoo3.hyperparams_opt import HYPERPARAMS_SAMPLER
 from rl_zoo3.utils import ALGOS, get_callback_list, get_class_by_name, get_latest_run_id, get_wrapper_class, linear_schedule
 
+try:
+    import envpool
+except ImportError:
+    envpool = None
+else:
+    from envpool.python.protocol import EnvPool
+
+    from rl_zoo3.vec_env_wrappers import EnvPoolAdapter
+
 
 class ExperimentManager:
     """
@@ -97,6 +107,7 @@ def __init__(
         device: Union[th.device, str] = "auto",
         config: Optional[str] = None,
         show_progress: bool = False,
+        use_envpool: bool = False,
     ):
         super().__init__()
         self.algo = algo
@@ -120,6 +131,7 @@ def __init__(
         self.seed = seed
         self.optimization_log_path = optimization_log_path
 
+        self.use_envpool = use_envpool
         self.vec_env_class = {"dummy": DummyVecEnv, "subproc": SubprocVecEnv}[vec_env_type]
         self.vec_env_wrapper = None
 
@@ -581,37 +593,59 @@ def create_envs(self, n_envs: int, eval_env: bool = False, no_log: bool = False)
         # Do not log eval env (issue with writing the same file)
         log_dir = None if eval_env or no_log else self.save_path
 
-        # Special case for GoalEnvs: log success rate too
-        if (
-            "Neck" in self.env_name.gym_id
-            or self.is_robotics_env(self.env_name.gym_id)
-            or "parking-v0" in self.env_name.gym_id
-            and len(self.monitor_kwargs) == 0  # do not overwrite custom kwargs
-        ):
-            self.monitor_kwargs = dict(info_keywords=("is_success",))
-
-        # Define make_env here so it works with subprocesses
-        # when the registry was modified with `--gym-packages`
-        # See https://github.com/HumanCompatibleAI/imitation/pull/160
-        spec = gym.spec(self.env_name.gym_id)
-
-        def make_env(**kwargs) -> gym.Env:
-            env = spec.make(**kwargs)
-            return env
-
-        # On most env, SubprocVecEnv does not help and is quite memory hungry
-        # therefore we use DummyVecEnv by default
-        env = make_vec_env(
-            make_env,
-            n_envs=n_envs,
-            seed=self.seed,
-            env_kwargs=self.env_kwargs,
-            monitor_dir=log_dir,
-            wrapper_class=self.env_wrapper,
-            vec_env_cls=self.vec_env_class,
-            vec_env_kwargs=self.vec_env_kwargs,
-            monitor_kwargs=self.monitor_kwargs,
-        )
+        if self.use_envpool:
+            if self.env_wrapper is not None:
+                warnings.warn("EnvPool does not support env wrappers, it will be ignored.")
+            if self.env_kwargs:
+                warnings.warn(
+                    "EnvPool does not support env_kwargs, it will be ignored. "
+                    "To pass keyword argument to envpool, use vec_env_kwargs instead."
+                )
+
+            # Convert Atari game names
+            # See https://github.com/sail-sg/envpool/issues/14
+            env_id = self.env_name.gym_id
+            if self._is_atari and "NoFrameskip-v4" in env_id:
+                env_id = env_id.split("NoFrameskip-v4")[0] + "-v5"
+
+            env = envpool.make(env_id, env_type="gym", num_envs=n_envs, seed=self.seed, **self.vec_env_kwargs)  # type: EnvPool
+            env.spec.id = self.env_name.gym_id
+            env = EnvPoolAdapter(env)
+            filename = None if log_dir is None else f"{log_dir}/monitor.csv"
+            env = VecMonitor(env, filename, **self.monitor_kwargs)
+
+        else:
+            # Special case for GoalEnvs: log success rate too
+            if (
+                "Neck" in self.env_name.gym_id
+                or self.is_robotics_env(self.env_name.gym_id)
+                or "parking-v0" in self.env_name.gym_id
+                and len(self.monitor_kwargs) == 0  # do not overwrite custom kwargs
+            ):
+                self.monitor_kwargs = dict(info_keywords=("is_success",))
+
+            # Define make_env here so it works with subprocesses
+            # when the registry was modified with `--gym-packages`
+            # See https://github.com/HumanCompatibleAI/imitation/pull/160
+            spec = gym.spec(self.env_name.gym_id)
+
+            def make_env(**kwargs) -> gym.Env:
+                env = spec.make(**kwargs)
+                return env
+
+            # On most env, SubprocVecEnv does not help and is quite memory hungry
+            # therefore we use DummyVecEnv by default
+            env = make_vec_env(
+                make_env,
+                n_envs=n_envs,
+                seed=self.seed,
+                env_kwargs=self.env_kwargs,
+                monitor_dir=log_dir,
+                wrapper_class=self.env_wrapper,
+                vec_env_cls=self.vec_env_class,
+                vec_env_kwargs=self.vec_env_kwargs,
+                monitor_kwargs=self.monitor_kwargs,
+            )
 
         if self.vec_env_wrapper is not None:
             env = self.vec_env_wrapper(env)

rl_zoo3/train.py

@@ -153,6 +153,13 @@ def train() -> None:
         default=False,
         help="if toggled, display a progress bar using tqdm and rich",
     )
+    parser.add_argument(
+        "-envpool",
+        "--use-envpool",
+        action="store_true",
+        default=False,
+        help="if toggled, try to use EnvPool to run the env, env_wrappers are not supported.",
+    )
     parser.add_argument(
         "-tags", "--wandb-tags", type=str, default=[], nargs="+", help="Tags for wandb run, e.g.: -tags optimized pr-123"
     )
@@ -183,7 +190,7 @@ def train() -> None:
     uuid_str = f"_{uuid.uuid4()}" if args.uuid else ""
     if args.seed < 0:
         # Seed but with a random one
-        args.seed = np.random.randint(2**32 - 1, dtype="int64").item()  # type: ignore[attr-defined]
+        args.seed = np.random.randint(2**31 - 1, dtype="int64").item()  # type: ignore[attr-defined]
 
     set_random_seed(args.seed)
 
@@ -259,6 +266,7 @@ def train() -> None:
         device=args.device,
         config=args.conf_file,
         show_progress=args.progress,
+        use_envpool=args.use_envpool,
     )
 
     # Prepare experiment and launch hyperparameter optimization if needed

rl_zoo3/vec_env_wrappers.py

@@ -0,0 +1,92 @@
+from typing import Any, Iterable, List, Optional, Sequence, Type, Union
+
+import gym
+import numpy as np
+from envpool.python.protocol import EnvPool
+from gym import spaces
+from stable_baselines3.common.vec_env import VecEnv
+from stable_baselines3.common.vec_env.base_vec_env import VecEnvObs, VecEnvStepReturn
+
+# Used when we want to access one or more VecEnv
+VecEnvIndices = Union[None, int, Iterable[int]]
+
+
+def _convert_dtype_to_float32(space: spaces.Space) -> spaces.Space:
+    """
+    Convert the dtype of a space to float32.
+
+    :param space: Space to convert
+    :return: Converted space
+    """
+    if isinstance(space, spaces.Box):
+        if space.dtype == np.float64:
+            space.dtype = np.dtype(np.float32)
+    elif isinstance(space, spaces.Dict):
+        for key, sub_space in space.spaces.items():
+            space.spaces[key] = _convert_dtype_to_float32(sub_space)
+    return space
+
+
+class EnvPoolAdapter(VecEnv):
+    """
+    Wrapper for EnvPool to make it compatible with Stable-Baselines3.
+
+    :param venv: EnvPool environment
+    """
+
+    def __init__(self, venv: EnvPool) -> None:
+        self.venv = venv
+        action_space = venv.action_space
+        observation_space = venv.observation_space
+        # Tmp fix for https://github.com/DLR-RM/stable-baselines3/issues/1145
+        observation_space = _convert_dtype_to_float32(observation_space)
+        action_space = _convert_dtype_to_float32(action_space)
+
+        super().__init__(
+            num_envs=venv.spec.config.num_envs,  # Retrieve the number of environments from the config
+            observation_space=observation_space,
+            action_space=action_space,
+        )
+
+    def reset(self) -> VecEnvObs:
+        return self.venv.reset()
+
+    def step_async(self, actions: np.ndarray) -> None:
+        self.actions = actions
+
+    def step_wait(self) -> VecEnvStepReturn:
+        obs, rewards, dones, info_dict = self.venv.step(self.actions)
+        infos = []
+        # Convert dict to list of dict and add terminal observation
+        for env_idx in range(self.num_envs):
+            infos.append({key: info_dict[key][env_idx] for key in info_dict.keys() if isinstance(info_dict[key], np.ndarray)})
+            if dones[env_idx]:
+                infos[env_idx]["terminal_observation"] = obs[env_idx]
+                obs[env_idx] = self.venv.reset(np.array([env_idx]))
+
+        return obs, rewards, dones, infos
+
+    def close(self) -> None:
+        return None  # No closing method in envpool
+
+    def get_attr(self, attr_name: str, indices: VecEnvIndices = None) -> List[Any]:
+        raise NotImplementedError("EnvPool does not support get_attr()")
+
+    def set_attr(self, attr_name: str, value: Any, indices: VecEnvIndices = None) -> None:
+        raise NotImplementedError("EnvPool does not support set_attr()")
+
+    def env_method(self, method_name: str, *method_args, indices: VecEnvIndices = None, **method_kwargs) -> List[Any]:
+        raise NotImplementedError("EnvPool does not support env_method()")
+
+    def env_is_wrapped(self, wrapper_class: Type[gym.Wrapper], indices: VecEnvIndices = None) -> List[bool]:
+        return [False for _ in range(self.num_envs)]
+
+    def get_images(self) -> Sequence[np.ndarray]:
+        raise NotImplementedError("EnvPool does not support get_images()")
+
+    def render(self, mode: str = "human") -> Optional[np.ndarray]:
+        raise NotImplementedError("EnvPool does not support render()")
+
+    def seed(self, seed: Optional[int] = None) -> Sequence[None]:  # type: ignore[override] # until SB3/#1318 is closed
+        # You can only seed EnvPool env by calling envpool.make()
+        return [None for _ in range(self.num_envs)]