Source code for ray.rllib.evaluation.sampler

from abc import abstractmethod, ABCMeta
from collections import defaultdict, namedtuple
import logging
import numpy as np
import queue
import threading
import time
from typing import Any, Callable, Dict, List, Iterable, Optional, Set, Tuple,\
    Type, TYPE_CHECKING, Union

from ray.util.debug import log_once
from ray.rllib.evaluation.collectors.sample_collector import \
    SampleCollector
from ray.rllib.evaluation.collectors.simple_list_collector import \
    SimpleListCollector
from ray.rllib.evaluation.episode import MultiAgentEpisode
from ray.rllib.evaluation.rollout_metrics import RolloutMetrics
from ray.rllib.evaluation.sample_batch_builder import \
    MultiAgentSampleBatchBuilder
from ray.rllib.env.base_env import BaseEnv, ASYNC_RESET_RETURN
from ray.rllib.env.wrappers.atari_wrappers import get_wrapper_by_cls, \
    MonitorEnv
from ray.rllib.models.preprocessors import Preprocessor
from ray.rllib.offline import InputReader
from ray.rllib.policy.policy import clip_action, Policy
from ray.rllib.utils.annotations import override, DeveloperAPI
from ray.rllib.utils.debug import summarize
from ray.rllib.utils.filter import Filter
from ray.rllib.utils.numpy import convert_to_numpy
from ray.rllib.utils.spaces.space_utils import unbatch
from ray.rllib.utils.tf_run_builder import TFRunBuilder
from ray.rllib.utils.typing import SampleBatchType, AgentID, PolicyID, \
    EnvObsType, EnvInfoDict, EnvID, MultiEnvDict, EnvActionType, \
    TensorStructType

if TYPE_CHECKING:
    from ray.rllib.agents.callbacks import DefaultCallbacks
    from ray.rllib.evaluation.observation_function import ObservationFunction
    from ray.rllib.evaluation.rollout_worker import RolloutWorker
    from ray.rllib.utils import try_import_tf
    _, tf, _ = try_import_tf()
    from gym.envs.classic_control.rendering import SimpleImageViewer

logger = logging.getLogger(__name__)

PolicyEvalData = namedtuple("PolicyEvalData", [
    "env_id", "agent_id", "obs", "info", "rnn_state", "prev_action",
    "prev_reward"
])

# A batch of RNN states with dimensions [state_index, batch, state_object].
StateBatch = List[List[Any]]


class NewEpisodeDefaultDict(defaultdict):
    def __missing__(self, env_id):
        if self.default_factory is None:
            raise KeyError(env_id)
        else:
            ret = self[env_id] = self.default_factory(env_id)
            return ret


class _PerfStats:
    """Sampler perf stats that will be included in rollout metrics."""

    def __init__(self):
        self.iters = 0
        self.raw_obs_processing_time = 0.0
        self.inference_time = 0.0
        self.action_processing_time = 0.0
        self.env_wait_time = 0.0
        self.env_render_time = 0.0

    def get(self):
        # Mean multiplicator (1000 = ms -> sec).
        factor = 1000 / self.iters
        return {
            # Raw observation preprocessing.
            "mean_raw_obs_processing_ms": self.raw_obs_processing_time *
            factor,
            # Computing actions through policy.
            "mean_inference_ms": self.inference_time * factor,
            # Processing actions (to be sent to env, e.g. clipping).
            "mean_action_processing_ms": self.action_processing_time * factor,
            # Waiting for environment (during poll).
            "mean_env_wait_ms": self.env_wait_time * factor,
            # Environment rendering (False by default).
            "mean_env_render_ms": self.env_render_time * factor,
        }


@DeveloperAPI
class SamplerInput(InputReader, metaclass=ABCMeta):
    """Reads input experiences from an existing sampler."""

    @override(InputReader)
    def next(self) -> SampleBatchType:
        batches = [self.get_data()]
        batches.extend(self.get_extra_batches())
        if len(batches) > 1:
            return batches[0].concat_samples(batches)
        else:
            return batches[0]

    @abstractmethod
    @DeveloperAPI
    def get_data(self) -> SampleBatchType:
        raise NotImplementedError

    @abstractmethod
    @DeveloperAPI
    def get_metrics(self) -> List[RolloutMetrics]:
        raise NotImplementedError

    @abstractmethod
    @DeveloperAPI
    def get_extra_batches(self) -> List[SampleBatchType]:
        raise NotImplementedError


[docs]@DeveloperAPI class SyncSampler(SamplerInput): """Sync SamplerInput that collects experiences when `get_data()` is called. """ def __init__( self, *, worker: "RolloutWorker", env: BaseEnv, policies: Dict[PolicyID, Policy], policy_mapping_fn: Callable[[AgentID], PolicyID], preprocessors: Dict[PolicyID, Preprocessor], obs_filters: Dict[PolicyID, Filter], clip_rewards: bool, rollout_fragment_length: int, count_steps_by: str = "env_steps", callbacks: "DefaultCallbacks", horizon: int = None, multiple_episodes_in_batch: bool = False, tf_sess=None, clip_actions: bool = True, soft_horizon: bool = False, no_done_at_end: bool = False, observation_fn: "ObservationFunction" = None, sample_collector_class: Optional[Type[SampleCollector]] = None, render: bool = False, ): """Initializes a SyncSampler object. Args: worker (RolloutWorker): The RolloutWorker that will use this Sampler for sampling. env (Env): Any Env object. Will be converted into an RLlib BaseEnv. policies (Dict[str,Policy]): Mapping from policy ID to Policy obj. policy_mapping_fn (callable): Callable that takes an agent ID and returns a Policy object. preprocessors (Dict[str,Preprocessor]): Mapping from policy ID to Preprocessor object for the observations prior to filtering. obs_filters (Dict[str,Filter]): Mapping from policy ID to env Filter object. clip_rewards (Union[bool,float]): True for +/-1.0 clipping, actual float value for +/- value clipping. False for no clipping. rollout_fragment_length (int): The length of a fragment to collect before building a SampleBatch from the data and resetting the SampleBatchBuilder object. callbacks (Callbacks): The Callbacks object to use when episode events happen during rollout. horizon (Optional[int]): Hard-reset the Env multiple_episodes_in_batch (bool): Whether to pack multiple episodes into each batch. This guarantees batches will be exactly `rollout_fragment_length` in size. tf_sess (Optional[tf.Session]): A tf.Session object to use (only if framework=tf). clip_actions (bool): Whether to clip actions according to the given action_space's bounds. soft_horizon (bool): If True, calculate bootstrapped values as if episode had ended, but don't physically reset the environment when the horizon is hit. no_done_at_end (bool): Ignore the done=True at the end of the episode and instead record done=False. observation_fn (Optional[ObservationFunction]): Optional multi-agent observation func to use for preprocessing observations. sample_collector_class (Optional[Type[SampleCollector]]): An optional Samplecollector sub-class to use to collect, store, and retrieve environment-, model-, and sampler data. render (bool): Whether to try to render the environment after each step. """ self.base_env = BaseEnv.to_base_env(env) self.rollout_fragment_length = rollout_fragment_length self.horizon = horizon self.policies = policies self.policy_mapping_fn = policy_mapping_fn self.preprocessors = preprocessors self.obs_filters = obs_filters self.extra_batches = queue.Queue() self.perf_stats = _PerfStats() if not sample_collector_class: sample_collector_class = SimpleListCollector self.sample_collector = sample_collector_class( policies, clip_rewards, callbacks, multiple_episodes_in_batch, rollout_fragment_length, count_steps_by=count_steps_by) self.render = render # Create the rollout generator to use for calls to `get_data()`. self.rollout_provider = _env_runner( worker, self.base_env, self.extra_batches.put, self.policies, self.policy_mapping_fn, self.rollout_fragment_length, self.horizon, self.preprocessors, self.obs_filters, clip_rewards, clip_actions, multiple_episodes_in_batch, callbacks, tf_sess, self.perf_stats, soft_horizon, no_done_at_end, observation_fn, self.sample_collector, self.render) self.metrics_queue = queue.Queue() @override(SamplerInput) def get_data(self) -> SampleBatchType: while True: item = next(self.rollout_provider) if isinstance(item, RolloutMetrics): self.metrics_queue.put(item) else: return item @override(SamplerInput) def get_metrics(self) -> List[RolloutMetrics]: completed = [] while True: try: completed.append(self.metrics_queue.get_nowait()._replace( perf_stats=self.perf_stats.get())) except queue.Empty: break return completed @override(SamplerInput) def get_extra_batches(self) -> List[SampleBatchType]: extra = [] while True: try: extra.append(self.extra_batches.get_nowait()) except queue.Empty: break return extra
[docs]@DeveloperAPI class AsyncSampler(threading.Thread, SamplerInput): """Async SamplerInput that collects experiences in thread and queues them. Once started, experiences are continuously collected and put into a Queue, from where they can be unqueued by the caller of `get_data()`. """ def __init__( self, *, worker: "RolloutWorker", env: BaseEnv, policies: Dict[PolicyID, Policy], policy_mapping_fn: Callable[[AgentID], PolicyID], preprocessors: Dict[PolicyID, Preprocessor], obs_filters: Dict[PolicyID, Filter], clip_rewards: bool, rollout_fragment_length: int, count_steps_by: str = "env_steps", callbacks: "DefaultCallbacks", horizon: int = None, multiple_episodes_in_batch: bool = False, tf_sess=None, clip_actions: bool = True, blackhole_outputs: bool = False, soft_horizon: bool = False, no_done_at_end: bool = False, observation_fn: "ObservationFunction" = None, sample_collector_class: Optional[Type[SampleCollector]] = None, render: bool = False, ): """Initializes a AsyncSampler object. Args: worker (RolloutWorker): The RolloutWorker that will use this Sampler for sampling. env (Env): Any Env object. Will be converted into an RLlib BaseEnv. policies (Dict[str, Policy]): Mapping from policy ID to Policy obj. policy_mapping_fn (callable): Callable that takes an agent ID and returns a Policy object. preprocessors (Dict[str, Preprocessor]): Mapping from policy ID to Preprocessor object for the observations prior to filtering. obs_filters (Dict[str, Filter]): Mapping from policy ID to env Filter object. clip_rewards (Union[bool, float]): True for +/-1.0 clipping, actual float value for +/- value clipping. False for no clipping. rollout_fragment_length (int): The length of a fragment to collect before building a SampleBatch from the data and resetting the SampleBatchBuilder object. count_steps_by (str): Either "env_steps" or "agent_steps". Refers to the unit of `rollout_fragment_length`. callbacks (Callbacks): The Callbacks object to use when episode events happen during rollout. horizon (Optional[int]): Hard-reset the Env multiple_episodes_in_batch (bool): Whether to pack multiple episodes into each batch. This guarantees batches will be exactly `rollout_fragment_length` in size. tf_sess (Optional[tf.Session]): A tf.Session object to use (only if framework=tf). clip_actions (bool): Whether to clip actions according to the given action_space's bounds. blackhole_outputs (bool): Whether to collect samples, but then not further process or store them (throw away all samples). soft_horizon (bool): If True, calculate bootstrapped values as if episode had ended, but don't physically reset the environment when the horizon is hit. no_done_at_end (bool): Ignore the done=True at the end of the episode and instead record done=False. observation_fn (Optional[ObservationFunction]): Optional multi-agent observation func to use for preprocessing observations. sample_collector_class (Optional[Type[SampleCollector]]): An optional Samplecollector sub-class to use to collect, store, and retrieve environment-, model-, and sampler data. render (bool): Whether to try to render the environment after each step. """ for _, f in obs_filters.items(): assert getattr(f, "is_concurrent", False), \ "Observation Filter must support concurrent updates." self.worker = worker self.base_env = BaseEnv.to_base_env(env) threading.Thread.__init__(self) self.queue = queue.Queue(5) self.extra_batches = queue.Queue() self.metrics_queue = queue.Queue() self.rollout_fragment_length = rollout_fragment_length self.horizon = horizon self.policies = policies self.policy_mapping_fn = policy_mapping_fn self.preprocessors = preprocessors self.obs_filters = obs_filters self.clip_rewards = clip_rewards self.daemon = True self.multiple_episodes_in_batch = multiple_episodes_in_batch self.tf_sess = tf_sess self.callbacks = callbacks self.clip_actions = clip_actions self.blackhole_outputs = blackhole_outputs self.soft_horizon = soft_horizon self.no_done_at_end = no_done_at_end self.perf_stats = _PerfStats() self.shutdown = False self.observation_fn = observation_fn self.render = render if not sample_collector_class: sample_collector_class = SimpleListCollector self.sample_collector = sample_collector_class( policies, clip_rewards, callbacks, multiple_episodes_in_batch, rollout_fragment_length, count_steps_by=count_steps_by)
[docs] @override(threading.Thread) def run(self): try: self._run() except BaseException as e: self.queue.put(e) raise e
def _run(self): if self.blackhole_outputs: queue_putter = (lambda x: None) extra_batches_putter = (lambda x: None) else: queue_putter = self.queue.put extra_batches_putter = ( lambda x: self.extra_batches.put(x, timeout=600.0)) rollout_provider = _env_runner( self.worker, self.base_env, extra_batches_putter, self.policies, self.policy_mapping_fn, self.rollout_fragment_length, self.horizon, self.preprocessors, self.obs_filters, self.clip_rewards, self.clip_actions, self.multiple_episodes_in_batch, self.callbacks, self.tf_sess, self.perf_stats, self.soft_horizon, self.no_done_at_end, self.observation_fn, self.sample_collector, self.render) while not self.shutdown: # The timeout variable exists because apparently, if one worker # dies, the other workers won't die with it, unless the timeout is # set to some large number. This is an empirical observation. item = next(rollout_provider) if isinstance(item, RolloutMetrics): self.metrics_queue.put(item) else: queue_putter(item) @override(SamplerInput) def get_data(self) -> SampleBatchType: if not self.is_alive(): raise RuntimeError("Sampling thread has died") rollout = self.queue.get(timeout=600.0) # Propagate errors. if isinstance(rollout, BaseException): raise rollout return rollout @override(SamplerInput) def get_metrics(self) -> List[RolloutMetrics]: completed = [] while True: try: completed.append(self.metrics_queue.get_nowait()._replace( perf_stats=self.perf_stats.get())) except queue.Empty: break return completed @override(SamplerInput) def get_extra_batches(self) -> List[SampleBatchType]: extra = [] while True: try: extra.append(self.extra_batches.get_nowait()) except queue.Empty: break return extra
def _env_runner( worker: "RolloutWorker", base_env: BaseEnv, extra_batch_callback: Callable[[SampleBatchType], None], policies: Dict[PolicyID, Policy], policy_mapping_fn: Callable[[AgentID], PolicyID], rollout_fragment_length: int, horizon: int, preprocessors: Dict[PolicyID, Preprocessor], obs_filters: Dict[PolicyID, Filter], clip_rewards: bool, clip_actions: bool, multiple_episodes_in_batch: bool, callbacks: "DefaultCallbacks", tf_sess: Optional["tf.Session"], perf_stats: _PerfStats, soft_horizon: bool, no_done_at_end: bool, observation_fn: "ObservationFunction", sample_collector: Optional[SampleCollector] = None, render: bool = None, ) -> Iterable[SampleBatchType]: """This implements the common experience collection logic. Args: worker (RolloutWorker): Reference to the current rollout worker. base_env (BaseEnv): Env implementing BaseEnv. extra_batch_callback (fn): function to send extra batch data to. policies (Dict[PolicyID, Policy]): Map of policy ids to Policy instances. policy_mapping_fn (func): Function that maps agent ids to policy ids. This is called when an agent first enters the environment. The agent is then "bound" to the returned policy for the episode. rollout_fragment_length (int): Number of episode steps before `SampleBatch` is yielded. Set to infinity to yield complete episodes. horizon (int): Horizon of the episode. preprocessors (dict): Map of policy id to preprocessor for the observations prior to filtering. obs_filters (dict): Map of policy id to filter used to process observations for the policy. clip_rewards (bool): Whether to clip rewards before postprocessing. multiple_episodes_in_batch (bool): Whether to pack multiple episodes into each batch. This guarantees batches will be exactly `rollout_fragment_length` in size. clip_actions (bool): Whether to clip actions to the space range. callbacks (DefaultCallbacks): User callbacks to run on episode events. tf_sess (Session|None): Optional tensorflow session to use for batching TF policy evaluations. perf_stats (_PerfStats): Record perf stats into this object. soft_horizon (bool): Calculate rewards but don't reset the environment when the horizon is hit. no_done_at_end (bool): Ignore the done=True at the end of the episode and instead record done=False. observation_fn (ObservationFunction): Optional multi-agent observation func to use for preprocessing observations. sample_collector (Optional[SampleCollector]): An optional SampleCollector object to use. render (bool): Whether to try to render the environment after each step. Yields: rollout (SampleBatch): Object containing state, action, reward, terminal condition, and other fields as dictated by `policy`. """ # May be populated with used for image rendering simple_image_viewer: Optional["SimpleImageViewer"] = None # Try to get Env's `max_episode_steps` prop. If it doesn't exist, ignore # error and continue with max_episode_steps=None. max_episode_steps = None try: max_episode_steps = base_env.get_unwrapped()[0].spec.max_episode_steps except Exception: pass # Trainer has a given `horizon` setting. if horizon: # `horizon` is larger than env's limit. if max_episode_steps and horizon > max_episode_steps: # Try to override the env's own max-step setting with our horizon. # If this won't work, throw an error. try: base_env.get_unwrapped()[0].spec.max_episode_steps = horizon base_env.get_unwrapped()[0]._max_episode_steps = horizon except Exception: raise ValueError( "Your `horizon` setting ({}) is larger than the Env's own " "timestep limit ({}), which seems to be unsettable! Try " "to increase the Env's built-in limit to be at least as " "large as your wanted `horizon`.".format( horizon, max_episode_steps)) # Otherwise, set Trainer's horizon to env's max-steps. elif max_episode_steps: horizon = max_episode_steps logger.debug( "No episode horizon specified, setting it to Env's limit ({}).". format(max_episode_steps)) # No horizon/max_episode_steps -> Episodes may be infinitely long. else: horizon = float("inf") logger.debug("No episode horizon specified, assuming inf.") # Pool of batch builders, which can be shared across episodes to pack # trajectory data. batch_builder_pool: List[MultiAgentSampleBatchBuilder] = [] def get_batch_builder(): if batch_builder_pool: return batch_builder_pool.pop() else: return None def new_episode(env_id): episode = MultiAgentEpisode( policies, policy_mapping_fn, get_batch_builder, extra_batch_callback, env_id=env_id) # Call each policy's Exploration.on_episode_start method. # type: Policy for p in policies.values(): if getattr(p, "exploration", None) is not None: p.exploration.on_episode_start( policy=p, environment=base_env, episode=episode, tf_sess=getattr(p, "_sess", None)) callbacks.on_episode_start( worker=worker, base_env=base_env, policies=policies, episode=episode, env_index=env_id, ) return episode active_episodes: Dict[str, MultiAgentEpisode] = \ NewEpisodeDefaultDict(new_episode) while True: perf_stats.iters += 1 t0 = time.time() # Get observations from all ready agents. # type: MultiEnvDict, MultiEnvDict, MultiEnvDict, MultiEnvDict, ... unfiltered_obs, rewards, dones, infos, off_policy_actions = \ base_env.poll() perf_stats.env_wait_time += time.time() - t0 if log_once("env_returns"): logger.info("Raw obs from env: {}".format( summarize(unfiltered_obs))) logger.info("Info return from env: {}".format(summarize(infos))) # Process observations and prepare for policy evaluation. t1 = time.time() # type: Set[EnvID], Dict[PolicyID, List[PolicyEvalData]], # List[Union[RolloutMetrics, SampleBatchType]] active_envs, to_eval, outputs = \ _process_observations( worker=worker, base_env=base_env, policies=policies, active_episodes=active_episodes, unfiltered_obs=unfiltered_obs, rewards=rewards, dones=dones, infos=infos, horizon=horizon, preprocessors=preprocessors, obs_filters=obs_filters, multiple_episodes_in_batch=multiple_episodes_in_batch, callbacks=callbacks, soft_horizon=soft_horizon, no_done_at_end=no_done_at_end, observation_fn=observation_fn, sample_collector=sample_collector, ) perf_stats.raw_obs_processing_time += time.time() - t1 for o in outputs: yield o # Do batched policy eval (accross vectorized envs). t2 = time.time() # type: Dict[PolicyID, Tuple[TensorStructType, StateBatch, dict]] eval_results = _do_policy_eval( to_eval=to_eval, policies=policies, sample_collector=sample_collector, active_episodes=active_episodes, tf_sess=tf_sess, ) perf_stats.inference_time += time.time() - t2 # Process results and update episode state. t3 = time.time() actions_to_send: Dict[EnvID, Dict[AgentID, EnvActionType]] = \ _process_policy_eval_results( to_eval=to_eval, eval_results=eval_results, active_episodes=active_episodes, active_envs=active_envs, off_policy_actions=off_policy_actions, policies=policies, clip_actions=clip_actions, ) perf_stats.action_processing_time += time.time() - t3 # Return computed actions to ready envs. We also send to envs that have # taken off-policy actions; those envs are free to ignore the action. t4 = time.time() base_env.send_actions(actions_to_send) perf_stats.env_wait_time += time.time() - t4 # Try to render the env, if required. if render: t5 = time.time() # Render can either return an RGB image (uint8 [w x h x 3] numpy # array) or take care of rendering itself (returning True). rendered = base_env.try_render() # Rendering returned an image -> Display it in a SimpleImageViewer. if isinstance(rendered, np.ndarray) and len(rendered.shape) == 3: # ImageViewer not defined yet, try to create one. if simple_image_viewer is None: try: from gym.envs.classic_control.rendering import \ SimpleImageViewer simple_image_viewer = SimpleImageViewer() except (ImportError, ModuleNotFoundError): render = False # disable rendering logger.warning( "Could not import gym.envs.classic_control." "rendering! Try `pip install gym[all]`.") if simple_image_viewer: simple_image_viewer.imshow(rendered) elif rendered not in [True, False, None]: raise ValueError( "The env's ({base_env}) `try_render()` method returned an" " unsupported value! Make sure you either return a " "uint8/w x h x 3 (RGB) image or handle rendering in a " "window and then return `True`.") perf_stats.env_render_time += time.time() - t5 def _process_observations( *, worker: "RolloutWorker", base_env: BaseEnv, policies: Dict[PolicyID, Policy], active_episodes: Dict[str, MultiAgentEpisode], unfiltered_obs: Dict[EnvID, Dict[AgentID, EnvObsType]], rewards: Dict[EnvID, Dict[AgentID, float]], dones: Dict[EnvID, Dict[AgentID, bool]], infos: Dict[EnvID, Dict[AgentID, EnvInfoDict]], horizon: int, preprocessors: Dict[PolicyID, Preprocessor], obs_filters: Dict[PolicyID, Filter], multiple_episodes_in_batch: bool, callbacks: "DefaultCallbacks", soft_horizon: bool, no_done_at_end: bool, observation_fn: "ObservationFunction", sample_collector: SampleCollector, ) -> Tuple[Set[EnvID], Dict[PolicyID, List[PolicyEvalData]], List[Union[ RolloutMetrics, SampleBatchType]]]: """Record new data from the environment and prepare for policy evaluation. Args: worker (RolloutWorker): Reference to the current rollout worker. base_env (BaseEnv): Env implementing BaseEnv. policies (dict): Map of policy ids to Policy instances. batch_builder_pool (List[SampleBatchBuilder]): List of pooled SampleBatchBuilder object for recycling. active_episodes (Dict[str, MultiAgentEpisode]): Mapping from episode ID to currently ongoing MultiAgentEpisode object. unfiltered_obs (dict): Doubly keyed dict of env-ids -> agent ids -> unfiltered observation tensor, returned by a `BaseEnv.poll()` call. rewards (dict): Doubly keyed dict of env-ids -> agent ids -> rewards tensor, returned by a `BaseEnv.poll()` call. dones (dict): Doubly keyed dict of env-ids -> agent ids -> boolean done flags, returned by a `BaseEnv.poll()` call. infos (dict): Doubly keyed dict of env-ids -> agent ids -> info dicts, returned by a `BaseEnv.poll()` call. horizon (int): Horizon of the episode. preprocessors (dict): Map of policy id to preprocessor for the observations prior to filtering. obs_filters (dict): Map of policy id to filter used to process observations for the policy. rollout_fragment_length (int): Number of episode steps before `SampleBatch` is yielded. Set to infinity to yield complete episodes. multiple_episodes_in_batch (bool): Whether to pack multiple episodes into each batch. This guarantees batches will be exactly `rollout_fragment_length` in size. callbacks (DefaultCallbacks): User callbacks to run on episode events. soft_horizon (bool): Calculate rewards but don't reset the environment when the horizon is hit. no_done_at_end (bool): Ignore the done=True at the end of the episode and instead record done=False. observation_fn (ObservationFunction): Optional multi-agent observation func to use for preprocessing observations. sample_collector (SampleCollector): The SampleCollector object used to store and retrieve environment samples. Returns: Tuple: - active_envs: Set of non-terminated env ids. - to_eval: Map of policy_id to list of agent PolicyEvalData. - outputs: List of metrics and samples to return from the sampler. """ # Output objects. active_envs: Set[EnvID] = set() to_eval: Dict[PolicyID, List[PolicyEvalData]] = defaultdict(list) outputs: List[Union[RolloutMetrics, SampleBatchType]] = [] # For each (vectorized) sub-environment. # type: EnvID, Dict[AgentID, EnvObsType] for env_id, all_agents_obs in unfiltered_obs.items(): is_new_episode: bool = env_id not in active_episodes episode: MultiAgentEpisode = active_episodes[env_id] if not is_new_episode: sample_collector.episode_step(episode) episode._add_agent_rewards(rewards[env_id]) # Check episode termination conditions. if dones[env_id]["__all__"] or episode.length >= horizon: hit_horizon = (episode.length >= horizon and not dones[env_id]["__all__"]) all_agents_done = True atari_metrics: List[RolloutMetrics] = _fetch_atari_metrics( base_env) if atari_metrics is not None: for m in atari_metrics: outputs.append( m._replace(custom_metrics=episode.custom_metrics)) else: outputs.append( RolloutMetrics(episode.length, episode.total_reward, dict(episode.agent_rewards), episode.custom_metrics, {}, episode.hist_data, episode.media)) else: hit_horizon = False all_agents_done = False active_envs.add(env_id) # Custom observation function is applied before preprocessing. if observation_fn: all_agents_obs: Dict[AgentID, EnvObsType] = observation_fn( agent_obs=all_agents_obs, worker=worker, base_env=base_env, policies=policies, episode=episode) if not isinstance(all_agents_obs, dict): raise ValueError( "observe() must return a dict of agent observations") # For each agent in the environment. # type: AgentID, EnvObsType for agent_id, raw_obs in all_agents_obs.items(): assert agent_id != "__all__" last_observation: EnvObsType = episode.last_observation_for( agent_id) agent_done = bool(all_agents_done or dones[env_id].get(agent_id)) # A new agent (initial obs) is already done -> Skip entirely. if last_observation is None and agent_done: continue policy_id: PolicyID = episode.policy_for(agent_id) prep_obs: EnvObsType = _get_or_raise(preprocessors, policy_id).transform(raw_obs) if log_once("prep_obs"): logger.info("Preprocessed obs: {}".format(summarize(prep_obs))) filtered_obs: EnvObsType = _get_or_raise(obs_filters, policy_id)(prep_obs) if log_once("filtered_obs"): logger.info("Filtered obs: {}".format(summarize(filtered_obs))) episode._set_last_observation(agent_id, filtered_obs) episode._set_last_raw_obs(agent_id, raw_obs) # Infos from the environment. agent_infos = infos[env_id].get(agent_id, {}) episode._set_last_info(agent_id, agent_infos) # Record transition info if applicable. if last_observation is None: sample_collector.add_init_obs(episode, agent_id, env_id, policy_id, episode.length - 1, filtered_obs) else: # Add actions, rewards, next-obs to collectors. values_dict = { "t": episode.length - 1, "env_id": env_id, "agent_index": episode._agent_index(agent_id), # Action (slot 0) taken at timestep t. "actions": episode.last_action_for(agent_id), # Reward received after taking a at timestep t. "rewards": rewards[env_id][agent_id], # After taking action=a, did we reach terminal? "dones": (False if (no_done_at_end or (hit_horizon and soft_horizon)) else agent_done), # Next observation. "new_obs": filtered_obs, } # Add extra-action-fetches to collectors. pol = policies[policy_id] for key, value in episode.last_pi_info_for(agent_id).items(): if key in pol.view_requirements: values_dict[key] = value # Env infos for this agent. if "infos" in pol.view_requirements: values_dict["infos"] = agent_infos sample_collector.add_action_reward_next_obs( episode.episode_id, agent_id, env_id, policy_id, agent_done, values_dict) if not agent_done: item = PolicyEvalData( env_id, agent_id, filtered_obs, agent_infos, None if last_observation is None else episode.rnn_state_for(agent_id), None if last_observation is None else episode.last_action_for(agent_id), rewards[env_id][agent_id] or 0.0) to_eval[policy_id].append(item) # Invoke the `on_episode_step` callback after the step is logged # to the episode. # Exception: The very first env.poll() call causes the env to get reset # (no step taken yet, just a single starting observation logged). # We need to skip this callback in this case. if episode.length > 0: callbacks.on_episode_step( worker=worker, base_env=base_env, episode=episode, env_index=env_id) # Episode is done for all agents (dones[__all__] == True) # or we hit the horizon. if all_agents_done: is_done = dones[env_id]["__all__"] check_dones = is_done and not no_done_at_end # If, we are not allowed to pack the next episode into the same # SampleBatch (batch_mode=complete_episodes) -> Build the # MultiAgentBatch from a single episode and add it to "outputs". # Otherwise, just postprocess and continue collecting across # episodes. ma_sample_batch = sample_collector.postprocess_episode( episode, is_done=is_done or (hit_horizon and not soft_horizon), check_dones=check_dones, build=not multiple_episodes_in_batch) if ma_sample_batch: outputs.append(ma_sample_batch) # Call each policy's Exploration.on_episode_end method. for p in policies.values(): if getattr(p, "exploration", None) is not None: p.exploration.on_episode_end( policy=p, environment=base_env, episode=episode, tf_sess=getattr(p, "_sess", None)) # Call custom on_episode_end callback. callbacks.on_episode_end( worker=worker, base_env=base_env, policies=policies, episode=episode, env_index=env_id, ) # Horizon hit and we have a soft horizon (no hard env reset). if hit_horizon and soft_horizon: episode.soft_reset() resetted_obs: Dict[AgentID, EnvObsType] = all_agents_obs else: del active_episodes[env_id] resetted_obs: Dict[AgentID, EnvObsType] = base_env.try_reset( env_id) # Reset not supported, drop this env from the ready list. if resetted_obs is None: if horizon != float("inf"): raise ValueError( "Setting episode horizon requires reset() support " "from the environment.") # Creates a new episode if this is not async return. # If reset is async, we will get its result in some future poll. elif resetted_obs != ASYNC_RESET_RETURN: new_episode: MultiAgentEpisode = active_episodes[env_id] if observation_fn: resetted_obs: Dict[AgentID, EnvObsType] = observation_fn( agent_obs=resetted_obs, worker=worker, base_env=base_env, policies=policies, episode=new_episode) # type: AgentID, EnvObsType for agent_id, raw_obs in resetted_obs.items(): policy_id: PolicyID = new_episode.policy_for(agent_id) prep_obs: EnvObsType = _get_or_raise( preprocessors, policy_id).transform(raw_obs) filtered_obs: EnvObsType = _get_or_raise( obs_filters, policy_id)(prep_obs) new_episode._set_last_observation(agent_id, filtered_obs) # Add initial obs to buffer. sample_collector.add_init_obs( new_episode, agent_id, env_id, policy_id, new_episode.length - 1, filtered_obs) item = PolicyEvalData( env_id, agent_id, filtered_obs, episode.last_info_for(agent_id) or {}, episode.rnn_state_for(agent_id), None, 0.0) to_eval[policy_id].append(item) # Try to build something. if multiple_episodes_in_batch: sample_batches = \ sample_collector.try_build_truncated_episode_multi_agent_batch() if sample_batches: outputs.extend(sample_batches) return active_envs, to_eval, outputs def _do_policy_eval( *, to_eval: Dict[PolicyID, List[PolicyEvalData]], policies: Dict[PolicyID, Policy], sample_collector, active_episodes: Dict[str, MultiAgentEpisode], tf_sess: Optional["tf.Session"] = None, ) -> Dict[PolicyID, Tuple[TensorStructType, StateBatch, dict]]: """Call compute_actions on collected episode/model data to get next action. Args: to_eval (Dict[PolicyID, List[PolicyEvalData]]): Mapping of policy IDs to lists of PolicyEvalData objects (items in these lists will be the batch's items for the model forward pass). policies (Dict[PolicyID, Policy]): Mapping from policy ID to Policy obj. sample_collector (SampleCollector): The SampleCollector object to use. tf_sess (Optional[tf.Session]): Optional tensorflow session to use for batching TF policy evaluations. Returns: eval_results: dict of policy to compute_action() outputs. """ eval_results: Dict[PolicyID, TensorStructType] = {} if tf_sess: builder = TFRunBuilder(tf_sess, "policy_eval") pending_fetches: Dict[PolicyID, Any] = {} else: builder = None if log_once("compute_actions_input"): logger.info("Inputs to compute_actions():\n\n{}\n".format( summarize(to_eval))) for policy_id, eval_data in to_eval.items(): policy: Policy = _get_or_raise(policies, policy_id) input_dict = sample_collector.get_inference_input_dict(policy_id) eval_results[policy_id] = \ policy.compute_actions_from_input_dict( input_dict, timestep=policy.global_timestep, episodes=[active_episodes[t.env_id] for t in eval_data]) if builder: # type: PolicyID, Tuple[TensorStructType, StateBatch, dict] for pid, v in pending_fetches.items(): eval_results[pid] = builder.get(v) if log_once("compute_actions_result"): logger.info("Outputs of compute_actions():\n\n{}\n".format( summarize(eval_results))) return eval_results def _process_policy_eval_results( *, to_eval: Dict[PolicyID, List[PolicyEvalData]], eval_results: Dict[PolicyID, Tuple[TensorStructType, StateBatch, dict]], active_episodes: Dict[str, MultiAgentEpisode], active_envs: Set[int], off_policy_actions: MultiEnvDict, policies: Dict[PolicyID, Policy], clip_actions: bool, ) -> Dict[EnvID, Dict[AgentID, EnvActionType]]: """Process the output of policy neural network evaluation. Records policy evaluation results into the given episode objects and returns replies to send back to agents in the env. Args: to_eval (Dict[PolicyID, List[PolicyEvalData]]): Mapping of policy IDs to lists of PolicyEvalData objects. eval_results (Dict[PolicyID, List]): Mapping of policy IDs to list of actions, rnn-out states, extra-action-fetches dicts. active_episodes (Dict[str, MultiAgentEpisode]): Mapping from episode ID to currently ongoing MultiAgentEpisode object. active_envs (Set[int]): Set of non-terminated env ids. off_policy_actions (dict): Doubly keyed dict of env-ids -> agent ids -> off-policy-action, returned by a `BaseEnv.poll()` call. policies (Dict[PolicyID, Policy]): Mapping from policy ID to Policy. clip_actions (bool): Whether to clip actions to the action space's bounds. Returns: actions_to_send: Nested dict of env id -> agent id -> actions to be sent to Env (np.ndarrays). """ actions_to_send: Dict[EnvID, Dict[AgentID, EnvActionType]] = \ defaultdict(dict) # type: int for env_id in active_envs: actions_to_send[env_id] = {} # at minimum send empty dict # type: PolicyID, List[PolicyEvalData] for policy_id, eval_data in to_eval.items(): actions: TensorStructType = eval_results[policy_id][0] actions = convert_to_numpy(actions) rnn_out_cols: StateBatch = eval_results[policy_id][1] pi_info_cols: dict = eval_results[policy_id][2] # In case actions is a list (representing the 0th dim of a batch of # primitive actions), try to convert it first. if isinstance(actions, list): actions = np.array(actions) # Store RNN state ins/outs and extra-action fetches to episode. for f_i, column in enumerate(rnn_out_cols): pi_info_cols["state_out_{}".format(f_i)] = column policy: Policy = _get_or_raise(policies, policy_id) # Split action-component batches into single action rows. actions: List[EnvActionType] = unbatch(actions) # type: int, EnvActionType for i, action in enumerate(actions): # Clip if necessary. if clip_actions: clipped_action = clip_action(action, policy.action_space_struct) else: clipped_action = action env_id: int = eval_data[i].env_id agent_id: AgentID = eval_data[i].agent_id episode: MultiAgentEpisode = active_episodes[env_id] episode._set_rnn_state(agent_id, [c[i] for c in rnn_out_cols]) episode._set_last_pi_info( agent_id, {k: v[i] for k, v in pi_info_cols.items()}) if env_id in off_policy_actions and \ agent_id in off_policy_actions[env_id]: episode._set_last_action(agent_id, off_policy_actions[env_id][agent_id]) else: episode._set_last_action(agent_id, action) assert agent_id not in actions_to_send[env_id] actions_to_send[env_id][agent_id] = clipped_action return actions_to_send def _fetch_atari_metrics(base_env: BaseEnv) -> List[RolloutMetrics]: """Atari games have multiple logical episodes, one per life. However, for metrics reporting we count full episodes, all lives included. """ unwrapped = base_env.get_unwrapped() if not unwrapped: return None atari_out = [] for u in unwrapped: monitor = get_wrapper_by_cls(u, MonitorEnv) if not monitor: return None for eps_rew, eps_len in monitor.next_episode_results(): atari_out.append(RolloutMetrics(eps_len, eps_rew)) return atari_out def _to_column_format(rnn_state_rows: List[List[Any]]) -> StateBatch: num_cols = len(rnn_state_rows[0]) return [[row[i] for row in rnn_state_rows] for i in range(num_cols)] def _get_or_raise(mapping: Dict[PolicyID, Union[Policy, Preprocessor, Filter]], policy_id: PolicyID) -> Union[Policy, Preprocessor, Filter]: """Returns an object under key `policy_id` in `mapping`. Args: mapping (Dict[PolicyID, Union[Policy, Preprocessor, Filter]]): The mapping dict from policy id (str) to actual object (Policy, Preprocessor, etc.). policy_id (str): The policy ID to lookup. Returns: Union[Policy, Preprocessor, Filter]: The found object. Raises: ValueError: If `policy_id` cannot be found in `mapping`. """ if policy_id not in mapping: raise ValueError( "Could not find policy for agent: agent policy id `{}` not " "in policy map keys {}.".format(policy_id, mapping.keys())) return mapping[policy_id]