ray/rllib/policy/tf_policy_template.py
2020-07-05 13:09:51 +02:00

209 lines
9.3 KiB
Python

from ray.rllib.policy.dynamic_tf_policy import DynamicTFPolicy
from ray.rllib.policy import eager_tf_policy
from ray.rllib.policy.policy import Policy, LEARNER_STATS_KEY
from ray.rllib.policy.tf_policy import TFPolicy
from ray.rllib.utils import add_mixins
from ray.rllib.utils.annotations import override, DeveloperAPI
@DeveloperAPI
def build_tf_policy(name,
*,
loss_fn,
get_default_config=None,
postprocess_fn=None,
stats_fn=None,
optimizer_fn=None,
gradients_fn=None,
apply_gradients_fn=None,
grad_stats_fn=None,
extra_action_fetches_fn=None,
extra_learn_fetches_fn=None,
validate_spaces=None,
before_init=None,
before_loss_init=None,
after_init=None,
make_model=None,
action_sampler_fn=None,
action_distribution_fn=None,
mixins=None,
get_batch_divisibility_req=None,
obs_include_prev_action_reward=True):
"""Helper function for creating a dynamic tf policy at runtime.
Functions will be run in this order to initialize the policy:
1. Placeholder setup: postprocess_fn
2. Loss init: loss_fn, stats_fn
3. Optimizer init: optimizer_fn, gradients_fn, apply_gradients_fn,
grad_stats_fn
This means that you can e.g., depend on any policy attributes created in
the running of `loss_fn` in later functions such as `stats_fn`.
In eager mode, the following functions will be run repeatedly on each
eager execution: loss_fn, stats_fn, gradients_fn, apply_gradients_fn,
and grad_stats_fn.
This means that these functions should not define any variables internally,
otherwise they will fail in eager mode execution. Variable should only
be created in make_model (if defined).
Arguments:
name (str): name of the policy (e.g., "PPOTFPolicy")
loss_fn (func): function that returns a loss tensor as arguments
(policy, model, dist_class, train_batch)
get_default_config (func): optional function that returns the default
config to merge with any overrides
postprocess_fn (func): optional experience postprocessing function
that takes the same args as Policy.postprocess_trajectory()
stats_fn (func): optional function that returns a dict of
TF fetches given the policy and batch input tensors
optimizer_fn (func): optional function that returns a tf.Optimizer
given the policy and config
gradients_fn (func): optional function that returns a list of gradients
given (policy, optimizer, loss). If not specified, this
defaults to optimizer.compute_gradients(loss)
apply_gradients_fn (func): optional function that returns an apply
gradients op given (policy, optimizer, grads_and_vars)
grad_stats_fn (func): optional function that returns a dict of
TF fetches given the policy, batch input, and gradient tensors
extra_action_fetches_fn (func): optional function that returns
a dict of TF fetches given the policy object
extra_learn_fetches_fn (func): optional function that returns a dict of
extra values to fetch and return when learning on a batch
validate_spaces (Optional[callable]): Optional callable that takes the
Policy, observation_space, action_space, and config to check for
correctness.
before_init (func): optional function to run at the beginning of
policy init that takes the same arguments as the policy constructor
before_loss_init (func): optional function to run prior to loss
init that takes the same arguments as the policy constructor
after_init (func): optional function to run at the end of policy init
that takes the same arguments as the policy constructor
make_model (func): optional function that returns a ModelV2 object
given (policy, obs_space, action_space, config).
All policy variables should be created in this function. If not
specified, a default model will be created.
action_sampler_fn (Optional[callable]): A callable returning a sampled
action and its log-likelihood given some (obs and state) inputs.
action_distribution_fn (Optional[callable]): A callable returning
distribution inputs (parameters), a dist-class to generate an
action distribution object from, and internal-state outputs (or an
empty list if not applicable).
mixins (list): list of any class mixins for the returned policy class.
These mixins will be applied in order and will have higher
precedence than the DynamicTFPolicy class
get_batch_divisibility_req (func): optional function that returns
the divisibility requirement for sample batches
obs_include_prev_action_reward (bool): whether to include the
previous action and reward in the model input
Returns:
a DynamicTFPolicy instance that uses the specified args
"""
original_kwargs = locals().copy()
base = add_mixins(DynamicTFPolicy, mixins)
class policy_cls(base):
def __init__(self,
obs_space,
action_space,
config,
existing_model=None,
existing_inputs=None):
if get_default_config:
config = dict(get_default_config(), **config)
if validate_spaces:
validate_spaces(self, obs_space, action_space, config)
if before_init:
before_init(self, obs_space, action_space, config)
def before_loss_init_wrapper(policy, obs_space, action_space,
config):
if before_loss_init:
before_loss_init(policy, obs_space, action_space, config)
if extra_action_fetches_fn is None:
self._extra_action_fetches = {}
else:
self._extra_action_fetches = extra_action_fetches_fn(self)
DynamicTFPolicy.__init__(
self,
obs_space=obs_space,
action_space=action_space,
config=config,
loss_fn=loss_fn,
stats_fn=stats_fn,
grad_stats_fn=grad_stats_fn,
before_loss_init=before_loss_init_wrapper,
make_model=make_model,
action_sampler_fn=action_sampler_fn,
action_distribution_fn=action_distribution_fn,
existing_model=existing_model,
existing_inputs=existing_inputs,
get_batch_divisibility_req=get_batch_divisibility_req,
obs_include_prev_action_reward=obs_include_prev_action_reward)
if after_init:
after_init(self, obs_space, action_space, config)
@override(Policy)
def postprocess_trajectory(self,
sample_batch,
other_agent_batches=None,
episode=None):
if postprocess_fn:
return postprocess_fn(self, sample_batch, other_agent_batches,
episode)
return sample_batch
@override(TFPolicy)
def optimizer(self):
if optimizer_fn:
return optimizer_fn(self, self.config)
else:
return base.optimizer(self)
@override(TFPolicy)
def gradients(self, optimizer, loss):
if gradients_fn:
return gradients_fn(self, optimizer, loss)
else:
return base.gradients(self, optimizer, loss)
@override(TFPolicy)
def build_apply_op(self, optimizer, grads_and_vars):
if apply_gradients_fn:
return apply_gradients_fn(self, optimizer, grads_and_vars)
else:
return base.build_apply_op(self, optimizer, grads_and_vars)
@override(TFPolicy)
def extra_compute_action_fetches(self):
return dict(
base.extra_compute_action_fetches(self),
**self._extra_action_fetches)
@override(TFPolicy)
def extra_compute_grad_fetches(self):
if extra_learn_fetches_fn:
# Auto-add empty learner stats dict if needed.
return dict({
LEARNER_STATS_KEY: {}
}, **extra_learn_fetches_fn(self))
else:
return base.extra_compute_grad_fetches(self)
def with_updates(**overrides):
return build_tf_policy(**dict(original_kwargs, **overrides))
def as_eager():
return eager_tf_policy.build_eager_tf_policy(**original_kwargs)
policy_cls.with_updates = staticmethod(with_updates)
policy_cls.as_eager = staticmethod(as_eager)
policy_cls.__name__ = name
policy_cls.__qualname__ = name
return policy_cls