# Copyright 2017 The TensorFlow Agents Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Utilities for using reinforcement learning algorithms."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import logging
import os
import re
import ruamel.yaml as yaml
import tensorflow as tf
from agents import tools
def define_simulation_graph(batch_env, algo_cls, config):
"""Define the algorithm and environment interaction.
Args:
batch_env: In-graph environments object.
algo_cls: Constructor of a batch algorithm.
config: Configuration object for the algorithm.
Returns:
Object providing graph elements via attributes.
"""
# pylint: disable=unused-variable
step = tf.Variable(0, False, dtype=tf.int32, name='global_step')
is_training = tf.placeholder(tf.bool, name='is_training')
should_log = tf.placeholder(tf.bool, name='should_log')
do_report = tf.placeholder(tf.bool, name='do_report')
force_reset = tf.placeholder(tf.bool, name='force_reset')
algo = algo_cls(batch_env, step, is_training, should_log, config)
done, score, summary = tools.simulate(
batch_env, algo, should_log, force_reset)
message = 'Graph contains {} trainable variables.'
tf.logging.info(message.format(tools.count_weights()))
# pylint: enable=unused-variable
return tools.AttrDict(locals())
def define_batch_env(constructor, num_agents, env_processes):
"""Create environments and apply all desired wrappers.
Args:
constructor: Constructor of an OpenAI gym environment.
num_agents: Number of environments to combine in the batch.
env_processes: Whether to step environment in external processes.
Returns:
In-graph environments object.
"""
with tf.variable_scope('environments'):
if env_processes:
envs = [
tools.wrappers.ExternalProcess(constructor)
for _ in range(num_agents)]
else:
envs = [constructor() for _ in range(num_agents)]
batch_env = tools.BatchEnv(envs, blocking=not env_processes)
batch_env = tools.InGraphBatchEnv(batch_env)
return batch_env
def define_saver(exclude=None):
"""Create a saver for the variables we want to checkpoint.
Args:
exclude: List of regexes to match variable names to exclude.
Returns:
Saver object.
"""
variables = []
exclude = exclude or []
exclude = [re.compile(regex) for regex in exclude]
for variable in tf.global_variables():
if any(regex.match(variable.name) for regex in exclude):
continue
variables.append(variable)
saver = tf.train.Saver(variables, keep_checkpoint_every_n_hours=5)
return saver
def initialize_variables(sess, saver, logdir, checkpoint=None, resume=None):
"""Initialize or restore variables from a checkpoint if available.
Args:
sess: Session to initialize variables in.
saver: Saver to restore variables.
logdir: Directory to search for checkpoints.
checkpoint: Specify what checkpoint name to use; defaults to most recent.
resume: Whether to expect recovering a checkpoint or starting a new run.
Raises:
ValueError: If resume expected but no log directory specified.
RuntimeError: If no resume expected but a checkpoint was found.
"""
sess.run(tf.group(
tf.local_variables_initializer(),
tf.global_variables_initializer()))
if resume and not (logdir or checkpoint):
raise ValueError('Need to specify logdir to resume a checkpoint.')
if logdir:
state = tf.train.get_checkpoint_state(logdir)
if checkpoint:
checkpoint = os.path.join(logdir, checkpoint)
if not checkpoint and state and state.model_checkpoint_path:
checkpoint = state.model_checkpoint_path
if checkpoint and resume is False:
message = 'Found unexpected checkpoint when starting a new run.'
raise RuntimeError(message)
if checkpoint:
saver.restore(sess, checkpoint)
def save_config(config, logdir=None):
"""Save a new configuration by name.
If a logging directory is specified, is will be created and the configuration
will be stored there. Otherwise, a log message will be printed.
Args:
config: Configuration object.
logdir: Location for writing summaries and checkpoints if specified.
Returns:
Configuration object.
"""
if logdir:
with config.unlocked:
config.logdir = logdir
message = 'Start a new run and write summaries and checkpoints to {}.'
tf.logging.info(message.format(config.logdir))
tf.gfile.MakeDirs(config.logdir)
config_path = os.path.join(config.logdir, 'config.yaml')
with tf.gfile.FastGFile(config_path, 'w') as file_:
yaml.dump(config, file_, default_flow_style=False)
else:
message = (
'Start a new run without storing summaries and checkpoints since no '
'logging directory was specified.')
tf.logging.info(message)
return config
def load_config(logdir):
# pylint: disable=missing-raises-doc
"""Load a configuration from the log directory.
Args:
logdir: The logging directory containing the configuration file.
Raises:
IOError: The logging directory does not contain a configuration file.
Returns:
Configuration object.
"""
config_path = logdir and os.path.join(logdir, 'config.yaml')
if not config_path or not tf.gfile.Exists(config_path):
message = (
'Cannot resume an existing run since the logging directory does not '
'contain a configuration file.')
raise IOError(message)
with tf.gfile.FastGFile(config_path, 'r') as file_:
config = yaml.load(file_, Loader=yaml.Loader)
message = 'Resume run and write summaries and checkpoints to {}.'
tf.logging.info(message.format(config.logdir))
return config
def set_up_logging():
"""Configure the TensorFlow logger."""
tf.logging.set_verbosity(tf.logging.INFO)
logging.getLogger('tensorflow').propagate = False
