2020-01-17 12:30:26 +08:00

127 lines
3.3 KiB
Python

from abc import ABC, abstractmethod
from baselines import logger
class AlreadySteppingError(Exception):
"""
Raised when an asynchronous step is running while
step_async() is called again.
"""
def __init__(self):
msg = 'already running an async step'
Exception.__init__(self, msg)
class NotSteppingError(Exception):
"""
Raised when an asynchronous step is not running but
step_wait() is called.
"""
def __init__(self):
msg = 'not running an async step'
Exception.__init__(self, msg)
class VecEnv(ABC):
"""
An abstract asynchronous, vectorized environment.
"""
def __init__(self, num_envs, observation_space, action_space):
self.num_envs = num_envs
self.observation_space = observation_space
self.action_space = action_space
@abstractmethod
def reset(self):
"""
Reset all the environments and return an array of
observations, or a tuple of observation arrays.
If step_async is still doing work, that work will
be cancelled and step_wait() should not be called
until step_async() is invoked again.
"""
pass
@abstractmethod
def step_async(self, actions):
"""
Tell all the environments to start taking a step
with the given actions.
Call step_wait() to get the results of the step.
You should not call this if a step_async run is
already pending.
"""
pass
@abstractmethod
def step_wait(self):
"""
Wait for the step taken with step_async().
Returns (obs, rews, dones, infos):
- obs: an array of observations, or a tuple of
arrays of observations.
- rews: an array of rewards
- dones: an array of "episode done" booleans
- infos: a sequence of info objects
"""
pass
@abstractmethod
def close(self):
"""
Clean up the environments' resources.
"""
pass
def step(self, actions):
self.step_async(actions)
return self.step_wait()
def render(self, mode='human'):
logger.warn('Render not defined for %s'%self)
@property
def unwrapped(self):
if isinstance(self, VecEnvWrapper):
return self.venv.unwrapped
else:
return self
class VecEnvWrapper(VecEnv):
def __init__(self, venv, observation_space=None, action_space=None):
self.venv = venv
VecEnv.__init__(self,
num_envs=venv.num_envs,
observation_space=observation_space or venv.observation_space,
action_space=action_space or venv.action_space)
def step_async(self, actions):
self.venv.step_async(actions)
@abstractmethod
def reset(self):
pass
@abstractmethod
def step_wait(self):
pass
def close(self):
return self.venv.close()
def render(self):
self.venv.render()
class CloudpickleWrapper(object):
"""
Uses cloudpickle to serialize contents (otherwise multiprocessing tries to use pickle)
"""
def __init__(self, x):
self.x = x
def __getstate__(self):
import cloudpickle
return cloudpickle.dumps(self.x)
def __setstate__(self, ob):
import pickle
self.x = pickle.loads(ob)