Tianshou/tianshou/env/wrapper.py
2020-03-13 17:49:22 +08:00

250 lines
7.3 KiB
Python

import numpy as np
from abc import ABC
from collections import deque
from multiprocessing import Process, Pipe
try:
import ray
except ImportError:
pass
from tianshou.utils import CloudpickleWrapper
class EnvWrapper(object):
def __init__(self, env):
self.env = env
def step(self, action):
return self.env.step(action)
def reset(self):
return self.env.reset()
def seed(self, seed=None):
if hasattr(self.env, 'seed'):
self.env.seed(seed)
def render(self):
if hasattr(self.env, 'render'):
self.env.render()
def close(self):
self.env.close()
class FrameStack(EnvWrapper):
def __init__(self, env, stack_num):
"""Stack last k frames."""
super().__init__(env)
self.stack_num = stack_num
self._frames = deque([], maxlen=stack_num)
def step(self, action):
obs, reward, done, info = self.env.step(action)
self._frames.append(obs)
return self._get_obs(), reward, done, info
def reset(self):
obs = self.env.reset()
for _ in range(self.stack_num):
self._frames.append(obs)
return self._get_obs()
def _get_obs(self):
try:
return np.concatenate(self._frames, axis=-1)
except ValueError:
return np.stack(self._frames, axis=-1)
class BaseVectorEnv(ABC):
def __init__(self):
pass
class VectorEnv(BaseVectorEnv):
"""docstring for VectorEnv"""
def __init__(self, env_fns, reset_after_done=False):
super().__init__()
self.envs = [_() for _ in env_fns]
self.env_num = len(self.envs)
self._reset_after_done = reset_after_done
def __len__(self):
return len(self.envs)
def reset(self):
return np.stack([e.reset() for e in self.envs])
def step(self, action):
assert len(action) == self.env_num
result = zip(*[e.step(a) for e, a in zip(self.envs, action)])
obs, rew, done, info = result
if self._reset_after_done and sum(done):
obs = np.stack(obs)
for i in np.where(done)[0]:
obs[i] = self.envs[i].reset()
return np.stack(obs), np.stack(rew), np.stack(done), np.stack(info)
def seed(self, seed=None):
if np.isscalar(seed) or seed is None:
seed = [seed for _ in range(self.env_num)]
for e, s in zip(self.envs, seed):
if hasattr(e, 'seed'):
e.seed(s)
def render(self):
for e in self.envs:
if hasattr(e, 'render'):
e.render()
def close(self):
for e in self.envs:
e.close()
def worker(parent, p, env_fn_wrapper, reset_after_done):
parent.close()
env = env_fn_wrapper.data()
while True:
cmd, data = p.recv()
if cmd == 'step':
obs, rew, done, info = env.step(data)
if reset_after_done and done:
# s_ is useless when episode finishes
obs = env.reset()
p.send([obs, rew, done, info])
elif cmd == 'reset':
p.send(env.reset())
elif cmd == 'close':
p.close()
break
elif cmd == 'render':
p.send(env.render() if hasattr(env, 'render') else None)
elif cmd == 'seed':
p.send(env.seed(data) if hasattr(env, 'seed') else None)
else:
raise NotImplementedError
class SubprocVectorEnv(BaseVectorEnv):
"""docstring for SubProcVectorEnv"""
def __init__(self, env_fns, reset_after_done=False):
super().__init__()
self.env_num = len(env_fns)
self.closed = False
self.parent_remote, self.child_remote = \
zip(*[Pipe() for _ in range(self.env_num)])
self.processes = [
Process(target=worker, args=(
parent, child,
CloudpickleWrapper(env_fn), reset_after_done), daemon=True)
for (parent, child, env_fn) in zip(
self.parent_remote, self.child_remote, env_fns)
]
for p in self.processes:
p.start()
for c in self.child_remote:
c.close()
def __len__(self):
return self.env_num
def step(self, action):
assert len(action) == self.env_num
for p, a in zip(self.parent_remote, action):
p.send(['step', a])
result = [p.recv() for p in self.parent_remote]
obs, rew, done, info = zip(*result)
return np.stack(obs), np.stack(rew), np.stack(done), np.stack(info)
def reset(self):
for p in self.parent_remote:
p.send(['reset', None])
return np.stack([p.recv() for p in self.parent_remote])
def seed(self, seed=None):
if np.isscalar(seed) or seed is None:
seed = [seed for _ in range(self.env_num)]
for p, s in zip(self.parent_remote, seed):
p.send(['seed', s])
for p in self.parent_remote:
p.recv()
def render(self):
for p in self.parent_remote:
p.send(['render', None])
for p in self.parent_remote:
p.recv()
def close(self):
if self.closed:
return
for p in self.parent_remote:
p.send(['close', None])
self.closed = True
for p in self.processes:
p.join()
class RayVectorEnv(BaseVectorEnv):
"""docstring for RayVectorEnv"""
def __init__(self, env_fns, reset_after_done=False):
super().__init__()
self.env_num = len(env_fns)
self._reset_after_done = reset_after_done
try:
if not ray.is_initialized():
ray.init()
except NameError:
raise ImportError(
'Please install ray to support VectorEnv: pip3 install ray -U')
self.envs = [
ray.remote(EnvWrapper).options(num_cpus=0).remote(e())
for e in env_fns]
def __len__(self):
return self.env_num
def step(self, action):
assert len(action) == self.env_num
result_obj = [e.step.remote(a) for e, a in zip(self.envs, action)]
obs, rew, done, info = zip(*[ray.get(r) for r in result_obj])
if self._reset_after_done and sum(done):
obs = np.stack(obs)
index = np.where(done)[0]
result_obj = []
for i in range(len(index)):
result_obj.append(self.envs[index[i]].reset.remote())
for i in range(len(index)):
obs[index[i]] = ray.get(result_obj[i])
return np.stack(obs), np.stack(rew), np.stack(done), np.stack(info)
def reset(self):
result_obj = [e.reset.remote() for e in self.envs]
return np.stack([ray.get(r) for r in result_obj])
def seed(self, seed=None):
if not hasattr(self.envs[0], 'seed'):
return
if np.isscalar(seed) or seed is None:
seed = [seed for _ in range(self.env_num)]
result_obj = [e.seed.remote(s) for e, s in zip(self.envs, seed)]
for r in result_obj:
ray.get(r)
def render(self):
if not hasattr(self.envs[0], 'render'):
return
result_obj = [e.render.remote() for e in self.envs]
for r in result_obj:
ray.get(r)
def close(self):
result_obj = [e.close.remote() for e in self.envs]
for r in result_obj:
ray.get(r)