def _subproc_worker(pipe, parent_pipe, env_fn_wrapper, obs_bufs, obs_shapes, obs_dtypes, keys):
    """
    Control a single environment instance using IPC and
    shared memory.
    """
    def _write_obs(maybe_dict_obs):
        flatdict = obs_to_dict(maybe_dict_obs)
        for k in keys:
            dst = obs_bufs[k].get_obj()
            dst_np = np.frombuffer(dst, dtype=obs_dtypes[k]).reshape(obs_shapes[k])  # pylint: disable=W0212
            np.copyto(dst_np, flatdict[k])

    env = env_fn_wrapper.x()
    parent_pipe.close()
    try:
        while True:
            cmd, data = pipe.recv()
            if cmd == 'reset':
                pipe.send(_write_obs(env.reset()))
            elif cmd == 'step':
                obs, reward, done, info = env.step(data)
                if done:
                    obs = env.reset()
                pipe.send((_write_obs(obs), reward, done, info))
            elif cmd == 'render':
                pipe.send(env.render(mode='rgb_array'))
            elif cmd == 'close':
                pipe.send(None)
                break
            else:
                raise RuntimeError('Got unrecognized cmd %s' % cmd)
    except KeyboardInterrupt:
        print('ShmemVecEnv worker: got KeyboardInterrupt')
    finally:
        env.close()
Control a single environment instance using IPC and
    shared memory.