ray/rllib/optimizers/rollout.py
2020-05-21 10:16:18 -07:00

35 lines
1.1 KiB
Python

import logging
import ray
from ray.rllib.policy.sample_batch import SampleBatch
logger = logging.getLogger(__name__)
def collect_samples(agents, rollout_fragment_length, num_envs_per_worker,
train_batch_size):
"""Collects at least train_batch_size samples, never discarding any."""
num_timesteps_so_far = 0
trajectories = []
agent_dict = {}
for agent in agents:
fut_sample = agent.sample.remote()
agent_dict[fut_sample] = agent
while agent_dict:
[fut_sample], _ = ray.wait(list(agent_dict))
agent = agent_dict.pop(fut_sample)
next_sample = ray.get(fut_sample)
num_timesteps_so_far += next_sample.count
trajectories.append(next_sample)
# Only launch more tasks if we don't already have enough pending
pending = len(
agent_dict) * rollout_fragment_length * num_envs_per_worker
if num_timesteps_so_far + pending < train_batch_size:
fut_sample2 = agent.sample.remote()
agent_dict[fut_sample2] = agent
return SampleBatch.concat_samples(trajectories)