Support A2C

utils/config.py

@@ -51,3 +51,4 @@ class Config:
         self.max_steps = 0
         self.success_threshold = float('inf')
         self.render_episode_freq = 0
+        self.rollout_length = None

utils/misc.py

@@ -60,6 +60,7 @@ def run_episodes(agent):
             if avg_reward > config.success_threshold:
                 break
 
+    agent.close()
     return steps, rewards, avg_test_rewards
 
 def sync_grad(target_network, src_network):