Semaphore is busy issue

[qbzztz123]

Dear author
I meet "posix_ipc.BusyError: Semaphore is busy" problem when I begin training SAC algorithm. It always happens when the algorithm has been trained for 15 episodes or more. The problem detail is in the attached pictures.

I wonder if you have encountered it before. If so, please offer me some useful solution. Any help is important for me.
The dependency I use is Holoocean 1.0.0, and I run this project on RTX2060 GPU.

[qbzztz123]

Here is the copy of the problem.
Traceback (most recent call last):
File "/home/cwh/RL_AUV_tracking/SB3_learning.py", line 449, in
main()
File "/home/cwh/RL_AUV_tracking/SB3_learning.py", line 229, in main
learn(env, model_dir, log_dir)
File "/home/cwh/RL_AUV_tracking/SB3_learning.py", line 307, in learn
model.learn(total_timesteps=1000000, tb_log_name="first_run", log_interval=5, callback=callback)
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/stable_baselines3/sac/sac.py", line 307, in learn
return super().learn(
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/stable_baselines3/common/off_policy_algorithm.py", line 328, in learn
rollout = self.collect_rollouts(
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/stable_baselines3/common/off_policy_algorithm.py", line 560, in collect_rollouts
new_obs, rewards, dones, infos = env.step(actions)
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/stable_baselines3/common/vec_env/base_vec_env.py", line 206, in step
return self.step_wait()
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/stable_baselines3/common/vec_env/vec_monitor.py", line 76, in step_wait
obs, rewards, dones, infos = self.venv.step_wait()
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/stable_baselines3/common/vec_env/dummy_vec_env.py", line 58, in step_wait
obs, self.buf_rews[env_idx], terminated, truncated, self.buf_infos[env_idx] = self.envs[env_idx].step(
File "/home/cwh/RL_AUV_tracking/auv_env/display_wrapper.py", line 49, in step
return self.env.step(action)
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/gymnasium/wrappers/common.py", line 125, in step
observation, reward, terminated, truncated, info = self.env.step(action)
File "/home/cwh/RL_AUV_tracking/auv_env/base.py", line 130, in step
return self.world.step(action_waypoint=action_waypoint)
File "/home/cwh/RL_AUV_tracking/auv_env/world_auv.py", line 134, in step
self.sensors = self.ocean.tick()
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/holoocean/environments.py", line 547, in tick
self._client.acquire(self._timeout)
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/holoocean/holooceanclient.py", line 116, in acquire
self._get_semaphore_fn(self._semaphore2, timeout)
File "/home/cwh/anaconda3/envs/RL_AUV_Tracking/lib/python3.10/site-packages/holoocean/holooceanclient.py", line 84, in posix_acquire_semaphore
sem.acquire(timeout)
posix_ipc.BusyError: Semaphore is busy

[Ice-mao]

I think it might be an issue related to multi-environment asynchronous communication. Please check the size of your memory, adjust the number of environments, and then give it another try; or you could run separate examples within HoloOcean to see if they work.