title: OpenAI gym and Python threading
body: <p>I am working on a variation of A3C/ACER and I have several workers, each running on its own thread. I am using OpenAI gym environments.</p>
  
  <p>Python threading works fine but it cannot fully utilize all cores. As there are no blocking I/O, it does not context switch. </p>
  
  <p>I would like workers to somehow to release the GIL while executing actions in their respective environments. </p>
  
  <p>I would appreciate your feedback: Does it make sense and it is possible? </p>