title: Get number of threads (HECs) at runtime
body: <p>How do I get the number of threads / HECs (the -N parameter) of a Haskell program that was compiled with <em>-threaded</em> during its runtime?</p>
  
  <p>[Edit]
  My question is about the number of HECs, not about the number of cores (even though the answer is related) - so the question is <strong>not</strong> a duplicate. </p>