title: Limit parallel processes in CherryPy?
body: <p>I have a CherryPy server running on a BeagleBone Black. Server generates a simple webpage and does local SPI reads / writes (hardware interface). The application is going to be used on a local network with 1-2 clients at a time.
  I need to prevent a CherryPy class function being called twice, two or more instances before it completes.
  Thoughts?</p>