title: python-twisted: fork for background non-returning processing
body: <p>How to correctly fork a child process in twisted that does not use anything from twisted (but uses data from the parent process) (e.g. to process a “snapshot” of some data from the parent process and write it to file, without blocking)?</p>
  
  <p>It seems if I do anything like clean shutdown in the child process after <code>os.fork()</code>, it closes some of the sockets / descriptors in the parent process; the only way to avoid that that I see is to do <code>os.kill(os.getpid(), signal.SIGKILL)</code>, which does seem like a bad idea (though not directly problematic).</p>
  
  <p>(additionally, if a dict is changed in the parent process, can it be that it will change in the child process too? Quick test shows that it doesn't change, though. OS/kernels are debian stable / sid)</p>