def process_file(filename, protocol):
   output_filename = '{0}-{1}.pcap'.format(filename, protocol)
   stdout_filename = '{0}.stdout'.format(filename)
   stderr_filename = '{0}.stderr'.format(filename)
   exitcode_filename = '{0}.exitcode'.format(filename)

   cmdline = ['tshark', '-r', filename, '-Y', protocol, 'P', '-w', output_filename]
   print('Command line: {0}'.format(repr(cmdline)))

   stdout_file = open(stdout_filename, 'w')
   stderr_file = open(stderr_filename, 'w')
   exitcode_file = open(exitcode_filename, 'w')
   exit_code = None
   try:
       shell_cmdline = ' '.join(cmdline)
       process = subprocess.Popen(shell_cmdline,
                                  stdin=subprocess.PIPE,
                                  stdout=stdout_file,
                                  stderr=stderr_file,
                                  shell=True)
       process.stdin.close()
       exit_code = process.wait()
   except:
       # Exception raised while waiting on process; kill child process,
       # then re-raise exception.
       exit_code = process.poll()
       process.kill()
       raise
   finally:
       # These file handles should have been closed already, but it doesn't hurt
       # to close them again.
       stdout_file.close()
       stderr_file.close()
       exitcode_file.write('%s\n' % str(exit_code))
       exitcode_file.close()

def thread_worker():
   while True:
       try:
           filename, protocol = global_q.get_nowait()
           print("Processing " + filename + "\n")
           process_file(filename, protocol)
           global_q.task_done()
       except queue.Empty:
           break