Multi-threaded http stress test code implemented in Python

# Python version 3.3
__author__ = 'Toil'
import sys, getopt
import threading
def httpGet(url, file):
  import http.client
  conn = http.client.HTTPConnection(url)
  conn.request("GET", file)
  r = conn.getresponse()
  #print(r.getheaders())
  while not r.closed:
    r.read(200)
  conn.close()
def Usage():
  print('''
  Options are:
  -c concurrency Number of multiple requests to make
  -u host     The host
  -f file     File on web
  Example: httpget.py -c 100 -u www.example.com -f /
  ''')
if __name__ == '__main__':
  opts, args = getopt.getopt(sys.argv[1:], "hc:u:f:")
  global u, c, f
  for op, value in opts:
    if op == '-c':
      c = int(value)
    elif op == '-u':
      u = value
    elif op == '-f':
      f = value
    elif op == '-h':
      Usage()
      sys.exit(0)
    else:
      sys.exit(0)
  threads = []
  times = c
  print('Test for ', u, f)
  print('waiting...')
  for i in range(0, times):
    t = threading.Thread(target=httpGet(u, f))
    threads.append(t)
  for i in range(0, times):
    threads[i].start()
  for i in range(0, times):
    threads[i].join()