Lib/test/test_wait4.py

   1 """This test checks for correct wait4() behavior.
   2 """
   3
   4 import os
   5 import time
   6 from test.fork_wait import ForkWait
   7 from test.test_support import TestSkipped, run_unittest, reap_children
   8
   9 try:
  10     os.fork
  11 except AttributeError:
  12     raise TestSkipped, "os.fork not defined -- skipping test_wait4"
  13
  14 try:
  15     os.wait4
  16 except AttributeError:
  17     raise TestSkipped, "os.wait4 not defined -- skipping test_wait4"
  18
  19 class Wait4Test(ForkWait):
  20     def wait_impl(self, cpid):
  21         for i in range(10):
  22             # wait4() shouldn't hang, but some of the buildbots seem to hang
  23             # in the forking tests.  This is an attempt to fix the problem.
  24             spid, status, rusage = os.wait4(cpid, os.WNOHANG)
  25             if spid == cpid:
  26                 break
  27             time.sleep(1.0)
  28         self.assertEqual(spid, cpid)
  29         self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
  30         self.assertTrue(rusage)
  31
  32 def test_main():
  33     run_unittest(Wait4Test)
  34     reap_children()
  35
  36 if __name__ == "__main__":
  37     test_main()