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 run_unittest, reap_children, get_attribute
   8
   9 # If either of these do not exist, skip this test.
  10 get_attribute(os, 'fork')
  11 get_attribute(os, 'wait4')
  12
  13
  14 class Wait4Test(ForkWait):
  15     def wait_impl(self, cpid):
  16         for i in range(10):
  17             # wait4() shouldn't hang, but some of the buildbots seem to hang
  18             # in the forking tests.  This is an attempt to fix the problem.
  19             spid, status, rusage = os.wait4(cpid, os.WNOHANG)
  20             if spid == cpid:
  21                 break
  22             time.sleep(1.0)
  23         self.assertEqual(spid, cpid)
  24         self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
  25         self.assertTrue(rusage)
  26
  27 def test_main():
  28     run_unittest(Wait4Test)
  29     reap_children()
  30
  31 if __name__ == "__main__":
  32     test_main()