text: """This test checks for correct wait4() behavior.
  """
  
  import os
  import time
  import sys
  from test.fork_wait import ForkWait
  from test.test_support import run_unittest, reap_children, get_attribute
  
  # If either of these do not exist, skip this test.
  get_attribute(os, 'fork')
  get_attribute(os, 'wait4')
  
  
  class Wait4Test(ForkWait):
      def wait_impl(self, cpid):
          option = os.WNOHANG
          if sys.platform.startswith('aix'):
              # Issue #11185: wait4 is broken on AIX and will always return 0
              # with WNOHANG.
              option = 0
          for i in range(10):
              # wait4() shouldn't hang, but some of the buildbots seem to hang
              # in the forking tests.  This is an attempt to fix the problem.
              spid, status, rusage = os.wait4(cpid, option)
              if spid == cpid:
                  break
              time.sleep(1.0)
          self.assertEqual(spid, cpid)
          self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
          self.assertTrue(rusage)
  
  def test_main():
      run_unittest(Wait4Test)
      reap_children()
  
  if __name__ == "__main__":
      test_main()
  