cpython/Lib/test/test_wait3.py

57 lines
1.8 KiB
Python

"""This test checks for correct wait3() behavior.
"""
import os
import subprocess
import sys
import time
import unittest
from test.fork_wait import ForkWait
from test import support
if not hasattr(os, 'fork'):
raise unittest.SkipTest("os.fork not defined")
if not hasattr(os, 'wait3'):
raise unittest.SkipTest("os.wait3 not defined")
class Wait3Test(ForkWait):
def wait_impl(self, cpid):
# This many iterations can be required, since some previously run
# tests (e.g. test_ctypes) could have spawned a lot of children
# very quickly.
deadline = time.monotonic() + support.SHORT_TIMEOUT
while time.monotonic() <= deadline:
# wait3() 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.wait3(os.WNOHANG)
if spid == cpid:
break
time.sleep(0.1)
self.assertEqual(spid, cpid)
self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
self.assertTrue(rusage)
def test_wait3_rusage_initialized(self):
# Ensure a successful wait3() call where no child was ready to report
# its exit status does not return uninitialized memory in the rusage
# structure. See bpo-36279.
args = [sys.executable, '-c', 'import sys; sys.stdin.read()']
proc = subprocess.Popen(args, stdin=subprocess.PIPE)
try:
pid, status, rusage = os.wait3(os.WNOHANG)
self.assertEqual(0, pid)
self.assertEqual(0, status)
self.assertEqual(0, sum(rusage))
finally:
proc.stdin.close()
proc.wait()
def tearDownModule():
support.reap_children()
if __name__ == "__main__":
unittest.main()