Python code coverage for Lib/test/fork_wait.py

#	count	content
1	n/a	"""This test case provides support for checking forking and wait behavior.
2	n/a
3	n/a	To test different wait behavior, override the wait_impl method.
4	n/a
5	n/a	We want fork1() semantics -- only the forking thread survives in the
6	n/a	child after a fork().
7	n/a
8	n/a	On some systems (e.g. Solaris without posix threads) we find that all
9	n/a	active threads survive in the child after a fork(); this is an error.
10	n/a	"""
11	n/a
12	n/a	import os, sys, time, unittest
13	n/a	import test.support as support
14	n/a	_thread = support.import_module('_thread')
15	n/a
16	n/a	LONGSLEEP = 2
17	n/a	SHORTSLEEP = 0.5
18	n/a	NUM_THREADS = 4
19	n/a
20	n/a	class ForkWait(unittest.TestCase):
21	n/a
22	n/a	def setUp(self):
23	n/a	self.alive = {}
24	n/a	self.stop = 0
25	n/a
26	n/a	def f(self, id):
27	n/a	while not self.stop:
28	n/a	self.alive[id] = os.getpid()
29	n/a	try:
30	n/a	time.sleep(SHORTSLEEP)
31	n/a	except OSError:
32	n/a	pass
33	n/a
34	n/a	def wait_impl(self, cpid):
35	n/a	for i in range(10):
36	n/a	# waitpid() shouldn't hang, but some of the buildbots seem to hang
37	n/a	# in the forking tests. This is an attempt to fix the problem.
38	n/a	spid, status = os.waitpid(cpid, os.WNOHANG)
39	n/a	if spid == cpid:
40	n/a	break
41	n/a	time.sleep(2 * SHORTSLEEP)
42	n/a
43	n/a	self.assertEqual(spid, cpid)
44	n/a	self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
45	n/a
46	n/a	@support.reap_threads
47	n/a	def test_wait(self):
48	n/a	for i in range(NUM_THREADS):
49	n/a	_thread.start_new(self.f, (i,))
50	n/a
51	n/a	# busy-loop to wait for threads
52	n/a	deadline = time.monotonic() + 10.0
53	n/a	while len(self.alive) < NUM_THREADS:
54	n/a	time.sleep(0.1)
55	n/a	if deadline < time.monotonic():
56	n/a	break
57	n/a
58	n/a	a = sorted(self.alive.keys())
59	n/a	self.assertEqual(a, list(range(NUM_THREADS)))
60	n/a
61	n/a	prefork_lives = self.alive.copy()
62	n/a
63	n/a	if sys.platform in ['unixware7']:
64	n/a	cpid = os.fork1()
65	n/a	else:
66	n/a	cpid = os.fork()
67	n/a
68	n/a	if cpid == 0:
69	n/a	# Child
70	n/a	time.sleep(LONGSLEEP)
71	n/a	n = 0
72	n/a	for key in self.alive:
73	n/a	if self.alive[key] != prefork_lives[key]:
74	n/a	n += 1
75	n/a	os._exit(n)
76	n/a	else:
77	n/a	# Parent
78	n/a	try:
79	n/a	self.wait_impl(cpid)
80	n/a	finally:
81	n/a	# Tell threads to die
82	n/a	self.stop = 1