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v0.8.1
v0.8.1
https://github.com/python/cpython
Tip revision: 376dd0edfa1dd77e2f59b4a09b444826b9fa9eb1 authored by Benjamin Peterson on 06 April 2013, 13:58:51 UTC
change version to 2.7.4
change version to 2.7.4
Tip revision: 376dd0e
fork_wait.py
"""This test case provides support for checking forking and wait behavior.
To test different wait behavior, override the wait_impl method.
We want fork1() semantics -- only the forking thread survives in the
child after a fork().
On some systems (e.g. Solaris without posix threads) we find that all
active threads survive in the child after a fork(); this is an error.
While BeOS doesn't officially support fork and native threading in
the same application, the present example should work just fine. DC
"""
import os, sys, time, unittest
import test.test_support as test_support
thread = test_support.import_module('thread')
LONGSLEEP = 2
SHORTSLEEP = 0.5
NUM_THREADS = 4
class ForkWait(unittest.TestCase):
def setUp(self):
self.alive = {}
self.stop = 0
def f(self, id):
while not self.stop:
self.alive[id] = os.getpid()
try:
time.sleep(SHORTSLEEP)
except IOError:
pass
def wait_impl(self, cpid):
for i in range(10):
# waitpid() 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 = os.waitpid(cpid, os.WNOHANG)
if spid == cpid:
break
time.sleep(2 * SHORTSLEEP)
self.assertEqual(spid, cpid)
self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
def test_wait(self):
for i in range(NUM_THREADS):
thread.start_new(self.f, (i,))
time.sleep(LONGSLEEP)
a = self.alive.keys()
a.sort()
self.assertEqual(a, range(NUM_THREADS))
prefork_lives = self.alive.copy()
if sys.platform in ['unixware7']:
cpid = os.fork1()
else:
cpid = os.fork()
if cpid == 0:
# Child
time.sleep(LONGSLEEP)
n = 0
for key in self.alive:
if self.alive[key] != prefork_lives[key]:
n += 1
os._exit(n)
else:
# Parent
self.wait_impl(cpid)
# Tell threads to die
self.stop = 1
time.sleep(2*SHORTSLEEP) # Wait for threads to die