Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 3d407dc564bd92b46ed00380213f545e515d6ddf authored by Barry Warsaw on 04 December 2008, 02:59:51 UTC
Prep for 2.6.1
Prep for 2.6.1
Tip revision: 3d407dc
fork_wait.py
"""This test case provides support for checking forking and wait behavior.
To test different wait behavior, overrise 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, thread, unittest
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.assertEquals(spid, cpid)
self.assertEquals(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.assertEquals(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