mirror of https://github.com/python/cpython
92 lines
2.5 KiB
Python
92 lines
2.5 KiB
Python
"""This test case provides support for checking forking and wait behavior.
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To test different wait behavior, override the wait_impl method.
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We want fork1() semantics -- only the forking thread survives in the
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child after a fork().
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On some systems (e.g. Solaris without posix threads) we find that all
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active threads survive in the child after a fork(); this is an error.
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"""
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import os, sys, time, unittest
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import threading
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from test import support
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LONGSLEEP = 2
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SHORTSLEEP = 0.5
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NUM_THREADS = 4
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class ForkWait(unittest.TestCase):
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def setUp(self):
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self._threading_key = support.threading_setup()
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self.alive = {}
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self.stop = 0
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self.threads = []
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def tearDown(self):
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# Stop threads
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self.stop = 1
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for thread in self.threads:
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thread.join()
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thread = None
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self.threads.clear()
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support.threading_cleanup(*self._threading_key)
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def f(self, id):
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while not self.stop:
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self.alive[id] = os.getpid()
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try:
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time.sleep(SHORTSLEEP)
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except OSError:
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pass
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def wait_impl(self, cpid):
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for i in range(10):
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# waitpid() shouldn't hang, but some of the buildbots seem to hang
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# in the forking tests. This is an attempt to fix the problem.
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spid, status = os.waitpid(cpid, os.WNOHANG)
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if spid == cpid:
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break
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time.sleep(2 * SHORTSLEEP)
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self.assertEqual(spid, cpid)
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self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
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def test_wait(self):
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for i in range(NUM_THREADS):
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thread = threading.Thread(target=self.f, args=(i,))
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thread.start()
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self.threads.append(thread)
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# busy-loop to wait for threads
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deadline = time.monotonic() + support.SHORT_TIMEOUT
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while len(self.alive) < NUM_THREADS:
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time.sleep(0.1)
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if deadline < time.monotonic():
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break
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a = sorted(self.alive.keys())
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self.assertEqual(a, list(range(NUM_THREADS)))
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prefork_lives = self.alive.copy()
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if sys.platform in ['unixware7']:
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cpid = os.fork1()
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else:
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cpid = os.fork()
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if cpid == 0:
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# Child
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time.sleep(LONGSLEEP)
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n = 0
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for key in self.alive:
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if self.alive[key] != prefork_lives[key]:
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n += 1
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os._exit(n)
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else:
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# Parent
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self.wait_impl(cpid)
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