mirror of https://github.com/python/cpython
153 lines
4.5 KiB
Python
153 lines
4.5 KiB
Python
from test.test_importlib import util as test_util
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init = test_util.import_importlib('importlib')
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import sys
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import threading
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import unittest
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import weakref
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from test import support
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from test.support import threading_helper
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from test import lock_tests
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threading_helper.requires_working_threading(module=True)
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class ModuleLockAsRLockTests:
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locktype = classmethod(lambda cls: cls.LockType("some_lock"))
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# _is_owned() unsupported
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test__is_owned = None
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# acquire(blocking=False) unsupported
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test_try_acquire = None
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test_try_acquire_contended = None
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# `with` unsupported
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test_with = None
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# acquire(timeout=...) unsupported
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test_timeout = None
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# _release_save() unsupported
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test_release_save_unacquired = None
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# lock status in repr unsupported
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test_repr = None
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test_locked_repr = None
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LOCK_TYPES = {kind: splitinit._bootstrap._ModuleLock
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for kind, splitinit in init.items()}
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(Frozen_ModuleLockAsRLockTests,
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Source_ModuleLockAsRLockTests
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) = test_util.test_both(ModuleLockAsRLockTests, lock_tests.RLockTests,
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LockType=LOCK_TYPES)
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class DeadlockAvoidanceTests:
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def setUp(self):
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try:
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self.old_switchinterval = sys.getswitchinterval()
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support.setswitchinterval(0.000001)
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except AttributeError:
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self.old_switchinterval = None
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def tearDown(self):
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if self.old_switchinterval is not None:
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sys.setswitchinterval(self.old_switchinterval)
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def run_deadlock_avoidance_test(self, create_deadlock):
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NLOCKS = 10
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locks = [self.LockType(str(i)) for i in range(NLOCKS)]
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pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)]
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if create_deadlock:
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NTHREADS = NLOCKS
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else:
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NTHREADS = NLOCKS - 1
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barrier = threading.Barrier(NTHREADS)
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results = []
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def _acquire(lock):
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"""Try to acquire the lock. Return True on success,
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False on deadlock."""
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try:
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lock.acquire()
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except self.DeadlockError:
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return False
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else:
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return True
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def f():
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a, b = pairs.pop()
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ra = _acquire(a)
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barrier.wait()
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rb = _acquire(b)
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results.append((ra, rb))
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if rb:
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b.release()
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if ra:
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a.release()
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lock_tests.Bunch(f, NTHREADS).wait_for_finished()
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self.assertEqual(len(results), NTHREADS)
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return results
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def test_deadlock(self):
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results = self.run_deadlock_avoidance_test(True)
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# At least one of the threads detected a potential deadlock on its
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# second acquire() call. It may be several of them, because the
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# deadlock avoidance mechanism is conservative.
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nb_deadlocks = results.count((True, False))
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self.assertGreaterEqual(nb_deadlocks, 1)
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self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks)
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def test_no_deadlock(self):
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results = self.run_deadlock_avoidance_test(False)
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self.assertEqual(results.count((True, False)), 0)
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self.assertEqual(results.count((True, True)), len(results))
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DEADLOCK_ERRORS = {kind: splitinit._bootstrap._DeadlockError
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for kind, splitinit in init.items()}
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(Frozen_DeadlockAvoidanceTests,
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Source_DeadlockAvoidanceTests
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) = test_util.test_both(DeadlockAvoidanceTests,
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LockType=LOCK_TYPES,
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DeadlockError=DEADLOCK_ERRORS)
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class LifetimeTests:
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@property
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def bootstrap(self):
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return self.init._bootstrap
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def test_lock_lifetime(self):
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name = "xyzzy"
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self.assertNotIn(name, self.bootstrap._module_locks)
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lock = self.bootstrap._get_module_lock(name)
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self.assertIn(name, self.bootstrap._module_locks)
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wr = weakref.ref(lock)
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del lock
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support.gc_collect()
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self.assertNotIn(name, self.bootstrap._module_locks)
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self.assertIsNone(wr())
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def test_all_locks(self):
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support.gc_collect()
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self.assertEqual(0, len(self.bootstrap._module_locks),
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self.bootstrap._module_locks)
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(Frozen_LifetimeTests,
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Source_LifetimeTests
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) = test_util.test_both(LifetimeTests, init=init)
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def setUpModule():
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thread_info = threading_helper.threading_setup()
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unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
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if __name__ == '__main__':
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unittest.main()
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