Python sys.setswitchinterval() Examples

The following are code examples for showing how to use sys.setswitchinterval(). They are extracted from open source Python projects. You can vote up the examples you like or vote down the ones you don't like. You can also save this page to your account.

Example 1
Project: zippy   Author: securesystemslab   File: test_threading.py    (license) View Source Project 6 votes vote down vote up
def test_enumerate_after_join(self):
        # Try hard to trigger #1703448: a thread is still returned in
        # threading.enumerate() after it has been join()ed.
        enum = threading.enumerate
        newgil = hasattr(sys, 'getswitchinterval')
        if newgil:
            geti, seti = sys.getswitchinterval, sys.setswitchinterval
        else:
            geti, seti = sys.getcheckinterval, sys.setcheckinterval
        old_interval = geti()
        try:
            for i in range(1, 100):
                seti(i * 0.0002 if newgil else i // 5)
                t = threading.Thread(target=lambda: None)
                t.start()
                t.join()
                l = enum()
                self.assertNotIn(t, l,
                    "#1703448 triggered after %d trials: %s" % (i, l))
        finally:
            seti(old_interval) 
Example 2
Project: web_ctp   Author: molebot   File: test_threading.py    (license) View Source Project 6 votes vote down vote up
def test_is_alive_after_fork(self):
        # Try hard to trigger #18418: is_alive() could sometimes be True on
        # threads that vanished after a fork.
        old_interval = sys.getswitchinterval()
        self.addCleanup(sys.setswitchinterval, old_interval)

        # Make the bug more likely to manifest.
        sys.setswitchinterval(1e-6)

        for i in range(20):
            t = threading.Thread(target=lambda: None)
            t.start()
            self.addCleanup(t.join)
            pid = os.fork()
            if pid == 0:
                os._exit(1 if t.is_alive() else 0)
            else:
                pid, status = os.waitpid(pid, 0)
                self.assertEqual(0, status) 
Example 3
Project: ouroboros   Author: pybee   File: test_threading.py    (license) View Source Project 6 votes vote down vote up
def test_is_alive_after_fork(self):
        # Try hard to trigger #18418: is_alive() could sometimes be True on
        # threads that vanished after a fork.
        old_interval = sys.getswitchinterval()
        self.addCleanup(sys.setswitchinterval, old_interval)

        # Make the bug more likely to manifest.
        sys.setswitchinterval(1e-6)

        for i in range(20):
            t = threading.Thread(target=lambda: None)
            t.start()
            self.addCleanup(t.join)
            pid = os.fork()
            if pid == 0:
                os._exit(1 if t.is_alive() else 0)
            else:
                pid, status = os.waitpid(pid, 0)
                self.assertEqual(0, status) 
Example 4
Project: kbe_server   Author: xiaohaoppy   File: test_threading.py    (license) View Source Project 6 votes vote down vote up
def test_is_alive_after_fork(self):
        # Try hard to trigger #18418: is_alive() could sometimes be True on
        # threads that vanished after a fork.
        old_interval = sys.getswitchinterval()
        self.addCleanup(sys.setswitchinterval, old_interval)

        # Make the bug more likely to manifest.
        sys.setswitchinterval(1e-6)

        for i in range(20):
            t = threading.Thread(target=lambda: None)
            t.start()
            self.addCleanup(t.join)
            pid = os.fork()
            if pid == 0:
                os._exit(1 if t.is_alive() else 0)
            else:
                pid, status = os.waitpid(pid, 0)
                self.assertEqual(0, status) 
Example 5
Project: zippy   Author: securesystemslab   File: test_sys.py    (license) View Source Project 5 votes vote down vote up
def test_switchinterval(self):
        self.assertRaises(TypeError, sys.setswitchinterval)
        self.assertRaises(TypeError, sys.setswitchinterval, "a")
        self.assertRaises(ValueError, sys.setswitchinterval, -1.0)
        self.assertRaises(ValueError, sys.setswitchinterval, 0.0)
        orig = sys.getswitchinterval()
        # sanity check
        self.assertTrue(orig < 0.5, orig)
        try:
            for n in 0.00001, 0.05, 3.0, orig:
                sys.setswitchinterval(n)
                self.assertAlmostEqual(sys.getswitchinterval(), n)
        finally:
            sys.setswitchinterval(orig) 
Example 6
Project: web_ctp   Author: molebot   File: test_sys.py    (license) View Source Project 5 votes vote down vote up
def test_switchinterval(self):
        self.assertRaises(TypeError, sys.setswitchinterval)
        self.assertRaises(TypeError, sys.setswitchinterval, "a")
        self.assertRaises(ValueError, sys.setswitchinterval, -1.0)
        self.assertRaises(ValueError, sys.setswitchinterval, 0.0)
        orig = sys.getswitchinterval()
        # sanity check
        self.assertTrue(orig < 0.5, orig)
        try:
            for n in 0.00001, 0.05, 3.0, orig:
                sys.setswitchinterval(n)
                self.assertAlmostEqual(sys.getswitchinterval(), n)
        finally:
            sys.setswitchinterval(orig) 
Example 7
Project: web_ctp   Author: molebot   File: test_threaded_import.py    (license) View Source Project 5 votes vote down vote up
def test_main():
    old_switchinterval = None
    try:
        old_switchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-5)
    except AttributeError:
        pass
    try:
        run_unittest(ThreadedImportTests)
    finally:
        if old_switchinterval is not None:
            sys.setswitchinterval(old_switchinterval) 
Example 8
Project: web_ctp   Author: molebot   File: test_locks.py    (license) View Source Project 5 votes vote down vote up
def setUp(self):
        try:
            self.old_switchinterval = sys.getswitchinterval()
            sys.setswitchinterval(0.000001)
        except AttributeError:
            self.old_switchinterval = None 
Example 9
Project: web_ctp   Author: molebot   File: test_locks.py    (license) View Source Project 5 votes vote down vote up
def tearDown(self):
        if self.old_switchinterval is not None:
            sys.setswitchinterval(self.old_switchinterval) 
Example 10
Project: web_ctp   Author: molebot   File: test_concurrent_futures.py    (license) View Source Project 5 votes vote down vote up
def test_pending_calls_race(self):
        # Issue #14406: multi-threaded race condition when waiting on all
        # futures.
        event = threading.Event()
        def future_func():
            event.wait()
        oldswitchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-6)
        try:
            fs = {self.executor.submit(future_func) for i in range(100)}
            event.set()
            futures.wait(fs, return_when=futures.ALL_COMPLETED)
        finally:
            sys.setswitchinterval(oldswitchinterval) 
Example 11
Project: ouroboros   Author: pybee   File: test_sys.py    (license) View Source Project 5 votes vote down vote up
def test_switchinterval(self):
        self.assertRaises(TypeError, sys.setswitchinterval)
        self.assertRaises(TypeError, sys.setswitchinterval, "a")
        self.assertRaises(ValueError, sys.setswitchinterval, -1.0)
        self.assertRaises(ValueError, sys.setswitchinterval, 0.0)
        orig = sys.getswitchinterval()
        # sanity check
        self.assertTrue(orig < 0.5, orig)
        try:
            for n in 0.00001, 0.05, 3.0, orig:
                sys.setswitchinterval(n)
                self.assertAlmostEqual(sys.getswitchinterval(), n)
        finally:
            sys.setswitchinterval(orig) 
Example 12
Project: ouroboros   Author: pybee   File: test_threaded_import.py    (license) View Source Project 5 votes vote down vote up
def test_main():
    old_switchinterval = None
    try:
        old_switchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-5)
    except AttributeError:
        pass
    try:
        run_unittest(ThreadedImportTests)
    finally:
        if old_switchinterval is not None:
            sys.setswitchinterval(old_switchinterval) 
Example 13
Project: ouroboros   Author: pybee   File: test_locks.py    (license) View Source Project 5 votes vote down vote up
def setUp(self):
        try:
            self.old_switchinterval = sys.getswitchinterval()
            sys.setswitchinterval(0.000001)
        except AttributeError:
            self.old_switchinterval = None 
Example 14
Project: ouroboros   Author: pybee   File: test_locks.py    (license) View Source Project 5 votes vote down vote up
def tearDown(self):
        if self.old_switchinterval is not None:
            sys.setswitchinterval(self.old_switchinterval) 
Example 15
Project: ouroboros   Author: pybee   File: test_concurrent_futures.py    (license) View Source Project 5 votes vote down vote up
def test_pending_calls_race(self):
        # Issue #14406: multi-threaded race condition when waiting on all
        # futures.
        event = threading.Event()
        def future_func():
            event.wait()
        oldswitchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-6)
        try:
            fs = {self.executor.submit(future_func) for i in range(100)}
            event.set()
            futures.wait(fs, return_when=futures.ALL_COMPLETED)
        finally:
            sys.setswitchinterval(oldswitchinterval) 
Example 16
Project: zenchmarks   Author: squeaky-pl   File: test_threadable.py    (license) View Source Project 5 votes vote down vote up
def setUp(self):
        """
        Reduce the CPython check interval so that thread switches happen much
        more often, hopefully exercising more possible race conditions.  Also,
        delay actual test startup until the reactor has been started.
        """
        if _PY3:
            if getattr(sys, 'getswitchinterval', None) is not None:
                self.addCleanup(sys.setswitchinterval, sys.getswitchinterval())
                sys.setswitchinterval(0.0000001)
        else:
            if getattr(sys, 'getcheckinterval', None) is not None:
                self.addCleanup(sys.setcheckinterval, sys.getcheckinterval())
                sys.setcheckinterval(7) 
Example 17
Project: kbe_server   Author: xiaohaoppy   File: test_sys.py    (license) View Source Project 5 votes vote down vote up
def test_switchinterval(self):
        self.assertRaises(TypeError, sys.setswitchinterval)
        self.assertRaises(TypeError, sys.setswitchinterval, "a")
        self.assertRaises(ValueError, sys.setswitchinterval, -1.0)
        self.assertRaises(ValueError, sys.setswitchinterval, 0.0)
        orig = sys.getswitchinterval()
        # sanity check
        self.assertTrue(orig < 0.5, orig)
        try:
            for n in 0.00001, 0.05, 3.0, orig:
                sys.setswitchinterval(n)
                self.assertAlmostEqual(sys.getswitchinterval(), n)
        finally:
            sys.setswitchinterval(orig) 
Example 18
Project: kbe_server   Author: xiaohaoppy   File: test_threaded_import.py    (license) View Source Project 5 votes vote down vote up
def test_main():
    old_switchinterval = None
    try:
        old_switchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-5)
    except AttributeError:
        pass
    try:
        run_unittest(ThreadedImportTests)
    finally:
        if old_switchinterval is not None:
            sys.setswitchinterval(old_switchinterval) 
Example 19
Project: kbe_server   Author: xiaohaoppy   File: test_locks.py    (license) View Source Project 5 votes vote down vote up
def setUp(self):
        try:
            self.old_switchinterval = sys.getswitchinterval()
            sys.setswitchinterval(0.000001)
        except AttributeError:
            self.old_switchinterval = None 
Example 20
Project: kbe_server   Author: xiaohaoppy   File: test_locks.py    (license) View Source Project 5 votes vote down vote up
def tearDown(self):
        if self.old_switchinterval is not None:
            sys.setswitchinterval(self.old_switchinterval) 
Example 21
Project: kbe_server   Author: xiaohaoppy   File: test_concurrent_futures.py    (license) View Source Project 5 votes vote down vote up
def test_pending_calls_race(self):
        # Issue #14406: multi-threaded race condition when waiting on all
        # futures.
        event = threading.Event()
        def future_func():
            event.wait()
        oldswitchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-6)
        try:
            fs = {self.executor.submit(future_func) for i in range(100)}
            event.set()
            futures.wait(fs, return_when=futures.ALL_COMPLETED)
        finally:
            sys.setswitchinterval(oldswitchinterval) 
Example 22
Project: deb-python-cassandra-driver   Author: openstack   File: test_policies.py    (Apache License 2.0) View Source Project 4 votes vote down vote up
def test_thread_safety_during_modification(self):
        hosts = range(100)
        policy = RoundRobinPolicy()
        policy.populate(None, hosts)

        errors = []

        def check_query_plan():
            try:
                for i in xrange(100):
                    list(policy.make_query_plan())
            except Exception as exc:
                errors.append(exc)

        def host_up():
            for i in xrange(1000):
                policy.on_up(randint(0, 99))

        def host_down():
            for i in xrange(1000):
                policy.on_down(randint(0, 99))

        threads = []
        for i in range(5):
            threads.append(Thread(target=check_query_plan))
            threads.append(Thread(target=host_up))
            threads.append(Thread(target=host_down))

        # make the GIL switch after every instruction, maximizing
        # the chance of race conditions
        check = six.PY2 or '__pypy__' in sys.builtin_module_names
        if check:
            original_interval = sys.getcheckinterval()
        else:
            original_interval = sys.getswitchinterval()

        try:
            if check:
                sys.setcheckinterval(0)
            else:
                sys.setswitchinterval(0.0001)
            map(lambda t: t.start(), threads)
            map(lambda t: t.join(), threads)
        finally:
            if check:
                sys.setcheckinterval(original_interval)
            else:
                sys.setswitchinterval(original_interval)

        if errors:
            self.fail("Saw errors: %s" % (errors,)) 
Example 23
Project: web_ctp   Author: molebot   File: test_gc.py    (license) View Source Project 4 votes vote down vote up
def test_trashcan_threads(self):
        # Issue #13992: trashcan mechanism should be thread-safe
        NESTING = 60
        N_THREADS = 2

        def sleeper_gen():
            """A generator that releases the GIL when closed or dealloc'ed."""
            try:
                yield
            finally:
                time.sleep(0.000001)

        class C(list):
            # Appending to a list is atomic, which avoids the use of a lock.
            inits = []
            dels = []
            def __init__(self, alist):
                self[:] = alist
                C.inits.append(None)
            def __del__(self):
                # This __del__ is called by subtype_dealloc().
                C.dels.append(None)
                # `g` will release the GIL when garbage-collected.  This
                # helps assert subtype_dealloc's behaviour when threads
                # switch in the middle of it.
                g = sleeper_gen()
                next(g)
                # Now that __del__ is finished, subtype_dealloc will proceed
                # to call list_dealloc, which also uses the trashcan mechanism.

        def make_nested():
            """Create a sufficiently nested container object so that the
            trashcan mechanism is invoked when deallocating it."""
            x = C([])
            for i in range(NESTING):
                x = [C([x])]
            del x

        def run_thread():
            """Exercise make_nested() in a loop."""
            while not exit:
                make_nested()

        old_switchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-5)
        try:
            exit = False
            threads = []
            for i in range(N_THREADS):
                t = threading.Thread(target=run_thread)
                threads.append(t)
            for t in threads:
                t.start()
            time.sleep(1.0)
            exit = True
            for t in threads:
                t.join()
        finally:
            sys.setswitchinterval(old_switchinterval)
        gc.collect()
        self.assertEqual(len(C.inits), len(C.dels)) 
Example 24
Project: ouroboros   Author: pybee   File: test_gc.py    (license) View Source Project 4 votes vote down vote up
def test_trashcan_threads(self):
        # Issue #13992: trashcan mechanism should be thread-safe
        NESTING = 60
        N_THREADS = 2

        def sleeper_gen():
            """A generator that releases the GIL when closed or dealloc'ed."""
            try:
                yield
            finally:
                time.sleep(0.000001)

        class C(list):
            # Appending to a list is atomic, which avoids the use of a lock.
            inits = []
            dels = []
            def __init__(self, alist):
                self[:] = alist
                C.inits.append(None)
            def __del__(self):
                # This __del__ is called by subtype_dealloc().
                C.dels.append(None)
                # `g` will release the GIL when garbage-collected.  This
                # helps assert subtype_dealloc's behaviour when threads
                # switch in the middle of it.
                g = sleeper_gen()
                next(g)
                # Now that __del__ is finished, subtype_dealloc will proceed
                # to call list_dealloc, which also uses the trashcan mechanism.

        def make_nested():
            """Create a sufficiently nested container object so that the
            trashcan mechanism is invoked when deallocating it."""
            x = C([])
            for i in range(NESTING):
                x = [C([x])]
            del x

        def run_thread():
            """Exercise make_nested() in a loop."""
            while not exit:
                make_nested()

        old_switchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-5)
        try:
            exit = []
            threads = []
            for i in range(N_THREADS):
                t = threading.Thread(target=run_thread)
                threads.append(t)
            with start_threads(threads, lambda: exit.append(1)):
                time.sleep(1.0)
        finally:
            sys.setswitchinterval(old_switchinterval)
        gc.collect()
        self.assertEqual(len(C.inits), len(C.dels)) 
Example 25
Project: kbe_server   Author: xiaohaoppy   File: test_gc.py    (license) View Source Project 4 votes vote down vote up
def test_trashcan_threads(self):
        # Issue #13992: trashcan mechanism should be thread-safe
        NESTING = 60
        N_THREADS = 2

        def sleeper_gen():
            """A generator that releases the GIL when closed or dealloc'ed."""
            try:
                yield
            finally:
                time.sleep(0.000001)

        class C(list):
            # Appending to a list is atomic, which avoids the use of a lock.
            inits = []
            dels = []
            def __init__(self, alist):
                self[:] = alist
                C.inits.append(None)
            def __del__(self):
                # This __del__ is called by subtype_dealloc().
                C.dels.append(None)
                # `g` will release the GIL when garbage-collected.  This
                # helps assert subtype_dealloc's behaviour when threads
                # switch in the middle of it.
                g = sleeper_gen()
                next(g)
                # Now that __del__ is finished, subtype_dealloc will proceed
                # to call list_dealloc, which also uses the trashcan mechanism.

        def make_nested():
            """Create a sufficiently nested container object so that the
            trashcan mechanism is invoked when deallocating it."""
            x = C([])
            for i in range(NESTING):
                x = [C([x])]
            del x

        def run_thread():
            """Exercise make_nested() in a loop."""
            while not exit:
                make_nested()

        old_switchinterval = sys.getswitchinterval()
        sys.setswitchinterval(1e-5)
        try:
            exit = False
            threads = []
            for i in range(N_THREADS):
                t = threading.Thread(target=run_thread)
                threads.append(t)
            for t in threads:
                t.start()
            time.sleep(1.0)
            exit = True
            for t in threads:
                t.join()
        finally:
            sys.setswitchinterval(old_switchinterval)
        gc.collect()
        self.assertEqual(len(C.inits), len(C.dels)) 
Example 26
Project: python-dse-driver   Author: datastax   File: test_policies.py    (license) View Source Project 4 votes vote down vote up
def test_thread_safety_during_modification(self):
        hosts = range(100)
        policy = RoundRobinPolicy()
        policy.populate(None, hosts)

        errors = []

        def check_query_plan():
            try:
                for i in xrange(100):
                    list(policy.make_query_plan())
            except Exception as exc:
                errors.append(exc)

        def host_up():
            for i in xrange(1000):
                policy.on_up(randint(0, 99))

        def host_down():
            for i in xrange(1000):
                policy.on_down(randint(0, 99))

        threads = []
        for i in range(5):
            threads.append(Thread(target=check_query_plan))
            threads.append(Thread(target=host_up))
            threads.append(Thread(target=host_down))

        # make the GIL switch after every instruction, maximizing
        # the chance of race conditions
        check = six.PY2 or '__pypy__' in sys.builtin_module_names
        if check:
            original_interval = sys.getcheckinterval()
        else:
            original_interval = sys.getswitchinterval()

        try:
            if check:
                sys.setcheckinterval(0)
            else:
                sys.setswitchinterval(0.0001)
            for t in threads:
                t.start()
            for t in threads:
                t.join()
        finally:
            if check:
                sys.setcheckinterval(original_interval)
            else:
                sys.setswitchinterval(original_interval)

        if errors:
            self.fail("Saw errors: %s" % (errors,))