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+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import gc
+import sys
+import time
+import threading
+
+from abc import ABCMeta, abstractmethod
+
+import greenlet
+from greenlet import greenlet as RawGreenlet
+from . import TestCase
+from .leakcheck import fails_leakcheck
+
+
+# We manually manage locks in many tests
+# pylint:disable=consider-using-with
+# pylint:disable=too-many-public-methods
+# This module is quite large.
+# TODO: Refactor into separate test files. For example,
+# put all the regression tests that used to produce
+# crashes in test_greenlet_no_crash; put tests that DO deliberately crash
+# the interpreter into test_greenlet_crash.
+# pylint:disable=too-many-lines
+
+class SomeError(Exception):
+ pass
+
+
+def fmain(seen):
+ try:
+ greenlet.getcurrent().parent.switch()
+ except:
+ seen.append(sys.exc_info()[0])
+ raise
+ raise SomeError
+
+
+def send_exception(g, exc):
+ # note: send_exception(g, exc) can be now done with g.throw(exc).
+ # the purpose of this test is to explicitly check the propagation rules.
+ def crasher(exc):
+ raise exc
+ g1 = RawGreenlet(crasher, parent=g)
+ g1.switch(exc)
+
+
+class TestGreenlet(TestCase):
+
+ def _do_simple_test(self):
+ lst = []
+
+ def f():
+ lst.append(1)
+ greenlet.getcurrent().parent.switch()
+ lst.append(3)
+ g = RawGreenlet(f)
+ lst.append(0)
+ g.switch()
+ lst.append(2)
+ g.switch()
+ lst.append(4)
+ self.assertEqual(lst, list(range(5)))
+
+ def test_simple(self):
+ self._do_simple_test()
+
+ def test_switch_no_run_raises_AttributeError(self):
+ g = RawGreenlet()
+ with self.assertRaises(AttributeError) as exc:
+ g.switch()
+
+ self.assertIn("run", str(exc.exception))
+
+ def test_throw_no_run_raises_AttributeError(self):
+ g = RawGreenlet()
+ with self.assertRaises(AttributeError) as exc:
+ g.throw(SomeError)
+
+ self.assertIn("run", str(exc.exception))
+
+ def test_parent_equals_None(self):
+ g = RawGreenlet(parent=None)
+ self.assertIsNotNone(g)
+ self.assertIs(g.parent, greenlet.getcurrent())
+
+ def test_run_equals_None(self):
+ g = RawGreenlet(run=None)
+ self.assertIsNotNone(g)
+ self.assertIsNone(g.run)
+
+ def test_two_children(self):
+ lst = []
+
+ def f():
+ lst.append(1)
+ greenlet.getcurrent().parent.switch()
+ lst.extend([1, 1])
+ g = RawGreenlet(f)
+ h = RawGreenlet(f)
+ g.switch()
+ self.assertEqual(len(lst), 1)
+ h.switch()
+ self.assertEqual(len(lst), 2)
+ h.switch()
+ self.assertEqual(len(lst), 4)
+ self.assertEqual(h.dead, True)
+ g.switch()
+ self.assertEqual(len(lst), 6)
+ self.assertEqual(g.dead, True)
+
+ def test_two_recursive_children(self):
+ lst = []
+
+ def f():
+ lst.append('b')
+ greenlet.getcurrent().parent.switch()
+
+ def g():
+ lst.append('a')
+ g = RawGreenlet(f)
+ g.switch()
+ lst.append('c')
+
+ g = RawGreenlet(g)
+ self.assertEqual(sys.getrefcount(g), 2)
+ g.switch()
+ self.assertEqual(lst, ['a', 'b', 'c'])
+ # Just the one in this frame, plus the one on the stack we pass to the function
+ self.assertEqual(sys.getrefcount(g), 2)
+
+ def test_threads(self):
+ success = []
+
+ def f():
+ self._do_simple_test()
+ success.append(True)
+ ths = [threading.Thread(target=f) for i in range(10)]
+ for th in ths:
+ th.start()
+ for th in ths:
+ th.join(10)
+ self.assertEqual(len(success), len(ths))
+
+ def test_exception(self):
+ seen = []
+ g1 = RawGreenlet(fmain)
+ g2 = RawGreenlet(fmain)
+ g1.switch(seen)
+ g2.switch(seen)
+ g2.parent = g1
+
+ self.assertEqual(seen, [])
+ #with self.assertRaises(SomeError):
+ # p("***Switching back")
+ # g2.switch()
+ # Creating this as a bound method can reveal bugs that
+ # are hidden on newer versions of Python that avoid creating
+ # bound methods for direct expressions; IOW, don't use the `with`
+ # form!
+ self.assertRaises(SomeError, g2.switch)
+ self.assertEqual(seen, [SomeError])
+
+ value = g2.switch()
+ self.assertEqual(value, ())
+ self.assertEqual(seen, [SomeError])
+
+ value = g2.switch(25)
+ self.assertEqual(value, 25)
+ self.assertEqual(seen, [SomeError])
+
+
+ def test_send_exception(self):
+ seen = []
+ g1 = RawGreenlet(fmain)
+ g1.switch(seen)
+ self.assertRaises(KeyError, send_exception, g1, KeyError)
+ self.assertEqual(seen, [KeyError])
+
+ def test_dealloc(self):
+ seen = []
+ g1 = RawGreenlet(fmain)
+ g2 = RawGreenlet(fmain)
+ g1.switch(seen)
+ g2.switch(seen)
+ self.assertEqual(seen, [])
+ del g1
+ gc.collect()
+ self.assertEqual(seen, [greenlet.GreenletExit])
+ del g2
+ gc.collect()
+ self.assertEqual(seen, [greenlet.GreenletExit, greenlet.GreenletExit])
+
+ def test_dealloc_catches_GreenletExit_throws_other(self):
+ def run():
+ try:
+ greenlet.getcurrent().parent.switch()
+ except greenlet.GreenletExit:
+ raise SomeError from None
+
+ g = RawGreenlet(run)
+ g.switch()
+ # Destroying the only reference to the greenlet causes it
+ # to get GreenletExit; when it in turn raises, even though we're the parent
+ # we don't get the exception, it just gets printed.
+ # When we run on 3.8 only, we can use sys.unraisablehook
+ oldstderr = sys.stderr
+ try:
+ from cStringIO import StringIO
+ except ImportError:
+ from io import StringIO
+ stderr = sys.stderr = StringIO()
+ try:
+ del g
+ finally:
+ sys.stderr = oldstderr
+
+ v = stderr.getvalue()
+ self.assertIn("Exception", v)
+ self.assertIn('ignored', v)
+ self.assertIn("SomeError", v)
+
+
+ def test_dealloc_other_thread(self):
+ seen = []
+ someref = []
+
+ bg_glet_created_running_and_no_longer_ref_in_bg = threading.Event()
+ fg_ref_released = threading.Event()
+ bg_should_be_clear = threading.Event()
+ ok_to_exit_bg_thread = threading.Event()
+
+ def f():
+ g1 = RawGreenlet(fmain)
+ g1.switch(seen)
+ someref.append(g1)
+ del g1
+ gc.collect()
+
+ bg_glet_created_running_and_no_longer_ref_in_bg.set()
+ fg_ref_released.wait(3)
+
+ RawGreenlet() # trigger release
+ bg_should_be_clear.set()
+ ok_to_exit_bg_thread.wait(3)
+ RawGreenlet() # One more time
+
+ t = threading.Thread(target=f)
+ t.start()
+ bg_glet_created_running_and_no_longer_ref_in_bg.wait(10)
+
+ self.assertEqual(seen, [])
+ self.assertEqual(len(someref), 1)
+ del someref[:]
+ gc.collect()
+ # g1 is not released immediately because it's from another thread
+ self.assertEqual(seen, [])
+ fg_ref_released.set()
+ bg_should_be_clear.wait(3)
+ try:
+ self.assertEqual(seen, [greenlet.GreenletExit])
+ finally:
+ ok_to_exit_bg_thread.set()
+ t.join(10)
+ del seen[:]
+ del someref[:]
+
+ def test_frame(self):
+ def f1():
+ f = sys._getframe(0) # pylint:disable=protected-access
+ self.assertEqual(f.f_back, None)
+ greenlet.getcurrent().parent.switch(f)
+ return "meaning of life"
+ g = RawGreenlet(f1)
+ frame = g.switch()
+ self.assertTrue(frame is g.gr_frame)
+ self.assertTrue(g)
+
+ from_g = g.switch()
+ self.assertFalse(g)
+ self.assertEqual(from_g, 'meaning of life')
+ self.assertEqual(g.gr_frame, None)
+
+ def test_thread_bug(self):
+ def runner(x):
+ g = RawGreenlet(lambda: time.sleep(x))
+ g.switch()
+ t1 = threading.Thread(target=runner, args=(0.2,))
+ t2 = threading.Thread(target=runner, args=(0.3,))
+ t1.start()
+ t2.start()
+ t1.join(10)
+ t2.join(10)
+
+ def test_switch_kwargs(self):
+ def run(a, b):
+ self.assertEqual(a, 4)
+ self.assertEqual(b, 2)
+ return 42
+ x = RawGreenlet(run).switch(a=4, b=2)
+ self.assertEqual(x, 42)
+
+ def test_switch_kwargs_to_parent(self):
+ def run(x):
+ greenlet.getcurrent().parent.switch(x=x)
+ greenlet.getcurrent().parent.switch(2, x=3)
+ return x, x ** 2
+ g = RawGreenlet(run)
+ self.assertEqual({'x': 3}, g.switch(3))
+ self.assertEqual(((2,), {'x': 3}), g.switch())
+ self.assertEqual((3, 9), g.switch())
+
+ def test_switch_to_another_thread(self):
+ data = {}
+ created_event = threading.Event()
+ done_event = threading.Event()
+
+ def run():
+ data['g'] = RawGreenlet(lambda: None)
+ created_event.set()
+ done_event.wait(10)
+ thread = threading.Thread(target=run)
+ thread.start()
+ created_event.wait(10)
+ with self.assertRaises(greenlet.error):
+ data['g'].switch()
+ done_event.set()
+ thread.join(10)
+ # XXX: Should handle this automatically
+ data.clear()
+
+ def test_exc_state(self):
+ def f():
+ try:
+ raise ValueError('fun')
+ except: # pylint:disable=bare-except
+ exc_info = sys.exc_info()
+ RawGreenlet(h).switch()
+ self.assertEqual(exc_info, sys.exc_info())
+
+ def h():
+ self.assertEqual(sys.exc_info(), (None, None, None))
+
+ RawGreenlet(f).switch()
+
+ def test_instance_dict(self):
+ def f():
+ greenlet.getcurrent().test = 42
+ def deldict(g):
+ del g.__dict__
+ def setdict(g, value):
+ g.__dict__ = value
+ g = RawGreenlet(f)
+ self.assertEqual(g.__dict__, {})
+ g.switch()
+ self.assertEqual(g.test, 42)
+ self.assertEqual(g.__dict__, {'test': 42})
+ g.__dict__ = g.__dict__
+ self.assertEqual(g.__dict__, {'test': 42})
+ self.assertRaises(TypeError, deldict, g)
+ self.assertRaises(TypeError, setdict, g, 42)
+
+ def test_running_greenlet_has_no_run(self):
+ has_run = []
+ def func():
+ has_run.append(
+ hasattr(greenlet.getcurrent(), 'run')
+ )
+
+ g = RawGreenlet(func)
+ g.switch()
+ self.assertEqual(has_run, [False])
+
+ def test_deepcopy(self):
+ import copy
+ self.assertRaises(TypeError, copy.copy, RawGreenlet())
+ self.assertRaises(TypeError, copy.deepcopy, RawGreenlet())
+
+ def test_parent_restored_on_kill(self):
+ hub = RawGreenlet(lambda: None)
+ main = greenlet.getcurrent()
+ result = []
+ def worker():
+ try:
+ # Wait to be killed by going back to the test.
+ main.switch()
+ except greenlet.GreenletExit:
+ # Resurrect and switch to parent
+ result.append(greenlet.getcurrent().parent)
+ result.append(greenlet.getcurrent())
+ hub.switch()
+ g = RawGreenlet(worker, parent=hub)
+ g.switch()
+ # delete the only reference, thereby raising GreenletExit
+ del g
+ self.assertTrue(result)
+ self.assertIs(result[0], main)
+ self.assertIs(result[1].parent, hub)
+ # Delete them, thereby breaking the cycle between the greenlet
+ # and the frame, which otherwise would never be collectable
+ # XXX: We should be able to automatically fix this.
+ del result[:]
+ hub = None
+ main = None
+
+ def test_parent_return_failure(self):
+ # No run causes AttributeError on switch
+ g1 = RawGreenlet()
+ # Greenlet that implicitly switches to parent
+ g2 = RawGreenlet(lambda: None, parent=g1)
+ # AttributeError should propagate to us, no fatal errors
+ with self.assertRaises(AttributeError):
+ g2.switch()
+
+ def test_throw_exception_not_lost(self):
+ class mygreenlet(RawGreenlet):
+ def __getattribute__(self, name):
+ try:
+ raise Exception # pylint:disable=broad-exception-raised
+ except: # pylint:disable=bare-except
+ pass
+ return RawGreenlet.__getattribute__(self, name)
+ g = mygreenlet(lambda: None)
+ self.assertRaises(SomeError, g.throw, SomeError())
+
+ @fails_leakcheck
+ def _do_test_throw_to_dead_thread_doesnt_crash(self, wait_for_cleanup=False):
+ result = []
+ def worker():
+ greenlet.getcurrent().parent.switch()
+
+ def creator():
+ g = RawGreenlet(worker)
+ g.switch()
+ result.append(g)
+ if wait_for_cleanup:
+ # Let this greenlet eventually be cleaned up.
+ g.switch()
+ greenlet.getcurrent()
+ t = threading.Thread(target=creator)
+ t.start()
+ t.join(10)
+ del t
+ # But, depending on the operating system, the thread
+ # deallocator may not actually have run yet! So we can't be
+ # sure about the error message unless we wait.
+ if wait_for_cleanup:
+ self.wait_for_pending_cleanups()
+ with self.assertRaises(greenlet.error) as exc:
+ result[0].throw(SomeError)
+
+ if not wait_for_cleanup:
+ self.assertIn(
+ str(exc.exception), [
+ "cannot switch to a different thread (which happens to have exited)",
+ "cannot switch to a different thread"
+ ]
+ )
+ else:
+ self.assertEqual(
+ str(exc.exception),
+ "cannot switch to a different thread (which happens to have exited)",
+ )
+
+ if hasattr(result[0].gr_frame, 'clear'):
+ # The frame is actually executing (it thinks), we can't clear it.
+ with self.assertRaises(RuntimeError):
+ result[0].gr_frame.clear()
+ # Unfortunately, this doesn't actually clear the references, they're in the
+ # fast local array.
+ if not wait_for_cleanup:
+ result[0].gr_frame.f_locals.clear()
+ else:
+ self.assertIsNone(result[0].gr_frame)
+
+ del creator
+ worker = None
+ del result[:]
+ # XXX: we ought to be able to automatically fix this.
+ # See issue 252
+ self.expect_greenlet_leak = True # direct us not to wait for it to go away
+
+ @fails_leakcheck
+ def test_throw_to_dead_thread_doesnt_crash(self):
+ self._do_test_throw_to_dead_thread_doesnt_crash()
+
+ def test_throw_to_dead_thread_doesnt_crash_wait(self):
+ self._do_test_throw_to_dead_thread_doesnt_crash(True)
+
+ @fails_leakcheck
+ def test_recursive_startup(self):
+ class convoluted(RawGreenlet):
+ def __init__(self):
+ RawGreenlet.__init__(self)
+ self.count = 0
+ def __getattribute__(self, name):
+ if name == 'run' and self.count == 0:
+ self.count = 1
+ self.switch(43)
+ return RawGreenlet.__getattribute__(self, name)
+ def run(self, value):
+ while True:
+ self.parent.switch(value)
+ g = convoluted()
+ self.assertEqual(g.switch(42), 43)
+ # Exits the running greenlet, otherwise it leaks
+ # XXX: We should be able to automatically fix this
+ #g.throw(greenlet.GreenletExit)
+ #del g
+ self.expect_greenlet_leak = True
+
+ def test_threaded_updatecurrent(self):
+ # released when main thread should execute
+ lock1 = threading.Lock()
+ lock1.acquire()
+ # released when another thread should execute
+ lock2 = threading.Lock()
+ lock2.acquire()
+ class finalized(object):
+ def __del__(self):
+ # happens while in green_updatecurrent() in main greenlet
+ # should be very careful not to accidentally call it again
+ # at the same time we must make sure another thread executes
+ lock2.release()
+ lock1.acquire()
+ # now ts_current belongs to another thread
+ def deallocator():
+ greenlet.getcurrent().parent.switch()
+ def fthread():
+ lock2.acquire()
+ greenlet.getcurrent()
+ del g[0]
+ lock1.release()
+ lock2.acquire()
+ greenlet.getcurrent()
+ lock1.release()
+ main = greenlet.getcurrent()
+ g = [RawGreenlet(deallocator)]
+ g[0].bomb = finalized()
+ g[0].switch()
+ t = threading.Thread(target=fthread)
+ t.start()
+ # let another thread grab ts_current and deallocate g[0]
+ lock2.release()
+ lock1.acquire()
+ # this is the corner stone
+ # getcurrent() will notice that ts_current belongs to another thread
+ # and start the update process, which would notice that g[0] should
+ # be deallocated, and that will execute an object's finalizer. Now,
+ # that object will let another thread run so it can grab ts_current
+ # again, which would likely crash the interpreter if there's no
+ # check for this case at the end of green_updatecurrent(). This test
+ # passes if getcurrent() returns correct result, but it's likely
+ # to randomly crash if it's not anyway.
+ self.assertEqual(greenlet.getcurrent(), main)
+ # wait for another thread to complete, just in case
+ t.join(10)
+
+ def test_dealloc_switch_args_not_lost(self):
+ seen = []
+ def worker():
+ # wait for the value
+ value = greenlet.getcurrent().parent.switch()
+ # delete all references to ourself
+ del worker[0]
+ initiator.parent = greenlet.getcurrent().parent
+ # switch to main with the value, but because
+ # ts_current is the last reference to us we
+ # return here immediately, where we resurrect ourself.
+ try:
+ greenlet.getcurrent().parent.switch(value)
+ finally:
+ seen.append(greenlet.getcurrent())
+ def initiator():
+ return 42 # implicitly falls thru to parent
+
+ worker = [RawGreenlet(worker)]
+
+ worker[0].switch() # prime worker
+ initiator = RawGreenlet(initiator, worker[0])
+ value = initiator.switch()
+ self.assertTrue(seen)
+ self.assertEqual(value, 42)
+
+ def test_tuple_subclass(self):
+ # The point of this test is to see what happens when a custom
+ # tuple subclass is used as an object passed directly to the C
+ # function ``green_switch``; part of ``green_switch`` checks
+ # the ``len()`` of the ``args`` tuple, and that can call back
+ # into Python. Here, when it calls back into Python, we
+ # recursively enter ``green_switch`` again.
+
+ # This test is really only relevant on Python 2. The builtin
+ # `apply` function directly passes the given args tuple object
+ # to the underlying function, whereas the Python 3 version
+ # unpacks and repacks into an actual tuple. This could still
+ # happen using the C API on Python 3 though. We should write a
+ # builtin version of apply() ourself.
+ def _apply(func, a, k):
+ func(*a, **k)
+
+ class mytuple(tuple):
+ def __len__(self):
+ greenlet.getcurrent().switch()
+ return tuple.__len__(self)
+ args = mytuple()
+ kwargs = dict(a=42)
+ def switchapply():
+ _apply(greenlet.getcurrent().parent.switch, args, kwargs)
+ g = RawGreenlet(switchapply)
+ self.assertEqual(g.switch(), kwargs)
+
+ def test_abstract_subclasses(self):
+ AbstractSubclass = ABCMeta(
+ 'AbstractSubclass',
+ (RawGreenlet,),
+ {'run': abstractmethod(lambda self: None)})
+
+ class BadSubclass(AbstractSubclass):
+ pass
+
+ class GoodSubclass(AbstractSubclass):
+ def run(self):
+ pass
+
+ GoodSubclass() # should not raise
+ self.assertRaises(TypeError, BadSubclass)
+
+ def test_implicit_parent_with_threads(self):
+ if not gc.isenabled():
+ return # cannot test with disabled gc
+ N = gc.get_threshold()[0]
+ if N < 50:
+ return # cannot test with such a small N
+ def attempt():
+ lock1 = threading.Lock()
+ lock1.acquire()
+ lock2 = threading.Lock()
+ lock2.acquire()
+ recycled = [False]
+ def another_thread():
+ lock1.acquire() # wait for gc
+ greenlet.getcurrent() # update ts_current
+ lock2.release() # release gc
+ t = threading.Thread(target=another_thread)
+ t.start()
+ class gc_callback(object):
+ def __del__(self):
+ lock1.release()
+ lock2.acquire()
+ recycled[0] = True
+ class garbage(object):
+ def __init__(self):
+ self.cycle = self
+ self.callback = gc_callback()
+ l = []
+ x = range(N*2)
+ current = greenlet.getcurrent()
+ g = garbage()
+ for _ in x:
+ g = None # lose reference to garbage
+ if recycled[0]:
+ # gc callback called prematurely
+ t.join(10)
+ return False
+ last = RawGreenlet()
+ if recycled[0]:
+ break # yes! gc called in green_new
+ l.append(last) # increase allocation counter
+ else:
+ # gc callback not called when expected
+ gc.collect()
+ if recycled[0]:
+ t.join(10)
+ return False
+ self.assertEqual(last.parent, current)
+ for g in l:
+ self.assertEqual(g.parent, current)
+ return True
+ for _ in range(5):
+ if attempt():
+ break
+
+ def test_issue_245_reference_counting_subclass_no_threads(self):
+ # https://github.com/python-greenlet/greenlet/issues/245
+ # Before the fix, this crashed pretty reliably on
+ # Python 3.10, at least on macOS; but much less reliably on other
+ # interpreters (memory layout must have changed).
+ # The threaded test crashed more reliably on more interpreters.
+ from greenlet import getcurrent
+ from greenlet import GreenletExit
+
+ class Greenlet(RawGreenlet):
+ pass
+
+ initial_refs = sys.getrefcount(Greenlet)
+ # This has to be an instance variable because
+ # Python 2 raises a SyntaxError if we delete a local
+ # variable referenced in an inner scope.
+ self.glets = [] # pylint:disable=attribute-defined-outside-init
+
+ def greenlet_main():
+ try:
+ getcurrent().parent.switch()
+ except GreenletExit:
+ self.glets.append(getcurrent())
+
+ # Before the
+ for _ in range(10):
+ Greenlet(greenlet_main).switch()
+
+ del self.glets
+ self.assertEqual(sys.getrefcount(Greenlet), initial_refs)
+
+ def test_issue_245_reference_counting_subclass_threads(self):
+ # https://github.com/python-greenlet/greenlet/issues/245
+ from threading import Thread
+ from threading import Event
+
+ from greenlet import getcurrent
+
+ class MyGreenlet(RawGreenlet):
+ pass
+
+ glets = []
+ ref_cleared = Event()
+
+ def greenlet_main():
+ getcurrent().parent.switch()
+
+ def thread_main(greenlet_running_event):
+ mine = MyGreenlet(greenlet_main)
+ glets.append(mine)
+ # The greenlets being deleted must be active
+ mine.switch()
+ # Don't keep any reference to it in this thread
+ del mine
+ # Let main know we published our greenlet.
+ greenlet_running_event.set()
+ # Wait for main to let us know the references are
+ # gone and the greenlet objects no longer reachable
+ ref_cleared.wait(10)
+ # The creating thread must call getcurrent() (or a few other
+ # greenlet APIs) because that's when the thread-local list of dead
+ # greenlets gets cleared.
+ getcurrent()
+
+ # We start with 3 references to the subclass:
+ # - This module
+ # - Its __mro__
+ # - The __subclassess__ attribute of greenlet
+ # - (If we call gc.get_referents(), we find four entries, including
+ # some other tuple ``(greenlet)`` that I'm not sure about but must be part
+ # of the machinery.)
+ #
+ # On Python 3.10 it's often enough to just run 3 threads; on Python 2.7,
+ # more threads are needed, and the results are still
+ # non-deterministic. Presumably the memory layouts are different
+ initial_refs = sys.getrefcount(MyGreenlet)
+ thread_ready_events = []
+ for _ in range(
+ initial_refs + 45
+ ):
+ event = Event()
+ thread = Thread(target=thread_main, args=(event,))
+ thread_ready_events.append(event)
+ thread.start()
+
+
+ for done_event in thread_ready_events:
+ done_event.wait(10)
+
+
+ del glets[:]
+ ref_cleared.set()
+ # Let any other thread run; it will crash the interpreter
+ # if not fixed (or silently corrupt memory and we possibly crash
+ # later).
+ self.wait_for_pending_cleanups()
+ self.assertEqual(sys.getrefcount(MyGreenlet), initial_refs)
+
+ def test_falling_off_end_switches_to_unstarted_parent_raises_error(self):
+ def no_args():
+ return 13
+
+ parent_never_started = RawGreenlet(no_args)
+
+ def leaf():
+ return 42
+
+ child = RawGreenlet(leaf, parent_never_started)
+
+ # Because the run function takes to arguments
+ with self.assertRaises(TypeError):
+ child.switch()
+
+ def test_falling_off_end_switches_to_unstarted_parent_works(self):
+ def one_arg(x):
+ return (x, 24)
+
+ parent_never_started = RawGreenlet(one_arg)
+
+ def leaf():
+ return 42
+
+ child = RawGreenlet(leaf, parent_never_started)
+
+ result = child.switch()
+ self.assertEqual(result, (42, 24))
+
+ def test_switch_to_dead_greenlet_with_unstarted_perverse_parent(self):
+ class Parent(RawGreenlet):
+ def __getattribute__(self, name):
+ if name == 'run':
+ raise SomeError
+
+
+ parent_never_started = Parent()
+ seen = []
+ child = RawGreenlet(lambda: seen.append(42), parent_never_started)
+ # Because we automatically start the parent when the child is
+ # finished
+ with self.assertRaises(SomeError):
+ child.switch()
+
+ self.assertEqual(seen, [42])
+
+ with self.assertRaises(SomeError):
+ child.switch()
+ self.assertEqual(seen, [42])
+
+ def test_switch_to_dead_greenlet_reparent(self):
+ seen = []
+ parent_never_started = RawGreenlet(lambda: seen.append(24))
+ child = RawGreenlet(lambda: seen.append(42))
+
+ child.switch()
+ self.assertEqual(seen, [42])
+
+ child.parent = parent_never_started
+ # This actually is the same as switching to the parent.
+ result = child.switch()
+ self.assertIsNone(result)
+ self.assertEqual(seen, [42, 24])
+
+ def test_can_access_f_back_of_suspended_greenlet(self):
+ # This tests our frame rewriting to work around Python 3.12+ having
+ # some interpreter frames on the C stack. It will crash in the absence
+ # of that logic.
+ main = greenlet.getcurrent()
+
+ def outer():
+ inner()
+
+ def inner():
+ main.switch(sys._getframe(0))
+
+ hub = RawGreenlet(outer)
+ # start it
+ hub.switch()
+
+ # start another greenlet to make sure we aren't relying on
+ # anything in `hub` still being on the C stack
+ unrelated = RawGreenlet(lambda: None)
+ unrelated.switch()
+
+ # now it is suspended
+ self.assertIsNotNone(hub.gr_frame)
+ self.assertEqual(hub.gr_frame.f_code.co_name, "inner")
+ self.assertIsNotNone(hub.gr_frame.f_back)
+ self.assertEqual(hub.gr_frame.f_back.f_code.co_name, "outer")
+ # The next line is what would crash
+ self.assertIsNone(hub.gr_frame.f_back.f_back)
+
+ def test_get_stack_with_nested_c_calls(self):
+ from functools import partial
+ from . import _test_extension_cpp
+
+ def recurse(v):
+ if v > 0:
+ return v * _test_extension_cpp.test_call(partial(recurse, v - 1))
+ return greenlet.getcurrent().parent.switch()
+
+ gr = RawGreenlet(recurse)
+ gr.switch(5)
+ frame = gr.gr_frame
+ for i in range(5):
+ self.assertEqual(frame.f_locals["v"], i)
+ frame = frame.f_back
+ self.assertEqual(frame.f_locals["v"], 5)
+ self.assertIsNone(frame.f_back)
+ self.assertEqual(gr.switch(10), 1200) # 1200 = 5! * 10
+
+ def test_frames_always_exposed(self):
+ # On Python 3.12 this will crash if we don't set the
+ # gr_frames_always_exposed attribute. More background:
+ # https://github.com/python-greenlet/greenlet/issues/388
+ main = greenlet.getcurrent()
+
+ def outer():
+ inner(sys._getframe(0))
+
+ def inner(frame):
+ main.switch(frame)
+
+ gr = RawGreenlet(outer)
+ frame = gr.switch()
+
+ # Do something else to clobber the part of the C stack used by `gr`,
+ # so we can't skate by on "it just happened to still be there"
+ unrelated = RawGreenlet(lambda: None)
+ unrelated.switch()
+
+ self.assertEqual(frame.f_code.co_name, "outer")
+ # The next line crashes on 3.12 if we haven't exposed the frames.
+ self.assertIsNone(frame.f_back)
+
+
+class TestGreenletSetParentErrors(TestCase):
+ def test_threaded_reparent(self):
+ data = {}
+ created_event = threading.Event()
+ done_event = threading.Event()
+
+ def run():
+ data['g'] = RawGreenlet(lambda: None)
+ created_event.set()
+ done_event.wait(10)
+
+ def blank():
+ greenlet.getcurrent().parent.switch()
+
+ thread = threading.Thread(target=run)
+ thread.start()
+ created_event.wait(10)
+ g = RawGreenlet(blank)
+ g.switch()
+ with self.assertRaises(ValueError) as exc:
+ g.parent = data['g']
+ done_event.set()
+ thread.join(10)
+
+ self.assertEqual(str(exc.exception), "parent cannot be on a different thread")
+
+ def test_unexpected_reparenting(self):
+ another = []
+ def worker():
+ g = RawGreenlet(lambda: None)
+ another.append(g)
+ g.switch()
+ t = threading.Thread(target=worker)
+ t.start()
+ t.join(10)
+ # The first time we switch (running g_initialstub(), which is
+ # when we look up the run attribute) we attempt to change the
+ # parent to one from another thread (which also happens to be
+ # dead). ``g_initialstub()`` should detect this and raise a
+ # greenlet error.
+ #
+ # EXCEPT: With the fix for #252, this is actually detected
+ # sooner, when setting the parent itself. Prior to that fix,
+ # the main greenlet from the background thread kept a valid
+ # value for ``run_info``, and appeared to be a valid parent
+ # until we actually started the greenlet. But now that it's
+ # cleared, this test is catching whether ``green_setparent``
+ # can detect the dead thread.
+ #
+ # Further refactoring once again changes this back to a greenlet.error
+ #
+ # We need to wait for the cleanup to happen, but we're
+ # deliberately leaking a main greenlet here.
+ self.wait_for_pending_cleanups(initial_main_greenlets=self.main_greenlets_before_test + 1)
+
+ class convoluted(RawGreenlet):
+ def __getattribute__(self, name):
+ if name == 'run':
+ self.parent = another[0] # pylint:disable=attribute-defined-outside-init
+ return RawGreenlet.__getattribute__(self, name)
+ g = convoluted(lambda: None)
+ with self.assertRaises(greenlet.error) as exc:
+ g.switch()
+ self.assertEqual(str(exc.exception),
+ "cannot switch to a different thread (which happens to have exited)")
+ del another[:]
+
+ def test_unexpected_reparenting_thread_running(self):
+ # Like ``test_unexpected_reparenting``, except the background thread is
+ # actually still alive.
+ another = []
+ switched_to_greenlet = threading.Event()
+ keep_main_alive = threading.Event()
+ def worker():
+ g = RawGreenlet(lambda: None)
+ another.append(g)
+ g.switch()
+ switched_to_greenlet.set()
+ keep_main_alive.wait(10)
+ class convoluted(RawGreenlet):
+ def __getattribute__(self, name):
+ if name == 'run':
+ self.parent = another[0] # pylint:disable=attribute-defined-outside-init
+ return RawGreenlet.__getattribute__(self, name)
+
+ t = threading.Thread(target=worker)
+ t.start()
+
+ switched_to_greenlet.wait(10)
+ try:
+ g = convoluted(lambda: None)
+
+ with self.assertRaises(greenlet.error) as exc:
+ g.switch()
+ self.assertEqual(str(exc.exception), "cannot switch to a different thread")
+ finally:
+ keep_main_alive.set()
+ t.join(10)
+ # XXX: Should handle this automatically.
+ del another[:]
+
+ def test_cannot_delete_parent(self):
+ worker = RawGreenlet(lambda: None)
+ self.assertIs(worker.parent, greenlet.getcurrent())
+
+ with self.assertRaises(AttributeError) as exc:
+ del worker.parent
+ self.assertEqual(str(exc.exception), "can't delete attribute")
+
+ def test_cannot_delete_parent_of_main(self):
+ with self.assertRaises(AttributeError) as exc:
+ del greenlet.getcurrent().parent
+ self.assertEqual(str(exc.exception), "can't delete attribute")
+
+
+ def test_main_greenlet_parent_is_none(self):
+ # assuming we're in a main greenlet here.
+ self.assertIsNone(greenlet.getcurrent().parent)
+
+ def test_set_parent_wrong_types(self):
+ def bg():
+ # Go back to main.
+ greenlet.getcurrent().parent.switch()
+
+ def check(glet):
+ for p in None, 1, self, "42":
+ with self.assertRaises(TypeError) as exc:
+ glet.parent = p
+
+ self.assertEqual(
+ str(exc.exception),
+ "GreenletChecker: Expected any type of greenlet, not " + type(p).__name__)
+
+ # First, not running
+ g = RawGreenlet(bg)
+ self.assertFalse(g)
+ check(g)
+
+ # Then when running.
+ g.switch()
+ self.assertTrue(g)
+ check(g)
+
+ # Let it finish
+ g.switch()
+
+
+ def test_trivial_cycle(self):
+ glet = RawGreenlet(lambda: None)
+ with self.assertRaises(ValueError) as exc:
+ glet.parent = glet
+ self.assertEqual(str(exc.exception), "cyclic parent chain")
+
+ def test_trivial_cycle_main(self):
+ # This used to produce a ValueError, but we catch it earlier than that now.
+ with self.assertRaises(AttributeError) as exc:
+ greenlet.getcurrent().parent = greenlet.getcurrent()
+ self.assertEqual(str(exc.exception), "cannot set the parent of a main greenlet")
+
+ def test_deeper_cycle(self):
+ g1 = RawGreenlet(lambda: None)
+ g2 = RawGreenlet(lambda: None)
+ g3 = RawGreenlet(lambda: None)
+
+ g1.parent = g2
+ g2.parent = g3
+ with self.assertRaises(ValueError) as exc:
+ g3.parent = g1
+ self.assertEqual(str(exc.exception), "cyclic parent chain")
+
+
+class TestRepr(TestCase):
+
+ def assertEndsWith(self, got, suffix):
+ self.assertTrue(got.endswith(suffix), (got, suffix))
+
+ def test_main_while_running(self):
+ r = repr(greenlet.getcurrent())
+ self.assertEndsWith(r, " current active started main>")
+
+ def test_main_in_background(self):
+ main = greenlet.getcurrent()
+ def run():
+ return repr(main)
+
+ g = RawGreenlet(run)
+ r = g.switch()
+ self.assertEndsWith(r, ' suspended active started main>')
+
+ def test_initial(self):
+ r = repr(RawGreenlet())
+ self.assertEndsWith(r, ' pending>')
+
+ def test_main_from_other_thread(self):
+ main = greenlet.getcurrent()
+
+ class T(threading.Thread):
+ original_main = thread_main = None
+ main_glet = None
+ def run(self):
+ self.original_main = repr(main)
+ self.main_glet = greenlet.getcurrent()
+ self.thread_main = repr(self.main_glet)
+
+ t = T()
+ t.start()
+ t.join(10)
+
+ self.assertEndsWith(t.original_main, ' suspended active started main>')
+ self.assertEndsWith(t.thread_main, ' current active started main>')
+ # give the machinery time to notice the death of the thread,
+ # and clean it up. Note that we don't use
+ # ``expect_greenlet_leak`` or wait_for_pending_cleanups,
+ # because at this point we know we have an extra greenlet
+ # still reachable.
+ for _ in range(3):
+ time.sleep(0.001)
+
+ # In the past, main greenlets, even from dead threads, never
+ # really appear dead. We have fixed that, and we also report
+ # that the thread is dead in the repr. (Do this multiple times
+ # to make sure that we don't self-modify and forget our state
+ # in the C++ code).
+ for _ in range(3):
+ self.assertTrue(t.main_glet.dead)
+ r = repr(t.main_glet)
+ self.assertEndsWith(r, ' (thread exited) dead>')
+
+ def test_dead(self):
+ g = RawGreenlet(lambda: None)
+ g.switch()
+ self.assertEndsWith(repr(g), ' dead>')
+ self.assertNotIn('suspended', repr(g))
+ self.assertNotIn('started', repr(g))
+ self.assertNotIn('active', repr(g))
+
+ def test_formatting_produces_native_str(self):
+ # https://github.com/python-greenlet/greenlet/issues/218
+ # %s formatting on Python 2 was producing unicode, not str.
+
+ g_dead = RawGreenlet(lambda: None)
+ g_not_started = RawGreenlet(lambda: None)
+ g_cur = greenlet.getcurrent()
+
+ for g in g_dead, g_not_started, g_cur:
+
+ self.assertIsInstance(
+ '%s' % (g,),
+ str
+ )
+ self.assertIsInstance(
+ '%r' % (g,),
+ str,
+ )
+
+
+class TestMainGreenlet(TestCase):
+ # Tests some implementation details, and relies on some
+ # implementation details.
+
+ def _check_current_is_main(self):
+ # implementation detail
+ assert 'main' in repr(greenlet.getcurrent())
+
+ t = type(greenlet.getcurrent())
+ assert 'main' not in repr(t)
+ return t
+
+ def test_main_greenlet_type_can_be_subclassed(self):
+ main_type = self._check_current_is_main()
+ subclass = type('subclass', (main_type,), {})
+ self.assertIsNotNone(subclass)
+
+ def test_main_greenlet_is_greenlet(self):
+ self._check_current_is_main()
+ self.assertIsInstance(greenlet.getcurrent(), RawGreenlet)
+
+
+
+class TestBrokenGreenlets(TestCase):
+ # Tests for things that used to, or still do, terminate the interpreter.
+ # This often means doing unsavory things.
+
+ def test_failed_to_initialstub(self):
+ def func():
+ raise AssertionError("Never get here")
+
+
+ g = greenlet._greenlet.UnswitchableGreenlet(func)
+ g.force_switch_error = True
+
+ with self.assertRaisesRegex(SystemError,
+ "Failed to switch stacks into a greenlet for the first time."):
+ g.switch()
+
+ def test_failed_to_switch_into_running(self):
+ runs = []
+ def func():
+ runs.append(1)
+ greenlet.getcurrent().parent.switch()
+ runs.append(2)
+ greenlet.getcurrent().parent.switch()
+ runs.append(3) # pragma: no cover
+
+ g = greenlet._greenlet.UnswitchableGreenlet(func)
+ g.switch()
+ self.assertEqual(runs, [1])
+ g.switch()
+ self.assertEqual(runs, [1, 2])
+ g.force_switch_error = True
+
+ with self.assertRaisesRegex(SystemError,
+ "Failed to switch stacks into a running greenlet."):
+ g.switch()
+
+ # If we stopped here, we would fail the leakcheck, because we've left
+ # the ``inner_bootstrap()`` C frame and its descendents hanging around,
+ # which have a bunch of Python references. They'll never get cleaned up
+ # if we don't let the greenlet finish.
+ g.force_switch_error = False
+ g.switch()
+ self.assertEqual(runs, [1, 2, 3])
+
+ def test_failed_to_slp_switch_into_running(self):
+ ex = self.assertScriptRaises('fail_slp_switch.py')
+
+ self.assertIn('fail_slp_switch is running', ex.output)
+ self.assertIn(ex.returncode, self.get_expected_returncodes_for_aborted_process())
+
+ def test_reentrant_switch_two_greenlets(self):
+ # Before we started capturing the arguments in g_switch_finish, this could crash.
+ output = self.run_script('fail_switch_two_greenlets.py')
+ self.assertIn('In g1_run', output)
+ self.assertIn('TRACE', output)
+ self.assertIn('LEAVE TRACE', output)
+ self.assertIn('Falling off end of main', output)
+ self.assertIn('Falling off end of g1_run', output)
+ self.assertIn('Falling off end of g2', output)
+
+ def test_reentrant_switch_three_greenlets(self):
+ # On debug builds of greenlet, this used to crash with an assertion error;
+ # on non-debug versions, it ran fine (which it should not do!).
+ # Now it always crashes correctly with a TypeError
+ ex = self.assertScriptRaises('fail_switch_three_greenlets.py', exitcodes=(1,))
+
+ self.assertIn('TypeError', ex.output)
+ self.assertIn('positional arguments', ex.output)
+
+ def test_reentrant_switch_three_greenlets2(self):
+ # This actually passed on debug and non-debug builds. It
+ # should probably have been triggering some debug assertions
+ # but it didn't.
+ #
+ # I think the fixes for the above test also kicked in here.
+ output = self.run_script('fail_switch_three_greenlets2.py')
+ self.assertIn(
+ "RESULTS: [('trace', 'switch'), "
+ "('trace', 'switch'), ('g2 arg', 'g2 from tracefunc'), "
+ "('trace', 'switch'), ('main g1', 'from g2_run'), ('trace', 'switch'), "
+ "('g1 arg', 'g1 from main'), ('trace', 'switch'), ('main g2', 'from g1_run'), "
+ "('trace', 'switch'), ('g1 from parent', 'g1 from main 2'), ('trace', 'switch'), "
+ "('main g1.2', 'g1 done'), ('trace', 'switch'), ('g2 from parent', ()), "
+ "('trace', 'switch'), ('main g2.2', 'g2 done')]",
+ output
+ )
+
+ def test_reentrant_switch_GreenletAlreadyStartedInPython(self):
+ output = self.run_script('fail_initialstub_already_started.py')
+
+ self.assertIn(
+ "RESULTS: ['Begin C', 'Switch to b from B.__getattribute__ in C', "
+ "('Begin B', ()), '_B_run switching to main', ('main from c', 'From B'), "
+ "'B.__getattribute__ back from main in C', ('Begin A', (None,)), "
+ "('A dead?', True, 'B dead?', True, 'C dead?', False), "
+ "'C done', ('main from c.2', None)]",
+ output
+ )
+
+ def test_reentrant_switch_run_callable_has_del(self):
+ output = self.run_script('fail_clearing_run_switches.py')
+ self.assertIn(
+ "RESULTS ["
+ "('G.__getattribute__', 'run'), ('RunCallable', '__del__'), "
+ "('main: g.switch()', 'from RunCallable'), ('run_func', 'enter')"
+ "]",
+ output
+ )
+
+if __name__ == '__main__':
+ import unittest
+ unittest.main()