Current File : //opt/hc_python/lib64/python3.8/site-packages/greenlet/tests/test_greenlet.py
import gc
import sys
import time
import threading
import unittest
from abc import ABCMeta
from abc import abstractmethod
import greenlet
from greenlet import greenlet as RawGreenlet
from . import TestCase
from . import RUNNING_ON_MANYLINUX
from . import PY313
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
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)
@unittest.skipIf(
PY313 and RUNNING_ON_MANYLINUX,
"Sometimes flaky (getting one GreenletExit in the second list)"
# Probably due to funky timing interactions?
# TODO: FIXME Make that work.
)
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:
s = str(exc.exception)
self.assertTrue(
s == "cannot switch to a different thread (which happens to have exited)"
or 'Cannot switch' in s
)
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:
# f_locals has no clear method in Python 3.13
if hasattr(result[0].gr_frame.f_locals, 'clear'):
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)
@unittest.skipIf(
PY313 and RUNNING_ON_MANYLINUX,
"The manylinux images appear to hang on this test on 3.13rc2"
# Or perhaps I just got tired of waiting for the 450s timeout.
# Still, it shouldn't take anywhere near that long. Does not reproduce in
# Ubuntu images, on macOS or Windows.
)
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.assertIn("Cannot switch to a different thread", str(exc.exception))
self.assertIn("Expected", str(exc.exception))
self.assertIn("Current", str(exc.exception))
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__':
unittest.main()
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