mirror of
https://github.com/python/cpython.git
synced 2024-12-12 03:04:15 +08:00
117 lines
2.9 KiB
Python
117 lines
2.9 KiB
Python
import gc
|
|
import sys
|
|
import unittest
|
|
import weakref
|
|
|
|
from test import support
|
|
|
|
|
|
class ClearTest(unittest.TestCase):
|
|
"""
|
|
Tests for frame.clear().
|
|
"""
|
|
|
|
def inner(self, x=5, **kwargs):
|
|
1/0
|
|
|
|
def outer(self, **kwargs):
|
|
try:
|
|
self.inner(**kwargs)
|
|
except ZeroDivisionError as e:
|
|
exc = e
|
|
return exc
|
|
|
|
def clear_traceback_frames(self, tb):
|
|
"""
|
|
Clear all frames in a traceback.
|
|
"""
|
|
while tb is not None:
|
|
tb.tb_frame.clear()
|
|
tb = tb.tb_next
|
|
|
|
def test_clear_locals(self):
|
|
class C:
|
|
pass
|
|
c = C()
|
|
wr = weakref.ref(c)
|
|
exc = self.outer(c=c)
|
|
del c
|
|
support.gc_collect()
|
|
# A reference to c is held through the frames
|
|
self.assertIsNot(None, wr())
|
|
self.clear_traceback_frames(exc.__traceback__)
|
|
support.gc_collect()
|
|
# The reference was released by .clear()
|
|
self.assertIs(None, wr())
|
|
|
|
def test_clear_generator(self):
|
|
endly = False
|
|
def g():
|
|
nonlocal endly
|
|
try:
|
|
yield
|
|
inner()
|
|
finally:
|
|
endly = True
|
|
gen = g()
|
|
next(gen)
|
|
self.assertFalse(endly)
|
|
# Clearing the frame closes the generator
|
|
gen.gi_frame.clear()
|
|
self.assertTrue(endly)
|
|
|
|
def test_clear_executing(self):
|
|
# Attempting to clear an executing frame is forbidden.
|
|
try:
|
|
1/0
|
|
except ZeroDivisionError as e:
|
|
f = e.__traceback__.tb_frame
|
|
with self.assertRaises(RuntimeError):
|
|
f.clear()
|
|
with self.assertRaises(RuntimeError):
|
|
f.f_back.clear()
|
|
|
|
def test_clear_executing_generator(self):
|
|
# Attempting to clear an executing generator frame is forbidden.
|
|
endly = False
|
|
def g():
|
|
nonlocal endly
|
|
try:
|
|
1/0
|
|
except ZeroDivisionError as e:
|
|
f = e.__traceback__.tb_frame
|
|
with self.assertRaises(RuntimeError):
|
|
f.clear()
|
|
with self.assertRaises(RuntimeError):
|
|
f.f_back.clear()
|
|
yield f
|
|
finally:
|
|
endly = True
|
|
gen = g()
|
|
f = next(gen)
|
|
self.assertFalse(endly)
|
|
# Clearing the frame closes the generator
|
|
f.clear()
|
|
self.assertTrue(endly)
|
|
|
|
@support.cpython_only
|
|
def test_clear_refcycles(self):
|
|
# .clear() doesn't leave any refcycle behind
|
|
with support.disable_gc():
|
|
class C:
|
|
pass
|
|
c = C()
|
|
wr = weakref.ref(c)
|
|
exc = self.outer(c=c)
|
|
del c
|
|
self.assertIsNot(None, wr())
|
|
self.clear_traceback_frames(exc.__traceback__)
|
|
self.assertIs(None, wr())
|
|
|
|
|
|
def test_main():
|
|
support.run_unittest(__name__)
|
|
|
|
if __name__ == "__main__":
|
|
test_main()
|