def test_passes(self):
def no_cycle():
b = []
b.append([])
return b
with assert_no_gc_cycles():
no_cycle()
assert_no_gc_cycles(no_cycle)
def test_passes(self):
def no_cycle():
b = []
b.append([])
return b
with assert_no_gc_cycles():
no_cycle()
assert_no_gc_cycles(no_cycle)
def test_asserts(self):
def make_cycle():
a = []
a.append(a)
a.append(a)
return a
with assert_raises(AssertionError):
with assert_no_gc_cycles():
make_cycle()
with assert_raises(AssertionError):
assert_no_gc_cycles(make_cycle)
def test_asserts(self):
def make_cycle():
a = []
a.append(a)
a.append(a)
return a
with assert_raises(AssertionError):
with assert_no_gc_cycles():
make_cycle()
with assert_raises(AssertionError):
assert_no_gc_cycles(make_cycle)
def test_fails(self):
"""
Test that in cases where the garbage cannot be collected, we raise an
error, instead of hanging forever trying to clear it.
"""
class ReferenceCycleInDel(object):
"""
An object that not only contains a reference cycle, but creates new
cycles whenever it's garbage-collected and its __del__ runs
"""
make_cycle = True
def __init__(self):
self.cycle = self
def __del__(self):
# break the current cycle so that `self` can be freed
self.cycle = None
if ReferenceCycleInDel.make_cycle:
# but create a new one so that the garbage collector has more
# work to do.
ReferenceCycleInDel()
try:
w = weakref.ref(ReferenceCycleInDel())
try:
with assert_raises(RuntimeError):
# this will be unable to get a baseline empty garbage
assert_no_gc_cycles(lambda: None)
except AssertionError:
# the above test is only necessary if the GC actually tried to free
# our object anyway, which python 2.7 does not.
if w() is not None:
pytest.skip("GC does not call __del__ on cyclic objects")
raise
finally:
# make sure that we stop creating reference cycles
ReferenceCycleInDel.make_cycle = False
def test_fails(self):
"""
Test that in cases where the garbage cannot be collected, we raise an
error, instead of hanging forever trying to clear it.
"""
class ReferenceCycleInDel(object):
"""
An object that not only contains a reference cycle, but creates new
cycles whenever it's garbage-collected and its __del__ runs
"""
make_cycle = True
def __init__(self):
self.cycle = self
def __del__(self):
# break the current cycle so that `self` can be freed
self.cycle = None
if ReferenceCycleInDel.make_cycle:
# but create a new one so that the garbage collector has more
# work to do.
ReferenceCycleInDel()
try:
w = weakref.ref(ReferenceCycleInDel())
try:
with assert_raises(RuntimeError):
# this will be unable to get a baseline empty garbage
assert_no_gc_cycles(lambda: None)
except AssertionError:
# the above test is only necessary if the GC actually tried to free
# our object anyway, which python 2.7 does not.
if w() is not None:
pytest.skip("GC does not call __del__ on cyclic objects")
raise
finally:
# make sure that we stop creating reference cycles
ReferenceCycleInDel.make_cycle = False
