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import gc
import sys
import pytest
from asgiref.local import Local
def disable_gc_for_garbage_collection_test() -> None:
# Disable automatic garbage collection. To have control over when
# garbage collection is performed. This is necessary to ensure that another
# that thread doesn't accidentally trigger it by simply executing code.
gc.disable()
# Delete the garbage list(`gc.garbage`) to ensure that other tests don't
# interfere with this test.
gc.collect()
# Set the garbage collection debugging flag to store all unreachable
# objects in `gc.garbage`. This is necessary to ensure that the
# garbage list is empty after execute test code. Otherwise, the test
# will always pass. The garbage list isn't automatically populated
# because it costs extra CPU cycles
gc.set_debug(gc.DEBUG_SAVEALL)
def clean_up_after_garbage_collection_test() -> None:
# Clean up the garbage collection settings. Re-enable automatic garbage
# collection. This step is mandatory to avoid running other tests without
# automatic garbage collection.
gc.set_debug(0)
gc.enable()
@pytest.mark.skipif(
sys.implementation.name == "pypy", reason="Test relies on CPython GC internals"
)
def test_thread_critical_Local_remove_all_reference_cycles() -> None:
try:
# given
# Disable automatic garbage collection and set debugging flag.
disable_gc_for_garbage_collection_test()
# when
# Create thread critical Local object in sync context.
try:
getattr(Local(thread_critical=True), "missing")
except AttributeError:
pass
# Enforce garbage collection to populate the garbage list for inspection.
gc.collect()
# then
# Ensure that the garbage list is empty. The garbage list is only valid
# until the next collection cycle so we can only make assertions about it
# before re-enabling automatic collection.
assert gc.garbage == []
# Restore garbage collection settings to their original state. This should always be run to avoid interfering
# with other tests to ensure that code should be executed in the `finally' block.
finally:
clean_up_after_garbage_collection_test()
|
