import quincy 17.2.0

[ceph.git] / ceph / src / arrow / python / pyarrow / tests / test_util.py

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#   http://www.apache.org/licenses/LICENSE-2.0
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import gc
import signal
import sys
import weakref

import pytest

from pyarrow import util
from pyarrow.tests.util import disabled_gc


def exhibit_signal_refcycle():
    # Put an object in the frame locals and return a weakref to it.
    # If `signal.getsignal` has a bug where it creates a reference cycle
    # keeping alive the current execution frames, `obj` will not be
    # destroyed immediately when this function returns.
    obj = set()
    signal.getsignal(signal.SIGINT)
    return weakref.ref(obj)


def test_signal_refcycle():
    # Test possible workaround for https://bugs.python.org/issue42248
    with disabled_gc():
        wr = exhibit_signal_refcycle()
        if wr() is None:
            pytest.skip(
                "Python version does not have the bug we're testing for")

    gc.collect()
    with disabled_gc():
        wr = exhibit_signal_refcycle()
        assert wr() is not None
        util._break_traceback_cycle_from_frame(sys._getframe(0))
        assert wr() is None