import unittest


PySet_MINSIZE = 8
SET_MASK = PySet_MINSIZE - 1
FIXED_HASH = 1
if not FIXED_HASH:
    hash_values = [None] * 1000
else:
    hash_values = [3, 2, 5, 6, 5, 1, 0, 3, 4, 2, 0, 1, 3, 2, 3, 4, 7, 7, 7, 2, 0, 1, 4, 6, 0, 3, 3, 1, 3, 2, 0, 7, 7, 7, 2]
hash_i = 0


class Thread2:
    def __init__(self):
        global hash_i

        if FIXED_HASH:
            # XXX: it seems like the leak occurs here:
            # a dict with shared keys is created
            self.hashvalue = hash_values[hash_i]
        else:
            k = hash(self) & SET_MASK
            hash_values[hash_i] = k
            print(hash_values[:hash_i+1])
        hash_i += 1

    if FIXED_HASH:
        def __hash__(self):
            return self.hashvalue


class LeakTest(unittest.TestCase):
    def test_leak(self):
        item = Thread2()
        dangling.add(item)
        dangling.discard(item)
        item = None


dangling = set()
main_thread = Thread2()
dangling.add(main_thread)