import sys


#############
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]

class Thread2:
    __slots__ = ('hashvalue',)

    def __init__(self, hashvalue):
        self.hashvalue = hashvalue

    def __hash__(self):
        return self.hashvalue


items = [Thread2(hash_values[i % len(hash_values)]) for i in range(11)]

dangling = set()
counter = 1

def test_current_frames():
    global counter, dangling
    i = counter % len(items)
    counter += 1
    dangling.add(items[0])
    dangling.add(items[i])
    dangling.discard(items[i])
    dangling.discard(items[0])
    assert len(dangling) == 0
###############



def dash_R():
    nwarmup, ntracked = (4, 30)
    repcount = nwarmup + ntracked
    alloc_deltas = [0] * ntracked
    # prealloc all integers for sys.getallocatedblocks() result
    integers = list(range(20_000))

    alloc_before = 0
    alloc_after = 0

    for i in range(nwarmup):
        test_current_frames()
        alloc_before = sys.getallocatedblocks()

    # The leak occurs somewhere here
    for i in range(ntracked):
        test_current_frames()

        if 0:
            print(sys.getallocatedblocks())
        else:
            alloc_after = sys.getallocatedblocks()
            alloc_deltas[i] = alloc_after - alloc_before
            alloc_before = alloc_after
            i = None
    # ---

    if any(delta >= 1 for delta in alloc_deltas):
        msg = 'test_leak leaked %s %s, sum=%s' % (
            alloc_deltas, 'memory blocks', sum(alloc_deltas))
        print(msg, file=sys.stderr, flush=True)
        failed = True
    else:
        print("no leak")
        failed = False

    return failed


def warm_caches():
    # char cache
    s = bytes(range(256))
    for i in range(256):
        s[i:i+1]
    # unicode cache
    [chr(i) for i in range(256)]
    # int cache
    list(range(-5, 257))

if __name__ == "__main__":
    warm_caches()
    dash_R()