import gc
import os
import random
import sys
import threading
import time

from multiprocessing import Queue
from multiprocessing import util


random.seed(42)


def cb(*args):
    pass

class Finalizable(object):

    def __init__(self):
        self.ref = self
        util.Finalize(self, cb, exitpriority=random.randint(1, 100))


def run_finalizers():
    while True:
        time.sleep(random.random() * 1e-1)
        try:
            util._run_finalizers()
        except Exception:
            print()
            print("-- Exception in run_finalizers --")
            sys.excepthook(*sys.exc_info())
            os._exit(1)


def make_finalizers():
    d = {}
    threshold = 60
    while True:
        try:
            d[random.getrandbits(32)] = {Finalizable() for i in range(10)}
            if len(d) > threshold:
                for i in range(len(d) // 2):
                    d.popitem()
        except Exception:
            print()
            print("-- Exception in make_finalizers --")
            sys.excepthook(*sys.exc_info())
            os._exit(1)


def main():
    sys.setswitchinterval(1e-6)
    gc.set_threshold(5, 5, 5)
    t = threading.Thread(target=run_finalizers)
    t.daemon = True
    t.start()
    t = threading.Thread(target=make_finalizers)
    t.daemon = True
    t.start()

    time.sleep(1e8)


if __name__ == "__main__":
    main()