import threading
import random
import time
import sys


sys.setswitchinterval(0.0001)

def hammer_dict(d={}):
    global running
    while running:
        k = key1 if random.randrange(2) else key2
        d[k] = 1
        try:
            del d[k]
        except KeyError:
            pass
        except:
            running = False
            raise

class Key:
    def __init__(self, x):
        self.value = x
    def __eq__(self, other):
        return self.value == other.value
    def __hash__(self):
        return hash(self.value)

key1 = Key(tuple(range(10000)))
key2 = Key(tuple(range(10000)))

num_threads = 2
threads = [threading.Thread(target=hammer_dict) for x in range(num_threads)]
running = True
for t in threads: t.start()
for t in threads: t.join()