gistfile1.txt

class shared_dict():

    def __init__(self):
        self.values = dict().copy()
        self.shmem = mmap.mmap(-1, 40000, mmap.MAP_SHARED)
        self.lock = mmap.mmap(-1, 1024, mmap.MAP_SHARED|mmap.MAP_ANONYMOUS)

    def save(self):
        self.__lock()
        self.shmem.seek(0)
        try:
            cache = pickle.loads(self.shmem.read(-1))
            self.values.update(cache.items() + self.values.items())
        except EOFError:
            pass
        self.shmem.seek(0)
        self.shmem.write(pickle.dumps(self.values))
        self.__unlock()

    def reload(self):
        self.shmem.seek(0)
        cache = pickle.loads(self.shmem.read(-1))
        self.values.update(cache.items() + self.values.items())

    def __lock(self):
        while True:
            self.lock.seek(0)
            if self.lock[0] == chr(1):
                sleep(0.1)
            else:
                self.lock[0] = chr(1)
                break
        return True

    def __unlock(self):
        self.lock[0] = chr(0)