import logging
import time
from threading import Thread


def process():
    while True:
        try:
            if len(queue) > 0:
                fn = queue.pop()
                fn()
        except Exception as e:
            logging.error(e)
        finally:
            time.sleep(1)


# 使用 gunicorn 时, gunicorn 会 fork 出若干个子进程, 每个进程都有自己的 worker_thread, 且内存不共享
worker_thread = None
queue = []


def submit(job, callback):
    global worker_thread
    if worker_thread is None:
        worker_thread = Thread(target=process)
        worker_thread.start()

    queue.append(lambda: job(callback))