如何向flask添加后台线程？

Question

我正在忙着编写一个小型游戏服务器来试用Flask。游戏通过REST向用户展示API。用户执行操作和查询数据很容易，但是我想在app.run（）循环之外为“游戏世界”提供服务，以更新游戏实体等。鉴于Flask的实现如此简洁，我希望看看是否有Flask方式可以做到这一点。

Answer 1

你的其他线程必须从WSGI服务器调用的同一应用程序启动。

下面的示例创建一个后台线程，该线程每5秒执行一次，并处理Flask路由函数也可用的数据结构。

import threading
import atexit
from flask import Flask

POOL_TIME = 5 #Seconds

# variables that are accessible from anywhere
commonDataStruct = {}
# lock to control access to variable
dataLock = threading.Lock()
# thread handler
yourThread = threading.Thread()

def create_app():
    app = Flask(__name__)

    def interrupt():
        global yourThread
        yourThread.cancel()

    def doStuff():
        global commonDataStruct
        global yourThread
        with dataLock:
        # Do your stuff with commonDataStruct Here

        # Set the next thread to happen
        yourThread = threading.Timer(POOL_TIME, doStuff, ())
        yourThread.start()   

    def doStuffStart():
        # Do initialisation stuff here
        global yourThread
        # Create your thread
        yourThread = threading.Timer(POOL_TIME, doStuff, ())
        yourThread.start()

    # Initiate
    doStuffStart()
    # When you kill Flask (SIGTERM), clear the trigger for the next thread
    atexit.register(interrupt)
    return app

app = create_app()     

从Gunicorn调用它，如下所示：

gunicorn -b 0.0.0.0:5000 --log-config log.conf --pid=app.pid myfile:app