如何停止 Tornado Web 服务器? [英] How do I stop Tornado web server?

问题描述

我一直在玩 Tornado 网络服务器，现在我想停止网络服务器(例如在单元测试期间).以下简单示例存在于 Tornado 网页上:

I've been playing around a bit with the Tornado web server and have come to a point where I want to stop the web server (for example during unit testing). The following simple example exists on the Tornado web page:

import tornado.ioloop
import tornado.web

class MainHandler(tornado.web.RequestHandler):
    def get(self):
        self.write("Hello, world")

application = tornado.web.Application([
    (r"/", MainHandler),
])

if __name__ == "__main__":
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

一旦 tornado.ioloop.IOLoop.instance().start() 被调用，它就会阻塞程序(或当前线程).阅读 IOLoop 对象的源代码给出stop 函数文档中的这个例子:

Once tornado.ioloop.IOLoop.instance().start() is called, it blocks the program (or current thread). Reading the source code for the IOLoop object gives this example in the documentation for the stop function:

To use asynchronous methods from otherwise-synchronous code (such as
unit tests), you can start and stop the event loop like this:
  ioloop = IOLoop()
  async_method(ioloop=ioloop, callback=ioloop.stop)
  ioloop.start()
ioloop.start() will return after async_method has run its callback,
whether that callback was invoked before or after ioloop.start.

但是，我不知道如何将其集成到我的程序中.我实际上有一个封装 web 服务器的类(有它自己的 start 和 stop 函数)，但是一旦我调用 start，程序(或测试)就会无论如何都要阻止.

However, I have no idea how to integrate this into my program. I actually have a class that encapsulates the web server (having it's own start and stop functions), but as soon as I call start, the program (or tests) will of course block anyway.

我尝试在另一个进程中启动 Web 服务器(使用 multiprocessing 包).这是包装 Web 服务器的类:

I've tried to start the web server in another process (using the multiprocessing package). This is the class that is wrapping the web server:

class Server:
    def __init__(self, port=8888):
        self.application = tornado.web.Application([ (r"/", Handler) ])

        def server_thread(application, port):
            http_server = tornado.httpserver.HTTPServer(application)
            http_server.listen(port)
            tornado.ioloop.IOLoop.instance().start()

        self.process = Process(target=server_thread,
                               args=(self.application, port,))

    def start(self):
        self.process.start()

    def stop(self):
        ioloop = tornado.ioloop.IOLoop.instance()
        ioloop.add_callback(ioloop.stop)

然而，stop 似乎并没有完全停止 Web 服务器，因为它在下一个测试中仍在运行，即使使用这个测试设置:

However, stop does not seem to entirely stop the web server since it is still running in the next test, even with this test setup:

def setup_method(self, _function):
    self.server = Server()
    self.server.start()
    time.sleep(0.5)  # Wait for web server to start

def teardown_method(self, _function):
    self.kstore.stop()
    time.sleep(0.5)

如何在 Python 程序中启动和停止 Tornado Web 服务器?

How can I start and stop a Tornado web server from within a Python program?

推荐答案

我刚刚遇到这个问题并自己发现了这个问题，并使用该线程中的信息提出了以下内容.我只是将我的工作独立 Tornado 代码(从所有示例复制)并将实际的起始代码移动到一个函数中.然后我将该函数称为线程线程.我的情况不同，因为线程调用是从我现有的代码中完成的，我刚刚导入了 startTornado 和 stopTornado 例程.

I just ran into this and found this issue myself, and using info from this thread came up with the following. I simply took my working stand alone Tornado code (copied from all the examples) and moved the actual starting code into a function. I then called the function as a threading thread. My case different as the threading call was done from my existing code where I just imported the startTornado and stopTornado routines.

上面的建议似乎很有效，所以我想我会提供缺少的示例代码.我在 FC16 系统上的 Linux 下测试了这段代码(并修复了我最初的 type-o).

The suggestion above seemed to work great, so I figured I would supply the missing example code. I tested this code under Linux on a FC16 system (and fixed my initial type-o).

import tornado.ioloop, tornado.web

class Handler(tornado.web.RequestHandler):
    def get(self):
        self.write("Hello, world")

application = tornado.web.Application([ (r"/", Handler) ])

def startTornado():
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

def stopTornado():
    tornado.ioloop.IOLoop.instance().stop()

if __name__ == "__main__":
    import time, threading
    threading.Thread(target=startTornado).start()
    print "Your web server will self destruct in 2 minutes"
    time.sleep(120)
    stopTornado()

希望这对下一个人有所帮助.

Hope this helps the next person.

这篇关于如何停止 Tornado Web 服务器?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！