为什么python中的这个线程没有停止？

Question

I am trying to setup a simple http server in python in a thread.

class MyHandler(SimpleHTTPRequestHandler):
    def do_GET(self):
        if self.path == '/shutdown':
            print 'Got shutdown request'
            self.server.running = False  
        self.send_response(200)

class Server():

  def __init__(self):
     self._http_server = HTTPServer(('0.0.0.0', 8123), MyHandler)
     self._http_server.running = True
     self._http_server_thread = threading.Thread(target = self._run_http_server, name = 'serverthread')
     self._http_server_thread.start()


  def _run_http_server(self):
      print 'Server started'
      while( self._http_server.running ):
          self._http_server.handle_request()

      print 'Server finished serving'
      self._http_server.shutdown()


  def check_status(self):
      l = threading.enumerate()
      for i in l:
          print i.name


serv = Server()
print 'Sleeping for 20 seconds'
time.sleep(20)
req = urllib2.urlopen('http://127.0.0.1:8123/shutdown')
print 'Finished sleeping'
serv.check()

My assumption is once the _run_http_server finishes running , the thread should stop running but it doesn't.I get this output but the thread keeps running. Can anyone point why the thread doesn't stop?

Server started
Sleeping for 20 seconds
Got shut down request
127.0.0.1 - - [09/Jul/2016 12:17:17] "GET /shutdown HTTP/1.1" 200 -
Server finished serving
Finished sleeping
MainThread
serverthread
True

Answer 1

In your code you have your own request processing loop (instead of using HTTPServer.serve_forever() ). Yet, you call HTTPServer.shutdown() whose job is to tell the serve_forever() loop to stop and wait until it does. Since serve_forever() wasn't even started, shutdown() never returns (it is actually waiting for serve_forever() to start and immediately stop). Removing the self._http_server.shutdown() line fixes the problem.