SocketServer.ForkingMixIn and zombie processes

[nisimura at gmail.com]

Hi,

I noticed that when I used SocketServer.ForkingMixIn
(ForkingTCPServer), there were always  zombie processes around.  I
searched for where waitpid() is called in ForkingMixIn and found it in
SocketServer.py:

    def process_request(self, request, client_address):
        """Fork a new subprocess to process the request."""
        self.collect_children()
        pid = os.fork()
        if pid:
            # Parent process
            if self.active_children is None:
                self.active_children = []
            self.active_children.append(pid)
            self.close_request(request)
            return
        else:
            # Child process.
            # This must never return, hence os._exit()!
            try:
                self.finish_request(request, client_address)
                os._exit(0)
            except:
                try:
                    self.handle_error(request, client_address)
                finally:
                    os._exit(1)

So waitpid() is called just before fork().  This means that if next
request does not come in, zombie processes are not reclaimed forever!
Is this an intentional behavior?  Is there any workaround?

--
Kazu Nisimura