zuul/zuul/lib/commandsocket.py

84 lines
3.0 KiB
Python

# Copyright 2014 OpenStack Foundation
# Copyright 2014 Hewlett-Packard Development Company, L.P.
# Copyright 2016 Red Hat
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import logging
import os
import socket
import threading
import queue
class CommandSocket(object):
log = logging.getLogger("zuul.CommandSocket")
def __init__(self, path):
self.running = False
self.path = path
self.queue = queue.Queue()
def start(self):
self.running = True
if os.path.exists(self.path):
os.unlink(self.path)
self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
self.socket.bind(self.path)
self.socket.listen(1)
self.socket_thread = threading.Thread(target=self._socketListener)
self.socket_thread.daemon = True
self.socket_thread.start()
def stop(self):
# First, wake up our listener thread with a connection and
# tell it to stop running.
self.running = False
with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as s:
s.connect(self.path)
s.sendall(b'_stop\n')
# The command '_stop' will be ignored by our listener, so
# directly inject it into the queue so that consumers of this
# class which are waiting in .get() are awakened. They can
# either handle '_stop' or just ignore the unknown command and
# then check to see if they should continue to run before
# re-entering their loop.
self.queue.put(b'_stop')
self.socket_thread.join()
def _socketListener(self):
while self.running:
try:
s, addr = self.socket.accept()
self.log.debug("Accepted socket connection %s" % (s,))
buf = b''
while True:
buf += s.recv(1)
if buf[-1:] == b'\n':
break
buf = buf.strip()
self.log.debug("Received %s from socket" % (buf,))
s.close()
# Because we use '_stop' internally to wake up a
# waiting thread, don't allow it to actually be
# injected externally.
if buf != b'_stop':
self.queue.put(buf)
except Exception:
self.log.exception("Exception in socket handler")
def get(self):
if not self.running:
raise Exception("CommandSocket.get called while stopped")
return self.queue.get()