def monitor(self):
prev_snapshot = NetworkSnapshot()
snapshot = NetworkSnapshot()
last_snapshot = time.time()
exceptionCount = 0
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('', self.port))
sock.listen(0)
self.logger.info('Listening on port %d' %(self.port))
readFds = set([sock])
while True:
try:
timeout = last_snapshot + snapshot.interval - time.time()
rs, ws, xs = select.select(readFds, [], [], timeout)
exceptionCount = 0
if not rs:
# timeout, so we take a snapshot with what we got
if snapshot != prev_snapshot:
self.logger.info('Taking snapshot with %s'
%(str(snapshot)))
self.cmap.assign_edge_locations(snapshot.edge_locations)
self.cmap.update_memcache()
snapshot.memcache_save()
last_snapshot = time.time()
prev_snapshot.edge_locations = snapshot.edge_locations
snapshot.clear()
continue
for readFd in rs:
if readFd == sock:
# incoming connection
conn, addr = sock.accept()
readFds.add(conn)
else:
self.read_and_close(readFd, snapshot.edge_locations)
readFds.remove(readFd)
except KeyboardInterrupt:
self.logger.info('Exiting...')
sock.close()
exit()
except select.error as e:
self.logger.exception(e)
# this might happen if we miss a deadline with other operations
if timeout < 0:
last_snapshot += snapshot.interval
exceptionCount += 1
# if we get more than 3 exceptions in a row, we give up
if exceptionCount > 3:
sock.close()
exit()
