[PATCH] Machine: fix timeout handling

From: Ondrej Lichtner <olichtne(a)redhat.com&gt; Before the reimplementation of controller <-> slave communication we used socket timeouts to implement command timeouts. However since now we are using select calls over all our connections this doesn't work anymore. Furthermore using select timeout isn't very usefull as we are continually recieving log messages from other slaves. This commit implements the timeout mechanism by using the signal.alarm call. The handler function raises an Exception that indicates a timeout of a command. Signed-off-by: Ondrej Lichtner <olichtne(a)redhat.com&gt; --- lnst/Controller/Machine.py | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/lnst/Controller/Machine.py b/lnst/Controller/Machine.py index d8162fc..006a5a0 100644 --- a/lnst/Controller/Machine.py +++ b/lnst/Controller/Machine.py @@ -17,6 +17,7 @@ import os import re import pickle import tempfile +import signal from time import sleep from xmlrpclib import Binary from pprint import pprint, pformat @@ -158,22 +159,24 @@ class Machine(object): self._configured = False + def _timeout_handler(self, signum, frame): + msg = "RPC connection to machine %s timed out" % self.get_id() + raise MachineError(msg) + def run_command(self, command): """ Run a command on the machine """ + prev_handler = signal.signal(signal.SIGALRM, self._timeout_handler) + if "timeout" in command: timeout = command["timeout"] - logging.debug("Setting socket timeout to \"%d\"", timeout) - socket.setdefaulttimeout(timeout) - try: - cmd_res = self._rpc_call("run_command", command) - except socket.timeout: - msg = "RPC connection to machine %s timed out" % self.get_id() - raise Machine(msg) - finally: - if "timeout" in command: - logging.debug("Setting socket timeout to default value") - socket.setdefaulttimeout(None) + logging.debug("Setting timeout to \"%d\"", timeout) + signal.alarm(timeout) + + cmd_res = self._rpc_call("run_command", command) + + signal.alarm(0) + signal.signal(signal.SIGALRM, prev_handler) return cmd_res -- 1.8.1.4