[lnst] Machine: fix timeout handling
commit 9cb6f1ce65ac294d08942fec38541bf9776c628a
Author: Ondrej Lichtner <olichtne(a)redhat.com>
Date: Mon May 27 15:53:32 2013 +0200
Machine: fix timeout handling
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>
Signed-off-by: Jiri Pirko <jiri(a)resnulli.us>
lnst/Controller/Machine.py | 25 ++++++++++++++-----------
1 files 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