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# Copyright (C) 2015-2016 Red Hat, Inc. All rights reserved.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions
# of the GNU General Public License v.2.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import dbus
import threading
# noinspection PyUnresolvedReferences
from gi.repository import GLib
from .job import Job
from . import cfg
from .utils import log_error, mt_async_call, extract_stack_trace
class RequestEntry(object):
def __init__(self, tmo, method, arguments, cb, cb_error,
return_tuple=True, job_state=None):
self.method = method
self.arguments = arguments
self.cb = cb
self.cb_error = cb_error
self.timer_id = -1
self.lock = threading.RLock()
self.done = False
self._result = None
self._job = None
self._rc = 0
self._rc_error = None
self._return_tuple = return_tuple
self._job_state = job_state
if tmo < 0:
# Client is willing to block forever
pass
elif tmo == 0:
self._return_job()
else:
# Note: using 990 instead of 1000 for second to ms conversion to
# account for overhead. Goal is to return just before the
# timeout amount has expired. Better to be a little early than
# late.
self.timer_id = GLib.timeout_add(
tmo * 990, RequestEntry._request_timeout, self)
@staticmethod
def _request_timeout(r):
"""
Method which gets called when the timer runs out!
:param r: RequestEntry which timed out
:return: Result of timer_expired
"""
return r.timer_expired()
def _return_job(self):
# Return job is only called when we create a request object or when
# we pop a timer. In both cases we are running in the correct context
# and do not need to schedule the call back in main context.
self._job = Job(self, self._job_state)
cfg.om.register_object(self._job, True)
if self._return_tuple:
self.cb(('/', self._job.dbus_object_path()))
else:
self.cb(self._job.dbus_object_path())
def run_cmd(self):
try:
result = self.method(*self.arguments)
self.register_result(result)
except SystemExit as se:
self.register_error(-1, str(se), se)
raise se
except dbus.exceptions.DBusException as dbe:
# This is an expected error path when something goes awry that
# we handled
self.register_error(-1, str(dbe), dbe)
except Exception as e:
# Use the request entry to return the result as the client may
# have gotten a job by the time we hit an error
# Lets set the exception text as the error message and log the
# exception in the journal for figuring out what went wrong.
cfg.debug.dump()
cfg.flightrecorder.dump()
tb = extract_stack_trace(e)
log_error("While processing %s: we encountered\n%s" % (str(self.method), tb))
log_error("Error returned to client: %s" % str(e))
self.register_error(-1, str(e), e)
def is_done(self):
with self.lock:
rc = self.done
return rc
def get_errors(self):
with self.lock:
return (self._rc, self._rc_error)
def result(self):
with self.lock:
if self.done:
return self._result
return '/'
def _reg_ending(self, result, error_rc=0, error_msg=None,
error_exception=None):
with self.lock:
self.done = True
if self.timer_id != -1:
# Try to prevent the timer from firing
GLib.source_remove(self.timer_id)
self._result = result
self._rc = error_rc
self._rc_error = error_msg
if not self._job:
# We finished and there is no job, so return result or error
# now!
# Note: If we don't have a valid cb or cbe, this indicates a
# request that doesn't need a response as we already returned
# one before the request was processed.
if error_rc == 0:
if self.cb:
if self._return_tuple:
mt_async_call(self.cb, (result, '/'))
else:
mt_async_call(self.cb, result)
else:
if self.cb_error:
if not error_exception:
if not error_msg:
error_exception = Exception(
"An error occurred, but no reason was "
"given, see service logs!")
else:
error_exception = Exception(error_msg)
mt_async_call(self.cb_error, error_exception)
else:
# We have a job, and it's complete, indicate that it's done.
self._job.Complete = True
self._job = None
def register_error(self, error_rc, error_message, error_exception):
self._reg_ending('/', error_rc, error_message, error_exception)
def register_result(self, result):
self._reg_ending(result)
def timer_expired(self):
with self.lock:
# Set the timer back to -1 as we will get a warning if we try
# to remove a timer that doesn't exist
self.timer_id = -1
if not self.done:
# Create dbus job object and return path to caller
self._return_job()
else:
# The job is done, we have nothing to do
pass
return False
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