204 lines
6.4 KiB
Python
204 lines
6.4 KiB
Python
|
# DBus Task interface.
|
||
|
|
#
|
||
|
|
# Base class of tasks.
|
||
|
|
# Task is used by modules to implement asynchronous time consuming installation
|
||
|
|
# or configuration tasks.
|
||
|
|
#
|
||
|
|
# Copyright (C) 2017 Red Hat, Inc.
|
||
|
|
#
|
||
|
|
# 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, or (at your option) any later version.
|
||
|
|
# This program is distributed in the hope that it will be useful, but WITHOUT
|
||
|
|
# ANY WARRANTY expressed or implied, including the implied warranties of
|
||
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
|
||
|
|
# Public License for more details. You should have received a copy of the
|
||
|
|
# GNU General Public License along with this program; if not, write to the
|
||
|
|
# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
||
|
|
# 02110-1301, USA. Any Red Hat trademarks that are incorporated in the
|
||
|
|
# source code or documentation are not subject to the GNU General Public
|
||
|
|
# License and may only be used or replicated with the express permission of
|
||
|
|
# Red Hat, Inc.
|
||
|
|
#
|
||
|
|
import traceback
|
||
|
|
from abc import abstractmethod
|
||
|
|
|
||
|
|
from pyanaconda.core.constants import THREAD_DBUS_TASK
|
||
|
|
from dasbus.server.publishable import Publishable
|
||
|
|
|
||
|
|
from pyanaconda.modules.common.errors.task import NoResultError
|
||
|
|
from pyanaconda.modules.common.task.task_interface import TaskInterface, ValidationTaskInterface
|
||
|
|
from pyanaconda.modules.common.task.cancellable import Cancellable
|
||
|
|
from pyanaconda.modules.common.task.progress import ProgressReporter
|
||
|
|
from pyanaconda.modules.common.task.result import ResultProvider
|
||
|
|
from pyanaconda.modules.common.task.runnable import Runnable
|
||
|
|
from pyanaconda.core.threads import thread_manager
|
||
|
|
|
||
|
|
from pyanaconda.anaconda_loggers import get_module_logger
|
||
|
|
log = get_module_logger(__name__)
|
||
|
|
|
||
|
|
__all__ = ['AbstractTask', 'Task', 'ValidationTask']
|
||
|
|
|
||
|
|
|
||
|
|
class AbstractTask(Runnable, Cancellable, Publishable, ProgressReporter, ResultProvider):
|
||
|
|
"""Abstract class for running a long-term task."""
|
||
|
|
|
||
|
|
@property
|
||
|
|
@abstractmethod
|
||
|
|
def name(self):
|
||
|
|
"""Name of this task.
|
||
|
|
|
||
|
|
For example: "Install the payload"
|
||
|
|
|
||
|
|
:returns: string with the task name
|
||
|
|
"""
|
||
|
|
return ""
|
||
|
|
|
||
|
|
def for_publication(self):
|
||
|
|
"""Return a DBus representation."""
|
||
|
|
return TaskInterface(self)
|
||
|
|
|
||
|
|
|
||
|
|
class Task(AbstractTask):
|
||
|
|
"""Abstract class for running a long-term task in a thread."""
|
||
|
|
|
||
|
|
_thread_counter = 0
|
||
|
|
|
||
|
|
def __init__(self):
|
||
|
|
super().__init__()
|
||
|
|
self._thread_name = self._generate_thread_name()
|
||
|
|
|
||
|
|
@property
|
||
|
|
def steps(self):
|
||
|
|
"""Total number of steps."""
|
||
|
|
return 1
|
||
|
|
|
||
|
|
@property
|
||
|
|
def is_running(self):
|
||
|
|
"""Is the task running."""
|
||
|
|
return thread_manager.exists(self._thread_name)
|
||
|
|
|
||
|
|
def start(self):
|
||
|
|
"""Start the task in a new thread."""
|
||
|
|
thread_manager.add_thread(
|
||
|
|
name=self._thread_name,
|
||
|
|
target=self._thread_run_callback,
|
||
|
|
target_started=self._task_started_callback,
|
||
|
|
target_stopped=self._task_stopped_callback,
|
||
|
|
target_failed=self._thread_failed_callback,
|
||
|
|
fatal=False
|
||
|
|
)
|
||
|
|
|
||
|
|
def _thread_run_callback(self):
|
||
|
|
"""Run a task and report the success."""
|
||
|
|
self._task_run_callback()
|
||
|
|
self._task_succeeded_callback()
|
||
|
|
|
||
|
|
def _task_run_callback(self):
|
||
|
|
"""Report the first step and run the task.
|
||
|
|
.
|
||
|
|
Don't run the task if the task was canceled.
|
||
|
|
"""
|
||
|
|
if self.check_cancel():
|
||
|
|
log.info("'%s' is canceled.", self.name)
|
||
|
|
return
|
||
|
|
|
||
|
|
log.info(self.name)
|
||
|
|
self._set_result(self.run())
|
||
|
|
|
||
|
|
def _task_succeeded_callback(self):
|
||
|
|
"""Callback for a successful task.
|
||
|
|
|
||
|
|
Don't report the success if the task was canceled.
|
||
|
|
"""
|
||
|
|
if not self.check_cancel():
|
||
|
|
super()._task_succeeded_callback()
|
||
|
|
|
||
|
|
def _thread_failed_callback(self, *exc_info):
|
||
|
|
"""Log the error and report the failure."""
|
||
|
|
# pylint: disable=no-value-for-parameter
|
||
|
|
formatted_info = "".join(traceback.format_exception(*exc_info))
|
||
|
|
log.error("Thread %s has failed: %s", self._thread_name, formatted_info)
|
||
|
|
self._task_failed_callback()
|
||
|
|
|
||
|
|
def run_with_signals(self):
|
||
|
|
"""Run the task in the current thread with enabled signals.
|
||
|
|
|
||
|
|
Call this method to run the task synchronously in the current
|
||
|
|
thread. It will emit all signals in the same order as the start
|
||
|
|
method.
|
||
|
|
|
||
|
|
:raise: an error if the task fails
|
||
|
|
:return: a result of the task if the task succeeds
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
self._task_started_callback()
|
||
|
|
self._task_run_callback()
|
||
|
|
except Exception: # pylint: disable=broad-except
|
||
|
|
self._task_failed_callback()
|
||
|
|
raise
|
||
|
|
else:
|
||
|
|
self._task_succeeded_callback()
|
||
|
|
finally:
|
||
|
|
self._task_stopped_callback()
|
||
|
|
|
||
|
|
try:
|
||
|
|
return self.get_result()
|
||
|
|
except NoResultError:
|
||
|
|
return None
|
||
|
|
|
||
|
|
@abstractmethod
|
||
|
|
def run(self):
|
||
|
|
"""The task implementation.
|
||
|
|
|
||
|
|
Report the progress of the task with the self.report_progress
|
||
|
|
method.
|
||
|
|
|
||
|
|
Call self.check_cancel to check if the task should be canceled
|
||
|
|
and terminate the task immediately if it returns True.
|
||
|
|
|
||
|
|
Return a result of the task or None if the task doesn't provide
|
||
|
|
a result.
|
||
|
|
|
||
|
|
:return: a result of the task
|
||
|
|
"""
|
||
|
|
return None
|
||
|
|
|
||
|
|
def finish(self):
|
||
|
|
"""Finish the task run.
|
||
|
|
|
||
|
|
Call this method after the task has stopped. If there was raised
|
||
|
|
an exception during the task run, it will be raised here again.
|
||
|
|
"""
|
||
|
|
thread_manager.raise_if_error(self._thread_name)
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def _generate_thread_name(cls):
|
||
|
|
"""Generate the name of the thread."""
|
||
|
|
cls._thread_counter += 1
|
||
|
|
|
||
|
|
return "{}-{}-{}".format(
|
||
|
|
THREAD_DBUS_TASK,
|
||
|
|
cls.__name__,
|
||
|
|
cls._thread_counter
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
class ValidationTask(Task):
|
||
|
|
"""Abstract class for running a validation task."""
|
||
|
|
|
||
|
|
def for_publication(self):
|
||
|
|
"""Return a DBus representation."""
|
||
|
|
return ValidationTaskInterface(self)
|
||
|
|
|
||
|
|
@abstractmethod
|
||
|
|
def run(self):
|
||
|
|
"""The validation implementation.
|
||
|
|
|
||
|
|
Run the validation and return an validation report
|
||
|
|
with error and warning messages.
|
||
|
|
|
||
|
|
:return: an instance of ValidationReport
|
||
|
|
"""
|
||
|
|
return None
|