# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: t -*-
# vi: set ft=python sts=4 ts=4 sw=4 noet :
# This file is part of Fail2Ban.
#
# Fail2Ban is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Fail2Ban is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty 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 Fail2Ban; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
# Author: Cyril Jaquier
#
__author__ = "Cyril Jaquier"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"
import sys
from threading import Thread
from abc import abstractmethod
from .utils import Utils
from ..helpers import excepthook, prctl_set_th_name
class JailThread(Thread):
"""Abstract class for threading elements in Fail2Ban.
Attributes
----------
daemon
ident
name
status
active : bool
Control the state of the thread.
idle : bool
Control the idle state of the thread.
sleeptime : int
The time the thread sleeps for in the loop.
"""
def __init__(self, name=None):
super(JailThread, self).__init__(name=name)
## Should going with main thread also:
self.daemon = True
## Control the state of the thread (None - was not started, True - active, False - stopped).
self.active = None
## Control the idle state of the thread.
self.idle = False
## The time the thread sleeps in the loop.
self.sleeptime = Utils.DEFAULT_SLEEP_TIME
# excepthook workaround for threads, derived from:
# http://bugs.python.org/issue1230540#msg91244
run = self.run
def run_with_except_hook(*args, **kwargs):
try:
run(*args, **kwargs)
# call on stop callback to do some finalizations:
self.onStop()
except Exception as e:
# avoid very sporadic error "'NoneType' object has no attribute 'exc_info'" (https://bugs.python.org/issue7336)
# only extremely fast systems are affected ATM (2.7 / 3.x), if thread ends nothing is available here.
if sys is not None:
excepthook(*sys.exc_info())
else:
print(e)
self.run = run_with_except_hook
def _bootstrap(self):
prctl_set_th_name(self.name)
return super(JailThread, self)._bootstrap();
@abstractmethod
def status(self, flavor="basic"): # pragma: no cover - abstract
"""Abstract - Should provide status information.
"""
pass
def start(self):
"""Sets active flag and starts thread.
"""
self.active = True
super(JailThread, self).start()
@abstractmethod
def onStop(self): # pragma: no cover - absract
"""Abstract - Called when thread ends (after run).
"""
pass
def stop(self):
"""Sets `active` property to False, to flag run method to return.
"""
self.active = False
@abstractmethod
def run(self): # pragma: no cover - absract
"""Abstract - Called when thread starts, thread stops when returns.
"""
pass
def join(self):
""" Safer join, that could be called also for not started (or ended) threads (used for cleanup).
"""
## if cleanup needed - create derivate and call it before join...
## if was really started - should call join:
if self.active is not None:
super(JailThread, self).join()
## python 3.9, restore isAlive method:
if not hasattr(JailThread, 'isAlive'):
JailThread.isAlive = JailThread.is_alive
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