8aefef51bd
From changeset 8087f5ff825cae3a699e5a60ca6dd0deb10fc8e5 dirs.py.template needs to be adopted for Ryu environment. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
137 lines
3.4 KiB
Python
137 lines
3.4 KiB
Python
# Copyright (c) 2010, 2011 Nicira, Inc.
|
||
#
|
||
# Licensed under the Apache License, Version 2.0 (the "License");
|
||
# you may not use this file except in compliance with the License.
|
||
# You may obtain a copy of the License at:
|
||
#
|
||
# http://www.apache.org/licenses/LICENSE-2.0
|
||
#
|
||
# Unless required by applicable law or agreed to in writing, software
|
||
# distributed under the License is distributed on an "AS IS" BASIS,
|
||
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
# See the License for the specific language governing permissions and
|
||
# limitations under the License.
|
||
|
||
import atexit
|
||
import os
|
||
import signal
|
||
|
||
import ovs.vlog
|
||
|
||
_hooks = []
|
||
vlog = ovs.vlog.Vlog("fatal-signal")
|
||
|
||
|
||
def add_hook(hook, cancel, run_at_exit):
|
||
_init()
|
||
_hooks.append((hook, cancel, run_at_exit))
|
||
|
||
|
||
def fork():
|
||
"""Clears all of the fatal signal hooks without executing them. If any of
|
||
the hooks passed a 'cancel' function to add_hook(), then those functions
|
||
will be called, allowing them to free resources, etc.
|
||
|
||
Following a fork, one of the resulting processes can call this function to
|
||
allow it to terminate without calling the hooks registered before calling
|
||
this function. New hooks registered after calling this function will take
|
||
effect normally."""
|
||
global _hooks
|
||
for hook, cancel, run_at_exit in _hooks:
|
||
if cancel:
|
||
cancel()
|
||
|
||
_hooks = []
|
||
|
||
_added_hook = False
|
||
_files = {}
|
||
|
||
|
||
def add_file_to_unlink(file):
|
||
"""Registers 'file' to be unlinked when the program terminates via
|
||
sys.exit() or a fatal signal."""
|
||
global _added_hook
|
||
if not _added_hook:
|
||
_added_hook = True
|
||
add_hook(_unlink_files, _cancel_files, True)
|
||
_files[file] = None
|
||
|
||
|
||
def remove_file_to_unlink(file):
|
||
"""Unregisters 'file' from being unlinked when the program terminates via
|
||
sys.exit() or a fatal signal."""
|
||
if file in _files:
|
||
del _files[file]
|
||
|
||
|
||
def unlink_file_now(file):
|
||
"""Like fatal_signal_remove_file_to_unlink(), but also unlinks 'file'.
|
||
Returns 0 if successful, otherwise a positive errno value."""
|
||
error = _unlink(file)
|
||
if error:
|
||
vlog.warn("could not unlink \"%s\" (%s)" % (file, os.strerror(error)))
|
||
remove_file_to_unlink(file)
|
||
return error
|
||
|
||
|
||
def _unlink_files():
|
||
for file_ in _files:
|
||
_unlink(file_)
|
||
|
||
|
||
def _cancel_files():
|
||
global _added_hook
|
||
global _files
|
||
_added_hook = False
|
||
_files = {}
|
||
|
||
|
||
def _unlink(file_):
|
||
try:
|
||
os.unlink(file_)
|
||
return 0
|
||
except OSError, e:
|
||
return e.errno
|
||
|
||
|
||
def _signal_handler(signr, _):
|
||
_call_hooks(signr)
|
||
|
||
# Re-raise the signal with the default handling so that the program
|
||
# termination status reflects that we were killed by this signal.
|
||
signal.signal(signr, signal.SIG_DFL)
|
||
os.kill(os.getpid(), signr)
|
||
|
||
|
||
def _atexit_handler():
|
||
_call_hooks(0)
|
||
|
||
|
||
recurse = False
|
||
|
||
|
||
def _call_hooks(signr):
|
||
global recurse
|
||
if recurse:
|
||
return
|
||
recurse = True
|
||
|
||
for hook, cancel, run_at_exit in _hooks:
|
||
if signr != 0 or run_at_exit:
|
||
hook()
|
||
|
||
|
||
_inited = False
|
||
|
||
|
||
def _init():
|
||
global _inited
|
||
if not _inited:
|
||
_inited = True
|
||
|
||
for signr in (signal.SIGTERM, signal.SIGINT,
|
||
signal.SIGHUP, signal.SIGALRM):
|
||
if signal.getsignal(signr) == signal.SIG_DFL:
|
||
signal.signal(signr, _signal_handler)
|
||
atexit.register(_atexit_handler)
|