/usr/lib/python3/dist-packages/os_win/utils/io/namedpipe.py is in python3-os-win 3.0.0-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 | # Copyright 2015 Cloudbase Solutions Srl
# All Rights Reserved.
#
# 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 errno
import os
from eventlet import patcher
from oslo_log import log as logging
from os_win._i18n import _
from os_win import constants
from os_win import exceptions
from os_win.utils.io import ioutils
from os_win.utils.winapi import constants as w_const
threading = patcher.original('threading')
time = patcher.original('time')
LOG = logging.getLogger(__name__)
class NamedPipeHandler(object):
"""Handles asynchronous I/O operations on a specified named pipe."""
_MAX_LOG_ROTATE_RETRIES = 5
def __init__(self, pipe_name, input_queue=None, output_queue=None,
connect_event=None, log_file=None):
self._pipe_name = pipe_name
self._input_queue = input_queue
self._output_queue = output_queue
self._log_file_path = log_file
self._connect_event = connect_event
self._stopped = threading.Event()
self._workers = []
self._pipe_handle = None
self._lock = threading.Lock()
self._ioutils = ioutils.IOUtils()
self._setup_io_structures()
def start(self):
try:
self._open_pipe()
if self._log_file_path:
self._log_file_handle = open(self._log_file_path, 'ab', 1)
jobs = [self._read_from_pipe]
if self._input_queue and self._connect_event:
jobs.append(self._write_to_pipe)
for job in jobs:
worker = threading.Thread(target=job)
worker.setDaemon(True)
worker.start()
self._workers.append(worker)
except Exception as err:
msg = (_("Named pipe handler failed to initialize. "
"Pipe Name: %(pipe_name)s "
"Error: %(err)s") %
{'pipe_name': self._pipe_name,
'err': err})
LOG.error(msg)
self.stop()
raise exceptions.OSWinException(msg)
def stop(self):
self._stopped.set()
# If any worker has been spawned already, we rely on it to have
# cleaned up the handles before ending its execution.
# Note that we expect the caller to synchronize the start/stop calls.
if not self._workers:
self._cleanup_handles()
for worker in self._workers:
# It may happen that another IO request was issued right after
# we've set the stopped event and canceled pending requests.
# In this case, retrying will ensure that the IO workers are
# stopped properly and that there are no more outstanding IO
# operations.
while (worker.is_alive() and
worker is not threading.current_thread()):
self._cancel_io()
worker.join(0.5)
self._workers = []
def _cleanup_handles(self):
self._close_pipe()
if self._log_file_handle:
self._log_file_handle.close()
self._log_file_handle = None
if self._r_overlapped.hEvent:
self._ioutils.close_handle(self._r_overlapped.hEvent)
self._r_overlapped.hEvent = None
if self._w_overlapped.hEvent:
self._ioutils.close_handle(self._w_overlapped.hEvent)
self._w_overlapped.hEvent = None
def _setup_io_structures(self):
self._r_buffer = self._ioutils.get_buffer(
constants.SERIAL_CONSOLE_BUFFER_SIZE)
self._w_buffer = self._ioutils.get_buffer(
constants.SERIAL_CONSOLE_BUFFER_SIZE)
self._r_overlapped = self._ioutils.get_new_overlapped_structure()
self._w_overlapped = self._ioutils.get_new_overlapped_structure()
self._r_completion_routine = self._ioutils.get_completion_routine(
self._read_callback)
self._w_completion_routine = self._ioutils.get_completion_routine()
self._log_file_handle = None
def _open_pipe(self):
"""Opens a named pipe in overlapped mode for asyncronous I/O."""
self._ioutils.wait_named_pipe(self._pipe_name)
self._pipe_handle = self._ioutils.open(
self._pipe_name,
desired_access=(w_const.GENERIC_READ | w_const.GENERIC_WRITE),
share_mode=(w_const.FILE_SHARE_READ | w_const.FILE_SHARE_WRITE),
creation_disposition=w_const.OPEN_EXISTING,
flags_and_attributes=w_const.FILE_FLAG_OVERLAPPED)
def _close_pipe(self):
if self._pipe_handle:
self._ioutils.close_handle(self._pipe_handle)
self._pipe_handle = None
def _cancel_io(self):
if self._pipe_handle:
# We ignore invalid handle errors. Even if the pipe is closed
# and the handle reused, by specifying the overlapped structures
# we ensure that we don't cancel IO operations other than the
# ones that we care about.
self._ioutils.cancel_io(self._pipe_handle, self._r_overlapped,
ignore_invalid_handle=True)
self._ioutils.cancel_io(self._pipe_handle, self._w_overlapped,
ignore_invalid_handle=True)
def _read_from_pipe(self):
self._start_io_worker(self._ioutils.read,
self._r_buffer,
self._r_overlapped,
self._r_completion_routine)
def _write_to_pipe(self):
self._start_io_worker(self._ioutils.write,
self._w_buffer,
self._w_overlapped,
self._w_completion_routine,
self._get_data_to_write)
def _start_io_worker(self, func, buff, overlapped_structure,
completion_routine, buff_update_func=None):
try:
while not self._stopped.isSet():
if buff_update_func:
num_bytes = buff_update_func()
if not num_bytes:
continue
else:
num_bytes = len(buff)
func(self._pipe_handle, buff, num_bytes,
overlapped_structure, completion_routine)
except Exception:
self._stopped.set()
finally:
with self._lock:
self._cleanup_handles()
def _read_callback(self, num_bytes):
data = self._ioutils.get_buffer_data(self._r_buffer,
num_bytes)
if self._output_queue:
self._output_queue.put(data)
if self._log_file_handle:
self._write_to_log(data)
def _get_data_to_write(self):
while not (self._stopped.isSet() or self._connect_event.isSet()):
time.sleep(1)
data = self._input_queue.get()
if data:
self._ioutils.write_buffer_data(self._w_buffer, data)
return len(data)
return 0
def _write_to_log(self, data):
if self._stopped.isSet():
return
try:
log_size = self._log_file_handle.tell() + len(data)
if log_size >= constants.MAX_CONSOLE_LOG_FILE_SIZE:
self._rotate_logs()
self._log_file_handle.write(data)
except Exception:
self._stopped.set()
def _rotate_logs(self):
self._log_file_handle.flush()
self._log_file_handle.close()
log_archive_path = self._log_file_path + '.1'
if os.path.exists(log_archive_path):
self._retry_if_file_in_use(os.remove,
log_archive_path)
self._retry_if_file_in_use(os.rename,
self._log_file_path,
log_archive_path)
self._log_file_handle = open(
self._log_file_path, 'ab', 1)
def _retry_if_file_in_use(self, f, *args, **kwargs):
# The log files might be in use if the console log is requested
# while a log rotation is attempted.
retry_count = 0
while True:
try:
return f(*args, **kwargs)
except WindowsError as err:
if (err.errno == errno.EACCES and
retry_count < self._MAX_LOG_ROTATE_RETRIES):
retry_count += 1
time.sleep(1)
else:
raise
|