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Diffstat (limited to 'harnesses/host_controller/utils/ipc/file_lock.py')
| -rw-r--r-- | harnesses/host_controller/utils/ipc/file_lock.py | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/harnesses/host_controller/utils/ipc/file_lock.py b/harnesses/host_controller/utils/ipc/file_lock.py deleted file mode 100644 index 67b6bf7..0000000 --- a/harnesses/host_controller/utils/ipc/file_lock.py +++ /dev/null @@ -1,119 +0,0 @@ -# -# Copyright (C) 2018 The Android Open Source Project -# -# 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 fcntl -import logging -import os - -from host_controller import common - - -class FileLock(object): - """Class for using files as a locking mechanism for devices. - - This is for checking whether a certain device is running a job or not when - the automated self-update happens. - - Attributes: - _devlock_dir: string, represent the home directory of the user. - _lock_fd: dict, maps serial number of the devices and file descriptor. - """ - - def __init__(self, file_name=None, mode=None): - """Initializes the file lock managing class instance. - - Args: - file_name: string, name of the file to be opened. Existing lock - files will be opened if given as None - mode: string, the mode argument to open() function. - """ - self._lock_fd = {} - self._devlock_dir = os.path.join( - os.path.expanduser("~"), common._DEVLOCK_DIR) - if not os.path.exists(self._devlock_dir): - os.mkdir(self._devlock_dir) - - if file_name: - file_list = [file_name] - else: - file_list = [file_name for file_name in os.listdir(self._devlock_dir)] - logging.debug("file_list for file lock: %s", file_list) - - for file_name in file_list: - if os.path.isfile(os.path.join(self._devlock_dir, file_name)): - self._OpenFile(file_name, mode) - - def _OpenFile(self, serial, mode=None): - """Opens the given lock file and store the file descriptor to _lock_fd. - - Args: - serial: string, serial number of a device. - mode: string, the mode argument to open() function. - Set to "w+" if given as None. - """ - if serial in self._lock_fd and self._lock_fd[serial]: - logging.info("Lock for the device %s already exists." % serial) - return - - try: - if not mode: - mode = "w+" - self._lock_fd[serial] = open( - os.path.join(self._devlock_dir, serial), mode, 0) - except IOError as e: - logging.exception(e) - return False - - def LockDevice(self, serial, suppress_lock_warning=False, block=False): - """Tries to lock the file corresponding to "serial". - - Args: - serial: string, serial number of a device. - suppress_lock_warning: bool, True to suppress warning log output. - block: bool, True to block at the fcntl.lockf(), waiting for it - to be unlocked. - - Returns: - True if successfully acquired the lock. False otherwise. - """ - if serial not in self._lock_fd: - ret = self._OpenFile(serial) - if ret == False: - return ret - - try: - operation = fcntl.LOCK_EX - if not block: - operation |= fcntl.LOCK_NB - fcntl.lockf(self._lock_fd[serial], operation) - except IOError as e: - if not suppress_lock_warning: - logging.exception(e) - return False - - return True - - def UnlockDevice(self, serial): - """Releases the lock file corresponding to "serial". - - Args: - serial: string, serial number of a device. - """ - if serial not in self._lock_fd: - logging.error("Lock for the device %s does not exist." % serial) - return False - - fcntl.lockf(self._lock_fd[serial], fcntl.LOCK_UN) |