1# SPDX-license-identifier: Apache-2.0 2# Copyright 2012-2021 The Meson development team 3# Copyright © 2021 Intel Corporation 4 5# Licensed under the Apache License, Version 2.0 (the "License"); 6# you may not use this file except in compliance with the License. 7# You may obtain a copy of the License at 8 9# http://www.apache.org/licenses/LICENSE-2.0 10 11# Unless required by applicable law or agreed to in writing, software 12# distributed under the License is distributed on an "AS IS" BASIS, 13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14# See the License for the specific language governing permissions and 15# limitations under the License. 16 17"""Posix specific implementations of mesonlib functionality.""" 18 19import fcntl 20import typing as T 21 22from .universal import MesonException 23from .platform import BuildDirLock as BuildDirLockBase 24 25__all__ = ['BuildDirLock'] 26 27class BuildDirLock(BuildDirLockBase): 28 29 def __enter__(self) -> None: 30 self.lockfile = open(self.lockfilename, 'w', encoding='utf-8') 31 try: 32 fcntl.flock(self.lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB) 33 except (BlockingIOError, PermissionError): 34 self.lockfile.close() 35 raise MesonException('Some other Meson process is already using this build directory. Exiting.') 36 37 def __exit__(self, *args: T.Any) -> None: 38 fcntl.flock(self.lockfile, fcntl.LOCK_UN) 39 self.lockfile.close() 40