1 // Copyright 2016 The Prometheus Authors
2 // Licensed under the Apache License, Version 2.0 (the "License");
3 // you may not use this file except in compliance with the License.
4 // You may obtain a copy of the License at
6 // http://www.apache.org/licenses/LICENSE-2.0
8 // Unless required by applicable law or agreed to in writing, software
9 // distributed under the License is distributed on an "AS IS" BASIS,
10 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 // See the License for the specific language governing permissions and
12 // limitations under the License.
23 type unixLock struct {
27 func (l *unixLock) Release() error {
28 if err := l.set(false); err != nil {
34 func (l *unixLock) set(lock bool) error {
35 flock := syscall.Flock_t{
36 Type: syscall.F_UNLCK,
42 flock.Type = syscall.F_WRLCK
44 return syscall.FcntlFlock(l.f.Fd(), syscall.F_SETLK, &flock)
47 func newLock(fileName string) (Releaser, error) {
48 f, err := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE, 0644)