mirror of https://github.com/k3s-io/k3s
46 lines
1.2 KiB
Go
46 lines
1.2 KiB
Go
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// Copyright 2015 The etcd Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package fileutil
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import (
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"os"
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"syscall"
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"time"
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)
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func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
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if err := os.Chmod(path, syscall.DMEXCL|PrivateFileMode); err != nil {
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return nil, err
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}
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f, err := os.Open(path, flag, perm)
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if err != nil {
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return nil, ErrLocked
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}
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return &LockedFile{f}, nil
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}
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func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
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if err := os.Chmod(path, syscall.DMEXCL|PrivateFileMode); err != nil {
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return nil, err
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}
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for {
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f, err := os.OpenFile(path, flag, perm)
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if err == nil {
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return &LockedFile{f}, nil
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}
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time.Sleep(10 * time.Millisecond)
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}
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}
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