-
Notifications
You must be signed in to change notification settings - Fork 702
/
lock_unix.go
63 lines (54 loc) · 1.5 KB
/
lock_unix.go
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
// Copyright 2020 Douyu
//
// 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.
// +build darwin dragonfly freebsd linux netbsd openbsd
package xfile
import (
"io"
"os"
"syscall"
)
// lockCloser hides all of an os.File's methods, except for Close.
type lockCloser struct {
f *os.File
}
// Close ...
func (l lockCloser) Close() error {
return l.f.Close()
}
// Lock ...
func Lock(name string) (io.Closer, error) {
f, err := os.Create(name)
if err != nil {
return nil, err
}
/*
Some people tell me FcntlFlock does not exist, so use flock here
*/
if err := syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB); err != nil {
f.Close()
return nil, err
}
// spec := syscall.Flock_t{
// Type: syscall.F_WRLCK,
// Whence: int16(os.SEEK_SET),
// Start: 0,
// Len: 0, // 0 means to lock the entire file.
// Pid: int32(os.Getpid()),
// }
// if err := syscall.FcntlFlock(f.Fd(), syscall.F_SETLK, &spec); err != nil {
// f.Close()
// return nil, err
// }
return lockCloser{f}, nil
}