This repository has been archived by the owner on Feb 27, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 774
/
locker.go
92 lines (77 loc) · 2.12 KB
/
locker.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
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
/*
* Copyright The Dragonfly Authors.
*
* 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.
*/
package util
import (
"sync"
)
var defaultLocker = NewLockerPool()
// GetLock locks key with defaultLocker.
func GetLock(key string, ro bool) {
defaultLocker.GetLock(key, ro)
}
// ReleaseLock unlocks key with defaultLocker.
func ReleaseLock(key string, ro bool) {
defaultLocker.ReleaseLock(key, ro)
}
// LockerPool is a set of reader/writer mutual exclusion locks.
type LockerPool struct {
// use syncPool to cache allocated but unused *countRWMutex items for later reuse
syncPool *sync.Pool
lockerMap map[string]*countRWMutex
sync.Mutex
}
// NewLockerPool returns a *LockerPool with self-defined prefix.
func NewLockerPool() *LockerPool {
return &LockerPool{
syncPool: &sync.Pool{
New: func() interface{} {
return newCountRWMutex()
},
},
lockerMap: make(map[string]*countRWMutex),
}
}
// GetLock locks key.
// If ro(readonly) is true, then it locks key for reading.
// Otherwise, locks key for writing.
func (l *LockerPool) GetLock(key string, ro bool) {
l.Lock()
locker, ok := l.lockerMap[key]
if !ok {
locker = l.syncPool.Get().(*countRWMutex)
l.lockerMap[key] = locker
}
locker.increaseCount()
l.Unlock()
locker.lock(ro)
}
// ReleaseLock unlocks key.
// If ro(readonly) is true, then it unlocks key for reading.
// Otherwise, unlocks key for writing.
func (l *LockerPool) ReleaseLock(key string, ro bool) {
l.Lock()
defer l.Unlock()
locker, ok := l.lockerMap[key]
if !ok {
return
}
locker.unlock(ro)
if locker.decreaseCount() < 1 {
locker.reset()
l.syncPool.Put(locker)
delete(l.lockerMap, key)
}
}