-
Notifications
You must be signed in to change notification settings - Fork 2
/
atomicbool.go
80 lines (69 loc) · 2.2 KB
/
atomicbool.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
//
// FrankyGo - UCI chess engine in GO for learning purposes
//
// MIT License
//
// Copyright (c) 2018-2020 Frank Kopp
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
package util
import (
"sync/atomic"
)
// Bool is a wrapper for atomic operations on bool
type Bool struct{ v uint32 }
// NewBool creates a Bool.
func NewBool(initial bool) *Bool {
return &Bool{boolToInt(initial)}
}
// Load atomically loads the Boolean.
func (b *Bool) Load() bool {
return truthy(atomic.LoadUint32(&b.v))
}
// CAS is an atomic compare-and-swap.
func (b *Bool) CAS(old, new bool) bool {
return atomic.CompareAndSwapUint32(&b.v, boolToInt(old), boolToInt(new))
}
// Store atomically stores the passed value.
func (b *Bool) Store(new bool) {
atomic.StoreUint32(&b.v, boolToInt(new))
}
// Swap sets the given value and returns the previous value.
func (b *Bool) Swap(new bool) bool {
return truthy(atomic.SwapUint32(&b.v, boolToInt(new)))
}
// Toggle atomically negates the Boolean and returns the previous value.
func (b *Bool) Toggle() bool {
for {
old := b.Load()
if b.CAS(old, !old) {
return old
}
}
}
func truthy(n uint32) bool {
return n == 1
}
func boolToInt(b bool) uint32 {
if b {
return 1
}
return 0
}