1 // Copyright (c) 2021-2022 Uber Technologies, Inc.
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining a copy
4 // of this software and associated documentation files (the "Software"), to deal
5 // in the Software without restriction, including without limitation the rights
6 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7 // copies of the Software, and to permit persons to whom the Software is
8 // furnished to do so, subject to the following conditions:
9 //
10 // The above copyright notice and this permission notice shall be included in
11 // all copies or substantial portions of the Software.
12 //
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19 // THE SOFTWARE.
20 21 package atomic
22 23 import (
24 "sync/atomic"
25 "unsafe"
26 )
27 28 // UnsafePointer is an atomic wrapper around unsafe.Pointer.
29 type UnsafePointer struct {
30 _ nocmp // disallow non-atomic comparison
31 32 v unsafe.Pointer
33 }
34 35 // NewUnsafePointer creates a new UnsafePointer.
36 func NewUnsafePointer(val unsafe.Pointer) *UnsafePointer {
37 return &UnsafePointer{v: val}
38 }
39 40 // Load atomically loads the wrapped value.
41 func (p *UnsafePointer) Load() unsafe.Pointer {
42 return atomic.LoadPointer(&p.v)
43 }
44 45 // Store atomically stores the passed value.
46 func (p *UnsafePointer) Store(val unsafe.Pointer) {
47 atomic.StorePointer(&p.v, val)
48 }
49 50 // Swap atomically swaps the wrapped unsafe.Pointer and returns the old value.
51 func (p *UnsafePointer) Swap(val unsafe.Pointer) (old unsafe.Pointer) {
52 return atomic.SwapPointer(&p.v, val)
53 }
54 55 // CAS is an atomic compare-and-swap.
56 //
57 // Deprecated: Use CompareAndSwap
58 func (p *UnsafePointer) CAS(old, new unsafe.Pointer) (swapped bool) {
59 return p.CompareAndSwap(old, new)
60 }
61 62 // CompareAndSwap is an atomic compare-and-swap.
63 func (p *UnsafePointer) CompareAndSwap(old, new unsafe.Pointer) (swapped bool) {
64 return atomic.CompareAndSwapPointer(&p.v, old, new)
65 }
66