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