61 lines
2.0 KiB
Go
61 lines
2.0 KiB
Go
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// Copyright (c) 2022 Uber Technologies, Inc.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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//go:build go1.18 && !go1.19
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// +build go1.18,!go1.19
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package atomic
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import "unsafe"
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type Pointer[T any] struct {
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_ nocmp // disallow non-atomic comparison
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p UnsafePointer
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}
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// NewPointer creates a new Pointer.
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func NewPointer[T any](v *T) *Pointer[T] {
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var p Pointer[T]
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if v != nil {
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p.p.Store(unsafe.Pointer(v))
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}
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return &p
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}
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// Load atomically loads the wrapped value.
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func (p *Pointer[T]) Load() *T {
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return (*T)(p.p.Load())
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}
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// Store atomically stores the passed value.
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func (p *Pointer[T]) Store(val *T) {
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p.p.Store(unsafe.Pointer(val))
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}
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// Swap atomically swaps the wrapped pointer and returns the old value.
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func (p *Pointer[T]) Swap(val *T) (old *T) {
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return (*T)(p.p.Swap(unsafe.Pointer(val)))
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}
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// CompareAndSwap is an atomic compare-and-swap.
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func (p *Pointer[T]) CompareAndSwap(old, new *T) (swapped bool) {
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return p.p.CompareAndSwap(unsafe.Pointer(old), unsafe.Pointer(new))
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}
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