forked from mirror/ants
38 lines
761 B
Go
38 lines
761 B
Go
// Copyright 2019 Andy Pan & Dietoad. All rights reserved.
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// Use of this source code is governed by an MIT-style
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// license that can be found in the LICENSE file.
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package internal
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import (
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"runtime"
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"sync"
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"sync/atomic"
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)
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type spinLock uint32
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const maxBackoff = 64
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func (sl *spinLock) Lock() {
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backoff := 1
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for !atomic.CompareAndSwapUint32((*uint32)(sl), 0, 1) {
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// Leverage the exponential backoff algorithm, see https://en.wikipedia.org/wiki/Exponential_backoff.
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for i := 0; i < backoff; i++ {
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runtime.Gosched()
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}
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if backoff < maxBackoff {
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backoff <<= 1
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}
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}
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}
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func (sl *spinLock) Unlock() {
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atomic.StoreUint32((*uint32)(sl), 0)
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}
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// NewSpinLock instantiates a spin-lock.
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func NewSpinLock() sync.Locker {
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return new(spinLock)
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}
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