You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
38 lines
761 B
Go
38 lines
761 B
Go
// Copyright 2019 Andy Pan & Dietoad. All rights reserved.
|
|
// Use of this source code is governed by an MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package internal
|
|
|
|
import (
|
|
"runtime"
|
|
"sync"
|
|
"sync/atomic"
|
|
)
|
|
|
|
type spinLock uint32
|
|
|
|
const maxBackoff = 16
|
|
|
|
func (sl *spinLock) Lock() {
|
|
backoff := 1
|
|
for !atomic.CompareAndSwapUint32((*uint32)(sl), 0, 1) {
|
|
// Leverage the exponential backoff algorithm, see https://en.wikipedia.org/wiki/Exponential_backoff.
|
|
for i := 0; i < backoff; i++ {
|
|
runtime.Gosched()
|
|
}
|
|
if backoff < maxBackoff {
|
|
backoff <<= 1
|
|
}
|
|
}
|
|
}
|
|
|
|
func (sl *spinLock) Unlock() {
|
|
atomic.StoreUint32((*uint32)(sl), 0)
|
|
}
|
|
|
|
// NewSpinLock instantiates a spin-lock.
|
|
func NewSpinLock() sync.Locker {
|
|
return new(spinLock)
|
|
}
|