mirror of
https://github.com/ergochat/ergo.git
synced 2024-12-25 12:12:35 +01:00
36 lines
614 B
Go
36 lines
614 B
Go
// Copyright 2009 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package utils
|
|
|
|
import (
|
|
"sync"
|
|
"sync/atomic"
|
|
)
|
|
|
|
// Once is a fork of sync.Once to expose a Done() method.
|
|
type Once struct {
|
|
done uint32
|
|
m sync.Mutex
|
|
}
|
|
|
|
func (o *Once) Do(f func()) {
|
|
if atomic.LoadUint32(&o.done) == 0 {
|
|
o.doSlow(f)
|
|
}
|
|
}
|
|
|
|
func (o *Once) doSlow(f func()) {
|
|
o.m.Lock()
|
|
defer o.m.Unlock()
|
|
if o.done == 0 {
|
|
defer atomic.StoreUint32(&o.done, 1)
|
|
f()
|
|
}
|
|
}
|
|
|
|
func (o *Once) Done() bool {
|
|
return atomic.LoadUint32(&o.done) == 1
|
|
}
|