You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
877 B
57 lines
877 B
// Copyright 2013, Google Inc. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package sync2
|
|
|
|
import (
|
|
"sync"
|
|
)
|
|
|
|
// Cond is an alternate implementation of sync.Cond
|
|
type Cond struct {
|
|
L sync.Locker
|
|
sema chan struct{}
|
|
waiters AtomicInt64
|
|
}
|
|
|
|
func NewCond(l sync.Locker) *Cond {
|
|
return &Cond{L: l, sema: make(chan struct{})}
|
|
}
|
|
|
|
func (c *Cond) Wait() {
|
|
c.waiters.Add(1)
|
|
c.L.Unlock()
|
|
<-c.sema
|
|
c.L.Lock()
|
|
}
|
|
|
|
func (c *Cond) Signal() {
|
|
for {
|
|
w := c.waiters.Get()
|
|
if w == 0 {
|
|
return
|
|
}
|
|
if c.waiters.CompareAndSwap(w, w-1) {
|
|
break
|
|
}
|
|
}
|
|
c.sema <- struct{}{}
|
|
}
|
|
|
|
func (c *Cond) Broadcast() {
|
|
var w int64
|
|
for {
|
|
w = c.waiters.Get()
|
|
if w == 0 {
|
|
return
|
|
}
|
|
if c.waiters.CompareAndSwap(w, 0) {
|
|
break
|
|
}
|
|
}
|
|
for i := int64(0); i < w; i++ {
|
|
c.sema <- struct{}{}
|
|
}
|
|
}
|