type Queue struct {
capacity int
Data []int
c *sync.Cond
}
func NewQueue(num int) *Queue {
return &Queue{
capacity: num,
Data: make([]int, 0, num),
c: sync.NewCond(&sync.Mutex{}),
}
}
func (q *Queue) push(val int) {
defer q.c.L.Unlock()
q.c.L.Lock()
for len(q.Data) == q.capacity {
q.c.Wait()
}
q.Data = append(q.Data, val)
q.c.Broadcast()
}
func (q *Queue) pop() int {
defer q.c.L.Unlock()
q.c.L.Lock()
for len(q.Data) == 0 {
q.c.Wait()
}
val := q.Data[0]
q.Data = q.Data[1:]
q.c.Broadcast()
return val
}
// Athlete race
func ExampleOne() {
c := sync.NewCond(&sync.Mutex{})
defer c.L.Unlock()
var ready int
for i := 0; i < 10; i++ {
go func(i int) {
defer c.L.Unlock()
time.Sleep(time.Duration(rand.Int63n(5)) * time.Second)
c.L.Lock()
ready++
log.Printf("Athlete: %d Ready", i)
//Wake up waiter
c.Signal()
}(i)
}
c.L.Lock()
for ready != 10 {
c.Wait()
log.Printf("The referee is awakened")
}
log.Printf("Game start")
}添加个测试用的code
func TestExampleOne(t *testing.T) {
ExampleOne()
}
func TestMyCondQueue(t *testing.T) {
q := NewQueue(5)
go func() {
for {
q.push(rand.Intn(20))
}
}()
for {
t.Log(q.pop())
time.Sleep(1 * time.Second)
}
}Once比较简单,单例模式惯用,配置初始化
type MyOnce struct {
m sync.Mutex
done uint32
}
func (o *MyOnce) Do(f func() error) error {
if atomic.LoadUint32(&o.done) == 1 {
return nil
}
return o.doSlow(f)
}
func (o *MyOnce) doSlow(f func() error) error {
defer o.m.Unlock()
o.m.Lock()
var err error
if o.done == 0 {
err = f()
if err != nil {
atomic.StoreUint32(&o.done, 1)
}
}
return err
}扩充下功能,方便判断是否成功