go语言用的不熟，没找到对应Java的CountDownLatch，就自己写一个......试了试好像能用（后面发现waitGroup就能实现）
ps:拿go造轮子真的快乐啊
package main
import (
"fmt"
"sync"
"time"
)
type DownLatch struct {
wg sync.WaitGroup
}
func instance(count int) DownLatch {
latch := DownLatch{}
latch.wg.Add(count)
return latch
}
func (latch *DownLatch) Down() {
latch.wg.Done()
}
func (latch *DownLatch) Wait() {
latch.wg.Wait()
}
func (latch *DownLatch) WaitTime(t time.Duration) {
waitCh := make(chan struct{})
go func() {
latch.wg.Wait()
close(waitCh)
}()
select {
case <-waitCh:
return
case <-time.After(t):
return
}
}
func main() {
latch := instance(3)
go func() {
for i := 0; i < 3; i++ {
time.Sleep(1 * time.Second)
go func() {
latch.Down()
fmt.Println("count down")
}()
}
}()
latch.WaitTime(4 * time.Second)
fmt.Println("keep going")
time.Sleep(3 * time.Second)
fmt.Println("end")
}
