增加工具类

utils/sync2/event.go

@@ -0,0 +1,48 @@
+package sync2
+
+import (
+	"context"
+	"errors"
+	"sync"
+)
+
+var ErrEventClosed = errors.New("event is closed")
+var ErrContextCanceled = errors.New("context canceled")
+
+type Event struct {
+	ch        chan any
+	closeOnce sync.Once
+}
+
+func NewEvent() Event {
+	return Event{
+		ch: make(chan any, 1),
+	}
+}
+
+func (e *Event) Set() {
+	select {
+	case e.ch <- nil:
+	default:
+	}
+}
+
+func (e *Event) Wait(ctx context.Context) error {
+	select {
+	case _, ok := <-e.ch:
+		if ok {
+			return nil
+		}
+
+		return ErrEventClosed
+
+	case <-ctx.Done():
+		return ErrContextCanceled
+	}
+}
+
+func (e *Event) Close() {
+	e.closeOnce.Do(func() {
+		close(e.ch)
+	})
+}