clientv3: fix barrier.Wait() still block after barrier.Release() in s…

…ome cases

Signed-off-by: Wenkang Zhang <[email protected]>

client/v3/experimental/recipes/barrier.go

@@ -60,7 +60,7 @@ func (b *Barrier) Wait() error {
 	_, err = WaitEvents(
 		b.client,
 		b.key,
-		resp.Header.Revision,
-		[]mvccpb.Event_EventType{mvccpb.PUT, mvccpb.DELETE})
+		resp.Header.Revision+1,
+		[]mvccpb.Event_EventType{mvccpb.DELETE})
 	return err
 }

tests/integration/clientv3/experimental/recipes/v3_barrier_test.go

@@ -15,6 +15,7 @@
 package recipes_test
 
 import (
+	"context"
 	"testing"
 	"time"
 
@@ -46,6 +47,11 @@ func testBarrier(t *testing.T, waiters int, chooseClient func() *clientv3.Client
 		t.Fatalf("able to double-hold barrier")
 	}
 
+	// put a random key to move the revision forward
+	if _, err := chooseClient().Put(context.Background(), "x", ""); err != nil {
+		t.Errorf("could not put x (%v)", err)
+	}
+
 	donec := make(chan struct{})
 	stopc := make(chan struct{})
 	defer close(stopc)