Fix datanode flush manager injection unit test (#15358)

Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>

internal/datanode/flush_manager.go

@@ -184,8 +184,7 @@ func (q *orderFlushQueue) inject(inject *taskInjection) {
 		return
 	}
 	// otherwise just handle injection here
-
-	q.handleInject(inject)
+	go q.handleInject(inject)
 }
 
 func (q *orderFlushQueue) handleInject(inject *taskInjection) {
@@ -194,6 +193,8 @@ func (q *orderFlushQueue) handleInject(inject *taskInjection) {
 	ok := <-inject.injectOver
 	// apply injection
 	if ok {
+		q.injectMut.Lock()
+		defer q.injectMut.Unlock()
 		q.postInjection = inject.postInjection
 	}
 }
@@ -455,7 +456,7 @@ func (m *rendezvousFlushManager) flushDelData(data *DelDataBuf, segmentID Unique
 func (m *rendezvousFlushManager) injectFlush(injection *taskInjection, segments ...UniqueID) {
 	go injection.waitForInjected()
 	for _, segmentID := range segments {
-		go m.getFlushQueue(segmentID).inject(injection)
+		m.getFlushQueue(segmentID).inject(injection)
 	}
 }
 

internal/datanode/flush_manager_test.go

@@ -222,7 +222,6 @@ func TestRendezvousFlushManager_Inject(t *testing.T) {
 	rand.Read(id)
 	id2 := make([]byte, 10)
 	rand.Read(id2)
-	rand.Read(id)
 	m.flushBufferData(nil, 2, true, false, &internalpb.MsgPosition{
 		MsgID: id,
 	})
@@ -235,16 +234,14 @@ func TestRendezvousFlushManager_Inject(t *testing.T) {
 	})
 	m.injectFlush(ti, 2, 3)
 
-	go func() {
-		<-ti.injected
-		ti.injectDone(true)
-	}()
 	m.flushDelData(nil, 2, &internalpb.MsgPosition{
 		MsgID: id,
 	})
 	m.flushDelData(nil, 3, &internalpb.MsgPosition{
 		MsgID: id2,
 	})
+	<-ti.Injected()
+	ti.injectDone(true)
 
 	finish.Wait()
 	assert.EqualValues(t, size+2, counter.Load())