fix: 停机排空计入正在发送的帧并为断开预留时间

internal/broker/b04_b06_b08_test.go

@@ -274,6 +274,27 @@ func TestShutdownCancelledContextReturnsQuickly(t *testing.T) {
 	}
 }
 
+func TestWaitConnsQuietSeesInSend(t *testing.T) {
+	b, err := New(Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = b.Close() }()
+	st := &connState{downCh: make(chan downItem, 1)}
+	st.inSend.Store(1)
+	ctx, cancel := context.WithTimeout(context.Background(), 40*time.Millisecond)
+	defer cancel()
+	if b.waitConnsQuiet(ctx, []*connState{st}) {
+		t.Fatal("inSend should keep shutdown from treating the conn as quiet")
+	}
+	st.inSend.Store(0)
+	ctx2, cancel2 := context.WithTimeout(context.Background(), 200*time.Millisecond)
+	defer cancel2()
+	if !b.waitConnsQuiet(ctx2, []*connState{st}) {
+		t.Fatal("quiet when inSend is 0 and queues are empty")
+	}
+}
+
 func TestEffectivePayloadLimitSubtractsOverhead(t *testing.T) {
 	got := EffectivePayloadLimit(200, 0)
 	if got != 200-packetOverheadBudget {

internal/broker/broker.go

@@ -142,6 +142,7 @@ type connState struct {
 	downDone       chan struct{}
 	downBytes      atomic.Int64
 	wirePending    atomic.Int64 // Publish 入 mochi outbound 后、OnPacketSent 前
+	inSend         atomic.Int32 // downLoop 已取出帧、尚未从 sendOne 返回
 	mu             sync.Mutex
 
 	// 带断开的下行帧：只等本帧 OnPacketSent，不用连接级计数。
@@ -237,8 +238,8 @@ func (b *Broker) Close() error {
 }
 
 // Shutdown 向所有连接发 MQTT 5 0x8B 后关闭。完整 HTTP 停机顺序见 L-03。
-// ctx 未取消时先等下行队列与 wirePending 排空，再 DisconnectClient（此时 outbound 空，
-// 0x8B 直写套接字），并在截止前等连接拆掉；ctx 已取消则发完即 Close，不等待。
+// ctx 未取消时先等下行队列、正在 sendOne 的帧与 wirePending 排空（若有截止时间则预留约 1 秒），
+// 再 DisconnectClient，并在截止前等连接拆掉；ctx 已取消则发完即 Close，不等待。
 func (b *Broker) Shutdown(ctx context.Context) error {
 	if b.closed.Load() {
 		return nil
@@ -275,17 +276,26 @@ func (b *Broker) Shutdown(ctx context.Context) error {
 
 	var waitErr error
 	if !alreadyCancelled {
-		if !b.waitConnsQuiet(ctx, states) {
+		// 留出约 1 秒给 0x8B 写出，避免排空把整个截止时间用完后立刻 Close。
+		quietCtx := ctx
+		cancelQuiet := func() {}
+		if dl, ok := ctx.Deadline(); ok && time.Until(dl) > time.Second {
+			quietCtx, cancelQuiet = context.WithDeadline(ctx, dl.Add(-time.Second))
+		}
+		if !b.waitConnsQuiet(quietCtx, states) && ctx.Err() != nil {
 			waitErr = ctx.Err()
 		}
+		cancelQuiet()
 	}
 
 	for _, cl := range clients {
 		_ = b.server.DisconnectClient(cl, packets.ErrServerShuttingDown)
 	}
 
-	if !alreadyCancelled && waitErr == nil {
-		waitErr = b.waitConnsGone(ctx)
+	if !alreadyCancelled && ctx.Err() == nil {
+		if err := b.waitConnsGone(ctx); err != nil {
+			waitErr = err
+		}
 	}
 
 	closeErr := b.Close()
@@ -299,7 +309,7 @@ func (b *Broker) waitConnsQuiet(ctx context.Context, states []*connState) bool {
 	for {
 		quiet := true
 		for _, st := range states {
-			if st.wirePending.Load() > 0 {
+			if st.inSend.Load() > 0 || st.wirePending.Load() > 0 {
 				quiet = false
 				break
 			}

internal/broker/downlink.go

@@ -118,6 +118,8 @@ func (st *connState) sendOne(b *Broker, item downItem) {
 		st.signalSent(item)
 		return
 	}
+	st.inSend.Add(1)
+	defer st.inSend.Add(-1)
 	large := len(item.payload) > largeFrameBytes
 	if large {
 		if err := b.acquireLarge(context.Background()); err != nil {