fix: 首次握手失败停止重连并修正 Java 限速在途计数

docs/DEVIATIONS.md

@@ -1757,3 +1757,13 @@ issue #3 未关闭，`feat/fix-3-downlink-deadlock` 未合入 `main`。下面是
    - 原因：原先只换 `rid` 并 `return`，连接未断时 `hello` 不再走，队列停泵，`send()` Promise 永不结束。  
    - 备选方案：按 `rate_limited` 同一条的退避再泵（否决本波，连接仍在线时立即重交更贴切，且避免与已有等待叠乘抖动）。  
    - 影响：仅 `sdk/js`；假传输失败一次后会再次上行且 `rid` 已变。
+
+### 复审修复 R3-06
+
+1. **Python/Java 首次握手失败应停止重连；Java rate_limited 在途计数只减一次**  
+   - 日期：2026-09-30  
+   - 原条款：DEVELOPMENT 第 9 节附录「首次连接超时或握手失败应停止重连，并向 connect() 返回未连接」；issue #70。  
+   - 实际做法：`sdk/python` 的 `connect()` 在 `_handshake_error` 或非 ONLINE 终态时置 `_stop_reconnect`/`_want_connected=False`；内部连接/握手超时改用 `not_connected`（不再用 `busy`）。`sdk/java` 的 `connectSync` 在 `handshakeError` 时同样置 `stopReconnect`；`rate_limited` 路径去掉第二次 `inflightSends--`，只换新 rid 再排队。Python `transport.py` 将 paho 改为惰性导入，便于本机无 paho 时仍跑 FakeTransport 单测。不改 Go/JS 重连公式。  
+   - 原因：原先抛错后工作线程仍按退避重连；Java 限速把在途计数减了两次。  
+   - 备选方案：在后台 `_attempt_connect`/`attemptConnect` 内首次失败即停（否决：应用再次 `connect()` 才应恢复，标志应在对外 `connect` 失败路径统一置位）。  
+   - 影响：仅 `sdk/python`、`sdk/java`；应用需再次调用 `connect()` 才会重连。

sdk/java/src/main/java/asia/asio/nixmsg/Client.java

@@ -143,6 +143,12 @@ public final class Client {
         return lastStopCode == null ? "" : lastStopCode;
     }
 
+    int inflightSendsForTest() {
+        synchronized (lock) {
+            return inflightSends;
+        }
+    }
+
     void setSendQueueLimitForTest(int n) {
         sendQueueLimit = n;
     }
@@ -211,6 +217,19 @@ public final class Client {
             }
         }
         if (handshakeError != null) {
+            synchronized (lock) {
+                stopReconnect = true;
+                wantConnected = false;
+                if (lastStopCode == null || lastStopCode.isEmpty()) {
+                    if (handshakeError instanceof NixMsgException) {
+                        lastStopCode = ((NixMsgException) handshakeError).getCode();
+                        lastStopErr = (NixMsgException) handshakeError;
+                    } else {
+                        lastStopCode = "not_connected";
+                        lastStopErr = new NixMsgException("not_connected", handshakeError.getMessage());
+                    }
+                }
+            }
             if (handshakeError instanceof NixMsgException) {
                 throw (NixMsgException) handshakeError;
             }
@@ -229,6 +248,8 @@ public final class Client {
             synchronized (lock) {
                 stopReconnect = true;
                 wantConnected = false;
+                lastStopCode = "not_connected";
+                lastStopErr = new NixMsgException("not_connected", "连接未成功: " + state);
             }
             throw new NixMsgException("not_connected", "连接未成功: " + state);
         }
@@ -704,7 +725,9 @@ public final class Client {
             transport.publish(Protocol.upTopic(endpointId), Protocol.dumps(hello));
             await(p.future, connectTimeoutMs);
             if (p.error != null) {
-                throw p.error instanceof RuntimeException ? (RuntimeException) p.error : new NixMsgException("busy", p.error.getMessage());
+                throw p.error instanceof RuntimeException
+                        ? (RuntimeException) p.error
+                        : new NixMsgException("not_connected", p.error.getMessage());
             }
             if (p.response == null) {
                 throw new NixMsgException("not_connected", "握手超时");
@@ -883,9 +906,9 @@ public final class Client {
             if (!Boolean.TRUE.equals(frame.get("ok"))) {
                 Map<String, Object> err = asMap(frame.get("error"));
                 if ("rate_limited".equals(str(err.get("code"), ""))) {
+                    // 在途计数已在上方减过一次；只换新 rid 再排队，勿再减。
                     synchronized (lock) {
                         pending.remove(rid);
-                        inflightSends = Math.max(0, inflightSends - 1);
                         p.rid = "";
                         p.response = null;
                         p.error = null;

sdk/java/src/test/java/asia/asio/nixmsg/K00Test.java

@@ -41,7 +41,7 @@ public class K00Test {
     }
 
     @Test
-    public void testK00FirstConnectTimeout() {
+    public void testK00FirstConnectTimeout() throws Exception {
         FakeTransport tr = new FakeTransport();
         tr.autoHello = null;
         client = new Client(tr, true, Types.DEFAULT_MAX_FRAME, Types.CLIENT_NAME, 150);
@@ -51,6 +51,9 @@ public class K00Test {
         } catch (NixMsgException e) {
             assertEquals("not_connected", e.getCode());
         }
+        int n = tr.connects.size();
+        Thread.sleep(350);
+        assertEquals("首次握手失败后不得自动重连", n, tr.connects.size());
         tr.autoHello = new LinkedHashMap<String, Object>();
         tr.autoHello.put("server_time_ms", 1750000000000L);
         tr.autoHello.put("server_version", "0.1.0");
@@ -63,6 +66,108 @@ public class K00Test {
         tr.autoHello.put("session_token", "nst_test_token");
         client.connectSync("ws://example.test/mqtt", "ep1", "p", null, false);
         assertEquals(ConnectionState.ONLINE, client.getState());
+        assertTrue(tr.connects.size() > n);
+    }
+
+    @Test
+    public void testK00RateLimitedInflightOnce() throws Exception {
+        Types.ReconnectBackoff.disableJitterForTest();
+        FakeTransport tr = new FakeTransport();
+        tr.autoSendOk = false;
+        final List<String> holdRids = new CopyOnWriteArrayList<String>();
+        final List<String> limitedRids = new CopyOnWriteArrayList<String>();
+        tr.onUp(new java.util.function.Function<Map<String, Object>, Map<String, Object>>() {
+            @Override
+            public Map<String, Object> apply(Map<String, Object> frame) {
+                if (!"send".equals(String.valueOf(frame.get("type")))) {
+                    return null;
+                }
+                String rid = String.valueOf(frame.get("rid"));
+                String id = String.valueOf(frame.get("id"));
+                if ("hold".equals(id)) {
+                    holdRids.add(rid);
+                    return null; // 保持在途
+                }
+                limitedRids.add(rid);
+                if (limitedRids.size() == 1) {
+                    Map<String, Object> err = new LinkedHashMap<String, Object>();
+                    err.put("code", "rate_limited");
+                    err.put("message", "slow");
+                    Map<String, Object> resp = new LinkedHashMap<String, Object>();
+                    resp.put("v", 1);
+                    resp.put("type", "resp");
+                    resp.put("rid", rid);
+                    resp.put("ok", false);
+                    resp.put("error", err);
+                    return resp;
+                }
+                Map<String, Object> data = new LinkedHashMap<String, Object>();
+                data.put("id", frame.get("id"));
+                data.put("send_at_ms", frame.get("send_at_ms"));
+                data.put("state", "scheduled");
+                Map<String, Object> resp = new LinkedHashMap<String, Object>();
+                resp.put("v", 1);
+                resp.put("type", "resp");
+                resp.put("rid", rid);
+                resp.put("ok", true);
+                resp.put("data", data);
+                return resp;
+            }
+        });
+        connectOnline(tr);
+        Thread holder = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    SendOptions opt = new SendOptions();
+                    opt.messageId = "hold";
+                    opt.sendAtMs = 1700000000001L;
+                    client.sendSync(new Target("endpoint", "ep2"), new Body("hold"), opt);
+                } catch (Exception ignored) {
+                }
+            }
+        });
+        holder.setDaemon(true);
+        holder.start();
+        long deadline = System.currentTimeMillis() + 2000;
+        while (holdRids.isEmpty() && System.currentTimeMillis() < deadline) {
+            Thread.sleep(10);
+        }
+        assertFalse(holdRids.isEmpty());
+        assertEquals(1, client.inflightSendsForTest());
+        final SendOptions opt = new SendOptions();
+        opt.messageId = "lim";
+        opt.sendAtMs = 1700000000002L;
+        Thread sender = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    client.sendSync(new Target("endpoint", "ep2"), new Body("lim"), opt);
+                } catch (Exception ignored) {
+                }
+            }
+        });
+        sender.setDaemon(true);
+        sender.start();
+        deadline = System.currentTimeMillis() + 3000;
+        while (limitedRids.size() < 1 && System.currentTimeMillis() < deadline) {
+            Thread.sleep(10);
+        }
+        assertTrue(limitedRids.size() >= 1);
+        // rate_limited 后只应减 1：仍剩 hold 那一条在途
+        deadline = System.currentTimeMillis() + 500;
+        int seen = -1;
+        while (System.currentTimeMillis() < deadline) {
+            seen = client.inflightSendsForTest();
+            if (seen == 1) {
+                break;
+            }
+            Thread.sleep(10);
+        }
+        assertEquals("rate_limited 后在途应只减 1", 1, seen);
+        client.close();
+        holder.join(1000);
+        sender.join(1000);
     }
 
     @Test

sdk/python/src/nixmsg/client.py

@@ -227,6 +227,15 @@ class Client:
                 raise NixMsgError("not_connected", "连接超时")
             err = self._handshake_error
             if err:
+                with self._lock:
+                    self._stop_reconnect = True
+                    self._want_connected = False
+                    if not self._last_stop_code:
+                        code = getattr(err, "code", None) or "not_connected"
+                        self._last_stop_code = str(code)
+                        self._last_stop_err = err if isinstance(err, NixMsgError) else NixMsgError(
+                            "not_connected", str(err)
+                        )
                 raise err
             if self._state not in (ConnectionState.ONLINE,):
                 if self._state == ConnectionState.AUTH_FAILED:
@@ -236,6 +245,11 @@ class Client:
                     )
                 if self._state == ConnectionState.KICKED:
                     raise NixMsgError("taken_over", "会话被接管")
+                with self._lock:
+                    self._stop_reconnect = True
+                    self._want_connected = False
+                    self._last_stop_code = "not_connected"
+                    self._last_stop_err = NixMsgError("not_connected", f"连接未成功: {self._state.value}")
                 raise NixMsgError("not_connected", f"连接未成功: {self._state.value}")
 
     def close(self) -> None:
@@ -576,7 +590,7 @@ class Client:
             except Exception:
                 pass
             with self._lock:
-                self._handshake_error = NixMsgError("busy", "连接超时")
+                self._handshake_error = NixMsgError("not_connected", "连接超时")
             return
 
     def _on_transport_connected(self) -> None:
@@ -598,7 +612,7 @@ class Client:
                 self._pending[rid] = pending
             self._transport.publish(up_topic(self._endpoint_id), dumps(hello))
             if not pending.event.wait(self._connect_timeout_s):
-                raise NixMsgError("busy", "握手超时")
+                raise NixMsgError("not_connected", "握手超时")
             if pending.error:
                 raise pending.error
             assert pending.response is not None

sdk/python/src/nixmsg/transport.py

@@ -8,16 +8,23 @@ from dataclasses import dataclass, field
 from typing import Any, Callable, Optional, Protocol
 from urllib.parse import urlparse
 
-from paho.mqtt.client import CallbackAPIVersion, Client as PahoClient, MQTT_ERR_SUCCESS, MQTTv5
-from paho.mqtt.enums import MQTTErrorCode
-from paho.mqtt.reasoncodes import ReasonCode
-
 DownHandler = Callable[[bytes], None]
 ConnHandler = Callable[[], None]
 DiscHandler = Callable[[Optional[str], bool], None]
 # reason_code_str, stop_reconnect
 
 
+def _require_paho():
+    """真实 MQTT 路径才加载 paho；假传输单测不依赖。"""
+    try:
+        from paho.mqtt.client import CallbackAPIVersion, Client as PahoClient, MQTT_ERR_SUCCESS, MQTTv5
+        from paho.mqtt.enums import MQTTErrorCode
+        from paho.mqtt.reasoncodes import ReasonCode
+    except ImportError as e:
+        raise ImportError("需要 paho-mqtt>=2.0（真实 MQTT 连接）") from e
+    return CallbackAPIVersion, PahoClient, MQTT_ERR_SUCCESS, MQTTv5, MQTTErrorCode, ReasonCode
+
+
 @dataclass
 class ConnectParams:
     url: str
@@ -180,7 +187,7 @@ class PahoTransport:
     """paho-mqtt 2.x CallbackAPIVersion.VERSION2。"""
 
     def __init__(self) -> None:
-        self._client: Optional[PahoClient] = None
+        self._client: Any = None
         self._on_connected: Optional[ConnHandler] = None
         self._on_disconnected: Optional[DiscHandler] = None
         self._on_down: Optional[DownHandler] = None
@@ -200,6 +207,7 @@ class PahoTransport:
         self._on_down = on_down
 
     def connect(self, params: ConnectParams) -> None:
+        CallbackAPIVersion, PahoClient, _, MQTTv5, _, _ = _require_paho()
         self.disconnect()
         url = params.url
         u = urlparse(url if "://" in url else "ws://" + url)
@@ -261,6 +269,7 @@ class PahoTransport:
         # 等待连接结果由回调驱动；超时由 Client 层处理
 
     def subscribe(self, topic: str) -> None:
+        _, _, MQTT_ERR_SUCCESS, _, _, _ = _require_paho()
         self._down_topic = topic
         if not self._client:
             return
@@ -273,6 +282,7 @@ class PahoTransport:
             raise RuntimeError("subscribe timeout")
 
     def publish(self, topic: str, payload: bytes) -> None:
+        _, _, MQTT_ERR_SUCCESS, _, _, _ = _require_paho()
         if not self._client:
             raise RuntimeError("not connected")
         info = self._client.publish(topic, payload, qos=1)
@@ -338,9 +348,14 @@ def _reason_to_int(reason_code) -> Optional[int]:
         return None
     if isinstance(reason_code, int):
         return reason_code
-    if isinstance(reason_code, ReasonCode):
+    try:
+        _, _, _, _, MQTTErrorCode, ReasonCode = _require_paho()
+    except ImportError:
+        MQTTErrorCode = ()  # type: ignore[assignment,misc]
+        ReasonCode = ()  # type: ignore[assignment,misc]
+    if ReasonCode and isinstance(reason_code, ReasonCode):
         return int(reason_code.value)
-    if isinstance(reason_code, MQTTErrorCode):
+    if MQTTErrorCode and isinstance(reason_code, MQTTErrorCode):
         return int(reason_code)
     # paho 偶发其它包装
     val = getattr(reason_code, "value", None)

sdk/python/tests/test_k00.py

@@ -30,11 +30,42 @@ class K00Tests(unittest.TestCase):
         with self.assertRaises(NixMsgError) as cm:
             c.connect("ws://example.test/mqtt", "ep1", password="p", wait=True)
         self.assertEqual(cm.exception.code, "not_connected")
+        n = len(tr.connects)
+        time.sleep(0.35)
+        self.assertEqual(len(tr.connects), n, "首次失败后不得自动重连")
         tr.auto_accept = True
         c.connect("ws://example.test/mqtt", "ep1", password="p", wait=True)
         self.assertEqual(c.state, ConnectionState.ONLINE)
         c.close()
 
+    def test_k00_first_hello_fail_stops_reconnect(self) -> None:
+        """MQTT 已通但 hello 失败：connect 返回未连接，且后台不再连。"""
+        tr = FakeTransport()
+        tr.auto_hello = None
+        c = Client(transport=tr, connect_timeout_s=0.2)
+        with self.assertRaises(NixMsgError) as cm:
+            c.connect("ws://example.test/mqtt", "ep1", password="p", wait=True)
+        self.assertEqual(cm.exception.code, "not_connected")
+        n = len(tr.connects)
+        self.assertGreaterEqual(n, 1)
+        time.sleep(0.45)
+        self.assertEqual(len(tr.connects), n, "hello 失败后不得自动重连")
+        tr.auto_hello = {
+            "server_time_ms": 1_750_000_000_000,
+            "server_version": "0.1.0",
+            "max_body_bytes": 262144,
+            "max_meta_bytes": 4096,
+            "max_frame_bytes": 786432,
+            "max_ttl_seconds": 2592000,
+            "max_schedule_seconds": 31536000,
+            "ack_timeout_seconds": 300,
+            "session_token": "nst_retry",
+        }
+        c.connect("ws://example.test/mqtt", "ep1", password="p", wait=True)
+        self.assertEqual(c.state, ConnectionState.ONLINE)
+        self.assertGreater(len(tr.connects), n)
+        c.close()
+
     def test_k00_taken_over_reason(self) -> None:
         c, tr = self._connect()
         got = []