[Fix] WebSocketClient：修正一个潜在Bug：因网络问题导致重连的exception不会被onError捕获

vnpy/restful/WebSocketClient.py

@@ -7,7 +7,7 @@ import ssl
 import sys
 import time
 from abc import abstractmethod
-from threading import Thread
+from threading import Thread, Lock
 
 import websocket
 
@@ -20,7 +20,9 @@ class WebsocketClient(object):
         """Constructor"""
         self.host = None  # type: str
         
+        self._ws_lock = Lock()
         self._ws = None  # type: websocket.WebSocket
+        
         self._workerThread = None  # type: Thread
         self._pingThread = None  # type: Thread
         self._active = False
@@ -55,17 +57,17 @@ class WebsocketClient(object):
     #----------------------------------------------------------------------
     def sendReq(self, req):  # type: (dict)->None
         """发出请求"""
-        return self._ws.send(json.dumps(req), opcode=websocket.ABNF.OPCODE_TEXT)
+        return self._get_ws().send(json.dumps(req), opcode=websocket.ABNF.OPCODE_TEXT)
     
     #----------------------------------------------------------------------
     def sendText(self, text):  # type: (str)->None
         """发出请求"""
-        return self._ws.send(text, opcode=websocket.ABNF.OPCODE_TEXT)
+        return self._get_ws().send(text, opcode=websocket.ABNF.OPCODE_TEXT)
     
     #----------------------------------------------------------------------
     def sendData(self, data):  # type: (bytes)->None
         """发出请求"""
-        return self._ws.send_binary(data)
+        return self._get_ws().send_binary(data)
     
     #----------------------------------------------------------------------
     def _reconnect(self):
@@ -81,22 +83,36 @@ class WebsocketClient(object):
     
     #----------------------------------------------------------------------
     def _disconnect(self):
-        """"""
+        """
+        断开连接
+        """
+        with self._ws_lock:
+            if self._ws:
                 self._ws.close()
+                self._ws = None
+
+    #----------------------------------------------------------------------
+    def _get_ws(self):
+        with self._ws_lock:
+            return self._ws
     
     #----------------------------------------------------------------------
     def _run(self):
         """运行"""
+        ws = self._get_ws()
         while self._active:
             try:
-                stream = self._ws.recv()
+                stream = ws.recv()
+                if not stream:
+                    if self._active:
+                        self._reconnect()
+                    continue
+                    
                 data = json.loads(stream)
                 self.onMessage(data)
             except:
                 et, ev, tb = sys.exc_info()
                 self.onError(et, ev, tb)
-                if self._active:
-                    self._reconnect()
     
     #----------------------------------------------------------------------
     def _runPing(self):
@@ -109,7 +125,7 @@ class WebsocketClient(object):
     
     #----------------------------------------------------------------------
     def _ping(self):
-        return self._ws.send('ping', websocket.ABNF.OPCODE_PING)
+        return self._get_ws().send('ping', websocket.ABNF.OPCODE_PING)
     
     #----------------------------------------------------------------------
     @abstractmethod