Delay disconnect on errors in order to make sending close messages mo…

…re robust

picows/picows.pyx

@@ -1212,15 +1212,15 @@ cdef class WSProtocol:
                     # But don't wait for any tcp confirmation, use abort()
                     # because normal disconnect may hang until OS TCP/IP timeout
                     # for ACK is fired.
-                    await sleep(0.01)
-                    self.transport.underlying_transport.abort()
+                    self._loop.call_later(0.01, self.transport.underlying_transport.abort)
+                    break
         except asyncio.CancelledError:
             if self._log_debug_enabled:
                 self._logger.log(PICOWS_DEBUG_LL, "Auto-ping loop cancelled")
         except:
             self._logger.exception("Auto-ping loop failed, disconnect websocket")
             self.transport.send_close(WSCloseCode.INTERNAL_ERROR, b"an exception occurred in auto-ping loop")
-            self.transport.disconnect()
+            self._loop.call_later(0.01, self.transport.disconnect)
 
     cdef inline tuple _try_read_upgrade_request(self):
         cdef bytes data = PyBytes_FromStringAndSize(self._buffer.data, self._f_new_data_start_pos)
@@ -1347,11 +1347,11 @@ cdef class WSProtocol:
         except _WSParserError as ex:
             self._logger.error("WS parser error: %s, initiate disconnect", ex.args)
             self.transport.send_close(ex.args[0], ex.args[1].encode())
-            self.transport.disconnect()
+            self._loop.call_later(0.01, self.transport.disconnect)
         except:
             self._logger.exception("WS parser failure, initiate disconnect")
             self.transport.send_close(WSCloseCode.PROTOCOL_ERROR)
-            self.transport.disconnect()
+            self._loop.call_later(0.01, self.transport.disconnect)
 
     cdef inline WSFrame _get_next_frame_impl(self): #  -> Optional[WSFrame]
         """Return the next frame from the socket."""
@@ -1482,7 +1482,7 @@ cdef class WSProtocol:
         except Exception as e:
             self._logger.exception("Unhandled exception in on_ws_connected, initiate disconnect")
             self.transport.send_close(WSCloseCode.INTERNAL_ERROR)
-            self.transport.disconnect()
+            self._loop.call_later(0.01, self.transport.disconnect)
 
     cdef inline _invoke_on_ws_frame(self, WSFrame frame):
         try:
@@ -1512,7 +1512,7 @@ cdef class WSProtocol:
             if self._disconnect_on_exception:
                 self._logger.exception("Unhandled exception in on_ws_frame, initiate disconnect")
                 self.transport.send_close(WSCloseCode.INTERNAL_ERROR)
-                self.transport.disconnect()
+                self._loop.call_later(0.01, self.transport.disconnect)
             else:
                 self._logger.exception("Unhandled exception in on_ws_frame")