Fix the monitor_callback invalid issue during calibration with variab…

…le input shapes

python/mxnet/executor.py

@@ -79,6 +79,7 @@ def __init__(self, handle, symbol, ctx, grad_req, group2ctx):
         self._aux_dict = None
         self._output_dict = None
         self._monitor_callback = None
+        self._monitor_all = None
         self._ctx = copy.deepcopy(ctx)
         self._grad_req = copy.deepcopy(grad_req)
         self._group2ctx = copy.deepcopy(group2ctx)
@@ -253,6 +254,7 @@ def set_monitor_callback(self, callback, monitor_all=False):
         """
         cb_type = ctypes.CFUNCTYPE(None, ctypes.c_char_p, NDArrayHandle, ctypes.c_void_p)
         self._monitor_callback = cb_type(_monitor_callback_wrapper(callback))
+        self._monitor_all = monitor_all
         check_call(_LIB.MXExecutorSetMonitorCallbackEX(
             self.handle,
             self._monitor_callback,
@@ -469,6 +471,13 @@ def reshape(self, partial_shaping=False, allow_up_sizing=False, **kwargs):
         executor.arg_arrays = arg_arrays
         executor.grad_arrays = grad_arrays
         executor.aux_arrays = aux_arrays
+        if (self._monitor_callback is not None) and (self._monitor_all is not None):
+            # rebind callback to the new executor if the callback is valid
+            check_call(_LIB.MXExecutorSetMonitorCallbackEX(
+                handle,
+                self._monitor_callback,
+                None,
+                ctypes.c_int(self._monitor_all)))
         return executor
 
     def debug_str(self):