return -1 for failed predict

core/general-client/src/general_model.cpp

@@ -237,7 +237,7 @@ int PredictorClient::batch_predict(
   res.Clear();
   if (_predictor->inference(&req, &res) != 0) {
     LOG(ERROR) << "failed call predictor with req: " << req.ShortDebugString();
-    exit(-1);
+    return -1;
   } else {
     client_infer_end = timeline.TimeStampUS();
     postprocess_start = client_infer_end;