Calling .value on OrtValue crash the programme

[guyluz11]

I am trying to summarize a text using the .onnx file from here https://huggingface.co/pszemraj/long-t5-tglobal-base-16384-book-summary.

I am getting OrtValue result and I am trying to get the value but the program crashes every time with no clear error

Lost connection to device.
the Dart compiler exited unexpectedly.

Here is a copy-paste example, I am running it on Linux

Code:

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:onnxruntime/onnxruntime.dart';

void main() {
  OrtEnv.instance.init();
  runApp(MaterialApp(
    home: TextSummarization(),
  ));
}

class TextSummarization extends StatefulWidget {
  @override
  _TextSummarizationState createState() => _TextSummarizationState();
}

class _TextSummarizationState extends State<TextSummarization> {
  // OrtSession? encoderSession;
  // OrtSession? decoderSession;
  OrtSession? longT5Session;
  String _summary = "";

  @override
  void initState() {
    super.initState();
    loadLongT5Session();
  }

  Future<void> loadLongT5Session() async {
    final sessionOptions = OrtSessionOptions();
    const assetFileName = 'assets/models/long_t5.onnx';
    final rawAssetFile = await rootBundle.load(assetFileName);
    final bytes = rawAssetFile.buffer.asUint8List();
    longT5Session = OrtSession.fromBuffer(bytes, sessionOptions);
  }

  Future<List<OrtValue?>?> summeryLongT5(String text) async {
    // List<int> tokenizedInput = _tokenizeText(inputText);
    List<List<int>> inputList = [
      [
        947,
        19,
        3,
        9,
        418,
        13,
        1499,
        27,
        278,
        31,
        17,
        241,
        12,
        608,
        3,
        1825,
        58,
        1,
      ]
    ];
    List<List<int>> attentionMask = [
      [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
    ];
    List<List<int>> decoderInputIds = [
      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    ];

    OrtValueTensor inputOrt =
        OrtValueTensor.createTensorWithDataList(inputList);
    OrtValueTensor attentionMaskOrt =
        OrtValueTensor.createTensorWithDataList(attentionMask);
    OrtValueTensor decoderInputIdsOrt =
        OrtValueTensor.createTensorWithDataList(decoderInputIds);

    final inputs = {
      'input_ids': inputOrt,
      'attention_mask': attentionMaskOrt,
      'decoder_input_ids': decoderInputIdsOrt,
    };

    final runOptions = OrtRunOptions();
    print('Input names');
    print(longT5Session?.inputNames);
    List<OrtValue?>? outputs =
        await longT5Session?.runAsync(runOptions, inputs);
    inputOrt.release();
    attentionMaskOrt.release();
    runOptions.release();
    outputs?.forEach((element) {
      element?.release();
    });
    if (outputs == null || outputs.isEmpty) {
      return null;
    }

    print(outputs);
    print('');

    OrtValue? b = outputs[0];
    try {
      Object? d = b?.value;
    } catch (e) {
      print(e);
      return null;
    }

    print('This is the output');
    print(outputs);

    return outputs;
    // Post-process the output
    // String summary = _decodeSummary(outputs);

    // setState(() {
    //   _summary = summary;
    // });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Text Summarization with ONNX'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(
              onChanged: (text) {
                setState(() {
                  _summary = "Generating summary...";
                });
                summeryLongT5(text);
              },
              decoration: InputDecoration(
                hintText: "Enter text to summarize",
                border: OutlineInputBorder(),
              ),
            ),
            SizedBox(height: 20),
            TextButton(
              onPressed: () => summeryLongT5('Your'),
              child: Text('Press to impress'),
            ),
            SizedBox(height: 20),
            Text('Summary: $_summary'),
          ],
        ),
      ),
    );
  }
}

[guyluz11]

Moving Object? d = b?.value; before all of the release() solve it.

The example project use release and then get the value which is confusing.

I think this should change in the example as well and get mentioned in the readme.