App crashes with memory leak when running for a long time

[SomaKishimoto]

Version

0.2.2

Problem Area

react-native-pytorch-core (core package)

Steps to Reproduce

Following the steps below, the memory heap increases at a pace of about 100MB per hour. We are developing an application that needs to run for long periods of time. Could you please tell me how to avoid this issue.

• Create empty project

$ npx react-native init AwesomeTSProject --template react-native-template-typescript
$ cd AwesomeTSProject

• Add PlayTorch to Existing App

$ yarn add react-native-pytorch-core
$ npx pod-install

• Rewrite App.ts based on Playground

import * as React from 'react';
import {useCallback} from 'react';
import {LayoutRectangle, StyleSheet} from 'react-native';
import {
  Camera,
  CameraFacing,
  Canvas,
  CanvasRenderingContext2D,
  Image,
  ImageUtil,
} from 'react-native-pytorch-core';

const App = () => {
  const contextRef = React.useRef<CanvasRenderingContext2D>();
  const [layout, setLayout] = React.useState<LayoutRectangle>();

  const handleCapture = useCallback(
    async (image: Image) => {
      const context = contextRef.current;
      if (context != null && layout != null) {
        context.clear();
        const imageWidth = image.getWidth();
        const imageHeight = image.getHeight();
        const scale = Math.min(
          layout.width / imageWidth,
          layout.height / imageHeight,
        );
        context.drawImage(image, 0, 0, imageWidth * scale, imageHeight * scale);
        const wholeImageData = await context.getImageData(
          0,
          0,
          imageWidth * scale,
          imageHeight * scale,
        );
        const wholeImage = await ImageUtil.fromImageData(wholeImageData);
        await wholeImageData.release();
        await wholeImage.release();
        await context.invalidate();
      }
      image.release();
    },
    [contextRef, layout],
  );

  return (
    <>
      <Camera
        onFrame={handleCapture}
        hideCaptureButton={true}
        style={styles.camera}
        facing={CameraFacing.BACK}
      />
      <Canvas
        style={styles.canvas}
        onContext2D={context => {
          contextRef.current = context;
        }}
        onLayout={event => {
          setLayout(event.nativeEvent.layout);
        }}
      />
    </>
  );
};

const styles = StyleSheet.create({
  camera: {
    display: 'none',
  },
  canvas: {
    flex: 1,
  },
});
export default App;

However, the code below is necessary for our application and cannot be removed.

        const wholeImage = await ImageUtil.fromImageData(wholeImageData);
        await wholeImageData.release();
        await wholeImage.release();
        await context.invalidate();

• Rewrite Info.plist for camera and microphone permissions

$ vim ./ios/AwesomeTSProject/Info.plist

<key>NSCameraUsageDescription</key>
<string>$(PRODUCT_NAME) needs access to your Camera.</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string></string>
<key>NSMicrophoneUsageDescription</key>
<string>$(PRODUCT_NAME) needs access to your Microphone.</string>

• Running On Device

$ npx react-native start
$ open /Applications/Xcode.app ./ios/AwesomeTSProject.xcworkspace

Expected Results

No response

Code example, screenshot, or link to repository

Related to this issue

[raedle]

@SomaKishimoto, I can't repro the issue with the provided code and an iPhone Xs (see screenshots at the start of the memory measurement and after 1 hour continuously running the code).

• What iOS device was used in the experiment?
• What JavaScript runtime is enabled in the app (e.g., Hermes or JSC)?

Start

End

[SomaKishimoto]

@raedle , thanks for trying to repro the issue.
my answers below

What iOS device was used in the experiment?

• device : iPhone SE 2nd
• OS : 16.11

What JavaScript runtime is enabled in the app (e.g., Hermes or JSC)?

• hermes => true

setting

• package.json + react-native-pytorch-core v0.2.3

Memory heap seems to increase slightly once every 10 minutes.
Do you use Expo? I create empty project with bare react native.
If it's possible, could you try to repro this issue with bare react native?

Start

30min

55min

(Stopped with an error unrelated to this issue [error.txt] )

[nh9k]

Hi, @raedle,
Does not doing image.release() or tensor release(current not implement) properly cause a memory leak?

[raedle]

@nh9k, each image has to be released from memory manually. For context, the current implementation holds a reference in the JSContext:

• Android JSContext.java
• iOS JSContext.swift

Not releasing the image will keep the reference around.

Tensors are implemented differently. They use jsi::HostObject from the JSI API. This will eventually clean up references when the JavaScript Runtime GC finds unused references (see TensorHostObject.h).

Have you profiled your app to check what leaks memory?

[nh9k]

@raedle, thank you for your kindness! I haven't profiled my app yet. My app also crashes, so I need a memory check. I'll report back!

[nh9k]

Hi, @raedle, i found out what leaks memory!!!

This code causes app crash when capture under about 100 times on Android.
A large image size causes a memory leak rapidly.

For example, the size of an image are 3000x4000.
This example size is captured image size using react-native-camera package.

for-loop was used instead of pressing the capture button 100 times.
Here is the code crashes the app on the 37th i variable using for-loop when tested by Galaxy A33 .
Galaxy S9+ crashes at 80th i variable in for-loop.

for (let i=0; i<100; i++){
 const width = image.getWidth();
 const height = image.getHeight();
 const blob = media.toBlob(image);
 let tensor = torch.fromBlob(blob, [height, width, 3]);
 tensor = tensor.permute([2, 0, 1]); 
 const newTensor = tensor.div(255);
}

Here is a Snack for test. 😢

[raedle]

Thanks for investigating in the issue, @nh9k.

My hunch is that it is not a memory leak per se, but the Hermes/JSC garbage collector will not run in fast enough intervals to free memory of variables that are out of scope (i.e., the tensor variables inside the for-loop aren't GC'ed fast enough and the system eventually runs out of memory).

This seems like a valid case for introducing manual memory management options to PlayTorch (although this will break with idiomatic JavaScript).

cc @chrisklaiber @justinhaaheim

[nh9k]

Thanks @raedle.
My app crashes are also occurs about 27th capture on Galaxy A33, it is similar to for-loop of test.