[Bug] Chrome out of memory on large programs

[laurensvalk]

While creating a few big programs to test the limits of our hub file storage, I noticed that Pybricks Code can crash Chrome. In one case, it dropped into the debugger before the potential memory issue. In other cases, Chrome crashes with SIGILL.

This is a bit of an unusual program, but not entirely out of the ordinary. If someone wants to include a binary blob to include some extra data, a program may look not unlike the one below.

Example. long_program.py.txt

It still works if you cut it in half. It's only 18Kb as a compiled .mpy program. Should probably retry with randomized strings to avoid string compression being a factor.

from pybricks.hubs import PrimeHub
from pybricks.pupdevices import Motor, ColorSensor, UltrasonicSensor, ForceSensor
from pybricks.parameters import Button, Color, Direction, Port, Side, Stop
from pybricks.robotics import DriveBase
from pybricks.tools import wait, StopWatch

hub = PrimeHub()

data = b"132456789132456789132456789132456789132456789132456789132456789132456789"
data = b"132456789132456789132456789132456789132456789132456789132456789132456789"
data = b"132456789132456789132456789132456789132456789132456789132456789132456789"

# Repeat this MANY more times. Too big for a GitHub post. See attachment for whole file.

data = b"132456789132456789132456789132456789132456789132456789132456789132456789"
data = b"132456789132456789132456789132456789132456789132456789132456789132456789"
data = b"132456789132456789132456789132456789132456789132456789132456789132456789"
data = b"132456789132456789132456789132456789132456789132456789132456789132456789"

hub.light.on(Color.BLUE)
wait(10000)

[dlech]

Apparently, this is caused by the Python parser that we are using to find resolve imports.

https://github.com/pybricks/python-program-analysis

[ggramlich]

@laurensvalk One of my boys uses Chrome and when trying to open code.pybricks.com, the browser and also screen recording software crashes after a few seconds, so I could not record a video.
I already tried to delete cookies and caches.
In incognito mode he can use pybricks.
I think that the programs are still in stored in chrome and that causes the problem, but I don't know how to delete them.
Might this be related with this bug? Can you help us deleting the programs, if that might cause the problem?

[laurensvalk]

Thanks for reporting. I watched your video. Very unusual.

I think that the programs are still in stored in chrome and that causes the problem, but I don't know how to delete them.

From your video, you can see clear site data. That should do it.

[ggramlich]

Hi Laurens, thanks for the help. We were able to clear the data. But that did not actually help. Chrome still crashes. https://photos.app.goo.gl/B4YsQY9EwGgTZ3KBA We will probably try to uninstall Chrome then. Do you have any other idea. Thanks Gregor laurensvalk ***@***.***> schrieb am Do., 3. Okt. 2024, 15:14:

…

Thanks for reporting. I watched your video. Very unusual. I think that the programs are still in stored in chrome and that causes the problem, but I don't know how to delete them. From your video, you can see clear site data. That should do it. image.png (view on web) <https://github.com/user-attachments/assets/179ec548-d6d8-4a8a-9738-d43a2f5067bc> — Reply to this email directly, view it on GitHub <#1804 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAQ5HCLKY5L3WVASEKBSPLZZU7LNAVCNFSM6AAAAABNWCR65CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGOJRGM4TGNJSG4> . You are receiving this because you commented.Message ID: ***@***.***>

[laurensvalk]

Is there anything left in local storage?

Or IndexedDB > pybricks.fileStorage > contents

[laurensvalk]

Does anything show in the console?

[ggramlich]

@laurensvalk Unfortunately I was not able to dig deeper into it and probably won't be able to do so within the next week as the boy has his laptop with him.
The boy now uses the beta version, which does not cause the problem (neither does incognito mode).
As you saw in the videos, you only have about one second to react after opening the page, so opening a specific node in the Indexed DB tree will be close to impossible. But I will try to see, what I can find in the file system under AppData\Local\Google\Chrome\User Data\Default\Local Storage

[ggramlich]

@laurensvalk We were able to look at the console output. It showed only the first output "starting Pyodide..." before Chrome crashed.
Then I was able to locate the IndexedDB Folder under AppData\Local\Google\Chrome\User Data\IndexedDB
The folder for code.pybricks.com showed 4 GB (3.73 GiB) Disk Usage. After deleting the folder, it is possible to use pybricks again.

[laurensvalk]

Were you able to create a backup of the folder before deleting it, by any chance?

[ggramlich]

Sorry - I don't have a backup. I wanted to copy the folder over to our Google Drive shared folder, but the 4 GB were too much. I could have used a USB Stick but we were in our practice under a bit of time pressure.

[laurensvalk]

No problem at all. Thanks as always for taking the time to report this.