Hard Crash when trying to Set/Update data which is > 64 KB, error 0xC0000005

[DDR12]

Please fill in the following fields:

Unity editor version: 2019.1.1f1 and 2019.2.8f1
Firebase Unity SDK version: 6.6.0 and 6.7.0
Firebase plugins in use : Auth and Database.
Additional SDKs you are using : None.
Platform you are using the Unity editor on : Windows.
Platform you are targeting : Desktop
Scripting Runtime (Mono, and/or IL2CPP): Reproduced on Both

Please describe the issue here:

1. Download the minimal reproducible sample from here: https://drive.google.com/open?id=1CeZprgFZz_dVhz2gLSytn6R-u2NWxNfG

2. Import the FirebaseDatabase package for sdk version 6.6.0 or 6.7.0.

3. Open the scene 'SampleScene' in _Scenes folder.

4. Run in editor, in the input field input any number below 65500 and press upload, this will create a string of length whatever number you input and upload it, i.e creates a sample data of size x bytes.

5. The upload should be success or an error if failed for some reason.

6. Now edit the data size in the input field for any value above 65600 bytes and press upload, and experience a hard editor crash, guaranteed 100 % every time you try to push data > 65500 size.

7. Open the dump files for the crash and you should see this error:
   0xC0000005
   The thread tried to read from or write to a virtual address for which it does not have the appropriate access.

Thanks!

Please answer the following, if applicable:

Have you been able to reproduce this issue with just the Firebase Unity quickstarts (this GitHub project)? Didn't test.

What's the issue repro rate? 100 %

[muflub]

Hi @DDR12,

Thanks for the bug report. From what I can tell it looks like you are exceeding the max websocket frame size supported by Firebase Database and causing the server to disconnecting the client at an unexpected time causing the client to hard crash.

Ive filed a bug internally to look into a proper fix for this but in the mean time you will need to add some logic to check for this case.

[DDR12]

Hi, thanks for your response and time!
Its not a max issue with firebase databse, it is a problem with the unity SDK, to prove that,

1. I uploaded data > 64 KB to the database from the firebase console and I was able to download it from the unity client.

2. I've also been able to upload data through the REST API, I simply created 2 extension methods to upload data using the REST API and I can upload data at any size.

For anyone having same problem

   ```
    public static Task SetRawJsonValueAsync_REST(this DatabaseReference reference, string json)
    {
        return FirebaseDatabaseREST.Instance.SetValue(GetRESTLink(reference), json);
    }

    public static Task SetValueAsync_REST(this DatabaseReference reference, object value)
    {
        return SetRawJsonValueAsync_REST(reference, JsonConvert.SerializeObject(value));
    }

    private static string GetRESTLink(this DatabaseReference reference)
    {
        string databasePath = reference.Database.App.Options.DatabaseUrl.AbsoluteUri;
        return $"{databasePath}{GetFullPath(reference)}.json";
    }

    public static string GetFullPath(this DatabaseReference reference)
    {
        List<string> keys = new List<string>(4);
        while(reference != null)
        {
            keys.Add(reference.Key);
            reference = reference.Parent;
        }
        keys.Reverse();
        return string.Join("/", keys).TrimStart('/');
    }

Now instead of using the SDK's `DatabaseReference.SetValueAsync,` use `DatabaseReference.SetValueAsync_REST`, and uploaded data at any size without crashes.

In the 2 Extension Methods `SetValueAsync_REST` and `SetRawJsonValueAsync_REST`, I'm using a dedicated class to send HTTP requests, that I can't share because the project is private, but you can use unity's `UnityWebRequest `or plugins like `BESTHTTP`.

[muflub]

Looking more into it, seems to be related to the rate of data transfer rather than the size. Putting break points in debug code allows the set to complete. The team is still investigating.

[Adnimistrator]

@muflub Is there any progress on this issue?

[Adnimistrator]

It's been a year since this bug is present. @stewartmiles Do you still work on firebase? I can remember you could fix this kind of bugs in a hours when firebase was on its start. Why does it take such a long time now?

[DellaBitta]

A fix for this issue will be in the next milesone release (7.2.0). I'm closing this issue for now, but please re-open it if the problem ensues.