Not able to create realm database on external file storage on Android 11 and plus

[umarpazir11]

Expected results

I want to create a realm database on external storage so two apps can use one single database. So I am using scope storage for android to give permission but I can create all other files but not realm database files. only realm.lock file is there

Actual Results

E/REALM: /tmp/realm-java/realm/realm-library/src/main/cpp/realm-core/src/realm/util/file.cpp:1023: [realm-core-11.3.0] Assertion failed: r == 0 && "File::unlock()" with (r, (*__errno())) = [-1, 38]

Steps & Code to Reproduce

Using scope storage for android.

Core version

Android 11 and 12

[fealebenpae]

Hey @umarpazir11,
This sounds very much like realm/realm-java#6893. I'm not very familiar with the internals myself, but it seems that Android 11 changed the permission model of working around scope storage in a way that breaks filesystem locks used by realm.

[cmelchior]

Yes, with Android 11 scoped storage is now enforced. This means the only way for apps to share files is through the Storage Access Framework (https://developer.android.com/guide/topics/providers/document-provider). Unfortunately, there isn't a way we can support this from the native side.

The only way to use it would be to copy a file from shared storage to internal storage, use it, and then copy it back. But that is probably too restrictive for any real usage.

[jedelbo]

@cmelchior So we can close this?

[cmelchior]

Yes

[umarpazir11]

@jedelbo inside of only closing it will be better if they bring some ContentProvidor for realm database similar to android one.

[jedelbo]

@cmelchior I will now close this, but I hope you have noted the comment above.