Racing conditions on MXStore (MXFileStore)

Hi all,

After some extensive debugging, I found that the paginate method is absolutely not thread safe. My chat app loads the rooms after login and starts the pagination for all rooms to fetch the latest (text/image/audio/video) messages. But doing so for all rooms at the same time causes racing conditions on the (file)store.

I've tried all sorts of things, with serial queues, dispatch groups, semaphores, no store, memory store, but nothing helps. The only thing that does work is to do the pagination on the main thread. But that would block the entire UI until all rooms finished paginating.

So my question here is two-fold:

1. Would it be possible to pass a queue to the pagination method, so all operations will be performed on that queue
2. The only reason I preload the messages is to display the latest message in the rooms list and to load the chat view faster. I can't use the latest summary event, because that could be a redact event.

To build a real chat app it would be very nice to:

1. Be able to see the latest text/audio/image/video message in the room summary
2. Be able to filter all the other events when paginating

Regards,

Victor.

The report names MXStore, MXFileStore, and the paginate method but no files or tests. Start by reproducing concurrent pagination across rooms with the file store, then trace the store access and pagination API. Done requires a defined thread-safe behavior and clear validation of the requested queue, message-summary, and event-filtering capabilities.