FFI: Crash on iOS in RoomList.entries_with_dynamic_adapters

[fl0lli]

Similar to #4009, I encounter an EXC_BAD_ACCESS crash using the FFI bindings for iOS.
Tried using the simulator and real devices, no difference. Used the current latest main branch.

The stacktrace indicates it could again be a problem in the poll method for rooms_stream, where the clone method throws an error for fetch_add.

I built the Swift package using cargo xtask swift build-framework --target aarch64-apple-ios --target aarch64-apple-ios-sim (as a result of #4009 the build defaults to the reldbg profile, as seen in the log).

My example code is the following:

import SwiftUI
import MatrixRustSDK

struct ContentView: View {
    var body: some View {
        VStack {
            Image(systemName: "globe")
                .imageScale(.large)
                .foregroundStyle(.tint)
            Text("Hello, world!")
        }
        .padding()
        .onAppear(perform: doLoginAndFetchMessages)
    }
    
    private func doLoginAndFetchMessages() {
        Task {
            do {
                let client = try await ClientBuilder()
                    .serverNameOrHomeserverUrl(serverNameOrUrl: "http://127.0.0.1:8008")
                    .slidingSyncVersionBuilder(versionBuilder: .discoverNative)
                    .sessionPaths(dataPath: URL.applicationSupportDirectory.path(percentEncoded: false), cachePath: URL.cachesDirectory.path(percentEncoded: false))
                    .build()
                
                if let userId = UserDefaults.standard.string(forKey: "matrix-client-swift.user-id") {
                    let restoredSession = try MatrixClientSessionDelegate.shared.retrieveSessionFromKeychain(userId: userId)
                    try await client.restoreSession(session: restoredSession)
                } else {
                    try await client.login(username: "admin", password: "admin", initialDeviceName: nil, deviceId: nil)
                    let session = try client.session()
                    MatrixClientSessionDelegate.shared.saveSessionInKeychain(session: session)
                    UserDefaults.standard.set(session.userId, forKey: "matrix-client-swift.user-id")
                }
                
                let syncService = try await client.syncService().finish()
                await syncService.start()
                
                let listener = AllRoomsListener() { roomListItems in
                    print("roomListItems=\(roomListItems)")
                }
                
                let roomListService = syncService.roomListService()
                
                let handle = try await roomListService.allRooms().entriesWithDynamicAdapters(pageSize: 10, listener: listener)
                
                let _ = handle.controller().setFilter(kind: .joined)
            } catch {
                print("error: \(error)")
            }
        }
    }
}

class AllRoomsListener: RoomListEntriesListener {
    let onGetRoomsCallback: ([RoomListItem]) -> Void
    
    init(onGetRoomsCallback: @escaping ([RoomListItem]) -> Void) {
        self.onGetRoomsCallback = onGetRoomsCallback
    }
    
    func onUpdate(roomEntriesUpdate: [MatrixRustSDK.RoomListEntriesUpdate]) {
        for update in roomEntriesUpdate {
            switch update {
            case .reset(values: let values):
                onGetRoomsCallback(values)
            default:
                break // Handle all the other cases accordingly.
            }
        }
    }
}

One thing to note is that on the first run (no saved user, user logging in manually) the RoomListEntriesListener returns a reset (expected) with no items (?). The crash only happens on the second run, but does not appear to be caused by the session restoration, as a deviceId hard-coding also produces this crash (initial login, save deviceId and hard-code it into client.login()).

Edit:

• If sessionPaths is not specified in the ClientBuilder constructor, the app does not crash, but the RoomListEntriesListener does not receive any Rooms.
• Using element-hq/matrix-rust-components-swift v25.3.6 (currently newest) or building in release (--release) also crashes, but with The file path does not exist on the file system: /rustc/xxx/library/alloc/src/boxed.rs (the error nonetheless is located in Client.rooms_stream, so this may be an expected error message).
• As described in RoomList.entries_with_dynamic_adapters if the call to setFilter is omitted, the app does not crash, as it does nothing.
• Using element-hq/element-web I created a private, public and DM room with the users "admin" and "test".

[Hywan]

Thanks for the bug report.

@stefanceriu Did you experience something similar?