Always use persistent handles when passing dart objects as userdata to callbacks

CHANGELOG.md

@@ -1,16 +1,17 @@
 ## vNext (TBD)
 
 ### Enhancements
-* None
+* Added `RealmObject.getBacklinks<SourceType>('sourceProperty')` which is a method allowing you to look up all objects of type `SourceType` which link to the current object via their `sourceProperty` property. (Issue [#1480](https://github.com/realm/realm-dart/issues/1480))
 
 ### Fixed
-* None
+* Fix a possible hang (or in rare cases crash) during notification handling. (Issue [#1492](https://github.com/realm/realm-dart/issues/1492))
+* Fix Flutter app build on Linux. A contribution from [thiagokisaki](https://github.com/thiagokisaki). (PR [#1488](https://github.com/realm/realm-dart/pull/1488))
 
 ### Compatibility
 * Realm Studio: 13.0.0 or later.
 
 ### Internal
-* Using Core x.y.z.
+* Using Core 13.26.0
 
 ## 1.7.0 (2024-01-23)
 
@@ -40,7 +41,6 @@
   The map keys may not contain `.` or start with `$`. (Issue [#685](https://github.com/realm/realm-dart/issues/685))
 * Added a new exception - `MigrationRequiredException` that will be thrown when a local Realm is opened with a schema that differs from the schema on disk and no migration callback is supplied. Additionally, a `helpLink` property has been added to `RealmException` and its subclasses to provide a link to the documentation for the error. (Issue [#1448](https://github.com/realm/realm-dart/issues/1448))
 * Downgrade minimum dependencies to Dart 3.0.0 and Flutter 3.10.0. (PR [#1457](https://github.com/realm/realm-dart/pull/1457))
-* Added `RealmObject.getBacklinks<SourceType>('sourceProperty')` which is a method allowing you to look up all objects of type `SourceType` which link to the current object via their `sourceProperty` property. (Issue [#1480](https://github.com/realm/realm-dart/issues/1480))
 
 ### Fixed
 * Fixed warnings being emitted by the realm generator requesting that `xyz.g.dart` be included with `part 'xyz.g.dart';` for `xyz.dart` files that import `realm` but don't have realm models defined. Those should not need generated parts and including the part file would have resulted in an empty file with `// ignore_for_file: type=lint` being generated. (PR [#1443](https://github.com/realm/realm-dart/pull/1443))

lib/src/native/realm_bindings.dart

@@ -3770,21 +3770,6 @@ class RealmLibrary {
       _realm_dart_object_to_persistent_handlePtr
           .asFunction<ffi.Pointer<ffi.Void> Function(Object)>();
 
-  ffi.Pointer<ffi.Void> realm_dart_object_to_weak_handle(
-    Object handle,
-  ) {
-    return _realm_dart_object_to_weak_handle(
-      handle,
-    );
-  }
-
-  late final _realm_dart_object_to_weak_handlePtr =
-      _lookup<ffi.NativeFunction<ffi.Pointer<ffi.Void> Function(ffi.Handle)>>(
-          'realm_dart_object_to_weak_handle');
-  late final _realm_dart_object_to_weak_handle =
-      _realm_dart_object_to_weak_handlePtr
-          .asFunction<ffi.Pointer<ffi.Void> Function(Object)>();
-
   Object realm_dart_persistent_handle_to_object(
     ffi.Pointer<ffi.Void> handle,
   ) {
@@ -4113,21 +4098,6 @@ class RealmLibrary {
           void Function(
               ffi.Pointer<ffi.Void>, ffi.Pointer<realm_app_error_t>)>();
 
-  Object realm_dart_weak_handle_to_object(
-    ffi.Pointer<ffi.Void> handle,
-  ) {
-    return _realm_dart_weak_handle_to_object(
-      handle,
-    );
-  }
-
-  late final _realm_dart_weak_handle_to_objectPtr =
-      _lookup<ffi.NativeFunction<ffi.Handle Function(ffi.Pointer<ffi.Void>)>>(
-          'realm_dart_weak_handle_to_object');
-  late final _realm_dart_weak_handle_to_object =
-      _realm_dart_weak_handle_to_objectPtr
-          .asFunction<Object Function(ffi.Pointer<ffi.Void>)>();
-
   /// Deletes the following files for the given `realm_file_path` if they exist:
   /// - the Realm file itself
   /// - the .management folder
@@ -11343,9 +11313,6 @@ class _SymbolAddresses {
   ffi.Pointer<ffi.NativeFunction<ffi.Pointer<ffi.Void> Function(ffi.Handle)>>
       get realm_dart_object_to_persistent_handle =>
           _library._realm_dart_object_to_persistent_handlePtr;
-  ffi.Pointer<ffi.NativeFunction<ffi.Pointer<ffi.Void> Function(ffi.Handle)>>
-      get realm_dart_object_to_weak_handle =>
-          _library._realm_dart_object_to_weak_handlePtr;
   ffi.Pointer<ffi.NativeFunction<ffi.Handle Function(ffi.Pointer<ffi.Void>)>>
       get realm_dart_persistent_handle_to_object =>
           _library._realm_dart_persistent_handle_to_objectPtr;
@@ -11431,9 +11398,6 @@ class _SymbolAddresses {
                   ffi.Pointer<ffi.Void>, ffi.Pointer<realm_app_error_t>)>>
       get realm_dart_void_completion_callback =>
           _library._realm_dart_void_completion_callbackPtr;
-  ffi.Pointer<ffi.NativeFunction<ffi.Handle Function(ffi.Pointer<ffi.Void>)>>
-      get realm_dart_weak_handle_to_object =>
-          _library._realm_dart_weak_handle_to_objectPtr;
   ffi.Pointer<ffi.NativeFunction<ffi.Void Function(ffi.Pointer<ffi.Void>)>>
       get realm_release => _library._realm_releasePtr;
 }

lib/src/native/realm_core.dart

@@ -258,8 +258,8 @@ class _RealmCore {
           _realmLib.realm_config_set_data_initialization_function(
             configHandle._pointer,
             Pointer.fromFunction(initial_data_callback, false),
-            config.toWeakHandle(),
-            nullptr,
+            config.toPersistentHandle(),
+            _realmLib.addresses.realm_dart_delete_persistent_handle,
           );
         }
         if (config.isReadOnly) {
@@ -274,12 +274,17 @@ class _RealmCore {
           _realmLib.realm_config_set_should_compact_on_launch_function(
             configHandle._pointer,
             Pointer.fromFunction(should_compact_callback, false),
-            config.toWeakHandle(),
-            nullptr,
+            config.toPersistentHandle(),
+            _realmLib.addresses.realm_dart_delete_persistent_handle,
           );
         }
         if (config.migrationCallback != null) {
-          _realmLib.realm_config_set_migration_function(configHandle._pointer, Pointer.fromFunction(migration_callback, false), config.toWeakHandle(), nullptr);
+          _realmLib.realm_config_set_migration_function(
+            configHandle._pointer,
+            Pointer.fromFunction(migration_callback, false),
+            config.toPersistentHandle(),
+            _realmLib.addresses.realm_dart_delete_persistent_handle,
+          );
         }
       } else if (config is InMemoryConfiguration) {
         _realmLib.realm_config_set_in_memory(configHandle._pointer, true);
@@ -317,8 +322,8 @@ class _RealmCore {
             _realmLib.realm_config_set_should_compact_on_launch_function(
               configHandle._pointer,
               Pointer.fromFunction(should_compact_callback, false),
-              config.toWeakHandle(),
-              nullptr,
+              config.toPersistentHandle(),
+              _realmLib.addresses.realm_dart_delete_persistent_handle,
             );
           }
 
@@ -893,12 +898,12 @@ class _RealmCore {
   }
 
   static void _completeAsyncBeginWrite(Pointer<Void> userdata) {
-    final Completer<void> completer = userdata.toObject(isPersistent: true);
+    final Completer<void> completer = userdata.toObject();
     completer.complete();
   }
 
   static void _completeAsyncCommit(Pointer<Void> userdata, bool error, Pointer<Char> description) {
-    final Completer<void> completer = userdata.toObject(isPersistent: true);
+    final Completer<void> completer = userdata.toObject();
     if (error) {
       completer.completeError(RealmException(description.cast<Utf8>().toDartString()));
     } else {
@@ -1532,8 +1537,8 @@ class _RealmCore {
   RealmNotificationTokenHandle subscribeSetNotifications(RealmSet realmSet, NotificationsController controller) {
     final pointer = _realmLib.invokeGetPointer(() => _realmLib.realm_set_add_notification_callback(
           realmSet.handle._pointer,
-          controller.toWeakHandle(),
-          nullptr,
+          controller.toPersistentHandle(),
+          _realmLib.addresses.realm_dart_delete_persistent_handle,
           nullptr,
           Pointer.fromFunction(collection_change_callback),
         ));
@@ -1733,8 +1738,8 @@ class _RealmCore {
   RealmNotificationTokenHandle subscribeResultsNotifications(RealmResults results, NotificationsController controller) {
     final pointer = _realmLib.invokeGetPointer(() => _realmLib.realm_results_add_notification_callback(
           results.handle._pointer,
-          controller.toWeakHandle(),
-          nullptr,
+          controller.toPersistentHandle(),
+          _realmLib.addresses.realm_dart_delete_persistent_handle,
           nullptr,
           Pointer.fromFunction(collection_change_callback),
         ));
@@ -1745,8 +1750,8 @@ class _RealmCore {
   RealmNotificationTokenHandle subscribeListNotifications(RealmList list, NotificationsController controller) {
     final pointer = _realmLib.invokeGetPointer(() => _realmLib.realm_list_add_notification_callback(
           list.handle._pointer,
-          controller.toWeakHandle(),
-          nullptr,
+          controller.toPersistentHandle(),
+          _realmLib.addresses.realm_dart_delete_persistent_handle,
           nullptr,
           Pointer.fromFunction(collection_change_callback),
         ));
@@ -1757,8 +1762,8 @@ class _RealmCore {
   RealmNotificationTokenHandle subscribeObjectNotifications(RealmObjectBase object, NotificationsController controller) {
     final pointer = _realmLib.invokeGetPointer(() => _realmLib.realm_object_add_notification_callback(
           object.handle._pointer,
-          controller.toWeakHandle(),
-          nullptr,
+          controller.toPersistentHandle(),
+          _realmLib.addresses.realm_dart_delete_persistent_handle,
           nullptr,
           Pointer.fromFunction(object_change_callback),
         ));
@@ -1769,8 +1774,8 @@ class _RealmCore {
   RealmNotificationTokenHandle subscribeMapNotifications(RealmMap map, NotificationsController controller) {
     final pointer = _realmLib.invokeGetPointer(() => _realmLib.realm_dictionary_add_notification_callback(
           map.handle._pointer,
-          controller.toWeakHandle(),
-          nullptr,
+          controller.toPersistentHandle(),
+          _realmLib.addresses.realm_dart_delete_persistent_handle,
           nullptr,
           Pointer.fromFunction(map_change_callback),
         ));
@@ -2076,7 +2081,7 @@ class _RealmCore {
   }
 
   static void _app_user_completion_callback(Pointer<Void> userdata, Pointer<realm_user> user, Pointer<realm_app_error> error) {
-    final Completer<UserHandle> completer = userdata.toObject(isPersistent: true);
+    final Completer<UserHandle> completer = userdata.toObject();
 
     if (error != nullptr) {
       completer.completeWithAppError(error);
@@ -2127,7 +2132,7 @@ class _RealmCore {
   }
 
   static void _void_completion_callback(Pointer<Void> userdata, Pointer<realm_app_error> error) {
-    final Completer<void> completer = userdata.toObject(isPersistent: true);
+    final Completer<void> completer = userdata.toObject();
 
     if (error != nullptr) {
       completer.completeWithAppError(error);
@@ -2707,7 +2712,7 @@ class _RealmCore {
   }
 
   static void _app_api_key_completion_callback(Pointer<Void> userdata, Pointer<realm_app_user_apikey> apiKey, Pointer<realm_app_error> error) {
-    final Completer<ApiKey> completer = userdata.toObject(isPersistent: true);
+    final Completer<ApiKey> completer = userdata.toObject();
     if (error != nullptr) {
       completer.completeWithAppError(error);
       return;
@@ -2716,7 +2721,7 @@ class _RealmCore {
   }
 
   static void _app_api_key_array_completion_callback(Pointer<Void> userdata, Pointer<realm_app_user_apikey> apiKey, int size, Pointer<realm_app_error> error) {
-    final Completer<List<ApiKey>> completer = userdata.toObject(isPersistent: true);
+    final Completer<List<ApiKey>> completer = userdata.toObject();
 
     if (error != nullptr) {
       completer.completeWithAppError(error);
@@ -2884,7 +2889,7 @@ class _RealmCore {
   }
 
   static void _call_app_function_callback(Pointer<Void> userdata, Pointer<Char> response, Pointer<realm_app_error> error) {
-    final Completer<String> completer = userdata.toObject(isPersistent: true);
+    final Completer<String> completer = userdata.toObject();
 
     if (error != nullptr) {
       completer.completeWithAppError(error);
@@ -3462,18 +3467,18 @@ extension on Pointer<realm_value> {
 }
 
 extension on Pointer<Void> {
-  T toObject<T extends Object>({bool isPersistent = false}) {
+  T toObject<T extends Object>() {
     assert(this != nullptr, "Pointer<Void> is null");
 
-    Object object = isPersistent ? _realmLib.realm_dart_persistent_handle_to_object(this) : _realmLib.realm_dart_weak_handle_to_object(this);
+    Object object = _realmLib.realm_dart_persistent_handle_to_object(this);
 
     assert(object is T, "$T expected");
     return object as T;
   }
 
   Object? toUserCodeError() {
     if (this != nullptr) {
-      final result = toObject(isPersistent: true);
+      final result = toObject();
       _realmLib.realm_dart_delete_persistent_handle(this);
       return result;
     }
@@ -3565,10 +3570,6 @@ extension on Pointer<realm_error_t> {
 }
 
 extension on Object {
-  Pointer<Void> toWeakHandle() {
-    return _realmLib.realm_dart_object_to_weak_handle(this);
-  }
-
   Pointer<Void> toPersistentHandle() {
     return _realmLib.realm_dart_object_to_persistent_handle(this);
   }

src/realm_dart.cpp

@@ -53,38 +53,6 @@ RLM_API void realm_dart_initializeDartApiDL(void* data) {
     Dart_InitializeApiDL(data);
 }
 
-class WeakHandle {
-public:
-    WeakHandle(Dart_Handle handle) : m_weakHandle(Dart_NewWeakPersistentHandle_DL(handle, this, 1, finalize_handle)) {
-    }
-
-    Dart_Handle value() {
-        return Dart_HandleFromWeakPersistent_DL(m_weakHandle);
-    }
-
-private:
-    ~WeakHandle() {
-        if (m_weakHandle) {
-            Dart_DeleteWeakPersistentHandle_DL(m_weakHandle);
-            m_weakHandle = nullptr;
-        }
-    }
-
-    static void finalize_handle(void* isolate_callback_data, void* peer) {
-        delete reinterpret_cast<WeakHandle*>(peer);
-    }
-
-    Dart_WeakPersistentHandle m_weakHandle;
-};
-
-RLM_API void* realm_dart_object_to_weak_handle(Dart_Handle handle) {
-    return new WeakHandle(handle);
-}
-
-RLM_API Dart_Handle realm_dart_weak_handle_to_object(void* handle) {
-    return reinterpret_cast<WeakHandle*>(handle)->value();
-}
-
 RLM_API void* realm_dart_object_to_persistent_handle(Dart_Handle handle) {
     return reinterpret_cast<void*>(Dart_NewPersistentHandle_DL(handle));
 }

src/realm_dart.h

@@ -24,9 +24,6 @@
 
 RLM_API void realm_dart_initializeDartApiDL(void* data);
 
-RLM_API void* realm_dart_object_to_weak_handle(Dart_Handle handle);
-RLM_API Dart_Handle realm_dart_weak_handle_to_object(void* handle);
-
 RLM_API void* realm_dart_object_to_persistent_handle(Dart_Handle handle);
 RLM_API Dart_Handle realm_dart_persistent_handle_to_object(void* handle);
 RLM_API void realm_dart_delete_persistent_handle(void* handle);