Fix TableKey / ObjKey conversion on Android x86 (#2477)

Author: Dominic Frei

CHANGELOG.md

@@ -4,15 +4,17 @@
 * \[Unity\] Fixed an issue where failing to weave an assembly due to modeling errors, would only show an error in the logs once and then fail opening a Realm with `No RealmObjects. Has linker stripped them?`. Now, the weaving errors will show up on every code change/weave attempt and the runtime error will explicitly suggest manually re-running the weaver. (Issue [#2310](https://github.com/realm/realm-dotnet/issues/2310))
 * \[Unity\] Fixed an issue that would cause the app to hang on exit when using Sync. (PR [#2467](https://github.com/realm/realm-dotnet/pull/2467))
 * \[Unity\] Fixed an issue that would cause the Unity editor on macOS to hang after assembly reload if the app uses Sync. (Issue [#2482](https://github.com/realm/realm-dotnet/issues/2482))
+* Fixed an issue where a crash could happen on Android x86 due to converting UInt32 into TableKey and Int64 into ObjKey incorrectly. (Issue [#2456](https://github.com/realm/realm-dotnet/issues/2456))
 
 ### Enhancements
 * None
 
 ### Compatibility
-* Realm Studio: 11.0.0-alpha.0 or later.
+* Realm Studio: 11.0.0 or later.
 
 ### Internal
 * Using Core 11.0.3.
+* GetHashCode() on objects now uses the table key in addition to the object key. (Issue [#2473](https://github.com/realm/realm-dotnet/issues/2473))
 
 ## 10.2.0 (2021-06-15)
 

Realm/Realm/DatabaseTypes/RealmObjectBase.cs

@@ -195,7 +195,7 @@ internal void SetOwner(Realm realm, ObjectHandle objectHandle, Metadata metadata
             _realm = realm;
             _objectHandle = objectHandle;
             _metadata = metadata;
-            _hashCode = new Lazy<int>(() => _objectHandle.GetObjKey().GetHashCode());
+            _hashCode = new Lazy<int>(() => _objectHandle.GetObjHash());
 
             if (_propertyChanged != null)
             {

Realm/Realm/Handles/ObjectHandle.cs

@@ -29,6 +29,7 @@ internal class ObjectHandle : NotifiableObjectHandleBase
         private static class NativeMethods
         {
 #pragma warning disable IDE1006 // Naming Styles
+#pragma warning disable IDE0049 // Naming Styles
 #pragma warning disable SA1121 // Use built-in type alias
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "object_get_is_valid", CallingConvention = CallingConvention.Cdecl)]
@@ -66,8 +67,8 @@ private static class NativeMethods
             [return: MarshalAs(UnmanagedType.U1)]
             public static extern bool equals_object(ObjectHandle handle, ObjectHandle otherHandle, out NativeException ex);
 
-            [DllImport(InteropConfig.DLL_NAME, EntryPoint = "object_get_obj_key", CallingConvention = CallingConvention.Cdecl)]
-            public static extern ObjKey get_obj_key(ObjectHandle handle, out NativeException ex);
+            [DllImport(InteropConfig.DLL_NAME, EntryPoint = "object_get_hashcode", CallingConvention = CallingConvention.Cdecl)]
+            public static extern Int32 get_hashcode(ObjectHandle handle, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "object_get_backlinks", CallingConvention = CallingConvention.Cdecl)]
             public static extern IntPtr get_backlinks(ObjectHandle objectHandle, IntPtr property_index, out NativeException nativeException);
@@ -95,6 +96,7 @@ private static class NativeMethods
             public static extern void get_schema(ObjectHandle objectHandle, IntPtr callback, out NativeException ex);
 
 #pragma warning restore SA1121 // Use built-in type alias
+#pragma warning restore IDE0049 // Naming Styles
 #pragma warning restore IDE1006 // Naming Styles
         }
 
@@ -138,9 +140,9 @@ public override bool Equals(object obj)
             return result;
         }
 
-        public ObjKey GetObjKey()
+        public int GetObjHash()
         {
-            var result = NativeMethods.get_obj_key(this, out var nativeException);
+            var result = NativeMethods.get_hashcode(this, out var nativeException);
             nativeException.ThrowIfNecessary();
 
             return result;

Realm/Realm/Handles/SharedRealmHandle.cs

@@ -36,6 +36,7 @@ internal class SharedRealmHandle : RealmHandle
         private static class NativeMethods
         {
 #pragma warning disable IDE1006 // Naming Styles
+#pragma warning disable SA1121 // Use built-in type alias
 
             [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
             public delegate void NotifyRealmCallback(IntPtr stateHandle);
@@ -118,7 +119,7 @@ public static extern IntPtr open_with_sync_async(Configuration configuration, Sy
             public static extern bool refresh(SharedRealmHandle sharedRealm, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "shared_realm_get_table_key", CallingConvention = CallingConvention.Cdecl)]
-            public static extern TableKey get_table_key(SharedRealmHandle sharedRealm, [MarshalAs(UnmanagedType.LPWStr)] string tableName, IntPtr tableNameLength, out NativeException ex);
+            public static extern UInt32 get_table_key(SharedRealmHandle sharedRealm, [MarshalAs(UnmanagedType.LPWStr)] string tableName, IntPtr tableNameLength, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "shared_realm_is_same_instance", CallingConvention = CallingConvention.Cdecl)]
             [return: MarshalAs(UnmanagedType.U1)]
@@ -141,10 +142,10 @@ public static extern IntPtr open_with_sync_async(Configuration configuration, Sy
             public static extern void write_copy(SharedRealmHandle sharedRealm, [MarshalAs(UnmanagedType.LPWStr)] string path, IntPtr path_len, byte[] encryptionKey, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "shared_realm_create_object", CallingConvention = CallingConvention.Cdecl)]
-            public static extern IntPtr create_object(SharedRealmHandle sharedRealm, TableKey table_key, out NativeException ex);
+            public static extern IntPtr create_object(SharedRealmHandle sharedRealm, UInt32 table_key, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "shared_realm_create_object_unique", CallingConvention = CallingConvention.Cdecl)]
-            public static extern IntPtr create_object_unique(SharedRealmHandle sharedRealm, TableKey table_key, PrimitiveValue value,
+            public static extern IntPtr create_object_unique(SharedRealmHandle sharedRealm, UInt32 table_key, PrimitiveValue value,
                                                              [MarshalAs(UnmanagedType.U1)] bool update,
                                                              [MarshalAs(UnmanagedType.U1)] out bool is_new, out NativeException ex);
 
@@ -175,11 +176,12 @@ public static extern void install_callbacks(
             public static extern IntPtr freeze(SharedRealmHandle sharedRealm, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "shared_realm_get_object_for_primary_key", CallingConvention = CallingConvention.Cdecl)]
-            public static extern IntPtr get_object_for_primary_key(SharedRealmHandle realmHandle, TableKey table_key, PrimitiveValue value, out NativeException ex);
+            public static extern IntPtr get_object_for_primary_key(SharedRealmHandle realmHandle, UInt32 table_key, PrimitiveValue value, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "shared_realm_create_results", CallingConvention = CallingConvention.Cdecl)]
-            public static extern IntPtr create_results(SharedRealmHandle sharedRealm, TableKey table_key, out NativeException ex);
+            public static extern IntPtr create_results(SharedRealmHandle sharedRealm, UInt32 table_key, out NativeException ex);
 
+#pragma warning restore SA1121 // Use built-in type alias
 #pragma warning restore IDE1006 // Naming Styles
         }
 
@@ -340,7 +342,7 @@ public TableKey GetTableKey(string tableName)
         {
             var tableKey = NativeMethods.get_table_key(this, tableName, (IntPtr)tableName.Length, out var nativeException);
             nativeException.ThrowIfNecessary();
-            return tableKey;
+            return new TableKey(tableKey);
         }
 
         public bool IsSameInstance(SharedRealmHandle other)
@@ -405,7 +407,7 @@ public RealmSchema GetSchema()
 
         public ObjectHandle CreateObject(TableKey tableKey)
         {
-            var result = NativeMethods.create_object(this, tableKey, out NativeException ex);
+            var result = NativeMethods.create_object(this, tableKey.Value, out NativeException ex);
             ex.ThrowIfNecessary();
             return new ObjectHandle(this, result);
         }
@@ -427,7 +429,7 @@ public ObjectHandle CreateObjectWithPrimaryKey(Property pkProperty, object prima
             };
 
             var (primitiveValue, handles) = pkValue.ToNative();
-            var result = NativeMethods.create_object_unique(this, tableKey, primitiveValue, update, out isNew, out var ex);
+            var result = NativeMethods.create_object_unique(this, tableKey.Value, primitiveValue, update, out isNew, out var ex);
             handles?.Dispose();
             ex.ThrowIfNecessary();
             return new ObjectHandle(this, result);
@@ -448,7 +450,7 @@ public SharedRealmHandle Freeze()
         public bool TryFindObject(TableKey tableKey, in RealmValue id, out ObjectHandle objectHandle)
         {
             var (primitiveValue, handles) = id.ToNative();
-            var result = NativeMethods.get_object_for_primary_key(this, tableKey, primitiveValue, out var ex);
+            var result = NativeMethods.get_object_for_primary_key(this, tableKey.Value, primitiveValue, out var ex);
             handles?.Dispose();
             ex.ThrowIfNecessary();
 
@@ -464,7 +466,7 @@ public bool TryFindObject(TableKey tableKey, in RealmValue id, out ObjectHandle
 
         public ResultsHandle CreateResults(TableKey tableKey)
         {
-            var result = NativeMethods.create_results(this, tableKey, out var nativeException);
+            var result = NativeMethods.create_results(this, tableKey.Value, out var nativeException);
             nativeException.ThrowIfNecessary();
             return new ResultsHandle(this, result);
         }

Realm/Realm/Handles/SortDescriptorHandle.cs

@@ -26,14 +26,18 @@ internal class SortDescriptorHandle : RealmHandle
     {
         private static class NativeMethods
         {
+#pragma warning disable SA1121 // Use built-in type alias
+
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "sort_descriptor_destroy", CallingConvention = CallingConvention.Cdecl)]
             public static extern void destroy(IntPtr queryHandle);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "sort_descriptor_add_clause", CallingConvention = CallingConvention.Cdecl)]
-            public static extern void add_clause(SortDescriptorHandle descriptor, TableKey table_key, SharedRealmHandle realm,
+            public static extern void add_clause(SortDescriptorHandle descriptor, UInt32 table_key, SharedRealmHandle realm,
                 [MarshalAs(UnmanagedType.LPArray), In] IntPtr[] property_index_chain, IntPtr column_keys_count,
                 [MarshalAs(UnmanagedType.U1)] bool ascending, [MarshalAs(UnmanagedType.U1)] bool replacing,
                 out NativeException ex);
+
+#pragma warning restore SA1121 // Use built-in type alias
         }
 
         public SortDescriptorHandle(RealmHandle root, IntPtr handle) : base(root, handle)
@@ -42,7 +46,7 @@ public SortDescriptorHandle(RealmHandle root, IntPtr handle) : base(root, handle
 
         public void AddClause(SharedRealmHandle realm, TableKey tableKey, IntPtr[] propertyIndexChain, bool ascending, bool replacing)
         {
-            NativeMethods.add_clause(this, tableKey, realm, propertyIndexChain, (IntPtr)propertyIndexChain.Length, ascending, replacing, out var nativeException);
+            NativeMethods.add_clause(this, tableKey.Value, realm, propertyIndexChain, (IntPtr)propertyIndexChain.Length, ascending, replacing, out var nativeException);
             nativeException.ThrowIfNecessary();
         }
 

Realm/Realm/Native/ObjKey.cs

@@ -17,23 +17,26 @@
 ////////////////////////////////////////////////////////////////////////////
 
 using System;
-using System.Runtime.InteropServices;
 
 namespace Realms.Native
 {
-    [StructLayout(LayoutKind.Sequential)]
     internal struct TableKey : IEquatable<TableKey>
     {
-        private UInt32 value;
+        public readonly UInt32 Value;
 
-        public bool Equals(TableKey other) => value.Equals(other.value);
+        public TableKey(UInt32 value)
+        {
+            Value = value;
+        }
+
+        public bool Equals(TableKey other) => Value.Equals(other.Value);
 
         public override bool Equals(object obj) => obj is TableKey other && Equals(other);
 
-        public override int GetHashCode() => value.GetHashCode();
+        public override int GetHashCode() => Value.GetHashCode();
 
-        public static bool operator ==(TableKey left, TableKey right) => left.value == right.value;
+        public static bool operator ==(TableKey left, TableKey right) => left.Value == right.Value;
 
-        public static bool operator !=(TableKey left, TableKey right) => left.value != right.value;
+        public static bool operator !=(TableKey left, TableKey right) => left.Value != right.Value;
     }
 }

Realm/Realm/Native/TableKey.cs

@@ -241,11 +241,16 @@ extern "C" {
         });
     }
 
-    REALM_EXPORT int64_t object_get_obj_key(const Object& object, NativeException::Marshallable& ex)
+    REALM_EXPORT int32_t object_get_hashcode(const Object& object, NativeException::Marshallable& ex)
     {
         return handle_errors(ex, [&]() {
-            // ObjKey is incompatible with C, so we return just the value.
-            return object.obj().get_key().value;
+            int32_t table_key_value = static_cast<int32_t>(object.obj().get_table()->get_key().value);
+            int32_t object_key_value = static_cast<int32_t>(object.obj().get_key().value);
+
+            int32_t hashCode = -986587137;
+            hashCode = (hashCode * -1521134295) + table_key_value;
+            hashCode = (hashCode * -1521134295) + object_key_value;
+            return hashCode;
         });
     }