Strict concurrency

Package.swift

@@ -2,6 +2,12 @@
 import PackageDescription
 import CompilerPluginSupport
 
+#if swift(>=5.10)
+let settings = [ .enableExperimentalFeature("StrictConcurrency") ]
+#else
+let settings = [ SwiftSetting ]()
+#endif
+
 let package = Package(
   name: "ManagedModels",
 
@@ -13,8 +19,12 @@ let package = Package(
     .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0")
   ],
   targets: [
-    .target(name: "ManagedModels", dependencies: [ "ManagedModelMacros" ]),
-
+    .target(
+      name: "ManagedModels",
+      dependencies: [ "ManagedModelMacros" ],
+      swiftSettings: settings
+    ),
+
     .macro(
       name: "ManagedModelMacros",
       dependencies: [

Sources/ManagedModels/Container/ModelConfiguration.swift

@@ -3,9 +3,9 @@
 //  Copyright © 2023 ZeeZide GmbH.
 //
 
-import CoreData
+@preconcurrency import CoreData
 
-public struct ModelConfiguration: Hashable {
+public struct ModelConfiguration: Hashable, Sendable {
   // TBD: Some of those are `let` in SwiftData
 
   public var path                        : String
@@ -83,7 +83,7 @@ extension ModelConfiguration: Identifiable {
 
 public extension ModelConfiguration {
 
-  struct GroupContainer: Hashable {
+  struct GroupContainer: Hashable, Sendable {
     enum Value: Hashable {
       case automatic, none
       case identifier(String)
@@ -100,7 +100,7 @@ public extension ModelConfiguration {
 
 public extension ModelConfiguration {
 
-  struct CloudKitDatabase: Hashable {
+  struct CloudKitDatabase: Hashable, Sendable {
     enum Value: Hashable {
       case automatic, none
       case `private`(String)

Sources/ManagedModels/PersistentModel/PropertyMetadata.swift

@@ -13,7 +13,7 @@ public extension NSManagedObjectModel {
    * All (code defined) properties of the ``NSManagedObjectModel`` are stored
    * in the `schemaMetadata` static property.
    */
-  struct PropertyMetadata {
+	struct PropertyMetadata: @unchecked Sendable {
 
     /// The name of the property instance variable, e.g. `street`.
     public let name         : String

Sources/ManagedModels/Schema/AttributeOption.swift

@@ -7,7 +7,7 @@ import class Foundation.ValueTransformer
 
 extension NSAttributeDescription {
 
-  public struct Option: Equatable {
+  public struct Option: Equatable, Sendable {
 
     let value : Value
 
@@ -39,7 +39,7 @@ extension NSAttributeDescription {
 
 extension NSAttributeDescription.Option {
 
-  enum Value {
+  enum Value: Sendable {
     case unique, externalStorage, preserveValueOnDeletion, ephemeral, spotlight
     case transformableByType(ValueTransformer.Type)
     case transformableByName(String)

Sources/ManagedModels/Schema/RelationshipOption.swift

@@ -7,9 +7,9 @@ import CoreData
 
 public extension NSRelationshipDescription {
 
-  struct Option: Equatable {
+  struct Option: Equatable, Sendable {
 
-    enum Value {
+    enum Value: Sendable {
       case unique
     }
     let value : Value

Sources/ManagedModels/SchemaCompatibility/CoreDataPrimitiveValue.swift

@@ -6,7 +6,7 @@
 import CoreData
 
 public extension CoreData.NSAttributeDescription {
-  struct TypeConfiguration {
+  struct TypeConfiguration: Sendable {
     let attributeType           : NSAttributeType
     let isOptional              : Bool
     let attributeValueClassName : String?

Sources/ManagedModels/SchemaCompatibility/NSManagedObjectModel+Data.swift

@@ -37,8 +37,14 @@ public extension NSManagedObjectModel {
 // MARK: - Cached ManagedObjectModels
 
 private let lock = NSLock()
+#if swift(>=5.10)
+nonisolated(unsafe) 
 private var map = [ Set<ObjectIdentifier> : NSManagedObjectModel ]()
-private let sharedBuilder = SchemaBuilder()
+nonisolated(unsafe) private let sharedBuilder = SchemaBuilder()
+#else // 5.9: nonisolated(unsafe) not available, nonisolated nor working on var
+private var map = [ Set<ObjectIdentifier> : NSManagedObjectModel ]()
+nonisolated private let sharedBuilder = SchemaBuilder()
+#endif
 
 public extension NSManagedObjectModel {
 

Sources/ManagedModels/SchemaCompatibility/NSPropertyDescription+Data.swift

@@ -3,29 +3,44 @@
 //  Copyright © 2023 ZeeZide GmbH.
 //
 
-private var _propertyIsUniqueAssociatedKey: UInt8 = 42
-
 extension NSPropertyDescription {
-
+  private struct AssociatedKeys {
+    #if swift(>=5.10)
+    nonisolated(unsafe) static var propertyIsUniqueAssociatedKey: Void? = nil
+    #else // 5.9: nonisolated(unsafe) not available
+    static var propertyIsUniqueAssociatedKey: Void? = nil
+    #endif
+  }
+
   public internal(set) var isUnique: Bool {
     // Note: isUnique is only used during schema construction!
     set {
       if newValue {
-        objc_setAssociatedObject(self, &_propertyIsUniqueAssociatedKey,
-                                 type(of: self), .OBJC_ASSOCIATION_ASSIGN)
+        objc_setAssociatedObject(
+          self, &AssociatedKeys.propertyIsUniqueAssociatedKey,
+          type(of: self), // Just used as a flag, type won't go away
+          .OBJC_ASSOCIATION_ASSIGN
+        )
       }
       else {
-        objc_setAssociatedObject(self, &_propertyIsUniqueAssociatedKey, nil, .OBJC_ASSOCIATION_RETAIN)
+        objc_setAssociatedObject(
+          self, &AssociatedKeys.propertyIsUniqueAssociatedKey, 
+          nil, // clear // clear flag
+          .OBJC_ASSOCIATION_ASSIGN
+        )
       }
-      #if false // do we need this? The entity might not yet be setup?
+#if false // do we need this? The entity might not yet be setup?
       guard !entity.isPropertyUnique(self) else { return }
       entity.uniquenessConstraints.append( [ self ])
-      #endif
+#endif
     }
     get {
-      objc_getAssociatedObject(self, &_propertyIsUniqueAssociatedKey) != nil
-        ? true
-        : entity.isPropertyUnique(self)
+      objc_getAssociatedObject(
+        self,
+        &AssociatedKeys.propertyIsUniqueAssociatedKey
+      ) != nil
+      ? true
+      : entity.isPropertyUnique(self)
     }
   }
 }

Sources/ManagedModels/SchemaCompatibility/NSRelationshipDescription+Data.swift

@@ -13,9 +13,9 @@ extension CoreData.NSRelationshipDescription {
 extension CoreData.NSRelationshipDescription: SchemaProperty {}
 
 public extension CoreData.NSRelationshipDescription {
-
+  
   @inlinable var isToOneRelationship : Bool { !isToMany }
-
+  
   @inlinable var isAttribute    : Bool { return false }
   @inlinable var isRelationship : Bool { return true  }
 
@@ -109,7 +109,7 @@ extension CoreData.NSRelationshipDescription {
 // MARK: - Initializer
 
 public extension CoreData.NSRelationshipDescription {
-
+  
   // Note: This matches what the `Relationship` macro takes.
   convenience init(_ options: Option..., deleteRule: NSDeleteRule = .nullify,
                    minimumModelCount: Int? = 0, maximumModelCount: Int? = 0,
@@ -122,16 +122,16 @@ public extension CoreData.NSRelationshipDescription {
     precondition(minimumModelCount ?? 0 >= 0)
     precondition(maximumModelCount ?? 0 >= 0)
     self.init()
-
+    
     self.name                = name ?? ""
     self.valueType           = valueType
     self.renamingIdentifier  = originalName ?? ""
     self.versionHashModifier = hashModifier
     self.deleteRule          = deleteRule
     self.inverseKeyPath      = inverse
-
+    
     if options.contains(.unique) { isUnique = true }
-
+    
     if let minimumModelCount { self.minCount = minimumModelCount }
     if let maximumModelCount {
       self.maxCount = maximumModelCount
@@ -140,7 +140,7 @@ public extension CoreData.NSRelationshipDescription {
       if valueType is any RelationshipCollection.Type {
         self.maxCount = 0
       }
-      else if valueType is NSOrderedSet.Type || 
+      else if valueType is NSOrderedSet.Type ||
               valueType is Optional<NSOrderedSet>.Type
       {
         self.maxCount = 0
@@ -155,10 +155,8 @@ public extension CoreData.NSRelationshipDescription {
 
 // MARK: - Storage
 
-private var _relationshipInfoAssociatedKey: UInt8 = 72
-
 extension CoreData.NSRelationshipDescription {
-
+  
   func internalCopy() -> Self {
     guard let copy = self.copy() as? Self else {
       fatalError("Could not copy relationship \(self)")
@@ -187,7 +185,7 @@ extension CoreData.NSRelationshipDescription {
     var inverseName         : String?
     var destination         : String?
     var isToOneRelationship : Bool?
-
+    
     override func copy() -> Any { internalCopy() }
 
     func internalCopy() -> MacroInfo {
@@ -201,11 +199,18 @@ extension CoreData.NSRelationshipDescription {
       return copy
     }
   }
-
+
+  private struct AssociatedKeys {
+    #if swift(>=5.10)
+    nonisolated(unsafe) static var relationshipInfoAssociatedKey: Void? = nil
+    #else // 5.9: nonisolated(unsafe) not available
+    static var relationshipInfoAssociatedKey: Void? = nil
+    #endif
+  }
+
   var writableRelationshipInfo : MacroInfo {
-    if let info =
-        objc_getAssociatedObject(self, &_relationshipInfoAssociatedKey)
-        as? MacroInfo
+    if let info = objc_getAssociatedObject(
+         self, &AssociatedKeys.relationshipInfoAssociatedKey) as? MacroInfo
     {
       return info
     }
@@ -214,16 +219,19 @@ extension CoreData.NSRelationshipDescription {
     self.relationshipInfo = info
     return info
   }
-
+  
   var relationshipInfo: MacroInfo? {
     // Note: isUnique is only used during schema construction!
     set {
-      objc_setAssociatedObject(self, &_relationshipInfoAssociatedKey,
-                               newValue, .OBJC_ASSOCIATION_RETAIN)
+      objc_setAssociatedObject(
+        self, &AssociatedKeys.relationshipInfoAssociatedKey,
+        newValue, .OBJC_ASSOCIATION_RETAIN
+      )
     }
     get {
-      objc_getAssociatedObject(self, &_relationshipInfoAssociatedKey)
-      as? MacroInfo
+      objc_getAssociatedObject(
+        self, &AssociatedKeys.relationshipInfoAssociatedKey
+      ) as? MacroInfo
     }
   }
 }

Sources/ManagedModels/SwiftUI/ModelContainer+SwiftUI.swift

@@ -25,6 +25,7 @@ public extension View {
     self.modelContext(container.viewContext)
   }
 
+  @MainActor
   @ViewBuilder
   func modelContainer(
     for    modelTypes : [ any PersistentModel.Type ],
@@ -48,6 +49,7 @@ public extension View {
     }
   }
 
+  @MainActor
   @inlinable
   func modelContainer(
     for     modelType : any PersistentModel.Type,
@@ -73,6 +75,7 @@ public extension Scene {
     self.modelContext(container.viewContext)
   }
 
+  @MainActor
   @SceneBuilder
   func modelContainer(
     for    modelTypes : [ any PersistentModel.Type ],
@@ -92,6 +95,7 @@ public extension Scene {
     self.modelContainer(try! result.get())
   }
 
+  @MainActor
   @inlinable
   func modelContainer(
     for     modelType : any PersistentModel.Type,
@@ -113,8 +117,10 @@ public extension Scene {
 // MARK: - Primitive
 
 // Note: The docs say that a container is only ever created once! So cache it.
+@MainActor
 private var modelToContainer = [ ObjectIdentifier: NSPersistentContainer ]()
 
+@MainActor
 private func makeModelContainer(
   for    modelTypes : [ any PersistentModel.Type ],
   inMemory          : Bool = false,