Make most of MainThreadOperation @MainActor.

Account/Sources/Account/CloudKit/CloudKitAccountDelegate.swift

@@ -120,10 +120,12 @@ final class CloudKitAccountDelegate: AccountDelegate {
 	func refreshArticleStatus(for account: Account, completion: @escaping ((Result<Void, Error>) -> Void)) {
 		let op = CloudKitReceiveStatusOperation(articlesZone: articlesZone)
 		op.completionBlock = { mainThreadOperation in
-			if mainThreadOperation.isCanceled {
-				completion(.failure(CloudKitAccountDelegateError.unknown))
-			} else {
-				completion(.success(()))
+			Task { @MainActor in
+				if mainThreadOperation.isCanceled {
+					completion(.failure(CloudKitAccountDelegateError.unknown))
+				} else {
+					completion(.success(()))
+				}
 			}
 		}
 		Task { @MainActor in
@@ -775,10 +777,12 @@ private extension CloudKitAccountDelegate {
 											 showProgress: showProgress,
 											 database: database)
 		op.completionBlock = { mainThreadOperaion in
-			if mainThreadOperaion.isCanceled {
-				completion(.failure(CloudKitAccountDelegateError.unknown))
-			} else {
-				completion(.success(()))
+			Task { @MainActor in
+				if mainThreadOperaion.isCanceled {
+					completion(.failure(CloudKitAccountDelegateError.unknown))
+				} else {
+					completion(.success(()))
+				}
 			}
 		}
 		Task { @MainActor in

Core/Sources/Core/MainThreadOperation.swift

@@ -18,12 +18,12 @@ import Foundation
 public protocol MainThreadOperation: AnyObject {
 
 	// These three properties are set by MainThreadOperationQueue. Don’t set them.
-	var isCanceled: Bool { get set } // Check this at appropriate times in case the operation has been canceled.
-	var id: Int? { get set }
-	var operationDelegate: MainThreadOperationDelegate? { get set } // Make this weak.
+	@MainActor var isCanceled: Bool { get set } // Check this at appropriate times in case the operation has been canceled.
+	@MainActor var id: Int? { get set }
+	@MainActor var operationDelegate: MainThreadOperationDelegate? { get set } // Make this weak.
 
 	/// Name may be useful for debugging. Unused otherwise.
-	var name: String? { get set }
+	@MainActor var name: String? { get set }
 
 	typealias MainThreadOperationCompletionBlock = (MainThreadOperation) -> Void
 
@@ -50,7 +50,7 @@ public protocol MainThreadOperation: AnyObject {
 	/// When this is called, you don’t need to check isCanceled:
 	/// it’s guaranteed to not be canceled. However, if you run code
 	/// in another thread, you should check isCanceled in that code.
-	func run()
+	@MainActor func run()
 
 	/// Cancel this operation.
 	///
@@ -59,7 +59,7 @@ public protocol MainThreadOperation: AnyObject {
 	///
 	/// This function has a default implementation. It’s super-rare
 	/// to need to provide your own.
-	func cancel()
+	@MainActor func cancel()
 
 	/// Make this operation dependent on an other operation.
 	///
@@ -70,7 +70,7 @@ public protocol MainThreadOperation: AnyObject {
 	///
 	/// This function has a default implementation. It’s super-rare
 	/// to need to provide your own.
-	func addDependency(_ parentOperation: MainThreadOperation)
+	@MainActor func addDependency(_ parentOperation: MainThreadOperation)
 }
 
 public extension MainThreadOperation {