First pass at strict concurrency checking

Packages/Duckable/Sources/Duckable/API.swift

@@ -7,6 +7,7 @@
 
 import UIKit
 
+@MainActor
 public protocol DuckableViewController: UIViewController {
     func duckableViewControllerShouldDuck() -> DuckAttemptAction
     

Packages/Pachyderm/Sources/Pachyderm/Model/SearchOperatorType.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-public enum SearchOperatorType: String, CaseIterable, Equatable {
+public enum SearchOperatorType: String, CaseIterable, Equatable, Sendable {
     case has
     case `is`
     case language

Packages/Pachyderm/Sources/Pachyderm/Model/StatusEdit.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-public struct StatusEdit: Decodable {
+public struct StatusEdit: Decodable, Sendable {
     public let content: String
     public let spoilerText: String
     public let sensitive: Bool
@@ -28,10 +28,10 @@ public struct StatusEdit: Decodable {
         case emojis
     }
     
-    public struct Poll: Decodable {
+    public struct Poll: Decodable, Sendable {
         public let options: [Option]
         
-        public struct Option: Decodable {
+        public struct Option: Decodable, Sendable {
             public let title: String
         }
     }

Packages/TuskerPreferences/Sources/TuskerPreferences/PostVisibility.swift

@@ -8,7 +8,7 @@
 import Foundation
 import Pachyderm
 
-public enum PostVisibility: Codable, Hashable, CaseIterable {
+public enum PostVisibility: Codable, Hashable, CaseIterable, Sendable {
     case serverDefault
     case visibility(Visibility)
     
@@ -59,6 +59,7 @@ public enum ReplyVisibility: Codable, Hashable, CaseIterable {
     
     public static var allCases: [ReplyVisibility] = [.sameAsPost] + Visibility.allCases.map { .visibility($0) }
     
+    @MainActor
     public func resolved(withServerDefault serverDefault: Visibility?) -> Visibility {
         switch self {
         case .sameAsPost:

Packages/TuskerPreferences/Sources/TuskerPreferences/Preferences.swift

@@ -12,12 +12,14 @@ import Combine
 
 public final class Preferences: Codable, ObservableObject {
 
+    @MainActor
     public static var shared: Preferences = load()
     
     private static var documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
     private static var appGroupDirectory = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.space.vaccor.Tusker")!
     private static var archiveURL = appGroupDirectory.appendingPathComponent("preferences").appendingPathExtension("plist")
     
+    @MainActor
     public static func save() {
         let encoder = PropertyListEncoder()
         let data = try? encoder.encode(shared)
@@ -33,6 +35,7 @@ public final class Preferences: Codable, ObservableObject {
         return Preferences()
     }
     
+    @MainActor
     public static func migrate(from url: URL) -> Result<Void, any Error> {
         do {
             try? FileManager.default.removeItem(at: archiveURL)

Packages/TuskerPreferences/Sources/TuskerPreferences/StatusSwipeAction.swift

@@ -9,7 +9,7 @@
 import UIKit
 import Pachyderm
 
-public enum StatusSwipeAction: String, Codable, Hashable, CaseIterable {
+public enum StatusSwipeAction: String, Codable, Hashable, CaseIterable, Sendable {
     case reply
     case favorite
     case reblog

ShareExtension/SwitchAccountContainerView.swift

@@ -54,6 +54,7 @@ struct SwitchAccountContainerView: View {
     }
 }
 
+@MainActor
 private struct AccountButtonLabel: View {
     static let urlSession = URLSession(configuration: .ephemeral)
     

Tusker.xcodeproj/project.pbxproj

@@ -2392,6 +2392,7 @@
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				SWIFT_OPTIMIZE_OBJECT_LIFETIME = YES;
+				SWIFT_STRICT_CONCURRENCY = complete;
 				VALIDATE_PRODUCT = YES;
 			};
 			name = Dist;
@@ -2636,6 +2637,7 @@
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_OPTIMIZE_OBJECT_LIFETIME = YES;
+				SWIFT_STRICT_CONCURRENCY = complete;
 			};
 			name = Debug;
 		};
@@ -2694,6 +2696,7 @@
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				SWIFT_OPTIMIZE_OBJECT_LIFETIME = YES;
+				SWIFT_STRICT_CONCURRENCY = complete;
 				VALIDATE_PRODUCT = YES;
 			};
 			name = Release;

Tusker/API/MastodonController.swift

@@ -18,11 +18,9 @@ private let oauthScopes = [Scope.read, .write, .follow]
 
 class MastodonController: ObservableObject {
 
+    @MainActor
     static private(set) var all = [UserAccountInfo: MastodonController]()
     
-    @available(*, message: "do something less dumb")
-    static var first: MastodonController { all.first!.value }
-    
     @MainActor
     static func getForAccount(_ account: UserAccountInfo) -> MastodonController {
         if let controller = all[account] {
@@ -34,10 +32,12 @@ class MastodonController: ObservableObject {
         }
     }
     
+    @MainActor
     static func removeForAccount(_ account: UserAccountInfo) {
         all.removeValue(forKey: account)
     }
     
+    @MainActor
     static func resetAll() {
         all = [:]
     }
@@ -544,6 +544,7 @@ class MastodonController: ObservableObject {
         filters = (try? persistentContainer.viewContext.fetch(FilterMO.fetchRequest())) ?? []
     }
     
+    @MainActor
     func createDraft(inReplyToID: String? = nil, mentioningAcct: String? = nil, text: String? = nil) -> Draft {
         var acctsToMention = [String]()
         

Tusker/AppDelegate.swift

@@ -19,7 +19,7 @@ typealias Preferences = TuskerPreferences.Preferences
 let stateRestorationLogger = Logger(subsystem: Bundle.main.bundleIdentifier!, category: "StateRestoration")
 private let logger = Logger(subsystem: Bundle.main.bundleIdentifier!, category: "AppDelegate")
 
-@UIApplicationMain
+@main
 class AppDelegate: UIResponder, UIApplicationDelegate {
     
     func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

Tusker/Caching/ImageCache.swift

@@ -8,11 +8,15 @@
 
 import UIKit
 
-class ImageCache {
+final class ImageCache: @unchecked Sendable {
     
+    @MainActor
     static let avatars = ImageCache(name: "Avatars", memoryExpiry: .seconds(60 * 60), diskExpiry: .seconds(60 * 60 * 24 * 7), desiredSize: CGSize(width: 50, height: 50))
+    @MainActor
     static let headers = ImageCache(name: "Headers", memoryExpiry: .seconds(60 * 5), diskExpiry: .seconds(60 * 60 * 24 * 7))
+    @MainActor
     static let attachments = ImageCache(name: "Attachments", memoryExpiry: .seconds(60 * 2))
+    @MainActor
     static let emojis = ImageCache(name: "Emojis", memoryExpiry: .seconds(60 * 5), diskExpiry: .seconds(60 * 60 * 24 * 7))
     
     #if DEBUG
@@ -24,6 +28,7 @@ class ImageCache {
     private let cache: ImageDataCache
     private let desiredPixelSize: CGSize?
     
+    @MainActor
     init(name: String, memoryExpiry: CacheExpiry, diskExpiry: CacheExpiry? = nil, desiredSize: CGSize? = nil) {
         // todo: might not always want to use UIScreen.main for this, e.g. Catalyst?
         let pixelSize = desiredSize?.applying(.init(scaleX: UIScreen.main.scale, y: UIScreen.main.scale))
@@ -31,7 +36,7 @@ class ImageCache {
         self.cache = ImageDataCache(name: name, memoryExpiry: memoryExpiry, diskExpiry: diskExpiry, storeOriginalDataInMemory: diskExpiry == nil, desiredPixelSize: pixelSize)
     }
     
-    func get(_ url: URL, loadOriginal: Bool = false, completion: ((Data?, UIImage?) -> Void)?) -> Request? {
+    func get(_ url: URL, loadOriginal: Bool = false, completion: (@Sendable (Data?, UIImage?) -> Void)?) -> Request? {
         if !ImageCache.disableCaching,
            let entry = try? cache.get(url.absoluteString, loadOriginal: loadOriginal) {
             completion?(entry.data, entry.image)
@@ -41,7 +46,7 @@ class ImageCache {
         }
     }
     
-    func getFromSource(_ url: URL, completion: ((Data?, UIImage?) -> Void)?) -> Request? {
+    func getFromSource(_ url: URL, completion: (@Sendable (Data?, UIImage?) -> Void)?) -> Request? {
         return Task.detached(priority: .userInitiated) {
             let result = await self.fetch(url: url)
             switch result {

Tusker/Extensions/MainActor+Unsafe.swift

@@ -9,7 +9,7 @@
 import Foundation
 
 /*
- Copied from https://github.com/ChimeHQ/ConcurrencyPlus/blob/fe3b3fd5436b196d8c5211ab2cc4b69fc35524fe/Sources/ConcurrencyPlus/MainActor%2BUnsafe.swift
+ Copied from https://github.com/ChimeHQ/ConcurrencyPlus/blob/daf69ed837fa04d4ba666f5a99378cf1815f0dab/Sources/ConcurrencyPlus/MainActor%2BUnsafe.swift
  
  Copyright (c) 2022, Chime
  All rights reserved.
@@ -46,10 +46,14 @@ public extension MainActor {
     /// This function exists to work around libraries with incorrect/inconsistent concurrency annotations. You should be **extremely** careful when using it, and only as a last resort.
     ///
     /// It will crash if run on any non-main thread.
-    @MainActor(unsafe)
+    @_unavailableFromAsync
     static func runUnsafely<T>(_ body: @MainActor () throws -> T) rethrows -> T {
-        dispatchPrecondition(condition: .onQueue(.main))
+        if #available(macOS 14.0, iOS 17.0, watchOS 10.0, tvOS 17.0, *) {
+            return try MainActor.assumeIsolated(body)
+        }
 
-        return try body()
+        dispatchPrecondition(condition: .onQueue(.main))
-    }
+        return try withoutActuallyEscaping(body) { fn in
+            try unsafeBitCast(fn, to: (() throws -> T).self)()
         }
+    }}

Tusker/Extensions/PKDrawing+Render.swift

@@ -11,7 +11,9 @@ import PencilKit
 
 extension PKDrawing {
     
-    func imageInLightMode(from rect: CGRect, scale: CGFloat = UIScreen.main.scale) -> UIImage {
+    @MainActor
+    func imageInLightMode(from rect: CGRect, scale: CGFloat? = nil) -> UIImage {
+        let scale = scale ?? UIScreen.main.scale
         let lightTraitCollection = UITraitCollection(userInterfaceStyle: .light)
         var drawingImage: UIImage!
         lightTraitCollection.performAsCurrent {

Tusker/Extensions/View+AppListStyle.swift

@@ -10,6 +10,7 @@ import SwiftUI
 import Combine
 
 extension View {
+    @MainActor
     @ViewBuilder
     func appGroupedListBackground(container: UIAppearanceContainer.Type, applyBackground: Bool = true) -> some View {
         if #available(iOS 16.0, *) {

Tusker/MenuController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 struct MenuController {
     
     static let composeCommand: UIKeyCommand = {

Tusker/MultiThreadDictionary.swift

@@ -12,7 +12,7 @@ import os
 // once we target iOS 16, replace uses of this with OSAllocatedUnfairLock<[Key: Value]>
 // to make the lock semantics more clear
 @available(iOS, obsoleted: 16.0)
-class MultiThreadDictionary<Key: Hashable & Sendable, Value: Sendable> {
+final class MultiThreadDictionary<Key: Hashable & Sendable, Value: Sendable>: @unchecked Sendable {
     private let lock: any Lock<[Key: Value]>
     
     init() {

Tusker/Preferences/StatusSwipeActions.swift

@@ -11,6 +11,7 @@ import Pachyderm
 import TuskerPreferences
 
 extension StatusSwipeAction {
+    @MainActor
     func createAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction? {
         switch self {
         case .reply:
@@ -40,6 +41,7 @@ protocol StatusSwipeActionContainer: UIView {
     func performReplyAction()
 }
 
+@MainActor
 private func createReplyAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction? {
     guard container.mastodonController.loggedIn else {
         return nil
@@ -53,6 +55,7 @@ private func createReplyAction(status: StatusMO, container: StatusSwipeActionCon
     return action
 }
 
+@MainActor
 private func createFavoriteAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction? {
     guard container.mastodonController.loggedIn else {
         return nil
@@ -69,6 +72,7 @@ private func createFavoriteAction(status: StatusMO, container: StatusSwipeAction
     return action
 }
 
+@MainActor
 private func createReblogAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction? {
     guard container.mastodonController.loggedIn,
           container.canReblog else {
@@ -86,6 +90,7 @@ private func createReblogAction(status: StatusMO, container: StatusSwipeActionCo
     return action
 }
 
+@MainActor
 private func createShareAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction {
     let action = UIContextualAction(style: .normal, title: "Share") { [unowned container] _, _, completion in
         MainActor.runUnsafely {
@@ -100,6 +105,7 @@ private func createShareAction(status: StatusMO, container: StatusSwipeActionCon
     return action
 }
 
+@MainActor
 private func createBookmarkAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction? {
     guard container.mastodonController.loggedIn else {
         return nil
@@ -124,11 +130,10 @@ private func createBookmarkAction(status: StatusMO, container: StatusSwipeAction
     return action
 }
 
+@MainActor
 private func createOpenInSafariAction(status: StatusMO, container: StatusSwipeActionContainer) -> UIContextualAction {
     let action = UIContextualAction(style: .normal, title: "Open in Safari") { [unowned container] _, _, completion in
-        MainActor.runUnsafely {
         container.navigationDelegate.selected(url: status.url!, allowUniversalLinks: false)
-        }
         completion(true)
     }
     action.image = UIImage(systemName: "safari")

Tusker/SavedDataManager.swift

@@ -10,10 +10,14 @@ import Foundation
 import Pachyderm
 import CoreData
 
+// TODO: remove this class eventually
 class SavedDataManager: Codable {
+    @MainActor
     private static var documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
+    @MainActor
     private static var archiveURL = SavedDataManager.documentsDirectory.appendingPathComponent("saved_data").appendingPathExtension("plist")
     
+    @MainActor
     static func load() -> SavedDataManager? {
         let decoder = PropertyListDecoder()
         if let data = try? Data(contentsOf: archiveURL),
@@ -23,6 +27,7 @@ class SavedDataManager: Codable {
         return nil
     }
     
+    @MainActor
     static func destroy() throws {
         try FileManager.default.removeItem(at: archiveURL)
     }
@@ -39,6 +44,7 @@ class SavedDataManager: Codable {
         return s
     }
     
+    @MainActor
     private func save() {
         let encoder = PropertyListEncoder()
         let data = try? encoder.encode(self)
@@ -46,8 +52,6 @@ class SavedDataManager: Codable {
     }
     
     func migrateToCoreData(accountID: String, context: NSManagedObjectContext) throws {
-        var changed = false
-        
         if let hashtags = savedHashtags[accountID] {
             let objects: [[String: Any]] = hashtags.map {
                 ["url": $0.url, "name": $0.name]
@@ -55,7 +59,6 @@ class SavedDataManager: Codable {
             let hashtagsReq = NSBatchInsertRequest(entity: SavedHashtag.entity(), objects: objects)
             try context.execute(hashtagsReq)
             savedHashtags.removeValue(forKey: accountID)
-            changed = true
         }
         
         if let instances = savedInstances[accountID] {
@@ -65,11 +68,6 @@ class SavedDataManager: Codable {
             let instancesReq = NSBatchInsertRequest(entity: SavedInstance.entity(), objects: objects)
             try context.execute(instancesReq)
             savedInstances.removeValue(forKey: accountID)
-            changed = true
-        }
-        
-        if changed {
-            save()
         }
     }
 }

Tusker/Scenes/TuskerSceneDelegate.swift

@@ -9,6 +9,7 @@
 import UIKit
 import Sentry
 
+@MainActor
 protocol TuskerSceneDelegate: UISceneDelegate {
     var window: UIWindow? { get }
     var rootViewController: TuskerRootViewController? { get }

Tusker/Screens/Compose/ComposeDrawingViewController.swift

@@ -9,6 +9,7 @@
 import UIKit
 import PencilKit
 
+@MainActor
 protocol ComposeDrawingViewControllerDelegate: AnyObject {
     func composeDrawingViewControllerClose(_ drawingController: ComposeDrawingViewController)
     func composeDrawingViewController(_ drawingController: ComposeDrawingViewController, saveDrawing drawing: PKDrawing)

Tusker/Screens/Compose/ComposeHostingController.swift

@@ -16,6 +16,7 @@ import Pachyderm
 import CoreData
 import Duckable
 
+@MainActor
 protocol ComposeHostingControllerDelegate: AnyObject {
     func dismissCompose(mode: DismissMode) -> Bool
 }

Tusker/Screens/Conversation/ConversationViewController.swift

@@ -216,7 +216,7 @@ class ConversationViewController: UIViewController {
         state = .loading(indicator)
         
         let effectiveURL: String
-        class RedirectBlocker: NSObject, URLSessionTaskDelegate {
+        final class RedirectBlocker: NSObject, URLSessionTaskDelegate, Sendable {
             func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: @escaping (URLRequest?) -> Void) {
                 completionHandler(nil)
             }

Tusker/Screens/Crash Reporter/IssueReporterViewController.swift

@@ -166,7 +166,8 @@ class IssueReporterViewController: UIViewController {
 }
 
 extension IssueReporterViewController: MFMailComposeViewControllerDelegate {
-    func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
+    nonisolated func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
+        MainActor.runUnsafely {
             controller.dismiss(animated: true) {
                 if result == .cancelled {
                     // don't dismiss ourself, to allowe the user to send the report a different way
@@ -177,3 +178,4 @@ extension IssueReporterViewController: MFMailComposeViewControllerDelegate {
             }
         }
     }
+}

Tusker/Screens/Fast Account Switcher/FastAccountSwitcherViewController.swift

@@ -9,6 +9,7 @@
 import UIKit
 import UserAccounts
 
+@MainActor
 protocol FastAccountSwitcherViewControllerDelegate: AnyObject {
     func fastAccountSwitcherAddToViewHierarchy(_ fastAccountSwitcher: FastAccountSwitcherViewController)
     /// - Parameter point: In the coordinate space of the view to which the pan gesture recognizer is attached.

Tusker/Screens/Large Image/GalleryFallbackViewController.swift

@@ -57,12 +57,14 @@ class GalleryFallbackViewController: QLPreviewController {
 }
 
 extension GalleryFallbackViewController: QLPreviewControllerDataSource {
-    func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
+    nonisolated func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
         return 1
     }
     
-    func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
+    nonisolated func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
-        return previewItem
+        return MainActor.runUnsafely {
+            previewItem
+        }
     }
 }
 

Tusker/Screens/Large Image/LargeImageContentView.swift

@@ -12,6 +12,7 @@ import Pachyderm
 @preconcurrency import VisionKit
 import TuskerComponents
 
+@MainActor
 protocol LargeImageContentView: UIView {
     var animationImage: UIImage? { get }
     var activityItemsForSharing: [Any] { get }

Tusker/Screens/Large Image/Transitions/LargeImageExpandAnimationController.swift

@@ -9,6 +9,7 @@
 import UIKit
 import TuskerComponents
 
+@MainActor
 protocol LargeImageAnimatableViewController: UIViewController {
     var animationSourceView: UIImageView? { get }
     var largeImageController: LargeImageViewController? { get }

Tusker/Screens/Main/AccountSwitchingContainerViewController.swift

@@ -11,6 +11,7 @@ import ScreenCorners
 import UserAccounts
 import ComposeUI
 
+@MainActor
 protocol AccountSwitchableViewController: TuskerRootViewController {
     var isFastAccountSwitcherActive: Bool { get }
 }

Tusker/Screens/Main/MainSidebarViewController.swift

@@ -10,6 +10,7 @@ import UIKit
 import Pachyderm
 import Combine
 
+@MainActor
 protocol MainSidebarViewControllerDelegate: AnyObject {
     func sidebarRequestPresentCompose(_ sidebarViewController: MainSidebarViewController)
     func sidebar(_ sidebarViewController: MainSidebarViewController, didSelectItem item: MainSidebarViewController.Item)

Tusker/Screens/Main/MainSplitViewController.swift

@@ -481,6 +481,7 @@ extension MainSplitViewController: MainSidebarViewControllerDelegate {
 }
 
 fileprivate extension MainSidebarViewController.Item {
+    @MainActor
     func createRootViewController(_ mastodonController: MastodonController) -> UIViewController? {
         switch self {
         case let .tab(tab):

Tusker/Screens/Main/MainTabBarViewController.swift

@@ -216,6 +216,7 @@ extension MainTabBarViewController {
         case explore
         case myProfile
         
+        @MainActor
         func createViewController(_ mastodonController: MastodonController) -> UIViewController {
             switch self {
             case .timelines:

Tusker/Screens/Main/TuskerRootViewController.swift

@@ -83,6 +83,7 @@ enum TuskerRoute {
 //    case myProfile
 //}
 //
+@MainActor
 protocol NavigationControllerProtocol: UIViewController {
     var viewControllers: [UIViewController] { get set }
     var topViewController: UIViewController? { get }

Tusker/Screens/Onboarding/InstanceSelectorTableViewController.swift

@@ -10,6 +10,7 @@ import UIKit
 import Combine
 import Pachyderm
 
+@MainActor
 protocol InstanceSelectorTableViewControllerDelegate: AnyObject {
     func didSelectInstance(url: URL)
 }

Tusker/Screens/Preferences/WidescreenNavigationPrefsView.swift

@@ -103,6 +103,7 @@ private struct WideCapsule: Shape {
     }
 }
 
+@MainActor
 private protocol NavigationModePreview: UIView {
     init(startAnimation: PassthroughSubject<Void, Never>)
 }
@@ -118,6 +119,7 @@ private struct NavigationModeRepresentable<UIViewType: NavigationModePreview>: U
     }
 }
 
+@MainActor
 private let timingParams = UISpringTimingParameters(mass: 1, stiffness: 70, damping: 16, initialVelocity: .zero)
 
 private final class StackNavigationPreview: UIView, NavigationModePreview {

Tusker/Screens/Search/SearchResultsViewController.swift

@@ -15,6 +15,7 @@ fileprivate let accountCell = "accountCell"
 fileprivate let statusCell = "statusCell"
 fileprivate let hashtagCell = "hashtagCell"
 
+@MainActor
 protocol SearchResultsViewControllerDelegate: AnyObject {
     func selectedSearchResult(account accountID: String)
     func selectedSearchResult(hashtag: Hashtag)
@@ -370,7 +371,7 @@ extension SearchResultsViewController {
 }
 
 extension SearchResultsViewController {
-    enum Section: Hashable {
+    enum Section: Hashable, Sendable {
         case tokenSuggestions(SearchOperatorType)
         case loadingIndicator
         case accounts
@@ -392,7 +393,7 @@ extension SearchResultsViewController {
             }
         }
     }
-    enum Item: Hashable {
+    enum Item: Hashable, Sendable {
         case tokenSuggestion(String)
         case loadingIndicator
         case account(String)

Tusker/Screens/Status Edit History/StatusEditHistoryViewController.swift

@@ -162,7 +162,7 @@ extension StatusEditHistoryViewController {
     enum Section {
         case edits
     }
-    enum Item: Hashable, Equatable {
+    enum Item: Hashable, Equatable, Sendable {
         case edit(StatusEdit, CollapseState, index: Int)
         case loadingIndicator
         

Tusker/Screens/Timeline/InstanceTimelineViewController.swift

@@ -9,6 +9,7 @@
 import UIKit
 import Pachyderm
 
+@MainActor
 protocol InstanceTimelineViewControllerDelegate: AnyObject {
     func didSaveInstance(url: URL)
     func didUnsaveInstance(url: URL)

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -11,6 +11,7 @@ import Pachyderm
 import Combine
 import Sentry
 
+@MainActor
 protocol TimelineViewControllerDelegate: AnyObject {
     func timelineViewController(_ timelineViewController: TimelineViewController, willShowJumpToPresentToastWith animator: UIViewPropertyAnimator?)
     func timelineViewController(_ timelineViewController: TimelineViewController, willDismissJumpToPresentToastWith animator: UIViewPropertyAnimator?)

Tusker/Screens/Utilities/BackgroundableViewController.swift

@@ -8,6 +8,7 @@
 
 import Foundation
 
+@MainActor
 protocol BackgroundableViewController {
     func sceneDidEnterBackground()
 }

Tusker/Screens/Utilities/CollectionViewController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 protocol CollectionViewController: UIViewController {
     var collectionView: UICollectionView! { get }
 }

Tusker/Screens/Utilities/RefreshableViewController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 @objc protocol RefreshableViewController {
     
     func refresh()

Tusker/Screens/Utilities/SplitNavigationController.swift

@@ -339,6 +339,7 @@ private class SplitSecondaryNavigationController: EnhancedNavigationViewControll
     
 }
 
+@MainActor
 protocol NestedResponderProvider {
     var innerResponder: UIResponder? { get }
 }

Tusker/Screens/Utilities/StateRestorableViewController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 protocol StateRestorableViewController: UIViewController {
     func stateRestorationActivity() -> NSUserActivity?
 }

Tusker/Screens/Utilities/StatusBarTappableViewController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 protocol StatusBarTappableViewController: UIViewController {
     func handleStatusBarTapped(xPosition: CGFloat) -> StatusBarTapActionResult
 }

Tusker/Screens/Utilities/TabBarScrollableViewController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 protocol TabBarScrollableViewController: UIViewController {
     func tabBarScrollToTop()
 }

Tusker/Screens/Utilities/TabbedPageViewController.swift

@@ -8,6 +8,7 @@
 
 import UIKit
 
+@MainActor
 @objc protocol TabbedPageViewController {
     func selectNextPage()
     func selectPrevPage()

Tusker/TuskerNavigationDelegate.swift

@@ -180,6 +180,7 @@ enum PopoverSource {
     case view(WeakHolder<UIView>)
     case barButtonItem(WeakHolder<UIBarButtonItem>)
     
+    @MainActor
     func apply(to viewController: UIViewController) {
         if let popoverPresentationController = viewController.popoverPresentationController {
             switch self {

Tusker/Views/Attachments/AttachmentView.swift

@@ -11,6 +11,7 @@ import Pachyderm
 import AVFoundation
 import TuskerComponents
 
+@MainActor
 protocol AttachmentViewDelegate: AnyObject {
     func attachmentViewGallery(startingAt index: Int) -> GalleryViewController?
     func attachmentViewPresent(_ vc: UIViewController, animated: Bool)

Tusker/Views/BaseEmojiLabel.swift

@@ -12,6 +12,7 @@ import WebURLFoundationExtras
 
 private let emojiRegex = try! NSRegularExpression(pattern: ":(\\w+):", options: [])
 
+@MainActor
 protocol BaseEmojiLabel: AnyObject {
     var emojiIdentifier: AnyHashable? { get set }
     var emojiRequests: [ImageCache.Request] { get set }
@@ -42,10 +43,11 @@ extension BaseEmojiLabel {
         
         // Based on https://github.com/ReticentJohn/Amaroq/blob/7c5b7088eb9fd1611dcb0f47d43bf8df093e142c/DireFloof/InlineImageHelpers.m
         let adjustedCapHeight = emojiFont.capHeight - 1
+        let screenScale = UIScreen.main.scale
+        @Sendable
         func emojiImageSize(_ image: UIImage) -> CGSize {
             var imageSizeMatchingFontSize = CGSize(width: image.size.width * (adjustedCapHeight / image.size.height), height: adjustedCapHeight)
-            var scale: CGFloat = 1.4
+            let scale = 1.4 * screenScale
-            scale *= UIScreen.main.scale
             imageSizeMatchingFontSize = CGSize(width: imageSizeMatchingFontSize.width * scale, height: imageSizeMatchingFontSize.height * scale)
             return imageSizeMatchingFontSize
         }
@@ -88,7 +90,7 @@ extension BaseEmojiLabel {
                     }
                     image.prepareThumbnail(of: emojiImageSize(image)) { thumbnail in
                         guard let thumbnail = thumbnail?.cgImage,
-                              case let rescaled = UIImage(cgImage: thumbnail, scale: UIScreen.main.scale, orientation: .up),
+                              case let rescaled = UIImage(cgImage: thumbnail, scale: screenScale, orientation: .up),
                               let transformedImage = ImageGrayscalifier.convertIfNecessary(url: URL(emoji.url)!, image: rescaled) else {
                             group.leave()
                             return

Tusker/Views/ContentTextView.swift

@@ -87,7 +87,9 @@ class ContentTextView: LinkTextView, BaseEmojiLabel {
         updateLinkUnderlineStyle()
     }
     
-    private func updateLinkUnderlineStyle(preference: Bool = Preferences.shared.underlineTextLinks) {
+    @MainActor
+    private func updateLinkUnderlineStyle(preference: Bool? = nil) {
+        let preference = preference ?? Preferences.shared.underlineTextLinks
         if UIAccessibility.buttonShapesEnabled || preference {
             linkTextAttributes[.underlineStyle] = NSUnderlineStyle.single.rawValue
         } else {

Tusker/Views/Profile Header/ProfileHeaderView.swift

@@ -9,6 +9,7 @@
 import UIKit
 import Pachyderm
 
+@MainActor
 protocol ProfileHeaderViewDelegate: TuskerNavigationDelegate, MenuActionProvider {
     func profileHeader(_ headerView: ProfileHeaderView, selectedPageChangedTo newPage: ProfileViewController.Page)
 }

Tusker/Views/Status/StatusContentContainer.swift

@@ -179,13 +179,16 @@ extension StatusContentContainer {
 }
 
 private extension UIView {
-    func observeIsHidden(_ f: @escaping () -> Void) -> NSKeyValueObservation {
+    func observeIsHidden(_ f: @escaping @Sendable @MainActor () -> Void) -> NSKeyValueObservation {
         self.observe(\.isHidden) { _, _ in
+            MainActor.runUnsafely {
                 f()
             }
         }
     }
+}
 
+@MainActor
 protocol StatusContentView: UIView {
     var statusContentFillsHorizontally: Bool { get }
     func estimateHeight(effectiveWidth: CGFloat) -> CGFloat

Tusker/Views/Toast/ToastConfiguration.swift

@@ -18,8 +18,8 @@ struct ToastConfiguration {
     var title: String
     var subtitle: String?
     var actionTitle: String?
-    var action: ((ToastView) -> Void)?
+    var action: (@MainActor (ToastView) -> Void)?
-    var longPressAction: ((ToastView) -> Void)?
+    var longPressAction: (@MainActor (ToastView) -> Void)?
     var edgeSpacing: CGFloat = 8
     var edge: Edge = .automatic
     var dismissOnScroll = true
@@ -40,7 +40,7 @@ struct ToastConfiguration {
 }
 
 extension ToastConfiguration {
-    init(from error: Error, with title: String, in viewController: TuskerNavigationDelegate, retryAction: ((ToastView) -> Void)?) {
+    init(from error: Error, with title: String, in viewController: TuskerNavigationDelegate, retryAction: (@MainActor (ToastView) -> Void)?) {
         self.init(title: title)
         // localizedDescription is statically dispatched, so we need to call it after the downcast
         if let error = error as? Pachyderm.Client.Error {
@@ -71,7 +71,7 @@ extension ToastConfiguration {
         }
     }
     
-    init(from error: Error, with title: String, in viewController: TuskerNavigationDelegate, retryAction: @escaping @MainActor (ToastView) async -> Void) {
+    init(from error: Error, with title: String, in viewController: TuskerNavigationDelegate, retryAction: @Sendable @escaping @MainActor (ToastView) async -> Void) {
         self.init(from: error, with: title, in: viewController) { toast in
             Task {
                 await retryAction(toast)