Tusker.xcodeproj/xcshareddata/xcschemes/Tusker.xcscheme

@@ -99,11 +99,6 @@
             value = "1"
             isEnabled = "NO">
          </EnvironmentVariable>
-         <EnvironmentVariable
-            key = "LIBDISPATCH_COOPERATIVE_POOL_STRICT"
-            value = "1"
-            isEnabled = "YES">
-         </EnvironmentVariable>
       </EnvironmentVariables>
    </LaunchAction>
    <ProfileAction

Tusker/Controllers/MastodonController.swift

@@ -46,8 +46,8 @@ class MastodonController: ObservableObject {
     @Published private(set) var instance: Instance!
     private(set) var customEmojis: [Emoji]?
     
-    @MainActor private var pendingOwnInstanceRequestCallbacks = [(Instance) -> Void]()
+    private var pendingOwnInstanceRequestCallbacks = [(Instance) -> Void]()
-    @MainActor private var ownInstanceRequest: URLSessionTask?
+    private var ownInstanceRequest: URLSessionTask?
     
     var loggedIn: Bool {
         accountInfo != nil
@@ -118,13 +118,14 @@ class MastodonController: ObservableObject {
         }
     }
     
-    @MainActor
     func getOwnInstance(completion: ((Instance) -> Void)? = nil) {
         getOwnInstanceInternal(retryAttempt: 0, completion: completion)
     }
     
-    @MainActor
     private func getOwnInstanceInternal(retryAttempt: Int, completion: ((Instance) -> Void)?) {
+        // this is main thread only to prevent concurrent access to ownInstanceRequest and pendingOwnInstanceRequestCallbacks
+        assert(Thread.isMainThread)
+        
         if let instance = self.instance {
             completion?(instance)
         } else {

Tusker/Models/CompositionAttachmentData.swift

@@ -104,14 +104,6 @@ enum CompositionAttachmentData {
         }
     }
     
-    func getData() async -> (Data, String) {
-        return await withCheckedContinuation { continuation in
-            getData { data, mimeType in
-                continuation.resume(returning: (data, mimeType))
-            }
-        }
-    }
-    
     private static func exportVideoData(session: AVAssetExportSession, completion: @escaping (Data, String) -> Void) {
         session.outputFileType = .mp4
         session.outputURL = FileManager.default.temporaryDirectory.appendingPathComponent("exported_video_\(UUID())").appendingPathExtension("mp4")

Tusker/Screens/Compose/ComposeView.swift

@@ -19,7 +19,7 @@ struct ComposeView: View {
     @State private var postProgress: Double = 0
     @State private var postTotalProgress: Double = 0
     @State private var isShowingPostErrorAlert = false
-    @State private var postError: Error?
+    @State private var postError: PostError?
     
     private let stackPadding: CGFloat = 8
     
@@ -148,11 +148,7 @@ struct ComposeView: View {
     }
     
     private var postButton: some View {
-        Button {
+        Button(action: self.postStatus) {
-            async {
-                await self.postStatus()
-            }
-        } label: {
             Text("Post")
         }
         .disabled(!postButtonEnabled)
@@ -194,7 +190,7 @@ struct ComposeView: View {
         ])
     }
     
-    private func postStatus() async {
+    private func postStatus() {
         guard draft.hasContent else { return }
         
         isPosting = true
@@ -209,18 +205,16 @@ struct ComposeView: View {
         postTotalProgress = Double(2 + (draft.attachments.count * 2))
         postProgress = 1
         
-        let uploadedAttachments: [Attachment]
+        uploadAttachments { (result) in
-        do {
+            switch result {
-            uploadedAttachments = try await uploadAttachments()
+            case let .failure(error):
-        } catch {
                 self.isShowingPostErrorAlert = true
                 self.postError = error
                 self.postProgress = 0
                 self.postTotalProgress = 0
                 self.isPosting = false
-            return
-        }
             
+            case let .success(uploadedAttachments):
                 let request = Client.createStatus(text: draft.textForPosting,
                                                   contentType: Preferences.shared.statusContentType,
                                                   inReplyTo: draft.inReplyToID,
@@ -232,8 +226,13 @@ struct ComposeView: View {
                                                   pollOptions: draft.poll?.options.map(\.text),
                                                   pollExpiresIn: draft.poll == nil ? nil : Int(draft.poll!.duration),
                                                   pollMultiple: draft.poll?.multiple)
-        do {
+                self.mastodonController.run(request) { (response) in
-            try await mastodonController.run(request)
+                    switch response {
+                    case let .failure(error):
+                        self.isShowingPostErrorAlert = true
+                        self.postError = error
+
+                    case .success(_, _):
                         self.postProgress += 1
                         
                         DraftsManager.shared.remove(self.draft)
@@ -242,25 +241,35 @@ struct ComposeView: View {
                         DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(250)) {
                             self.uiState.delegate?.dismissCompose(mode: .post)
                         }
-        } catch {
+                    }
-            self.isShowingPostErrorAlert = true
+                }
-            self.postError = error
+            }
         }
     }
     
-    private func uploadAttachments() async throws -> [Attachment] {
+    private func uploadAttachments(_ completion: @escaping (Result<[Attachment], AttachmentUploadError>) -> Void) {
-        guard !draft.attachments.isEmpty else {
+        let group = DispatchGroup()
-            return []
-        }
         
-        return try await withThrowingTaskGroup(of: (CompositionAttachment, (Data, String)).self) { taskGroup in
+        var attachmentDatas = [(Data, String)?]()
-            for compAttachment in draft.attachments {
+        
+        for (index, compAttachment) in draft.attachments.enumerated() {
+            group.enter()
+            
+            attachmentDatas.append(nil)
+            
+            compAttachment.data.getData { (data, mimeType) in
                 postProgress += 1
-                taskGroup.async {
+                
-                    return (compAttachment, await compAttachment.data.getData())
+                attachmentDatas[index] = (data, mimeType)
+                group.leave()
             }
         }
         
+        group.notify(queue: .global(qos: .userInitiated)) {
+            
+            var anyFailed = false
+            var uploadedAttachments = [Result<Attachment, Error>?]()
+        
             // Mastodon does not respect the order of the `media_ids` parameter in the create post request,
             // it determines attachment order by which was uploaded first. Since the upload attachment request
             // does not include any timestamp data, and requests may arrive at the server out-of-order,
@@ -268,40 +277,67 @@ struct ComposeView: View {
             // posted status reflects order the user set.
             // Pleroma does respect the order of the `media_ids` parameter.
             
-            var anyFailed = false
+            for (index, (data, mimeType)) in attachmentDatas.map(\.unsafelyUnwrapped).enumerated() {
-            var uploaded = [Result<Attachment, Error>]()
+                group.enter()
                 
-            for try await (compAttachment, (data, mimeType)) in taskGroup {
+                let compAttachment = draft.attachments[index]
                 let formAttachment = FormAttachment(mimeType: mimeType, data: data, fileName: "file")
                 let request = Client.upload(attachment: formAttachment, description: compAttachment.attachmentDescription)
-
+                self.mastodonController.run(request) { (response) in
-                do {
+                    switch response {
-                    let (uploadedAttachment, _) = try await mastodonController.run(request)
+                    case let .failure(error):
-                    uploaded.append(.success(uploadedAttachment))
+                        uploadedAttachments.append(.failure(error))
-                    postProgress += 1
-                } catch {
-                    uploaded.append(.failure(error))
                         anyFailed = true
+                        
+                    case let .success(attachment, _):
+                        self.postProgress += 1
+                        uploadedAttachments.append(.success(attachment))
                     }
+                    
+                    group.leave()
                 }
                 
+                group.wait()
+            }
+            
+            
             if anyFailed {
-                let errors = uploaded.map { result -> Error? in
+                let errors = uploadedAttachments.map { (result) -> Error? in
                     if case let .failure(error) = result {
                         return error
                     } else {
                         return nil
                     }
                 }
-                throw AttachmentUploadError(errors: errors)
+                completion(.failure(AttachmentUploadError(errors: errors)))
             } else {
-                return uploaded.map { try! $0.get() }
+                let uploadedAttachments = uploadedAttachments.map {
+                    try! $0!.get()
                 }
+                completion(.success(uploadedAttachments))
+            }
+
         }
     }
 }
 
-fileprivate struct AttachmentUploadError: LocalizedError {
+fileprivate protocol PostError: LocalizedError {}
+
+extension PostError {
+    var localizedDescription: String {
+        if let self = self as? Client.Error {
+            return self.localizedDescription
+        } else if let self = self as? AttachmentUploadError {
+            return self.localizedDescription
+        } else {
+            return "Unknown Error"
+        }
+    }
+}
+
+extension Client.Error: PostError {}
+
+fileprivate struct AttachmentUploadError: PostError {
     let errors: [Error?]
     
     var localizedDescription: String {