[AltStore] Tracks background refresh attempts for debugging

AltStore.xcodeproj/project.pbxproj

@@ -11,6 +11,8 @@
 		BF0201BB22C2EFA3000B93E4 /* AltSign.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = BF5AB3A72285FE6C00DC914B /* AltSign.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		BF0201BD22C2EFBC000B93E4 /* openssl.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = BF4713A422976CFC00784A2F /* openssl.framework */; };
 		BF0201BE22C2EFBC000B93E4 /* openssl.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = BF4713A422976CFC00784A2F /* openssl.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		BF02419422F2156E00129732 /* RefreshAttempt.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF02419322F2156E00129732 /* RefreshAttempt.swift */; };
+		BF02419622F2199300129732 /* RefreshAttemptsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF02419522F2199300129732 /* RefreshAttemptsViewController.swift */; };
 		BF08858322DE795100DE9F1E /* MyAppsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF08858222DE795100DE9F1E /* MyAppsViewController.swift */; };
 		BF08858522DE7EC800DE9F1E /* UpdateCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF08858422DE7EC800DE9F1E /* UpdateCollectionViewCell.swift */; };
 		BF0C4EBD22A1BD8B009A2DD7 /* AppManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF0C4EBC22A1BD8B009A2DD7 /* AppManager.swift */; };
@@ -252,6 +254,8 @@
 /* Begin PBXFileReference section */
 		1039C07E517311FC499A0B64 /* Pods_AltStore.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_AltStore.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		A136EE677716B80768E9F0A2 /* Pods-AltStore.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-AltStore.release.xcconfig"; path = "Target Support Files/Pods-AltStore/Pods-AltStore.release.xcconfig"; sourceTree = "<group>"; };
+		BF02419322F2156E00129732 /* RefreshAttempt.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RefreshAttempt.swift; sourceTree = "<group>"; };
+		BF02419522F2199300129732 /* RefreshAttemptsViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RefreshAttemptsViewController.swift; sourceTree = "<group>"; };
 		BF08858222DE795100DE9F1E /* MyAppsViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MyAppsViewController.swift; sourceTree = "<group>"; };
 		BF08858422DE7EC800DE9F1E /* UpdateCollectionViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UpdateCollectionViewCell.swift; sourceTree = "<group>"; };
 		BF0C4EBC22A1BD8B009A2DD7 /* AppManager.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AppManager.swift; sourceTree = "<group>"; };
@@ -853,6 +857,7 @@
 				BFBBE2DE22931F73002097FA /* App.swift */,
 				BF3D648722E79A3700E9056B /* AppPermission.swift */,
 				BFBBE2E022931F81002097FA /* InstalledApp.swift */,
+				BF02419322F2156E00129732 /* RefreshAttempt.swift */,
 				BFE338DC22F0E7F3002E24B9 /* Source.swift */,
 				BFE6326522A857C100F30809 /* Team.swift */,
 			);
@@ -883,6 +888,7 @@
 			isa = PBXGroup;
 			children = (
 				BFDB69FC22A9A7B7007EA6D6 /* SettingsViewController.swift */,
+				BF02419522F2199300129732 /* RefreshAttemptsViewController.swift */,
 			);
 			path = Settings;
 			sourceTree = "<group>";
@@ -1300,6 +1306,7 @@
 				BF770E6722BD57C4002A40FE /* BackgroundTaskManager.swift in Sources */,
 				BF3D64B022E8D4B800E9056B /* AppContentViewControllerCells.swift in Sources */,
 				BFBBE2DD22931B20002097FA /* AltStore.xcdatamodeld in Sources */,
+				BF02419422F2156E00129732 /* RefreshAttempt.swift in Sources */,
 				BFE338E822F10E56002E24B9 /* LaunchViewController.swift in Sources */,
 				BFE6325C22A83C0100F30809 /* AuthenticationViewController.swift in Sources */,
 				BFB1169B2293274D00BB457C /* JSONDecoder+ManagedObjectContext.swift in Sources */,
@@ -1312,6 +1319,7 @@
 				BF770E5822BC3D0F002A40FE /* OperationGroup.swift in Sources */,
 				BF18B0F122E25DF9005C4CF5 /* ToastView.swift in Sources */,
 				BF3D649F22E7B24C00E9056B /* CollapsingTextView.swift in Sources */,
+				BF02419622F2199300129732 /* RefreshAttemptsViewController.swift in Sources */,
 				BF08858322DE795100DE9F1E /* MyAppsViewController.swift in Sources */,
 				BF9ABA4F22DD41A9008935CF /* UIColor+Hex.swift in Sources */,
 				BFD52BD422A0800A000B7ED1 /* ServerManager.swift in Sources */,

AltStore/AppDelegate.swift

@@ -13,6 +13,18 @@ import AVFoundation
 import AltSign
 import Roxas
 
+private enum RefreshError: LocalizedError
+{
+    case noInstalledApps
+    
+    var errorDescription: String? {
+        switch self
+        {
+        case .noInstalledApps: return NSLocalizedString("No installed apps to refresh.", comment: "")
+        }
+    }
+}
+
 private extension CFNotificationName
 {
     static let requestAppState = CFNotificationName("com.altstore.RequestAppState" as CFString)
@@ -43,12 +55,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
     var window: UIWindow?
     
     private var runningApplications: Set<String>?
-    private var isLaunching = false
 
     func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool
     {
-        self.isLaunching = true
-        
         self.setTintColor()
         
         ServerManager.shared.startDiscovering()
@@ -61,10 +70,6 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
         
         self.prepareForBackgroundFetch()
         
-        DispatchQueue.main.async {
-            self.isLaunching = false
-        }
-                
         return true
     }
     
@@ -118,36 +123,12 @@ extension AppDelegate
         self.application(application, performFetchWithCompletionHandler: completionHandler)
     }
     
-    func application(_ application: UIApplication, performFetchWithCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void)
+    func application(_ application: UIApplication, performFetchWithCompletionHandler backgroundFetchCompletionHandler: @escaping (UIBackgroundFetchResult) -> Void)
     {
-        let isLaunching = self.isLaunching
+        ServerManager.shared.startDiscovering()
+        
         let refreshIdentifier = UUID().uuidString
         
-        let installedApps = InstalledApp.fetchAppsForBackgroundRefresh(in: DatabaseManager.shared.viewContext)
-        guard !installedApps.isEmpty else {
-            ServerManager.shared.stopDiscovering()
-            completionHandler(.noData)
-            return
-        }
-        
-        self.runningApplications = []
-        
-        let identifiers = installedApps.compactMap { $0.bundleIdentifier }
-        print("Apps to refresh:", identifiers)
-        
-        DispatchQueue.global().async {
-            let notificationCenter = CFNotificationCenterGetDarwinNotifyCenter()
-            
-            for identifier in identifiers
-            {
-                let appIsRunningNotification = CFNotificationName.appIsRunning(for: identifier)
-                CFNotificationCenterAddObserver(notificationCenter, nil, ReceivedApplicationState, appIsRunningNotification.rawValue, nil, .deliverImmediately)
-                
-                let requestAppStateNotification = CFNotificationName.requestAppState(for: identifier)
-                CFNotificationCenterPostNotification(notificationCenter, requestAppStateNotification, nil, nil, true)
-            }
-        }
-        
         BackgroundTaskManager.shared.performExtendedBackgroundTask { (taskResult, taskCompletionHandler) in
             
             func finish(_ result: Result<[String: Result<InstalledApp, Error>], Error>)
@@ -156,26 +137,74 @@ extension AppDelegate
                 
                 ServerManager.shared.stopDiscovering()
                 
-                self.scheduleFinishedRefreshingNotification(for: result, identifier: refreshIdentifier, isLaunching: isLaunching, delay: 0)
+                self.scheduleFinishedRefreshingNotification(for: result, identifier: refreshIdentifier, delay: 0)
                 
                 taskCompletionHandler()
-                
-                DispatchQueue.main.async {
-                    guard UIApplication.shared.applicationState == .background else { return }
-                    
-                    // Exit so that if background fetch occurs again soon we're not suspended.
-                    exit(0)
-                }
             }
             
             if let error = taskResult.error
             {
                 print("Error starting extended background task. Aborting.", error)
-                completionHandler(.failed)
+                backgroundFetchCompletionHandler(.failed)
                 finish(.failure(error))
                 return
             }
             
+            if !DatabaseManager.shared.isStarted
+            {
+                DatabaseManager.shared.start() { (error) in
+                    if let error = error
+                    {
+                        backgroundFetchCompletionHandler(.failed)
+                        finish(.failure(error))
+                    }
+                    else
+                    {
+                        self.refreshApps(identifier: refreshIdentifier, backgroundFetchCompletionHandler: backgroundFetchCompletionHandler, completionHandler: finish(_:))
+                    }
+                }
+            }
+            else
+            {
+                self.refreshApps(identifier: refreshIdentifier, backgroundFetchCompletionHandler: backgroundFetchCompletionHandler, completionHandler: finish(_:))
+            }
+        }
+    }
+}
+
+private extension AppDelegate
+{
+    func refreshApps(identifier: String,
+                     backgroundFetchCompletionHandler: @escaping (UIBackgroundFetchResult) -> Void,
+                     completionHandler: @escaping (Result<[String: Result<InstalledApp, Error>], Error>) -> Void)
+    {
+        DatabaseManager.shared.persistentContainer.performBackgroundTask { (context) in
+            
+            let installedApps = InstalledApp.fetchAppsForBackgroundRefresh(in: context)
+            guard !installedApps.isEmpty else {
+                backgroundFetchCompletionHandler(.noData)
+                completionHandler(.failure(RefreshError.noInstalledApps))
+                return
+            }
+            
+            self.runningApplications = []
+            
+            let identifiers = installedApps.compactMap { $0.bundleIdentifier }
+            print("Apps to refresh:", identifiers)
+            
+            DispatchQueue.global().async {
+                let notificationCenter = CFNotificationCenterGetDarwinNotifyCenter()
+                
+                for identifier in identifiers
+                {
+                    let appIsRunningNotification = CFNotificationName.appIsRunning(for: identifier)
+                    CFNotificationCenterAddObserver(notificationCenter, nil, ReceivedApplicationState, appIsRunningNotification.rawValue, nil, .deliverImmediately)
+                    
+                    let requestAppStateNotification = CFNotificationName.requestAppState(for: identifier)
+                    CFNotificationCenterPostNotification(notificationCenter, requestAppStateNotification, nil, nil, true)
+                }
+            }
+            
             var fetchSourceResult: Result<Source, Error>?
             var serversResult: Result<Void, Error>?
             
@@ -231,16 +260,16 @@ extension AppDelegate
             
             dispatchGroup.notify(queue: .main) {
                 guard let fetchSourceResult = fetchSourceResult, let serversResult = serversResult else {
-                    completionHandler(.failed)
+                    backgroundFetchCompletionHandler(.failed)
                     return
                 }
                 
                 // Call completionHandler early to improve chances of refreshing in the background again.
                 switch (fetchSourceResult, serversResult)
                 {
-                case (.success, .success): completionHandler(.newData)
+                case (.success, .success): backgroundFetchCompletionHandler(.newData)
-                case (.success, .failure(ConnectionError.serverNotFound)): completionHandler(.newData)
+                case (.success, .failure(ConnectionError.serverNotFound)): backgroundFetchCompletionHandler(.newData)
-                case (.failure, _), (_, .failure): completionHandler(.failed)
+                case (.failure, _), (_, .failure): backgroundFetchCompletionHandler(.failed)
                 }
             }
             
@@ -248,45 +277,47 @@ extension AppDelegate
             // a) give us time to discover AltServers
             // b) give other processes a chance to respond to requestAppState notification
             DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) {
-                if ServerManager.shared.discoveredServers.isEmpty
+                context.perform {
-                {
+                    if ServerManager.shared.discoveredServers.isEmpty
-                    serversResult = .failure(ConnectionError.serverNotFound)
-                }
-                else
-                {
-                    serversResult = .success(())
-                }
-                
-                dispatchGroup.leave()
-                
-                let filteredApps = installedApps.filter { !(self.runningApplications?.contains($0.bundleIdentifier) ?? false) }
-                print("Filtered Apps to Refresh:", filteredApps.map { $0.bundleIdentifier })
-                
-                let group = AppManager.shared.refresh(filteredApps, presentingViewController: nil)
-                group.beginInstallationHandler = { (installedApp) in
-                    guard installedApp.bundleIdentifier == App.altstoreAppID else { return }
-                    
-                    // We're starting to install AltStore, which means the app is about to quit.
-                    // So, we schedule a "refresh successful" local notification to be displayed after a delay,
-                    // but if the app is still running, we cancel the notification.
-                    // Then, we schedule another notification and repeat the process.
-                    
-                    // Also since AltServer has already received the app, it can finish installing even if we're no longer running in background.
-
-                    if let error = group.error
                     {
-                        self.scheduleFinishedRefreshingNotification(for: .failure(error), identifier: refreshIdentifier, isLaunching: isLaunching)
+                        serversResult = .failure(ConnectionError.serverNotFound)
                     }
                     else
                     {
-                        var results = group.results
+                        serversResult = .success(())
-                        results[installedApp.bundleIdentifier] = .success(installedApp)
+                    }
-
+                    
-                        self.scheduleFinishedRefreshingNotification(for: .success(results), identifier: refreshIdentifier, isLaunching: isLaunching)
+                    dispatchGroup.leave()
+                    
+                    let filteredApps = installedApps.filter { !(self.runningApplications?.contains($0.bundleIdentifier) ?? false) }
+                    print("Filtered Apps to Refresh:", filteredApps.map { $0.bundleIdentifier })
+                    
+                    let group = AppManager.shared.refresh(filteredApps, presentingViewController: nil)
+                    group.beginInstallationHandler = { (installedApp) in
+                        guard installedApp.bundleIdentifier == App.altstoreAppID else { return }
+                        
+                        // We're starting to install AltStore, which means the app is about to quit.
+                        // So, we schedule a "refresh successful" local notification to be displayed after a delay,
+                        // but if the app is still running, we cancel the notification.
+                        // Then, we schedule another notification and repeat the process.
+                        
+                        // Also since AltServer has already received the app, it can finish installing even if we're no longer running in background.
+                        
+                        if let error = group.error
+                        {
+                            self.scheduleFinishedRefreshingNotification(for: .failure(error), identifier: identifier)
+                        }
+                        else
+                        {
+                            var results = group.results
+                            results[installedApp.bundleIdentifier] = .success(installedApp)
+                            
+                            self.scheduleFinishedRefreshingNotification(for: .success(results), identifier: identifier)
+                        }
+                    }
+                    group.completionHandler = { (result) in
+                        completionHandler(result)
                     }
-                }
-                group.completionHandler = { (result) in
-                    finish(result)
                 }
             }
         }
@@ -300,69 +331,76 @@ extension AppDelegate
         self.runningApplications?.insert(appID)
     }
     
-    func scheduleFinishedRefreshingNotification(for result: Result<[String: Result<InstalledApp, Error>], Error>, identifier: String, isLaunching: Bool, delay: TimeInterval = 5)
+    func scheduleFinishedRefreshingNotification(for result: Result<[String: Result<InstalledApp, Error>], Error>, identifier: String, delay: TimeInterval = 5)
     {
-        self.cancelFinishedRefreshingNotification(identifier: identifier)
+        func scheduleFinishedRefreshingNotification()
-        
-        let content = UNMutableNotificationContent()
-        
-        var shouldPresentAlert = true
-        
-        do
         {
-            let results = try result.get()
+            self.cancelFinishedRefreshingNotification(identifier: identifier)
-            shouldPresentAlert = !results.isEmpty
             
-            for (_, result) in results
+            let content = UNMutableNotificationContent()
+            
+            var shouldPresentAlert = true
+            
+            do
             {
-                guard case let .failure(error) = result else { continue }
+                let results = try result.get()
-                throw error
+                shouldPresentAlert = !results.isEmpty
+                
+                for (_, result) in results
+                {
+                    guard case let .failure(error) = result else { continue }
+                    throw error
+                }
+                
+                content.title = NSLocalizedString("Refreshed Apps", comment: "")
+                content.body = NSLocalizedString("All apps have been refreshed.", comment: "")
+            }
+            catch ConnectionError.serverNotFound
+            {
+                shouldPresentAlert = false
+            }
+            catch RefreshError.noInstalledApps
+            {
+                shouldPresentAlert = false
+            }
+            catch
+            {
+                print("Failed to refresh apps in background.", error)
+                
+                content.title = NSLocalizedString("Failed to Refresh Apps", comment: "")
+                content.body = error.localizedDescription
+                
+                shouldPresentAlert = true
             }
             
-            content.title = NSLocalizedString("Refreshed Apps", comment: "")
+            if shouldPresentAlert
-            content.body = NSLocalizedString("All apps have been refreshed.", comment: "")
-        }
-        catch let error as NSError where
-            (error.domain == NSOSStatusErrorDomain || error.domain == AVFoundationErrorDomain) &&
-                error.code == AVAudioSession.ErrorCode.cannotStartPlaying.rawValue &&
-                !isLaunching
-        {
-            // We can only start background audio when the app is being launched,
-            // and _not_ if it's already suspended in background.
-            // Since we are currently suspended in background and not launching, we'll just ignore the error.
-
-            shouldPresentAlert = false
-        }
-        catch ConnectionError.serverNotFound
-        {
-            shouldPresentAlert = false
-        }
-        catch
-        {
-            print("Failed to refresh apps in background.", error)
-            
-            content.title = NSLocalizedString("Failed to Refresh Apps", comment: "")
-            content.body = error.localizedDescription
-            
-            shouldPresentAlert = true
-        }
-        
-        if shouldPresentAlert
-        {
-            let trigger = UNTimeIntervalNotificationTrigger(timeInterval: delay + 1, repeats: false)
-            
-            let request = UNNotificationRequest(identifier: identifier, content: content, trigger: trigger)
-            UNUserNotificationCenter.current().add(request)
-            
-            if delay > 0
             {
-                DispatchQueue.global().asyncAfter(deadline: .now() + delay) {
+                let trigger = UNTimeIntervalNotificationTrigger(timeInterval: delay + 1, repeats: false)
-                    // If app is still running at this point, we schedule another notification with same identifier.
+                
-                    // This prevents the currently scheduled notification from displaying, and starts another countdown timer.
+                let request = UNNotificationRequest(identifier: identifier, content: content, trigger: trigger)
-                    self.scheduleFinishedRefreshingNotification(for: result, identifier: identifier, isLaunching: isLaunching)
+                UNUserNotificationCenter.current().add(request)
+                
+                if delay > 0
+                {
+                    DispatchQueue.global().asyncAfter(deadline: .now() + delay) {
+                        // If app is still running at this point, we schedule another notification with same identifier.
+                        // This prevents the currently scheduled notification from displaying, and starts another countdown timer.
+                        scheduleFinishedRefreshingNotification()
+                    }
                 }
             }
         }
+        
+        scheduleFinishedRefreshingNotification()
+        
+        // Perform synchronously to ensure app doesn't quit before we've finishing saving to disk.
+        let context = DatabaseManager.shared.persistentContainer.newBackgroundContext()
+        context.performAndWait {
+            _ = RefreshAttempt(identifier: identifier, result: result, context: context)
+            
+            do { try context.save() }
+            catch { print("Failed to save refresh attempt.", error) }
+        }
     }
     
     func cancelFinishedRefreshingNotification(identifier: String)

AltStore/Base.lproj/Main.storyboard

@@ -693,6 +693,30 @@ World</string>
                                     </tableViewCell>
                                 </cells>
                             </tableViewSection>
+                            <tableViewSection headerTitle="Debug" id="K7R-6x-gHl">
+                                <cells>
+                                    <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="none" accessoryType="disclosureIndicator" indentationWidth="10" textLabel="nQj-qq-PmI" style="IBUITableViewCellStyleDefault" id="8M3-mu-gRd">
+                                        <rect key="frame" x="0.0" y="299.5" width="375" height="44"/>
+                                        <autoresizingMask key="autoresizingMask"/>
+                                        <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" preservesSuperviewLayoutMargins="YES" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="8M3-mu-gRd" id="6TQ-nF-Rkl">
+                                            <rect key="frame" x="0.0" y="0.0" width="341" height="43.5"/>
+                                            <autoresizingMask key="autoresizingMask"/>
+                                            <subviews>
+                                                <label opaque="NO" multipleTouchEnabled="YES" contentMode="left" insetsLayoutMarginsFromSafeArea="NO" text="Background Refresh Attempts" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" id="nQj-qq-PmI">
+                                                    <rect key="frame" x="16" y="0.0" width="324" height="43.5"/>
+                                                    <autoresizingMask key="autoresizingMask"/>
+                                                    <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                                    <nil key="textColor"/>
+                                                    <nil key="highlightedColor"/>
+                                                </label>
+                                            </subviews>
+                                        </tableViewCellContentView>
+                                        <connections>
+                                            <segue destination="RUB-gO-oQ6" kind="show" id="tkT-F7-PA4"/>
+                                        </connections>
+                                    </tableViewCell>
+                                </cells>
+                            </tableViewSection>
                             <tableViewSection footerTitle="" id="Yg2-vc-vLQ">
                                 <cells/>
                             </tableViewSection>
@@ -721,6 +745,82 @@ World</string>
             </objects>
             <point key="canvasLocation" x="1518" y="515"/>
         </scene>
+        <!--Refresh Attempts-->
+        <scene sceneID="tCt-AY-k3Z">
+            <objects>
+                <tableViewController id="RUB-gO-oQ6" customClass="RefreshAttemptsViewController" customModule="AltStore" customModuleProvider="target" sceneMemberID="viewController">
+                    <tableView key="view" clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="prototypes" style="plain" separatorStyle="default" rowHeight="-1" estimatedRowHeight="-1" sectionHeaderHeight="28" sectionFooterHeight="28" id="g2y-h0-0xu">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                        <prototypes>
+                            <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="default" indentationWidth="10" reuseIdentifier="Cell" id="bBs-eV-Rlj" customClass="RefreshAttemptTableViewCell">
+                                <rect key="frame" x="0.0" y="28" width="375" height="44"/>
+                                <autoresizingMask key="autoresizingMask"/>
+                                <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" preservesSuperviewLayoutMargins="YES" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="bBs-eV-Rlj" id="YfI-8z-wCv">
+                                    <rect key="frame" x="0.0" y="0.0" width="375" height="43.5"/>
+                                    <autoresizingMask key="autoresizingMask"/>
+                                    <subviews>
+                                        <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" spacing="4" translatesAutoresizingMaskIntoConstraints="NO" id="SFD-t6-Qk3">
+                                            <rect key="frame" x="16" y="11" width="343" height="22"/>
+                                            <subviews>
+                                                <stackView opaque="NO" contentMode="scaleToFill" distribution="equalSpacing" translatesAutoresizingMaskIntoConstraints="NO" id="gQk-PG-cjg">
+                                                    <rect key="frame" x="0.0" y="0.0" width="343" height="17"/>
+                                                    <subviews>
+                                                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Success" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="CZj-FM-9Qv">
+                                                            <rect key="frame" x="0.0" y="0.0" width="67.5" height="17"/>
+                                                            <fontDescription key="fontDescription" type="system" weight="semibold" pointSize="17"/>
+                                                            <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
+                                                            <nil key="highlightedColor"/>
+                                                        </label>
+                                                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Date" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="0Md-jd-XXe">
+                                                            <rect key="frame" x="312.5" y="0.0" width="30.5" height="17"/>
+                                                            <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                                                            <color key="textColor" white="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                                                            <nil key="highlightedColor"/>
+                                                        </label>
+                                                    </subviews>
+                                                </stackView>
+                                                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Could not connect to AltServer." textAlignment="natural" lineBreakMode="tailTruncation" numberOfLines="0" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Pwo-OM-Gm3">
+                                                    <rect key="frame" x="0.0" y="21" width="343" height="1"/>
+                                                    <fontDescription key="fontDescription" type="system" pointSize="15"/>
+                                                    <nil key="highlightedColor"/>
+                                                </label>
+                                            </subviews>
+                                        </stackView>
+                                    </subviews>
+                                    <constraints>
+                                        <constraint firstItem="SFD-t6-Qk3" firstAttribute="leading" secondItem="YfI-8z-wCv" secondAttribute="leadingMargin" id="ehs-Sf-kyZ"/>
+                                        <constraint firstAttribute="trailingMargin" secondItem="SFD-t6-Qk3" secondAttribute="trailing" id="g4i-l8-aln"/>
+                                        <constraint firstAttribute="bottomMargin" secondItem="SFD-t6-Qk3" secondAttribute="bottom" id="h38-79-xRT"/>
+                                        <constraint firstItem="SFD-t6-Qk3" firstAttribute="top" secondItem="YfI-8z-wCv" secondAttribute="topMargin" id="mCE-eA-UKd"/>
+                                    </constraints>
+                                </tableViewCellContentView>
+                                <connections>
+                                    <outlet property="dateLabel" destination="0Md-jd-XXe" id="znM-W1-cZi"/>
+                                    <outlet property="errorDescriptionLabel" destination="Pwo-OM-Gm3" id="3zi-gX-I5t"/>
+                                    <outlet property="successLabel" destination="CZj-FM-9Qv" id="vtL-iu-aHR"/>
+                                </connections>
+                            </tableViewCell>
+                        </prototypes>
+                        <connections>
+                            <outlet property="dataSource" destination="RUB-gO-oQ6" id="vqw-LK-wuY"/>
+                            <outlet property="delegate" destination="RUB-gO-oQ6" id="9uY-h3-7qR"/>
+                        </connections>
+                    </tableView>
+                    <navigationItem key="navigationItem" title="Refresh Attempts" largeTitleDisplayMode="never" id="jO4-kG-Alq">
+                        <barButtonItem key="rightBarButtonItem" title="Sign Out" id="9Pj-GZ-Rra">
+                            <color key="tintColor" red="1" green="0.14901960780000001" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                            <connections>
+                                <action selector="signOut:" destination="VBC-qD-V1a" id="m55-18-kgT"/>
+                            </connections>
+                        </barButtonItem>
+                    </navigationItem>
+                </tableViewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="Wk8-xA-fxp" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="2313" y="515"/>
+        </scene>
         <!--Browse-->
         <scene sceneID="VHa-uP-bFU">
             <objects>

AltStore/Components/BackgroundTaskManager.swift

@@ -56,7 +56,7 @@ extension BackgroundTaskManager
             self.isPlaying = false
         }
         
-        self.audioEngineQueue.async {
+        self.audioEngineQueue.sync {
             do
             {
                 try AVAudioSession.sharedInstance().setCategory(.playback, options: .mixWithOthers)

AltStore/Model/AltStore.xcdatamodeld/AltStore.xcdatamodel/contents

@@ -56,6 +56,17 @@
             </uniquenessConstraint>
         </uniquenessConstraints>
     </entity>
+    <entity name="RefreshAttempt" representedClassName="RefreshAttempt" syncable="YES">
+        <attribute name="date" attributeType="Date" usesScalarValueType="NO" syncable="YES"/>
+        <attribute name="errorDescription" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="identifier" attributeType="String" syncable="YES"/>
+        <attribute name="isSuccess" attributeType="Boolean" defaultValueString="YES" usesScalarValueType="YES" syncable="YES"/>
+        <uniquenessConstraints>
+            <uniquenessConstraint>
+                <constraint value="identifier"/>
+            </uniquenessConstraint>
+        </uniquenessConstraints>
+    </entity>
     <entity name="Source" representedClassName="Source" syncable="YES">
         <attribute name="identifier" attributeType="String" syncable="YES"/>
         <attribute name="name" attributeType="String" syncable="YES"/>
@@ -84,7 +95,8 @@
         <element name="App" positionX="-63" positionY="-18" width="128" height="300"/>
         <element name="AppPermission" positionX="-45" positionY="90" width="128" height="90"/>
         <element name="InstalledApp" positionX="-63" positionY="0" width="128" height="150"/>
-        <element name="Team" positionX="-45" positionY="81" width="128" height="120"/>
         <element name="Source" positionX="-45" positionY="99" width="128" height="105"/>
+        <element name="Team" positionX="-45" positionY="81" width="128" height="120"/>
+        <element name="RefreshAttempt" positionX="-45" positionY="117" width="128" height="105"/>
     </elements>
 </model>

AltStore/Model/RefreshAttempt.swift

@@ -0,0 +1,51 @@
+//
+//  RefreshAttempt.swift
+//  AltStore
+//
+//  Created by Riley Testut on 7/31/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import CoreData
+
+@objc(RefreshAttempt)
+class RefreshAttempt: NSManagedObject, Fetchable
+{
+    @NSManaged var identifier: String
+    @NSManaged var date: Date
+    
+    @NSManaged var isSuccess: Bool
+    @NSManaged var errorDescription: String?
+    
+    private override init(entity: NSEntityDescription, insertInto context: NSManagedObjectContext?)
+    {
+        super.init(entity: entity, insertInto: context)
+    }
+    
+    init<T>(identifier: String, result: Result<T, Error>, context: NSManagedObjectContext)
+    {
+        super.init(entity: RefreshAttempt.entity(), insertInto: context)
+        
+        self.identifier = identifier
+        self.date = Date()
+        
+        switch result
+        {
+        case .success:
+            self.isSuccess = true
+            self.errorDescription = nil
+            
+        case .failure(let error):
+            self.isSuccess = false
+            self.errorDescription = error.localizedDescription
+        }
+    }
+}
+
+extension RefreshAttempt
+{
+    @nonobjc class func fetchRequest() -> NSFetchRequest<RefreshAttempt>
+    {
+        return NSFetchRequest<RefreshAttempt>(entityName: "RefreshAttempt")
+    }
+}

AltStore/Settings/RefreshAttemptsViewController.swift

@@ -0,0 +1,73 @@
+//
+//  RefreshAttemptsViewController.swift
+//  AltStore
+//
+//  Created by Riley Testut on 7/31/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+import Roxas
+
+@objc(RefreshAttemptTableViewCell)
+private class RefreshAttemptTableViewCell: UITableViewCell
+{
+    @IBOutlet var successLabel: UILabel!
+    @IBOutlet var dateLabel: UILabel!
+    @IBOutlet var errorDescriptionLabel: UILabel!
+}
+
+class RefreshAttemptsViewController: UITableViewController
+{
+    private lazy var dataSource = self.makeDataSource()
+    
+    private lazy var dateFormatter: DateFormatter = {
+        let dateFormatter = DateFormatter()
+        dateFormatter.dateStyle = .short
+        dateFormatter.timeStyle = .short
+        return dateFormatter
+    }()
+    
+    override func viewDidLoad()
+    {
+        super.viewDidLoad()
+        
+        self.tableView.dataSource = self.dataSource
+    }
+}
+
+private extension RefreshAttemptsViewController
+{
+    func makeDataSource() -> RSTFetchedResultsTableViewDataSource<RefreshAttempt>
+    {
+        let fetchRequest = RefreshAttempt.fetchRequest() as NSFetchRequest<RefreshAttempt>
+        fetchRequest.sortDescriptors = [NSSortDescriptor(keyPath: \RefreshAttempt.date, ascending: false)]
+        fetchRequest.returnsObjectsAsFaults = false
+        
+        let dataSource = RSTFetchedResultsTableViewDataSource(fetchRequest: fetchRequest, managedObjectContext: DatabaseManager.shared.viewContext)
+        dataSource.cellConfigurationHandler = { [weak self] (cell, attempt, indexPath) in
+            let cell = cell as! RefreshAttemptTableViewCell
+            cell.dateLabel.text = self?.dateFormatter.string(from: attempt.date)
+            cell.errorDescriptionLabel.text = attempt.errorDescription
+            
+            if attempt.isSuccess
+            {
+                cell.successLabel.text = NSLocalizedString("Success", comment: "")
+                cell.successLabel.textColor = .altGreen
+            }
+            else
+            {
+                cell.successLabel.text = NSLocalizedString("Failure", comment: "")
+                cell.successLabel.textColor = .refreshRed
+            }
+        }
+        
+        let placeholderView = RSTPlaceholderView()
+        placeholderView.textLabel.text = NSLocalizedString("No Refresh Attempts", comment: "")
+        placeholderView.detailTextLabel.text = NSLocalizedString("The more you use AltStore, the more often iOS will allow it to refresh apps in the background.", comment: "")
+        dataSource.placeholderView = placeholderView
+        
+        return dataSource
+    }
+}