Diagnosability improvements - fix log flushing, log unhandled excepti…

…ons, enforce failfast of unhandled exceptions (#3211)

src/App.xaml.cs

@@ -81,15 +81,6 @@ public App()
         InitializeComponent();
         _dispatcherQueue = DispatcherQueue.GetForCurrentThread();
 
-        // Set up Logging
-        Environment.SetEnvironmentVariable("DEVHOME_LOGS_ROOT", Path.Join(Common.Logging.LogFolderRoot, "DevHome"));
-        var configuration = new ConfigurationBuilder()
-            .AddJsonFile("appsettings.json")
-            .Build();
-        Log.Logger = new LoggerConfiguration()
-            .ReadFrom.Configuration(configuration)
-            .CreateLogger();
-
         Host = Microsoft.Extensions.Hosting.Host.
         CreateDefaultBuilder().
         UseContentRoot(AppContext.BaseDirectory).
@@ -199,10 +190,15 @@ public void ShowMainWindow()
 
     private async void App_UnhandledException(object sender, Microsoft.UI.Xaml.UnhandledExceptionEventArgs e)
     {
-        // TODO: Log and handle exceptions as appropriate.
         // https://docs.microsoft.com/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.application.unhandledexception.
-        // https://github.com/microsoft/devhome/issues/613
+        Log.Fatal(e.Exception, $"Unhandled exception: {e.Message}");
+
+        // We are about to crash, so signal the extensions to stop.
         await GetService<IExtensionService>().SignalStopExtensionsAsync();
+        Log.CloseAndFlush();
+
+        // We are very likely in a bad and unrecoverable state, so ensure Dev Home crashes w/ the exception info.
+        Environment.FailFast(e.Message, e.Exception);
     }
 
     protected async override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
@@ -225,9 +221,4 @@ private async void OnActivated(object? sender, AppActivationArguments args)
         // Activate the app and ensure the appropriate handlers are called.
         await _dispatcherQueue.EnqueueAsync(async () => await GetService<IActivationService>().ActivateAsync(localArgsDataReference));
     }
-
-    private void Window_Closed(object sender, EventArgs e)
-    {
-        Log.CloseAndFlush();
-    }
 }

src/MainWindow.xaml.cs

@@ -6,6 +6,7 @@
 using DevHome.Telemetry;
 using DevHome.TelemetryEvents;
 using Microsoft.UI.Xaml;
+using Serilog;
 
 namespace DevHome;
 
@@ -27,5 +28,6 @@ private void MainWindow_Closed(object sender, WindowEventArgs args)
     {
         Application.Current.GetService<IExtensionService>().SignalStopExtensionsAsync();
         TelemetryFactory.Get<ITelemetry>().Log("DevHome_MainWindow_Closed_Event", LogLevel.Critical, new DevHomeClosedEvent(mainWindowCreated));
+        Log.Information("Terminating via MainWindow_Closed.");
     }
 }

src/Program.cs

@@ -17,6 +17,17 @@ public static class Program
     [STAThread]
     public static void Main(string[] args)
     {
+        // Set up Logging
+        Environment.SetEnvironmentVariable("DEVHOME_LOGS_ROOT", Path.Join(Common.Logging.LogFolderRoot, "DevHome"));
+        var configuration = new ConfigurationBuilder()
+            .AddJsonFile("appsettings.json")
+            .Build();
+        Log.Logger = new LoggerConfiguration()
+            .ReadFrom.Configuration(configuration)
+            .CreateLogger();
+
+        Log.Information($"Launched with args: {string.Join(' ', [.. args])}");
+
         // Be sure to parse these args in this instance of the exe... don't redirect this to another instance for parsing which
         // may be running in a different security context.
         ParseCommandLine(args);
@@ -35,6 +46,9 @@ public static void Main(string[] args)
                 _app = new App();
             });
         }
+
+        Log.Information("Terminating Dev Home");
+        Log.CloseAndFlush();
     }
 
     private static async Task<bool> DecideRedirection()

src/appsettings.json

@@ -34,7 +34,7 @@
     ],
     "Enrich": [ "FromLogContext" ],
     "Properties": {
-      "SourceContext": "CoreWidgetExtension"
+      "SourceContext": "DevHome"
     }
   }
 }