[Ide] Load AddinManager data on the UI thread. (#9391)

* [Ide] Load AddinManager data on the UI thread.

We need to run this on the UI thread since AddinManager is not thread safe.
Invoking extension changed handlers on non-UI thread can lead to weird results

Fixes VSTS #1027414 - [FATAL] SigTerm signal in Mono.Addins.dll!Mono.Addins.RuntimeAddin::LoadModule+82"

Synchronously run the OnInitialize of the service to load the addin assemblies on the UI thread, then dispatch the actual composing to a background task.
This should prevent deadlock issues, and ensure that the first init is called on the UI thread

* Use Runtime.RunInMainThread

Some tests (i.e. MD.Core) cannot initialize the composition manager in the UI thread. The Razor extension ends up calling CompositionManager.Instance in the constructor, thus the init will throw and the Core test suite hangs.

Author: Therzok

main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Composition/CompositionManager.cs

@@ -56,23 +56,12 @@ public partial class CompositionManager: Service
 			new AttributedPartDiscoveryV1 (StandardResolver),
 			new AttributedPartDiscovery (StandardResolver, true));
 
-		static Action HandleMefQueriedBeforeCompletion = UninitializedLogWarning;
-
-		static void UninitializedLogWarning ()
-			=> LoggingService.LogWarning ("UI thread queried MEF while it was still being built:{0}{1}", Environment.NewLine, Environment.StackTrace);
-
-		static void UninitializedThrowException ()
-			=> throw new InvalidOperationException ("MEF queried while it was still being built");
-
-		internal static void ConfigureUninitializedMefHandling (bool throwException)
-			=> HandleMefQueriedBeforeCompletion = throwException ? new Action (UninitializedThrowException) : new Action (UninitializedLogWarning);
-
 		public static CompositionManager Instance {
 			get {
 				if (instance == null) {
 					var task = Runtime.GetService<CompositionManager> ();
 					if (!task.IsCompleted && Runtime.IsMainThread) {
-						HandleMefQueriedBeforeCompletion ();
+						LoggingService.LogWarning ("UI thread queried MEF while it was still being built:{0}{1}", Environment.NewLine, Environment.StackTrace);
 					}
 					instance = task.WaitAndGetResult ();
 				}
@@ -82,8 +71,20 @@ public static CompositionManager Instance {
 		}
 
 		protected override Task OnInitialize (ServiceProvider serviceProvider)
-		{
-			return Task.Run (async () => await InitializeInstanceAsync ());
+		{
+			return Runtime.RunInMainThread (() => {
+				var timings = new Dictionary<string, long> ();
+				var metadata = new CompositionLoadMetadata (timings);
+
+				var timer = Counters.CompositionLoad.BeginTiming (metadata);
+				var stepTimer = System.Diagnostics.Stopwatch.StartNew ();
+
+				var mefAssemblies = ReadAssembliesFromAddins (timer);
+
+				timings ["ReadFromAddins"] = stepTimer.ElapsedMilliseconds;
+
+				return Task.Run (() => InitializeInstanceAsync (timer, mefAssemblies));
+			});
 		}
 
 		/// <summary>
@@ -115,49 +116,42 @@ internal CompositionManager ()
 		{
 		}
 
-		async Task InitializeInstanceAsync ()
+		async Task InitializeInstanceAsync (ITimeTracker<CompositionLoadMetadata> timer, HashSet<Assembly> mefAssemblies)
 		{
-			var timings = new Dictionary<string, long> ();
-			var metadata = new CompositionLoadMetadata (timings);
-
-			using (var timer = Counters.CompositionLoad.BeginTiming (metadata)) {
-				var fullTimer = System.Diagnostics.Stopwatch.StartNew ();
-				var stepTimer = System.Diagnostics.Stopwatch.StartNew ();
-
-				var mefAssemblies = ReadAssembliesFromAddins (timer);
-				timings ["ReadFromAddins"] = stepTimer.ElapsedMilliseconds;
-				stepTimer.Restart ();
-
-				var caching = new Caching (mefAssemblies, new IdeRuntimeCompositionExceptionHandler ());
+			var metadata = timer.Metadata;
+			var fullTimer = System.Diagnostics.Stopwatch.StartNew ();
+			var stepTimer = System.Diagnostics.Stopwatch.StartNew ();
 
-				// Try to use cached MEF data
+			var caching = new Caching (mefAssemblies, new IdeRuntimeCompositionExceptionHandler ());
 
+			// Try to use cached MEF data
+			using (timer) {
 				var canUse = metadata.ValidCache = caching.CanUse ();
-				if (canUse) {
+				if (canUse) {
 					LoggingService.LogInfo ("Creating MEF composition from cache");
 					RuntimeComposition = await TryCreateRuntimeCompositionFromCache (caching);
-				}
-				timings ["LoadFromCache"] = stepTimer.ElapsedMilliseconds;
+				}
+				metadata.Timings ["LoadFromCache"] = stepTimer.ElapsedMilliseconds;
 				stepTimer.Restart ();
 
 				// Otherwise fallback to runtime discovery.
-				if (RuntimeComposition == null) {
+				if (RuntimeComposition == null) {
 					LoggingService.LogInfo ("Creating MEF composition from runtime");
-					var (runtimeComposition, catalog) = await CreateRuntimeCompositionFromDiscovery (caching, timer);
+					var (runtimeComposition, catalog) = await CreateRuntimeCompositionFromDiscovery (caching, timer);
 					RuntimeComposition = runtimeComposition;
 
 					CachedComposition cacheManager = new CachedComposition ();
 					caching.Write (RuntimeComposition, catalog, cacheManager).Ignore ();
-				}
-				timings ["LoadRuntimeComposition"] = stepTimer.ElapsedMilliseconds;
-				stepTimer.Restart ();
+				}
+				metadata.Timings ["LoadRuntimeComposition"] = stepTimer.ElapsedMilliseconds;
+				stepTimer.Restart ();
 
 				ExportProviderFactory = RuntimeComposition.CreateExportProviderFactory ();
 				ExportProvider = ExportProviderFactory.CreateExportProvider ();
 				HostServices = Microsoft.VisualStudio.LanguageServices.VisualStudioMefHostServices.Create (ExportProvider);
-
-				timings ["CreateServices"] = stepTimer.ElapsedMilliseconds;
-				metadata.Duration = fullTimer.ElapsedMilliseconds;
+
+				metadata.Timings ["CreateServices"] = stepTimer.ElapsedMilliseconds;
+				metadata.Duration = fullTimer.ElapsedMilliseconds;
 			}
 		}
 

main/src/core/MonoDevelop.Ide/MonoDevelop.Ide/Ide.cs

@@ -315,8 +315,6 @@ static void OnInitialized ()
 			Counters.InitializationTracker.Trace ("Running Startup Commands");
 			AddinManager.AddExtensionNodeHandler ("/MonoDevelop/Ide/StartupHandlers", OnExtensionChanged);
 
-			// Let extensions now access CompositionManager.Instance and start asynchronously composing the catalog
-			CompositionManager.ConfigureUninitializedMefHandling (throwException: false);
 			Runtime.GetService<CompositionManager> ().Ignore ();
 		}
 

main/src/core/MonoDevelop.Ide/MonoDevelop.Ide/IdeStartup.cs

@@ -88,8 +88,6 @@ int Run (MonoDevelopOptions options)
 		{
 			UnsetEnvironmentVariables ();
 
-			CompositionManager.ConfigureUninitializedMefHandling (throwException: true);
-
 			LoggingService.LogInfo ("Starting {0} {1}", BrandingService.ApplicationLongName, IdeVersionInfo.MonoDevelopVersion);
 			LoggingService.LogInfo ("Build Information{0}{1}", Environment.NewLine, SystemInformation.GetBuildInformation ());
 			LoggingService.LogInfo ("Running on {0}", RuntimeVersionInfo.GetRuntimeInfo ());