Merge pull request #12287 from rchande/snippetsAfterSolutionLoad

Initialize snippets after solution load is complete

src/VisualStudio/Core/Def/Implementation/LanguageService/AbstractPackage`2.cs

@@ -96,6 +96,8 @@ protected override void LoadComponentsInUIContext()
 
             _packageInstallerService?.Connect(this.RoslynLanguageName);
             _symbolSearchService?.Connect(this.RoslynLanguageName);
+
+            HACK_AbstractCreateServicesOnUiThread.CreateServicesOnUIThread(ComponentModel, RoslynLanguageName);
         }
 
         protected abstract VisualStudioWorkspaceImpl CreateWorkspace();

src/VisualStudio/Core/Def/Implementation/Snippets/AbstractSnippetInfoService.cs

@@ -113,32 +113,16 @@ private void PopulateSnippetCaches()
         {
             Debug.Assert(_expansionManager != null);
 
-            // If the expansion manager is an IExpansionManager, then we can use the asynchronous
-            // population mechanism it provides. Otherwise, getting snippet information from the
-            // IVsExpansionManager must be done synchronously on the UI thread.
-
-            // IExpansionManager was introduced in Visual Studio 2015 Update 1, but will be enabled
-            // by default for the first time in Visual Studio 2015 Update 2. However, the platform
-            // still supports returning the IVsExpansionManager if a major problem in the 
-            // IExpansionManager is discovered, so we must continue supporting the fallback.            
-
             var token = _waiter.BeginAsyncOperation(GetType().Name + ".Start");
 
-            var asyncExpansionManager = _expansionManager as IExpansionManager;
-            if (asyncExpansionManager != null)
-            {
-                // Call the asynchronous IExpansionManager API from a background thread
-                Task.Run(() => PopulateSnippetCacheAsync(asyncExpansionManager))
-                    .CompletesAsyncOperation(token);
-            }
-            else
-            {
-                // Call the synchronous IVsExpansionManager API from the UI thread
-                Task.Factory.StartNew(() => PopulateSnippetCacheOnForeground(_expansionManager),
-                    CancellationToken.None,
-                    TaskCreationOptions.None,
-                    ForegroundTaskScheduler).CompletesAsyncOperation(token);                
-            }
+            // In Dev14 Update2+ the platform always provides an IExpansion Manager
+            var asyncExpansionManager = (IExpansionManager)_expansionManager;
+            // Call the asynchronous IExpansionManager API from a background thread
+            Task.Factory.StartNew(() => PopulateSnippetCacheAsync(asyncExpansionManager),
+                            CancellationToken.None,
+                            TaskCreationOptions.None,
+                            TaskScheduler.Default).CompletesAsyncOperation(token);
+
         }
 
         private async Task PopulateSnippetCacheAsync(IExpansionManager expansionManager)
@@ -162,26 +146,6 @@ private async Task PopulateSnippetCacheAsync(IExpansionManager expansionManager)
                 ForegroundTaskScheduler).ConfigureAwait(false);
         }
 
-        /// <remarks>
-        /// Changes to the <see cref="IVsExpansionManager.EnumerateExpansions"/> invocation
-        /// should also be made to the IExpansionManager.EnumerateExpansionsAsync
-        /// invocation in <see cref="PopulateSnippetCacheAsync(IExpansionManager)"/>.
-        /// </remarks>
-        private void PopulateSnippetCacheOnForeground(IVsExpansionManager expansionManager)
-        {
-            AssertIsForeground();
-            expansionManager.EnumerateExpansions(
-                _languageGuidForSnippets,
-                fShortCutOnly: 0,
-                bstrTypes: null,
-                iCountTypes: 0,
-                fIncludeNULLType: 1,
-                fIncludeDuplicates: 1, // Allows snippets with the same title but different shortcuts
-                pEnum: out var expansionEnumerator);
-
-            PopulateSnippetCacheFromExpansionEnumeration(expansionEnumerator);
-        }
-
         /// <remarks>
         /// This method must be called on the UI thread because it eventually calls into
         /// IVsExpansionEnumeration.Next, which must be called on the UI thread due to an issue