Merge pull request #15873 from CyrusNajmabadi/noFarProgress

Remove call to SetProgress for performance reasons.

src/VisualStudio/Core/Next/FindReferences/StreamingFindReferencesPresenter.TableDataSourceFindReferencesContext.cs

@@ -580,6 +580,12 @@ private RoslynDefinitionBucket GetOrCreateDefinitionBucket(DefinitionItem defini
 
             public override Task ReportProgressAsync(int current, int maximum)
             {
+                // https://devdiv.visualstudio.com/web/wi.aspx?pcguid=011b8bdf-6d56-4f87-be0d-0092136884d9&id=359162
+                // Right now VS actually responds to each SetProgess call by enqueueing a UI task
+                // to do the progress bar update.  This can made FindReferences feel extremely slow
+                // when thousands of SetProgress calls are made.  So, for now, we're removing
+                // the progress update until the FindRefs window fixes that perf issue.
+#if false
                 try
                 {
                     // The original FAR window exposed a SetProgress(double). Ensure that we 
@@ -589,6 +595,7 @@ public override Task ReportProgressAsync(int current, int maximum)
                 catch
                 {
                 }
+#endif
 
                 return SpecializedTasks.EmptyTask;
             }

src/Workspaces/Core/Portable/FindSymbols/FindReferences/Finders/AbstractReferenceFinder.cs

@@ -87,6 +87,11 @@ protected Task<ImmutableArray<Document>> FindDocumentsAsync(Project project, IIm
             PredefinedType predefinedType,
             CancellationToken cancellationToken)
         {
+            if (predefinedType == PredefinedType.None)
+            {
+                return SpecializedTasks.EmptyImmutableArray<Document>();
+            }
+
             return FindDocumentsAsync(project, documents, async (d, c) =>
             {
                 var info = await SyntaxTreeInfo.GetContextInfoAsync(d, c).ConfigureAwait(false);
@@ -94,7 +99,7 @@ protected Task<ImmutableArray<Document>> FindDocumentsAsync(Project project, IIm
             }, cancellationToken);
         }
 
-        protected async Task<ImmutableArray<Document>> FindDocumentsAsync(
+        protected Task<ImmutableArray<Document>> FindDocumentsAsync(
             Project project,
             IImmutableSet<Document> documents,
             PredefinedOperator op,
@@ -102,14 +107,14 @@ protected Task<ImmutableArray<Document>> FindDocumentsAsync(Project project, IIm
         {
             if (op == PredefinedOperator.None)
             {
-                return ImmutableArray<Document>.Empty;
+                return SpecializedTasks.EmptyImmutableArray<Document>();
             }
 
-            return await FindDocumentsAsync(project, documents, async (d, c) =>
+            return FindDocumentsAsync(project, documents, async (d, c) =>
             {
                 var info = await SyntaxTreeInfo.GetContextInfoAsync(d, c).ConfigureAwait(false);
                 return info.ContainsPredefinedOperator(op);
-            }, cancellationToken).ConfigureAwait(false);
+            }, cancellationToken);
         }
 
         protected static bool IdentifiersMatch(ISyntaxFactsService syntaxFacts, string name, SyntaxToken token)