Remove the cancellation token from the calculation of InProgressState…

src/Workspaces/Core/Portable/Workspace/Solution/SolutionCompilationState.CompilationTracker.CompilationTrackerState.cs

@@ -72,7 +72,7 @@ private sealed class InProgressState : CompilationTrackerState
             /// correct snapshot in that the generators have not been rerun, but may be reusable if the generators
             /// are later found to give the same output.
             /// </summary>
-            public readonly Lazy<Compilation?> LazyStaleCompilationWithGeneratedDocuments;
+            public readonly CancellableLazy<Compilation?> LazyStaleCompilationWithGeneratedDocuments;
 
             /// <summary>
             /// The list of changes that have happened since we last computed a compilation. The oldState corresponds to
@@ -86,7 +86,7 @@ public InProgressState(
                 CreationPolicy creationPolicy,
                 Lazy<Compilation> compilationWithoutGeneratedDocuments,
                 CompilationTrackerGeneratorInfo generatorInfo,
-                Lazy<Compilation?> staleCompilationWithGeneratedDocuments,
+                CancellableLazy<Compilation?> staleCompilationWithGeneratedDocuments,
                 ImmutableList<TranslationAction> pendingTranslationActions)
                 : base(creationPolicy, generatorInfo)
             {
@@ -123,8 +123,8 @@ public InProgressState(
             {
             }
 
-            private static Lazy<Compilation?> CreateLazyCompilation(Compilation? staleCompilationWithGeneratedDocuments)
-                => new(() => staleCompilationWithGeneratedDocuments);
+            private static CancellableLazy<Compilation?> CreateLazyCompilation(Compilation? staleCompilationWithGeneratedDocuments)
+                => new(staleCompilationWithGeneratedDocuments);
         }
 
         /// <summary>

src/Workspaces/Core/Portable/Workspace/Solution/SolutionCompilationState.CompilationTracker.cs

@@ -32,7 +32,7 @@ private partial class CompilationTracker : ICompilationTracker
             private static readonly Func<ProjectState, string> s_logBuildCompilationAsync =
                 state => string.Join(",", state.AssemblyName, state.DocumentStates.Count);
 
-            private static readonly Lazy<Compilation?> s_lazyNullCompilation = new Lazy<Compilation?>(() => null);
+            private static readonly CancellableLazy<Compilation?> s_lazyNullCompilation = new CancellableLazy<Compilation?>((Compilation?)null);
 
             public ProjectState ProjectState { get; }
 
@@ -145,7 +145,7 @@ public ICompilationTracker Fork(
                     var (compilationWithoutGeneratedDocuments, staleCompilationWithGeneratedDocuments) = state switch
                     {
                         InProgressState inProgressState => (inProgressState.LazyCompilationWithoutGeneratedDocuments, inProgressState.LazyStaleCompilationWithGeneratedDocuments),
-                        FinalCompilationTrackerState finalState => (new Lazy<Compilation>(() => finalState.CompilationWithoutGeneratedDocuments), new Lazy<Compilation?>(() => finalState.FinalCompilationWithGeneratedDocuments)),
+                        FinalCompilationTrackerState finalState => (new Lazy<Compilation>(() => finalState.CompilationWithoutGeneratedDocuments), new CancellableLazy<Compilation?>(finalState.FinalCompilationWithGeneratedDocuments)),
                         _ => throw ExceptionUtilities.UnexpectedValue(state.GetType()),
                     };
 
@@ -404,7 +404,7 @@ async Task<InProgressState> CollapseInProgressStateAsync(InProgressState initial
                         var translationAction = inProgressState.PendingTranslationActions[0];
 
                         var compilationWithoutGeneratedDocuments = inProgressState.CompilationWithoutGeneratedDocuments;
-                        var staleCompilationWithGeneratedDocuments = inProgressState.LazyStaleCompilationWithGeneratedDocuments.Value;
+                        var staleCompilationWithGeneratedDocuments = inProgressState.LazyStaleCompilationWithGeneratedDocuments.GetValue(cancellationToken);
 
                         // If staleCompilationWithGeneratedDocuments is the same as compilationWithoutGeneratedDocuments,
                         // then it means a prior run of generators didn't produce any files. In that case, we'll just make
@@ -476,7 +476,7 @@ async Task<FinalCompilationTrackerState> FinalizeCompilationWorkerAsync(InProgre
                     var creationPolicy = inProgressState.CreationPolicy;
                     var generatorInfo = inProgressState.GeneratorInfo;
                     var compilationWithoutGeneratedDocuments = inProgressState.CompilationWithoutGeneratedDocuments;
-                    var staleCompilationWithGeneratedDocuments = inProgressState.LazyStaleCompilationWithGeneratedDocuments.Value;
+                    var staleCompilationWithGeneratedDocuments = inProgressState.LazyStaleCompilationWithGeneratedDocuments.GetValue(cancellationToken);
 
                     // Project is complete only if the following are all true:
                     //  1. HasAllInformation flag is set for the project
@@ -735,7 +735,7 @@ public ICompilationTracker WithCreateCreationPolicy(bool forceRegeneration)
                     skeletonReferenceCacheToClone: _skeletonReferenceCache);
             }
 
-            public ICompilationTracker WithDoNotCreateCreationPolicy(CancellationToken cancellationToken)
+            public ICompilationTracker WithDoNotCreateCreationPolicy()
             {
                 var state = this.ReadState();
 
@@ -792,8 +792,7 @@ public ICompilationTracker WithDoNotCreateCreationPolicy(CancellationToken cance
                     var alreadyParsedTrees = alreadyParsedTreesBuilder.ToImmutableAndClear();
                     var lazyCompilationWithoutGeneratedDocuments = new Lazy<Compilation>(() => this.CreateEmptyCompilation().AddSyntaxTrees(alreadyParsedTrees));
 
-                    // Safe cast to appease NRT system.
-                    var lazyCompilationWithGeneratedDocuments = (Lazy<Compilation?>)lazyCompilationWithoutGeneratedDocuments!;
+                    var lazyCompilationWithGeneratedDocuments = new CancellableLazy<Compilation?>(cancellationToken => lazyCompilationWithoutGeneratedDocuments.Value);
 
                     return new CompilationTracker(
                         frozenProjectState,
@@ -818,8 +817,12 @@ public ICompilationTracker WithDoNotCreateCreationPolicy(CancellationToken cance
                     // us to a frozen state with that information.
                     var generatorInfo = inProgressState.GeneratorInfo;
                     var compilationWithoutGeneratedDocuments = inProgressState.LazyCompilationWithoutGeneratedDocuments;
-                    var compilationWithGeneratedDocuments = new Lazy<Compilation?>(() => compilationWithoutGeneratedDocuments.Value.AddSyntaxTrees(
-                        generatorInfo.Documents.States.Values.Select(state => state.GetSyntaxTree(cancellationToken))));
+
+                    var compilationWithGeneratedDocuments = new CancellableLazy<Compilation?>(cancellationToken =>
+                    {
+                        var syntaxTrees = generatorInfo.Documents.States.Values.Select(state => state.GetSyntaxTree(cancellationToken));
+                        return compilationWithoutGeneratedDocuments.Value.AddSyntaxTrees(syntaxTrees);
+                    });
 
                     return new CompilationTracker(
                         frozenProjectState,
@@ -957,9 +960,9 @@ private void ValidateState(CompilationTrackerState? state)
 
                     ValidateCompilationTreesMatchesProjectState(inProgressState.CompilationWithoutGeneratedDocuments, projectState, generatorInfo: null);
 
-                    if (inProgressState.LazyStaleCompilationWithGeneratedDocuments.Value != null)
+                    if (inProgressState.LazyStaleCompilationWithGeneratedDocuments.GetValue(CancellationToken.None) is Compilation staleCompilationWithGeneratedDocuments)
                     {
-                        ValidateCompilationTreesMatchesProjectState(inProgressState.LazyStaleCompilationWithGeneratedDocuments.Value, projectState, inProgressState.GeneratorInfo);
+                        ValidateCompilationTreesMatchesProjectState(staleCompilationWithGeneratedDocuments, projectState, inProgressState.GeneratorInfo);
                     }
                 }
                 else

src/Workspaces/Core/Portable/Workspace/Solution/SolutionCompilationState.GeneratedFileReplacingCompilationTracker.cs

@@ -83,9 +83,9 @@ public ICompilationTracker WithCreateCreationPolicy(bool forceRegeneration)
                 : new GeneratedFileReplacingCompilationTracker(underlyingTracker, _replacementDocumentStates);
         }
 
-        public ICompilationTracker WithDoNotCreateCreationPolicy(CancellationToken cancellationToken)
+        public ICompilationTracker WithDoNotCreateCreationPolicy()
         {
-            var underlyingTracker = this.UnderlyingTracker.WithDoNotCreateCreationPolicy(cancellationToken);
+            var underlyingTracker = this.UnderlyingTracker.WithDoNotCreateCreationPolicy();
             return underlyingTracker == this.UnderlyingTracker
                 ? this
                 : new GeneratedFileReplacingCompilationTracker(underlyingTracker, _replacementDocumentStates);

src/Workspaces/Core/Portable/Workspace/Solution/SolutionCompilationState.ICompilationTracker.cs

@@ -49,7 +49,7 @@ bool ContainsAssemblyOrModuleOrDynamic(
         /// <summary>
         /// Updates the creation policy for this tracker.  Setting it to <see cref="CreationPolicy.DoNotCreate"/>.
         /// </summary>
-        ICompilationTracker WithDoNotCreateCreationPolicy(CancellationToken cancellationToken);
+        ICompilationTracker WithDoNotCreateCreationPolicy();
 
         Task<VersionStamp> GetDependentVersionAsync(SolutionCompilationState compilationState, CancellationToken cancellationToken);
         Task<VersionStamp> GetDependentSemanticVersionAsync(SolutionCompilationState compilationState, CancellationToken cancellationToken);

src/Workspaces/Core/Portable/Workspace/Solution/SolutionCompilationState.cs

@@ -1323,7 +1323,7 @@ private SolutionCompilationState ComputeFrozenSnapshot(CancellationToken cancell
 
             // Since we're freezing, set both generators and skeletons to not be created.  We don't want to take any
             // perf hit on either of those at all for our clients.
-            var newTracker = oldTracker.WithDoNotCreateCreationPolicy(cancellationToken);
+            var newTracker = oldTracker.WithDoNotCreateCreationPolicy();
             if (oldTracker == newTracker)
                 continue;