Revert "Simplify updating the primary workspace without passing in a version"

src/EditorFeatures/Core/Remote/SolutionChecksumUpdater.cs

@@ -60,6 +60,9 @@ public SolutionChecksumUpdater(
             listener,
             shutdownToken);
 
+        // Use an equality comparer here as we will commonly get lots of change notifications that will all be
+        // associated with the same cancellation token controlling that batch of work.  No need to enqueue the same
+        // token a huge number of times when we only need the single value of it when doing the work.
         _synchronizeWorkspaceQueue = new AsyncBatchingWorkQueue(
             DelayTimeSpan.NearImmediate,
             SynchronizePrimaryWorkspaceAsync,
@@ -139,15 +142,17 @@ private void OnWorkspaceChanged(object? sender, WorkspaceChangeEventArgs e)
 
     private async ValueTask SynchronizePrimaryWorkspaceAsync(CancellationToken cancellationToken)
     {
+        var solution = _workspace.CurrentSolution;
         var client = await RemoteHostClient.TryGetClientAsync(_workspace, cancellationToken).ConfigureAwait(false);
         if (client == null)
             return;
 
         using (Logger.LogBlock(FunctionId.SolutionChecksumUpdater_SynchronizePrimaryWorkspace, cancellationToken))
         {
+            var workspaceVersion = solution.WorkspaceVersion;
             await client.TryInvokeAsync<IRemoteAssetSynchronizationService>(
-                _workspace.CurrentSolution,
-                (service, solution, cancellationToken) => service.SynchronizePrimaryWorkspaceAsync(solution, cancellationToken),
+                solution,
+                (service, solution, cancellationToken) => service.SynchronizePrimaryWorkspaceAsync(solution, workspaceVersion, cancellationToken),
                 cancellationToken).ConfigureAwait(false);
         }
     }

src/VisualStudio/Core/Test.Next/Services/ServiceHubServicesTests.cs

@@ -137,7 +137,7 @@ public async Task TestDesignerAttributes()
             // Ensure remote workspace is in sync with normal workspace.
             var assetProvider = await GetAssetProviderAsync(workspace, remoteWorkspace, solution);
             var solutionChecksum = await solution.CompilationState.GetChecksumAsync(CancellationToken.None);
-            await remoteWorkspace.UpdatePrimaryBranchSolutionAsync(assetProvider, solutionChecksum, CancellationToken.None);
+            await remoteWorkspace.UpdatePrimaryBranchSolutionAsync(assetProvider, solutionChecksum, solution.WorkspaceVersion, CancellationToken.None);
 
             var callback = new DesignerAttributeComputerCallback();
 
@@ -188,7 +188,7 @@ public async Task TestDesignerAttributesUnsupportedLanguage()
             // Ensure remote workspace is in sync with normal workspace.
             var assetProvider = await GetAssetProviderAsync(workspace, remoteWorkspace, solution);
             var solutionChecksum = await solution.CompilationState.GetChecksumAsync(CancellationToken.None);
-            await remoteWorkspace.UpdatePrimaryBranchSolutionAsync(assetProvider, solutionChecksum, CancellationToken.None);
+            await remoteWorkspace.UpdatePrimaryBranchSolutionAsync(assetProvider, solutionChecksum, solution.WorkspaceVersion, CancellationToken.None);
 
             var callback = new DesignerAttributeComputerCallback();
 
@@ -359,8 +359,9 @@ public async Task TestRemoteWorkspaceCircularReferences()
             using var remoteWorkspace = new RemoteWorkspace(FeaturesTestCompositions.RemoteHost.GetHostServices());
 
             // this shouldn't throw exception
-            var solution = await remoteWorkspace.GetTestAccessor().UpdateWorkspaceCurrentSolutionAsync(
-                remoteWorkspace.GetTestAccessor().CreateSolutionFromInfo(solutionInfo));
+            var (solution, updated) = await remoteWorkspace.GetTestAccessor().TryUpdateWorkspaceCurrentSolutionAsync(
+                remoteWorkspace.GetTestAccessor().CreateSolutionFromInfo(solutionInfo), workspaceVersion: 1);
+            Assert.True(updated);
             Assert.NotNull(solution);
         }
 
@@ -827,9 +828,10 @@ private static (Project project, ImmutableArray<Document> documents) GetProjectA
 
         private static async Task UpdatePrimaryWorkspace(RemoteHostClient client, Solution solution)
         {
+            var workspaceVersion = solution.WorkspaceVersion;
             await client.TryInvokeAsync<IRemoteAssetSynchronizationService>(
                 solution,
-                async (service, solutionInfo, cancellationToken) => await service.SynchronizePrimaryWorkspaceAsync(solutionInfo, cancellationToken),
+                async (service, solutionInfo, cancellationToken) => await service.SynchronizePrimaryWorkspaceAsync(solutionInfo, workspaceVersion, cancellationToken),
                 CancellationToken.None);
         }