Fix failure to initialize RemoteWorkspace in the out-of-process host

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

@@ -381,7 +381,7 @@ private static async Task<SolutionService> GetSolutionServiceAsync(Solution solu
             var storage = new AssetStorage();
             var source = new TestAssetSource(storage, map);
             var remoteWorkspace = new RemoteWorkspace();
-            var service = new SolutionService(new AssetService(sessionId, storage, remoteWorkspace), remoteWorkspace);
+            var service = new SolutionService(new AssetService(sessionId, storage, remoteWorkspace));
 
             return service;
         }

src/Workspaces/Remote/Core/Services/RoslynServices.cs

@@ -78,7 +78,7 @@ public RoslynServices(int scopeId, AssetStorage storage, HostServices hostServic
             var workspace = (RemoteWorkspace)primaryWorkspace.Workspace ?? new RemoteWorkspace();
 
             AssetService = new AssetService(_scopeId, storage, workspace);
-            SolutionService = new SolutionService(AssetService, workspace);
+            SolutionService = new SolutionService(AssetService);
             CompilationService = new CompilationService(SolutionService);
         }
 

src/Workspaces/Remote/Core/Services/SolutionService.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Host.Mef;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Remote
@@ -22,15 +24,27 @@ internal class SolutionService : ISolutionController
         private volatile static Tuple<Checksum, Solution> s_primarySolution;
         private volatile static Tuple<Checksum, Solution> s_lastSolution;
 
-        public SolutionService(AssetService assetService, RemoteWorkspace remoteWorkspace)
+        public SolutionService(AssetService assetService)
         {
             _assetService = assetService;
-            PrimaryWorkspace = remoteWorkspace;
         }
 
-        public RemoteWorkspace PrimaryWorkspace
+        public static RemoteWorkspace PrimaryWorkspace
         {
-            get;
+            get
+            {
+                var exportProvider = (IMefHostExportProvider)RoslynServices.HostServices;
+                var primaryWorkspace = exportProvider.GetExports<PrimaryWorkspace>().Single().Value;
+                if (primaryWorkspace.Workspace == null)
+                {
+                    // The Roslyn OOP service assumes a singleton workspace exists, but doesn't initialize it anywhere.
+                    // If we get here, code is asking for a workspace before it exists, so we create one on the fly.
+                    // The RemoteWorkspace constructor assigns itself as the new singleton instance.
+                    new RemoteWorkspace();
+                }
+
+                return (RemoteWorkspace)primaryWorkspace.Workspace;
+            }
         }
 
         public Task<Solution> GetSolutionAsync(Checksum solutionChecksum, CancellationToken cancellationToken)

src/Workspaces/Remote/ServiceHub/Services/CodeAnalysisService_Diagnostics.cs

@@ -62,7 +62,7 @@ public void ReportAnalyzerPerformance(List<AnalyzerPerformanceInfo> snapshot, in
                 {
                     token.ThrowIfCancellationRequested();
 
-                    var service = RoslynServices.SolutionService.PrimaryWorkspace.Services.GetService<IPerformanceTrackerService>();
+                    var service = SolutionService.PrimaryWorkspace.Services.GetService<IPerformanceTrackerService>();
                     if (service == null)
                     {
                         return;

src/Workspaces/Remote/ServiceHub/Services/RemoteHostService.cs

@@ -220,10 +220,10 @@ private void SetGlobalContext(int uiCultureLCID, int cultureLCID, string seriali
             FatalError.NonFatalHandler = WatsonReporter.Report;
 
             // start performance reporter
-            var diagnosticAnalyzerPerformanceTracker = RoslynServices.SolutionService.PrimaryWorkspace.Services.GetService<IPerformanceTrackerService>();
+            var diagnosticAnalyzerPerformanceTracker = SolutionService.PrimaryWorkspace.Services.GetService<IPerformanceTrackerService>();
             if (diagnosticAnalyzerPerformanceTracker != null)
             {
-                var globalOperationNotificationService = RoslynServices.SolutionService.PrimaryWorkspace.Services.GetService<IGlobalOperationNotificationService>();
+                var globalOperationNotificationService = SolutionService.PrimaryWorkspace.Services.GetService<IGlobalOperationNotificationService>();
                 _performanceReporter = new PerformanceReporter(Logger, diagnosticAnalyzerPerformanceTracker, globalOperationNotificationService, s_reportInterval, ShutdownCancellationToken);
             }
         }
@@ -265,12 +265,12 @@ private static TelemetrySession GetTelemetrySession(string serializedSession)
 
         private RemotePersistentStorageLocationService GetPersistentStorageService()
         {
-            return (RemotePersistentStorageLocationService)RoslynServices.SolutionService.PrimaryWorkspace.Services.GetService<IPersistentStorageLocationService>();
+            return (RemotePersistentStorageLocationService)SolutionService.PrimaryWorkspace.Services.GetService<IPersistentStorageLocationService>();
         }
 
         private RemoteGlobalOperationNotificationService GetGlobalOperationNotificationService()
         {
-            var notificationService = RoslynServices.SolutionService.PrimaryWorkspace.Services.GetService<IGlobalOperationNotificationService>() as RemoteGlobalOperationNotificationService;
+            var notificationService = SolutionService.PrimaryWorkspace.Services.GetService<IGlobalOperationNotificationService>() as RemoteGlobalOperationNotificationService;
             return notificationService;
         }