First major portion of refactor 90%

The overall architecture of the service host is completed here. However,
this doesn't build because the EditorSession dependencies haven't been
worked out just yet.

src/ServiceHost/LanguageService/Contracts/Completion.cs

@@ -4,9 +4,10 @@
 //
 
 using System.Diagnostics;
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class CompletionRequest
     {

src/ServiceHost/LanguageService/Contracts/Definition.cs

@@ -3,9 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class DefinitionRequest
     {

src/ServiceHost/LanguageService/Contracts/Diagnostics.cs

@@ -3,9 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class PublishDiagnosticsNotification
     {

src/ServiceHost/LanguageService/Contracts/DocumentHighlight.cs

@@ -3,9 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public enum DocumentHighlightKind 
     {

src/ServiceHost/LanguageService/Contracts/ExpandAliasRequest.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class ExpandAliasRequest
     {

src/ServiceHost/LanguageService/Contracts/FindModuleRequest.cs

@@ -3,10 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
 using System.Collections.Generic;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class FindModuleRequest
     {

src/ServiceHost/LanguageService/Contracts/Hover.cs

@@ -3,9 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class MarkedString
     {

src/ServiceHost/LanguageService/Contracts/InstallModuleRequest.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     class InstallModuleRequest
     {

src/ServiceHost/LanguageService/Contracts/References.cs

@@ -3,9 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class ReferencesRequest
     {

src/ServiceHost/LanguageService/Contracts/ShowOnlineHelpRequest.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class ShowOnlineHelpRequest
     {

src/ServiceHost/LanguageService/Contracts/SignatureHelp.cs

@@ -3,9 +3,10 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts
 {
     public class SignatureHelpRequest
     {

src/ServiceHost/LanguageService/LanguageService.cs

@@ -3,31 +3,160 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices;
+using System.Threading.Tasks;
 using Microsoft.SqlTools.EditorServices.Session;
+using Microsoft.SqlTools.EditorServices.Utility;
+using Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
-namespace Microsoft.SqlTools.LanguageSupport
+namespace Microsoft.SqlTools.ServiceLayer.LanguageService
 {
     /// <summary>
     /// Main class for Language Service functionality
     /// </summary>
     public class LanguageService
     {
+
+        #region Singleton Instance Implementation
+
+        private static LanguageService instance;
+
+        public static LanguageService Instance
+        {
+            get
+            {
+                if (instance == null)
+                {
+                    instance = new LanguageService();
+                }
+                return instance;
+            }
+        }
+
+        /// <summary>
+        /// Constructor for the Language Service class
+        /// </summary>
+        /// <param name="context"></param>
+        private LanguageService(SqlToolsContext context)
+        {
+            this.Context = context;
+        }
+
+        /// <summary>
+        /// Default, parameterless contstructor.
+        /// TODO: Remove once the SqlToolsContext stuff is sorted out
+        /// </summary>
+        private LanguageService()
+        {
+            
+        }
+
+        #endregion
+
         /// <summary>
         /// Gets or sets the current SQL Tools context
         /// </summary>
         /// <returns></returns>
         private SqlToolsContext Context { get; set; }
 
-        /// <summary>
-        /// Constructor for the Language Service class
-        /// </summary>
-        /// <param name="context"></param>
-        public LanguageService(SqlToolsContext context)
+        public void InitializeService(ServiceHost.ServiceHost serviceHost)
         {
-            this.Context = context;
+            // Register the requests that this service will handle
+            serviceHost.SetRequestHandler(DefinitionRequest.Type, HandleDefinitionRequest);
+            serviceHost.SetRequestHandler(ReferencesRequest.Type, HandleReferencesRequest);
+            serviceHost.SetRequestHandler(CompletionRequest.Type, HandleCompletionRequest);
+            serviceHost.SetRequestHandler(CompletionResolveRequest.Type, HandleCompletionResolveRequest);
+            serviceHost.SetRequestHandler(SignatureHelpRequest.Type, HandleSignatureHelpRequest);
+            serviceHost.SetRequestHandler(DocumentHighlightRequest.Type, HandleDocumentHighlightRequest);
+            serviceHost.SetRequestHandler(HoverRequest.Type, HandleHoverRequest);
+            serviceHost.SetRequestHandler(DocumentSymbolRequest.Type, HandleDocumentSymbolRequest);
+            serviceHost.SetRequestHandler(WorkspaceSymbolRequest.Type, HandleWorkspaceSymbolRequest);
+
+            // Register a no-op shutdown task for validation of the shutdown logic
+            serviceHost.RegisterShutdownTask(async (shutdownParams, shutdownRequestContext) =>
+            {
+                Logger.Write(LogLevel.Verbose, "Shutting down language service");
+                await Task.FromResult(0);
+            });
         }
 
+        #region Request Handlers
+
+        private static async Task HandleDefinitionRequest(
+            TextDocumentPosition textDocumentPosition,
+            RequestContext<Location[]> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleDefinitionRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleReferencesRequest(
+            ReferencesParams referencesParams,
+            RequestContext<Location[]> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleReferencesRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleCompletionRequest(
+            TextDocumentPosition textDocumentPosition,
+            RequestContext<CompletionItem[]> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleCompletionRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleCompletionResolveRequest(
+            CompletionItem completionItem,
+            RequestContext<CompletionItem> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleCompletionResolveRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleSignatureHelpRequest(
+            TextDocumentPosition textDocumentPosition,
+            RequestContext<SignatureHelp> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleSignatureHelpRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleDocumentHighlightRequest(
+            TextDocumentPosition textDocumentPosition,
+            RequestContext<DocumentHighlight[]> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleDocumentHighlightRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleHoverRequest(
+            TextDocumentPosition textDocumentPosition,
+            RequestContext<Hover> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleHoverRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleDocumentSymbolRequest(
+            TextDocumentIdentifier textDocumentIdentifier,
+            RequestContext<SymbolInformation[]> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleDocumentSymbolRequest");
+            await Task.FromResult(true);
+        }
+
+        private static async Task HandleWorkspaceSymbolRequest(
+            WorkspaceSymbolParams workspaceSymbolParams,
+            RequestContext<SymbolInformation[]> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleWorkspaceSymbolRequest");
+            await Task.FromResult(true);
+        }
+
+        #endregion
+
         /// <summary>
         /// Gets a list of semantic diagnostic marks for the provided script file
         /// </summary>

src/ServiceHost/Program.cs

@@ -2,11 +2,10 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 using System;
-using Microsoft.SqlTools.EditorServices.Protocol.Server;
 using Microsoft.SqlTools.EditorServices.Session;
 using Microsoft.SqlTools.EditorServices.Utility;
 
-namespace Microsoft.SqlTools.ServiceHost
+namespace Microsoft.SqlTools.ServiceLayer
 {     
     /// <summary>
     /// Main application class for SQL Tools API Service Host executable
@@ -31,10 +30,15 @@ namespace Microsoft.SqlTools.ServiceHost
             var hostDetails = new HostDetails(hostName, hostProfileId, hostVersion);     
             var profilePaths = new ProfilePaths(hostProfileId, "baseAllUsersPath", "baseCurrentUserPath");
 
-            // create and run the language server
-            var languageServer = new LanguageServer(hostDetails, profilePaths);            
-            languageServer.Start().Wait();            
-            languageServer.WaitForExit();
+            // Create the service host
+            ServiceHost.ServiceHost serviceHost = ServiceHost.ServiceHost.Create(hostDetails, profilePaths);
+
+            // Initialize the services that will be hosted here
+            LanguageService.LanguageService.Instance.InitializeService(serviceHost);
+
+            // Start the service
+            serviceHost.Start().Wait();
+            serviceHost.WaitForExit();
         }
     }
 }

src/ServiceHost/ServiceHost/Contracts/ClientCapabilities.cs

@@ -4,7 +4,7 @@
 //
 
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Contracts
 {
     /// <summary>
     /// Defines a class that describes the capabilities of a language

src/ServiceHost/ServiceHost/Contracts/Initialize.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Contracts
 {
     public class InitializeRequest
     {

src/ServiceHost/ServiceHost/Contracts/ServerCapabilities.cs

@@ -3,7 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Contracts
 {
     public class ServerCapabilities
     {

src/ServiceHost/ServiceHost/Contracts/Shutdown.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Contracts
 {
     /// <summary>
     /// Defines a message that is sent from the client to request

src/ServiceHost/ServiceHost/Protocol/Channel/ChannelBase.cs

@@ -3,8 +3,8 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol.Serializers;
 using System.Threading.Tasks;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Serializers;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Channel
 {

src/ServiceHost/ServiceHost/Protocol/Channel/StdioClientChannel.cs

@@ -7,6 +7,7 @@ using System.Diagnostics;
 using System.IO;
 using System.Text;
 using System.Threading.Tasks;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Serializers;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Channel
 {

src/ServiceHost/ServiceHost/Protocol/Channel/StdioServerChannel.cs

@@ -6,6 +6,7 @@
 using System.IO;
 using System.Text;
 using System.Threading.Tasks;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Serializers;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Channel
 {

src/ServiceHost/ServiceHost/Protocol/MessageDispatcher.cs

@@ -10,6 +10,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Channel;
 using Microsoft.SqlTools.EditorServices.Utility;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol
 {

src/ServiceHost/ServiceHost/Protocol/Serializers/IMessageSerializer.cs

@@ -3,6 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 using Newtonsoft.Json.Linq;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Serializers

src/ServiceHost/ServiceHost/Protocol/Serializers/JsonRpcMessageSerializer.cs

@@ -3,6 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 using Newtonsoft.Json.Linq;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Serializers

src/ServiceHost/ServiceHost/Protocol/Serializers/V8MessageSerializer.cs

@@ -5,6 +5,7 @@
 
 using Newtonsoft.Json.Linq;
 using System;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Serializers
 {

src/ServiceHost/ServiceHost/ServiceHost.cs

@@ -10,11 +10,13 @@ using System.Threading;
 using System.Linq;
 using System;
 using Microsoft.SqlTools.EditorServices;
-using Microsoft.SqlTools.EditorServices.Protocol.LanguageServer;
 using Microsoft.SqlTools.EditorServices.Session;
 using Microsoft.SqlTools.EditorServices.Utility;
+using Microsoft.SqlTools.ServiceLayer.LanguageService.Contracts;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Contracts;
 using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol;
 using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Channel;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
 {
@@ -23,59 +25,115 @@ namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
     /// </summary>
     public class ServiceHost : ServiceHostBase
     {
+        #region Singleton Instance Code
+
+        /// <summary>
+        /// Singleton instance of the instance
+        /// </summary>
+        private static ServiceHost instance;
+
+        /// <summary>
+        /// Creates or retrieves the current instance of the ServiceHost
+        /// </summary>
+        /// <param name="hostDetails">Details about the host application</param>
+        /// <param name="profilePaths">Details about the profile</param>
+        /// <returns>Instance of the service host</returns>
+        public static ServiceHost Create(HostDetails hostDetails, ProfilePaths profilePaths)
+        {
+            if (instance == null)
+            {
+                instance = new ServiceHost(hostDetails, profilePaths);
+            }
+            // TODO: hostDetails and profilePaths are thrown out in SqlDataToolsContext,
+            // so we don't need to keep track of whether these have changed for now.
+
+            return instance;
+        }
+
+        /// <summary>
+        /// Constructs new instance of ServiceHost using the host and profile details provided.
+        /// Access is private to ensure only one instance exists at a time.
+        /// </summary>
+        /// <param name="hostDetails">Details about the host application</param>
+        /// <param name="profilePaths">Details about the profile</param>
+        private ServiceHost(HostDetails hostDetails, ProfilePaths profilePaths)
+            : base(new StdioServerChannel())
+        {
+            // Initialize the shutdown activities
+            shutdownActivities = new List<ShutdownHandler>();
+
+            // Create an editor session that we'll use for keeping track of state
+            this.editorSession = new EditorSession();
+            this.editorSession.StartSession(hostDetails, profilePaths);
+
+            // Register the requests that this service host will handle
+            this.SetRequestHandler(InitializeRequest.Type, this.HandleInitializeRequest);
+            this.SetRequestHandler(ShutdownRequest.Type, this.HandleShutdownRequest);
+        }
+
+        #endregion
+
+        #region Member Variables
+
         private static CancellationTokenSource existingRequestCancellation;
 
         private ServiceHostSettings currentSettings = new ServiceHostSettings();
         
         private EditorSession editorSession;
 
-        /// <param name="hostDetails">
-        /// Provides details about the host application.
-        /// </param>
-        public ServiceHost(HostDetails hostDetails, ProfilePaths profilePaths)
-            : base(new StdioServerChannel())
+        public delegate Task ShutdownHandler(object shutdownParams, RequestContext<object> shutdownRequestContext);
+
+        private readonly List<ShutdownHandler> shutdownActivities;
+
+        #endregion
+
+        #region Public Methods
+
+        /// <summary>
+        /// Adds a new method to be called when the shutdown request is submitted
+        /// </summary>
+        /// <param name="activity"></param>
+        public void RegisterShutdownTask(ShutdownHandler activity)
         {
-            this.editorSession = new EditorSession();
-            this.editorSession.StartSession(hostDetails, profilePaths);
+            shutdownActivities.Add(activity);
         }
 
+        #endregion
+
+        #region Private Methods
+
         /// <summary>
         /// Initialize the VS Code request/response callbacks
         /// </summary>
-        protected override void Initialize()
+        private void Initialize()
         {
             // Register all supported message types
-            this.SetRequestHandler(InitializeRequest.Type, this.HandleInitializeRequest);
+
             this.SetEventHandler(DidChangeTextDocumentNotification.Type, this.HandleDidChangeTextDocumentNotification);
             this.SetEventHandler(DidOpenTextDocumentNotification.Type, this.HandleDidOpenTextDocumentNotification);
             this.SetEventHandler(DidCloseTextDocumentNotification.Type, this.HandleDidCloseTextDocumentNotification);
             this.SetEventHandler(DidChangeConfigurationNotification<LanguageServerSettingsWrapper>.Type, this.HandleDidChangeConfigurationNotification);
 
-            this.SetRequestHandler(DefinitionRequest.Type, this.HandleDefinitionRequest);
-            this.SetRequestHandler(ReferencesRequest.Type, this.HandleReferencesRequest);
-            this.SetRequestHandler(CompletionRequest.Type, this.HandleCompletionRequest);
-            this.SetRequestHandler(CompletionResolveRequest.Type, this.HandleCompletionResolveRequest);
-            this.SetRequestHandler(SignatureHelpRequest.Type, this.HandleSignatureHelpRequest);
-            this.SetRequestHandler(DocumentHighlightRequest.Type, this.HandleDocumentHighlightRequest);
-            this.SetRequestHandler(HoverRequest.Type, this.HandleHoverRequest);
-            this.SetRequestHandler(DocumentSymbolRequest.Type, this.HandleDocumentSymbolRequest);
-            this.SetRequestHandler(WorkspaceSymbolRequest.Type, this.HandleWorkspaceSymbolRequest);               
+                          
         }
 
         /// <summary>
         /// Handles the shutdown event for the Language Server
         /// </summary>
-        protected override async Task Shutdown()
+        private async Task HandleShutdownRequest(object shutdownParams, RequestContext<object> requestContext)
         {
-            Logger.Write(LogLevel.Normal, "Language service is shutting down...");
+            Logger.Write(LogLevel.Normal, "Service host is shutting down...");
 
+            // Call all the shutdown methods provided by the service components
+            Task[] shutdownTasks = shutdownActivities.Select(t => t(shutdownParams, requestContext)).ToArray();
+            await Task.WhenAll(shutdownTasks);
+
+            // Shutdown the editor session
             if (this.editorSession != null)
             {
                 this.editorSession.Dispose();
                 this.editorSession = null;
             }
-
-            await Task.FromResult(true);
         }
 
         /// <summary>
@@ -84,11 +142,9 @@ namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
         /// <param name="initializeParams"></param>
         /// <param name="requestContext"></param>
         /// <returns></returns>
-        protected async Task HandleInitializeRequest(
-            InitializeRequest initializeParams,
-            RequestContext<InitializeResult> requestContext)
+        private async Task HandleInitializeRequest(InitializeRequest initializeParams, RequestContext<InitializeResult> requestContext)
         {
-            Logger.Write(LogLevel.Verbose, "HandleDidChangeTextDocumentNotification");
+            Logger.Write(LogLevel.Verbose, "HandleInitializationRequest");
 
             // Grab the workspace path from the parameters
            editorSession.Workspace.WorkspacePath = initializeParams.RootPath;
@@ -118,6 +174,11 @@ namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
                 });
         }
 
+        #endregion
+
+        ///////////////////////////////////////////////
+
+
         /// <summary>
         /// Handles text document change events
         /// </summary>
@@ -226,78 +287,6 @@ namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
             await Task.FromResult(true);
         }
 
-        protected async Task HandleDefinitionRequest(
-            TextDocumentPosition textDocumentPosition,
-            RequestContext<Location[]> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleDefinitionRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleReferencesRequest(
-            ReferencesParams referencesParams,
-            RequestContext<Location[]> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleReferencesRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleCompletionRequest(
-            TextDocumentPosition textDocumentPosition,
-            RequestContext<CompletionItem[]> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleCompletionRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleCompletionResolveRequest(
-            CompletionItem completionItem,
-            RequestContext<CompletionItem> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleCompletionResolveRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleSignatureHelpRequest(
-            TextDocumentPosition textDocumentPosition,
-            RequestContext<SignatureHelp> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleSignatureHelpRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleDocumentHighlightRequest(
-            TextDocumentPosition textDocumentPosition,
-            RequestContext<DocumentHighlight[]> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleDocumentHighlightRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleHoverRequest(
-            TextDocumentPosition textDocumentPosition,
-            RequestContext<Hover> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleHoverRequest");
-            await Task.FromResult(true);
-        }
-
-        protected async Task HandleDocumentSymbolRequest(
-            TextDocumentIdentifier textDocumentIdentifier,
-            RequestContext<SymbolInformation[]> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleDocumentSymbolRequest");
-            await Task.FromResult(true);     
-        }
-
-        protected async Task HandleWorkspaceSymbolRequest(
-            WorkspaceSymbolParams workspaceSymbolParams,
-            RequestContext<SymbolInformation[]> requestContext)
-        {
-            Logger.Write(LogLevel.Verbose, "HandleWorkspaceSymbolRequest");
-            await Task.FromResult(true);
-        }
-
         /// <summary>
         /// Runs script diagnostics on changed files
         /// </summary>
@@ -333,7 +322,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
             {
                 Logger.Write(
                     LogLevel.Error,
-                    string.Format(
+                    String.Format(
                         "Exception while cancelling analysis task:\n\n{0}",
                         e.ToString()));
 

src/ServiceHost/ServiceHost/ServiceHostBase.cs

@@ -4,7 +4,7 @@
 //
 
 using System.Threading.Tasks;
-using Microsoft.SqlTools.EditorServices.Protocol.LanguageServer;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Contracts;
 using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol;
 using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Channel;
 
@@ -13,59 +13,22 @@ namespace Microsoft.SqlTools.ServiceLayer.ServiceHost
     public abstract class ServiceHostBase : ProtocolEndpoint
     {
         private bool isStarted;
-        private ChannelBase serverChannel;
         private TaskCompletionSource<bool> serverExitedTask;
 
         public ServiceHostBase(ChannelBase serverChannel) : 
             base(serverChannel, MessageProtocolType.LanguageServer)
         {
-            this.serverChannel = serverChannel;
         }
 
         protected override Task OnStart()
         {
             // Register handlers for server lifetime messages
-            this.SetRequestHandler(ShutdownRequest.Type, this.HandleShutdownRequest);
+            
             this.SetEventHandler(ExitNotification.Type, this.HandleExitNotification);
 
-            // Initialize the implementation class
-            this.Initialize();
-
             return Task.FromResult(true);
         }
 
-        protected override async Task OnStop()
-        {
-            await this.Shutdown();
-        }
-
-        /// <summary>
-        /// Overridden by the subclass to provide initialization
-        /// logic after the server channel is started.
-        /// </summary>
-        protected abstract void Initialize();
-
-        /// <summary>
-        /// Can be overridden by the subclass to provide shutdown
-        /// logic before the server exits.  Subclasses do not need
-        /// to invoke or return the value of the base implementation.
-        /// </summary>
-        protected virtual Task Shutdown()
-        {
-            // No default implementation yet.
-            return Task.FromResult(true);
-        }
-
-        private async Task HandleShutdownRequest(
-            object shutdownParams,
-            RequestContext<object> requestContext)
-        {
-            // Allow the implementor to shut down gracefully
-            await this.Shutdown();
-
-            await requestContext.SendResult(new object());
-        }
-
         private async Task HandleExitNotification(
             object exitParams,
             EventContext eventContext)

src/ServiceHost/Session/EditorSession.cs

@@ -5,7 +5,8 @@
 
 using System;
 using Microsoft.SqlTools.EditorServices.Session;
-using Microsoft.SqlTools.LanguageSupport;
+using Microsoft.SqlTools.ServiceLayer.LanguageService;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts;
 
 namespace Microsoft.SqlTools.EditorServices
 {

src/ServiceHost/WorkspaceService/Contracts/BufferPosition.cs

@@ -5,7 +5,7 @@
 
 using System.Diagnostics;
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Provides details about a position in a file buffer.  All

src/ServiceHost/WorkspaceService/Contracts/BufferRange.cs

@@ -6,7 +6,7 @@
 using System;
 using System.Diagnostics;
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Provides details about a range between two positions in

src/ServiceHost/WorkspaceService/Contracts/Configuration.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     public class DidChangeConfigurationNotification<TConfig> 
     {

src/ServiceHost/WorkspaceService/Contracts/FileChange.cs

@@ -3,7 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Contains details relating to a content change in an open file.

src/ServiceHost/WorkspaceService/Contracts/FilePosition.cs

@@ -3,7 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Provides details and operations for a buffer position in a

src/ServiceHost/WorkspaceService/Contracts/ScriptFile.cs

@@ -9,7 +9,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Contains the details and contents of an open script file.

src/ServiceHost/WorkspaceService/Contracts/ScriptFileMarker.cs

@@ -3,7 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Defines the message level of a script file marker.

src/ServiceHost/WorkspaceService/Contracts/ScriptRegion.cs

@@ -5,7 +5,7 @@
 
 //using System.Management.Automation.Language;
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Contains details about a specific region of text in script file.

src/ServiceHost/WorkspaceService/Contracts/TextDocument.cs

@@ -4,9 +4,9 @@
 //
 
 using System.Diagnostics;
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Defines a base parameter class for identifying a text document.

src/ServiceHost/WorkspaceService/Contracts/Workspace.cs

@@ -11,7 +11,7 @@ using System.Text;
 using System.Text.RegularExpressions;
 using System.Linq;
 
-namespace Microsoft.SqlTools.EditorServices
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     /// <summary>
     /// Manages a "workspace" of script files that are open for a particular

src/ServiceHost/WorkspaceService/Contracts/WorkspaceSymbols.cs

@@ -3,9 +3,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+using Microsoft.SqlTools.ServiceLayer.ServiceHost.Protocol.Contracts;
 
-namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+namespace Microsoft.SqlTools.ServiceLayer.WorkspaceService.Contracts
 {
     public enum SymbolKind 
     {