Added cancelation support for client.

src/Build/BackEnd/Client/MSBuildClient.cs

@@ -188,6 +188,9 @@ public MSBuildClientExitResult Execute(string commandLine, CancellationToken can
                     {
                         case 0:
                             HandleCancellation();
+                            // After the cancelation, we want to wait to server gracefuly finish the build.
+                            // We have to replace the cancelation handle, because WaitAny would cause to repeatedly hit this branch of code.
+                            waitHandles[0] = CancellationToken.None.WaitHandle;
                             break;
 
                         case 1:
@@ -196,8 +199,7 @@ public MSBuildClientExitResult Execute(string commandLine, CancellationToken can
 
                         case 2:
                             while (packetPump.ReceivedPacketsQueue.TryDequeue(out INodePacket? packet) &&
-                                   !_buildFinished &&
-                                   !cancellationToken.IsCancellationRequested)
+                                   !_buildFinished)
                             {
                                 if (packet != null)
                                 {
@@ -230,7 +232,24 @@ private void SupportVT100()
             }
         }
 
-        private void SendCancelCommand(NamedPipeClientStream nodeStream) => throw new NotImplementedException();
+        private bool TrySendPacket(Func<INodePacket> packetResolver)
+        {
+            INodePacket? packet = null;
+            try
+            {
+                packet = packetResolver();
+                WritePacket(_nodeStream, packet);
+                CommunicationsUtilities.Trace($"Command packet of type '{packet.Type}' sent...");
+            }
+            catch (Exception ex)
+            {
+                CommunicationsUtilities.Trace($"Failed to send command packet of type '{packet?.Type.ToString() ?? "Unknown"}' to server: {0}", ex);
+                _exitResult.MSBuildClientExitType = MSBuildClientExitType.ConnectionError;
+                return false;
+            }
+
+            return true;
+        }
 
         /// <summary>
         /// Launches MSBuild server. 
@@ -278,23 +297,9 @@ private bool TryLaunchServer()
             return true;
         }
 
-        private bool TrySendBuildCommand(string commandLine)
-        {
-            try
-            {
-                ServerNodeBuildCommand buildCommand = GetServerNodeBuildCommand(commandLine);
-                WritePacket(_nodeStream, buildCommand);
-                CommunicationsUtilities.Trace("Build command sent...");
-            }
-            catch (Exception ex)
-            {
-                CommunicationsUtilities.Trace("Failed to send build command to server: {0}", ex);
-                _exitResult.MSBuildClientExitType = MSBuildClientExitType.ConnectionError;
-                return false;
-            }
+        private bool TrySendBuildCommand(string commandLine) => TrySendPacket(() => GetServerNodeBuildCommand(commandLine));
 
-            return true;
-        }
+        private bool TrySendCancelCommand() => TrySendPacket(() => new ServerNodeBuildCancel());
 
         private ServerNodeBuildCommand GetServerNodeBuildCommand(string commandLine)
         {
@@ -331,14 +336,9 @@ private ServerNodeHandshake GetHandshake()
         /// </summary>
         private void HandleCancellation()
         {
-            // TODO.
-            // Send cancellation command to server.
-            // SendCancelCommand(_nodeStream);
+            TrySendCancelCommand();
 
-            Console.WriteLine("MSBuild client cancelled.");
-            CommunicationsUtilities.Trace("MSBuild client cancelled.");
-            _exitResult.MSBuildClientExitType = MSBuildClientExitType.Cancelled;
-            _buildFinished = true;
+            CommunicationsUtilities.Trace("MSBuild client sent cancelation command.");
         }
 
         /// <summary>

src/Build/BackEnd/Client/MSBuildClientExitType.cs

@@ -24,10 +24,6 @@ public enum MSBuildClientExitType
         /// The build stopped unexpectedly, for example,
         /// because a named pipe between the server and the client was unexpectedly closed.
         /// </summary>
-        Unexpected,
-        /// <summary>
-        /// The build was cancelled.
-        /// </summary>
-        Cancelled
+        Unexpected
     }
 }

src/Build/BackEnd/Node/OutOfProcServerNode.cs

@@ -20,8 +20,6 @@ public sealed class OutOfProcServerNode : INode, INodePacketFactory, INodePacket
     {
         private readonly Func<string, (int exitCode, string exitType)> _buildFunction;
 
-        private readonly Action _onCancel;
-
         /// <summary>
         /// The endpoint used to talk to the host.
         /// </summary>
@@ -62,14 +60,11 @@ public sealed class OutOfProcServerNode : INode, INodePacketFactory, INodePacket
         /// </summary>
         private readonly bool _debugCommunications;
 
-        private Task? _buildTask;
-
         private string _serverBusyMutexName = default!;
 
-        public OutOfProcServerNode(Func<string, (int exitCode, string exitType)> buildFunction, Action onCancel)
+        public OutOfProcServerNode(Func<string, (int exitCode, string exitType)> buildFunction)
         {
             _buildFunction = buildFunction;
-            _onCancel = onCancel;
             new Dictionary<string, string>();
             _debugCommunications = (Environment.GetEnvironmentVariable("MSBUILDDEBUGCOMM") == "1");
 
@@ -279,14 +274,14 @@ private void HandlePacket(INodePacket packet)
                     HandleServerNodeBuildCommandAsync((ServerNodeBuildCommand)packet);
                     break;
                 case NodePacketType.ServerNodeBuildCancel:
-                    _onCancel();
+                    BuildManager.DefaultBuildManager.CancelAllSubmissions();
                     break;
             }
         }
 
         private void HandleServerNodeBuildCommandAsync(ServerNodeBuildCommand command)
         {
-            _buildTask = Task.Run(() =>
+            Task.Run(() =>
             {
                 try
                 {
@@ -298,10 +293,6 @@ private void HandleServerNodeBuildCommandAsync(ServerNodeBuildCommand command)
                     _shutdownReason = NodeEngineShutdownReason.Error;
                     _shutdownEvent.Set();
                 }
-                finally
-                {
-                    _buildTask = null;
-                }
             });
         }
 

src/Build/BackEnd/Node/ServerNodeBuildCancel.cs

@@ -5,7 +5,7 @@
 namespace Microsoft.Build.BackEnd
 {
     internal sealed class ServerNodeBuildCancel : INodePacket
-    {
+    { 
         public NodePacketType Type => NodePacketType.ServerNodeBuildCancel;
 
         public void Translate(ITranslator translator)

src/Build/PublicAPI/net/PublicAPI.Unshipped.txt

@@ -9,12 +9,11 @@ Microsoft.Build.Execution.MSBuildClientExitResult.MSBuildClientExitResult() -> v
 Microsoft.Build.Execution.MSBuildClientExitResult.MSBuildClientExitType.get -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitResult.MSBuildClientExitType.set -> void
 Microsoft.Build.Execution.MSBuildClientExitType
-Microsoft.Build.Execution.MSBuildClientExitType.Cancelled = 5 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.ConnectionError = 2 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.LaunchError = 3 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.ServerBusy = 1 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.Success = 0 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.Unexpected = 4 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.OutOfProcServerNode
-Microsoft.Build.Execution.OutOfProcServerNode.OutOfProcServerNode(System.Func<string, (int exitCode, string exitType)> buildFunction, System.Action onCancel) -> void
+Microsoft.Build.Execution.OutOfProcServerNode.OutOfProcServerNode(System.Func<string, (int exitCode, string exitType)> buildFunction) -> void
 Microsoft.Build.Execution.OutOfProcServerNode.Run(out System.Exception shutdownException) -> Microsoft.Build.Execution.NodeEngineShutdownReason

src/Build/PublicAPI/netstandard/PublicAPI.Unshipped.txt

@@ -9,12 +9,11 @@ Microsoft.Build.Execution.MSBuildClientExitResult.MSBuildClientExitResult() -> v
 Microsoft.Build.Execution.MSBuildClientExitResult.MSBuildClientExitType.get -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitResult.MSBuildClientExitType.set -> void
 Microsoft.Build.Execution.MSBuildClientExitType
-Microsoft.Build.Execution.MSBuildClientExitType.Cancelled = 5 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.ConnectionError = 2 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.LaunchError = 3 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.ServerBusy = 1 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.Success = 0 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.MSBuildClientExitType.Unexpected = 4 -> Microsoft.Build.Execution.MSBuildClientExitType
 Microsoft.Build.Execution.OutOfProcServerNode
-Microsoft.Build.Execution.OutOfProcServerNode.OutOfProcServerNode(System.Func<string, (int exitCode, string exitType)> buildFunction, System.Action onCancel) -> void
+Microsoft.Build.Execution.OutOfProcServerNode.OutOfProcServerNode(System.Func<string, (int exitCode, string exitType)> buildFunction) -> void
 Microsoft.Build.Execution.OutOfProcServerNode.Run(out System.Exception shutdownException) -> Microsoft.Build.Execution.NodeEngineShutdownReason

src/MSBuild/XMake.cs

@@ -224,6 +224,8 @@ string[] args
             int exitCode;
             if (ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave17_4) && Environment.GetEnvironmentVariable(Traits.UseMSBuildServerEnvVarName) == "1")
             {
+                Console.CancelKeyPress += Console_CancelKeyPress;
+
                 DebuggerLaunchCheck();
 
                 // Use the client app to execute build in msbuild server. Opt-in feature.
@@ -876,8 +878,7 @@ private static void Console_CancelKeyPress(object sender, ConsoleCancelEventArgs
         {
             if (e.SpecialKey == ConsoleSpecialKey.ControlBreak)
             {
-                e.Cancel = false; // required; the process will now be terminated rudely
-                return;
+                Environment.Exit(1); // the process will now be terminated rudely
             }
 
             e.Cancel = true; // do not terminate rudely
@@ -2702,14 +2703,7 @@ private static void StartLocalNode(CommandLineSwitches commandLineSwitches, bool
                         return (exitCode, exitType.ToString());
                     };
 
-                    Action onCancel = () =>
-                    {
-                        Console.WriteLine(ResourceUtilities.GetResourceString("AbortingBuild"));
-
-                        BuildManager.DefaultBuildManager.CancelAllSubmissions();
-                    };
-
-                    OutOfProcServerNode node = new(buildFunction, onCancel);
+                    OutOfProcServerNode node = new(buildFunction);
 
                     s_isServerNode = true;
                     shutdownReason = node.Run(out nodeException);