Shutdown Gracefully on Kill or Interrupt.

neo-cli/Services/ConsoleServiceBase.cs

@@ -4,9 +4,12 @@
 using System.Globalization;
 using System.IO;
 using System.Reflection;
+using System.Runtime.Loader;
 using System.Security;
 using System.ServiceProcess;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace Neo.Services
 {
@@ -19,6 +22,10 @@ public abstract class ConsoleServiceBase
 
         protected bool ShowPrompt { get; set; } = true;
 
+        private bool _running;
+        private readonly CancellationTokenSource _shutdownTokenSource = new CancellationTokenSource();
+        private readonly CountdownEvent _shutdownAcknowledged = new CountdownEvent(1);
+
         protected virtual bool OnCommand(string[] args)
         {
             switch (args[0].ToLower())
@@ -211,6 +218,27 @@ public static SecureString ReadSecureString(string prompt)
             return securePwd;
         }
 
+        private void TriggerGracefulShutdown()
+        {
+            if (!_running) return;
+            _running = false;
+            _shutdownTokenSource.Cancel();
+            // Wait for us to have triggered shutdown.
+            _shutdownAcknowledged.Wait();
+            // Wait slightly longer for the main thread to finish.
+            Thread.Sleep(100);
+        }
+
+        private void SigTermEventHandler(AssemblyLoadContext obj)
+        {
+            TriggerGracefulShutdown();
+        }
+
+        private void CancelHandler(object sender, ConsoleCancelEventArgs e)
+        {
+            TriggerGracefulShutdown();
+        }
+
         public void Run(string[] args)
         {
             if (Environment.UserInteractive)
@@ -259,6 +287,7 @@ public void Run(string[] args)
                     OnStart(args);
                     RunConsole();
                     OnStop();
+                    _shutdownAcknowledged.Signal();
                 }
             }
             else
@@ -267,9 +296,28 @@ public void Run(string[] args)
             }
         }
 
+        protected string ReadLine()
+        {
+            Task<string> readLineTask = Task.Run(() => Console.ReadLine());
+            try
+            {
+                readLineTask.Wait(_shutdownTokenSource.Token);
+            }
+            catch (OperationCanceledException)
+            {
+                return null;
+            }
+
+            return readLineTask.Result;
+        }
+
         private void RunConsole()
         {
-            bool running = true;
+            _running = true;
+            // Register sigterm event handler
+            AssemblyLoadContext.Default.Unloading += SigTermEventHandler;
+            // Register sigint event handler
+            Console.CancelKeyPress += CancelHandler;
             string[] emptyarg = new string[] { "" };
             if (Environment.OSVersion.Platform == PlatformID.Win32NT)
                 Console.Title = ServiceName;
@@ -278,7 +326,7 @@ private void RunConsole()
             Console.WriteLine($"{ServiceName} Version: {Assembly.GetEntryAssembly().GetVersion()}");
             Console.WriteLine();
 
-            while (running)
+            while (_running)
             {
                 if (ShowPrompt)
                 {
@@ -287,7 +335,7 @@ private void RunConsole()
                 }
 
                 Console.ForegroundColor = ConsoleColor.Yellow;
-                string line = Console.ReadLine()?.Trim();
+                string line = ReadLine()?.Trim();
                 if (line == null) break;
                 Console.ForegroundColor = ConsoleColor.White;
 
@@ -297,7 +345,7 @@ private void RunConsole()
                     if (args.Length == 0)
                         args = emptyarg;
 
-                    running = OnCommand(args);
+                    _running = OnCommand(args);
                 }
                 catch (Exception ex)
                 {

neo-cli/Shell/MainService.cs

@@ -953,7 +953,7 @@ private bool OnShowStateCommand(string[] args)
                     await Task.Delay(500);
                 }
             });
-            Console.ReadLine();
+            ReadLine();
             stop = true;
             task.Wait();
             Console.WriteLine();