Add functionality to shutdown Kusto process when parent process exits (#1609)

src/Microsoft.SqlTools.Hosting/Utility/ProcessExitTimer.cs

@@ -0,0 +1,44 @@
+//
+// 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 System.Diagnostics;
+using System.Threading;
+
+namespace Microsoft.SqlTools.Utility
+{
+    public static class ProcessExitTimer
+    {
+        /// <summary>
+        /// Starts a thread that checks if the provided parent process has exited each time the provided interval has elapsed.
+        /// Once the parent process has exited the process that started the timer also exits.
+        /// </summary>
+        /// <param name="parentProcessId">The ID of the parent process to monitor.</param>
+        /// <param name="intervalMs">The time interval in milliseconds for when to poll the parent process.</param>
+        /// <returns>The ID of the thread running the timer.</returns>
+        public static int Start(int parentProcessId, int intervalMs = 10000)
+        {
+            var statusThread = new Thread(() => CheckParentStatusLoop(parentProcessId, intervalMs));
+            statusThread.Start();
+            return statusThread.ManagedThreadId;
+        }
+
+        private static void CheckParentStatusLoop(int parentProcessId, int intervalMs)
+        {
+            var parent = Process.GetProcessById(parentProcessId);
+            Logger.Write(TraceEventType.Information, $"Starting thread to check status of parent process. Parent PID: {parent.Id}");
+            while (true)
+            {
+                if (parent.HasExited)
+                {
+                    var processName = Process.GetCurrentProcess().ProcessName;
+                    Logger.Write(TraceEventType.Information, $"Terminating {processName} process because parent process has exited. Parent PID: {parent.Id}");
+                    Environment.Exit(0);
+                }
+                Thread.Sleep(intervalMs);
+            }
+        }
+    }
+}