From 92787fbfee1e53b4c8fc0740025b441c91455df3 Mon Sep 17 00:00:00 2001
From: Ilya Reva <ilya.reva@gmail.com>
Date: Tue, 19 Dec 2023 13:48:23 +0100
Subject: [PATCH] fix(tools): kill child process on timeout

---
 source/Nuke.Tooling/IProcess.cs               |  11 +-
 source/Nuke.Tooling/NativeProcessExtension.cs | 114 ++++++++++++++++++
 source/Nuke.Tooling/Process2.cs               |   9 +-
 3 files changed, 131 insertions(+), 3 deletions(-)
 create mode 100644 source/Nuke.Tooling/NativeProcessExtension.cs

diff --git a/source/Nuke.Tooling/IProcess.cs b/source/Nuke.Tooling/IProcess.cs
index 365d26b53..18d9d57b5 100644
--- a/source/Nuke.Tooling/IProcess.cs
+++ b/source/Nuke.Tooling/IProcess.cs
@@ -57,7 +57,16 @@ public interface IProcess : IDisposable
     void Kill();
 
     /// <summary>
-    /// Waits for the process to exit. If the process is not exiting within a given timeout, <see cref="Kill"/> is called.
+    /// Calls platform specific code to kill entire process tree.
+    /// </summary>
+    /// <remarks>
+    ///     For Windows it call "taskkill /T /F /PID {process.Id}"
+    ///     For Unix it call combination of "pgrep and kill commands"
+    /// </remarks>
+    void KillTree();
+
+    /// <summary>
+    /// Waits for the process to exit. If the process is not exiting within a given timeout, <see cref="KillTree"/> is called.
     /// </summary>
     /// <returns>
     /// Returns <c>true</c>, if the process exited on its own.
diff --git a/source/Nuke.Tooling/NativeProcessExtension.cs b/source/Nuke.Tooling/NativeProcessExtension.cs
new file mode 100644
index 000000000..920ed986e
--- /dev/null
+++ b/source/Nuke.Tooling/NativeProcessExtension.cs
@@ -0,0 +1,114 @@
+// Copyright 2023 Maintainers of NUKE.
+// Distributed under the MIT License.
+// https://github.com/nuke-build/nuke/blob/master/LICENSE
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Runtime.InteropServices;
+
+namespace Nuke.Common.Tooling;
+
+// https://raw.githubusercontent.com/dotnet/cli/master/test/Microsoft.DotNet.Tools.Tests.Utilities/Extensions/ProcessExtensions.cs
+internal static class NativeProcessExtension
+{
+    private static readonly bool _isWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+    private static readonly TimeSpan _defaultTimeout = TimeSpan.FromSeconds(30);
+
+    internal static void KillTree(this Process process)
+    {
+        process.KillTree(_defaultTimeout);
+    }
+
+    internal static void KillTree(this Process process, TimeSpan timeout)
+    {
+        string stdout;
+        if (_isWindows)
+        {
+            RunProcessAndWaitForExit(
+                "taskkill",
+                $"/T /F /PID {process.Id}",
+                timeout,
+                out stdout);
+        }
+        else
+        {
+            var children = new HashSet<int>();
+            GetAllChildIdsUnix(process.Id, children, timeout);
+            foreach (var childId in children)
+            {
+                KillProcessUnix(childId, timeout);
+            }
+            KillProcessUnix(process.Id, timeout);
+        }
+    }
+
+    private static void GetAllChildIdsUnix(int parentId, ISet<int> children, TimeSpan timeout)
+    {
+        string stdout;
+        var exitCode = RunProcessAndWaitForExit(
+            "pgrep",
+            $"-P {parentId}",
+            timeout,
+            out stdout);
+
+        if (exitCode == 0 && !string.IsNullOrEmpty(stdout))
+        {
+            using (var reader = new StringReader(stdout))
+            {
+                while (true)
+                {
+                    var text = reader.ReadLine();
+                    if (text == null)
+                    {
+                        return;
+                    }
+
+                    int id;
+                    if (int.TryParse(text, out id))
+                    {
+                        children.Add(id);
+                        // Recursively get the children
+                        GetAllChildIdsUnix(id, children, timeout);
+                    }
+                }
+            }
+        }
+    }
+
+    private static void KillProcessUnix(int processId, TimeSpan timeout)
+    {
+        string stdout;
+        RunProcessAndWaitForExit(
+            "kill",
+            $"-TERM {processId}",
+            timeout,
+            out stdout);
+    }
+
+    private static int RunProcessAndWaitForExit(string fileName, string arguments, TimeSpan timeout, out string stdout)
+    {
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = fileName,
+            Arguments = arguments,
+            RedirectStandardOutput = true,
+            UseShellExecute = false
+        };
+
+        var process = Process.Start(startInfo);
+
+        stdout = null;
+        if (process.WaitForExit((int)timeout.TotalMilliseconds))
+        {
+            stdout = process.StandardOutput.ReadToEnd();
+        }
+        else
+        {
+            process.Kill();
+        }
+
+        return process.ExitCode;
+    }
+}
diff --git a/source/Nuke.Tooling/Process2.cs b/source/Nuke.Tooling/Process2.cs
index fb3f1f8ca..56a2eaeb0 100644
--- a/source/Nuke.Tooling/Process2.cs
+++ b/source/Nuke.Tooling/Process2.cs
@@ -44,7 +44,12 @@ public void Dispose()
 
     public void Kill()
     {
-        _process.Kill();
+        _process.Kill(); 
+    }
+
+    public void KillTree()
+    {
+        _process.KillTree();
     }
 
     public bool WaitForExit()
@@ -53,7 +58,7 @@ public bool WaitForExit()
         // use _process.StartTime
         var hasExited = _process.WaitForExit(_timeout ?? -1);
         if (!hasExited)
-            _process.Kill();
+            _process.KillTree();
         return hasExited;
     }
 }