Here a the source code for a small utility app I built
(it is based on Alan Hensel solution, which I found quite useful).
It is called ChildrenProcessKiller and it is a watcher that enables to kill all descendants process of a given parent process when the parent process exits (even if the parent process crashes)
Usage :
ChildrenProcessKiller.exe parentProcessId
Warning : this code is provided "as is", and it might kill small babies ;-)
ChildrenProcessKiller.cs
using System;
using System.Collections.Generic;
using System.Diagnostics;
namespace ChildrenProcessKiller
{
static class ChildrenProcessKiller
{
[STAThread]
static void Main(string[] args)
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
string message = "This is a watcher that enables to kill all descendants process of a given parent process\n";
message += "when the parent process exits (even if the parent process crashes) \n\n";
message += "Usage : " + Application.ExecutablePath + " parentProcessId";
if (args.Length != 1)
{
MessageBox.Show(message);
System.Environment.Exit(1);
}
int parentProcessId;
if (!Int32.TryParse(args[0], out parentProcessId))
{
MessageBox.Show(message);
System.Environment.Exit(1);
}
try
{
mParentProcess = Process.GetProcessById(parentProcessId);
}
catch (System.ArgumentException ex)
{
//Parent process cannot be found!
System.Environment.Exit(2);
}
Run();
}
private static List<Process> mChildrenProcesses;
private static Process mParentProcess;
private static void Run()
{
int thisProcessId = Process.GetCurrentProcess().Id;
while ( ! mParentProcess.HasExited )
{
RefreshChildrenProcesses();
System.Threading.Thread.Sleep(1000);
}
foreach (Process childProcess in mChildrenProcesses)
{
if ((!childProcess.HasExited) && (childProcess.Id != thisProcessId))
{
KillGracefullyThenViolently(childProcess);
}
}
}
private static void KillGracefullyThenViolently(Process process)
{
if (process.HasExited)
return;
try
{
process.CloseMainWindow();
}
catch (PlatformNotSupportedException)
{}
catch (InvalidOperationException)
{}//do nothing : this app is meant to be "unstoppable", unless the parent process has exited
for (int i = 0; i < 15; i++)
{
System.Threading.Thread.Sleep(100);
if (process.HasExited)
return;
}
try
{
process.Kill();
}
catch (System.ComponentModel.Win32Exception)
{}
catch(NotSupportedException)
{}
catch(InvalidOperationException)
{} //same comment here
}
private static void RefreshChildrenProcesses()
{
if (mParentProcess.HasExited)
return;
List<Process> newChildren;
try
{
newChildren = Utils.ProcessTree.GetProcessDescendants(mParentProcess);
mChildrenProcesses = newChildren;
}
catch (System.Exception ex)
{
;
}
}
}
}
ProcessTree.cs
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Collections.Generic;
using System.IO;
using System.Windows.Forms;
namespace Utils
{
public static class ProcessTree
{
public static List<Process> GetProcessDescendants(Process process)
{
List<Process> result = new List<Process>();
foreach (Process eachProcess in Process.GetProcesses())
{
if (ParentPid(eachProcess) == process.Id)
{
result.Add(eachProcess);
}
}
return result;
}
public static void KillDescendants(Process processToNotKillYet)
{
foreach (Process eachProcess in Process.GetProcesses())
{
if (ParentPid(eachProcess) == processToNotKillYet.Id)
{
if (eachProcess.Id != Process.GetCurrentProcess().Id)
KillTree(eachProcess);
}
}
}
public static void KillTree(Process processToKill)
{
KillDescendants(processToKill);
processToKill.Kill();
}
public static PROCESS_BASIC_INFORMATION Info(Process process)
{
PROCESS_BASIC_INFORMATION processInfo = new PROCESS_BASIC_INFORMATION();
try
{
uint bytesWritten;
NtQueryInformationProcess(process.Handle,
0,
ref processInfo,
(uint)Marshal.SizeOf(processInfo),
out bytesWritten); // == 0 is OK
}
catch (Win32Exception e)
{
if (!e.Message.Equals("Access is denied")) throw;
}
return processInfo;
}
public static int ParentPid(Process process)
{
return Info(process).ParentPid;
}
[DllImport("ntdll.dll")]
private static extern int NtQueryInformationProcess(
IntPtr hProcess,
int processInformationClass /* 0 */,
ref PROCESS_BASIC_INFORMATION processBasicInformation,
uint processInformationLength,
out uint returnLength);
[StructLayout(LayoutKind.Sequential)]
public struct PROCESS_BASIC_INFORMATION
{
public int ExitStatus;
public int PebBaseAddress;
public int AffinityMask;
public int BasePriority;
public int Pid;
public int ParentPid;
}
}
}