Job objects in .NET

Job.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

internal class Job : IDisposable
{
    [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
    static extern IntPtr CreateJobObject(IntPtr a, string lpName);

    [DllImport("kernel32.dll")]
    static extern bool SetInformationJobObject(IntPtr hJob, JobObjectInfoType infoType, IntPtr lpJobObjectInfo, UInt32 cbJobObjectInfoLength);

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool AssignProcessToJobObject(IntPtr job, IntPtr process);

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool CloseHandle(IntPtr hObject);

    private IntPtr handle;
    private bool disposed;

    public Job()
    {
        handle = CreateJobObject(IntPtr.Zero, null);

        var info = new JOBOBJECT_BASIC_LIMIT_INFORMATION
        {
            LimitFlags = 0x2000 // JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE.
        };

        var extendedInfo = new JOBOBJECT_EXTENDED_LIMIT_INFORMATION
        {
            BasicLimitInformation = info
        };

        int length = Marshal.SizeOf(typeof(JOBOBJECT_EXTENDED_LIMIT_INFORMATION));
        IntPtr extendedInfoPtr = Marshal.AllocHGlobal(length);
        Marshal.StructureToPtr(extendedInfo, extendedInfoPtr, false);

        if (!SetInformationJobObject(handle, JobObjectInfoType.ExtendedLimitInformation, extendedInfoPtr, (uint)length))
            throw new Exception(string.Format("Unable to set information.  Error: {0}", Marshal.GetLastWin32Error()));
    }

    public void Dispose()
    {
        Dispose(true);
    }

    private void Dispose(bool disposing)
    {
        if (disposed)
            return;

        if (disposing) { }

        Close();
        disposed = true;
    }

    public void Close()
    {
        CloseHandle(handle);
        handle = IntPtr.Zero;
    }

    public bool AddProcess(IntPtr processHandle)
    {
        return AssignProcessToJobObject(handle, processHandle);
    }

    public bool AddProcess(int processId)
    {
        return AddProcess(Process.GetProcessById(processId).Handle);
    }

    [StructLayout(LayoutKind.Sequential)]
    struct IO_COUNTERS
    {
        public UInt64 ReadOperationCount;
        public UInt64 WriteOperationCount;
        public UInt64 OtherOperationCount;
        public UInt64 ReadTransferCount;
        public UInt64 WriteTransferCount;
        public UInt64 OtherTransferCount;
    }


    [StructLayout(LayoutKind.Sequential)]
    struct JOBOBJECT_BASIC_LIMIT_INFORMATION
    {
        public Int64 PerProcessUserTimeLimit;
        public Int64 PerJobUserTimeLimit;
        public UInt32 LimitFlags;
        public UIntPtr MinimumWorkingSetSize;
        public UIntPtr MaximumWorkingSetSize;
        public UInt32 ActiveProcessLimit;
        public UIntPtr Affinity;
        public UInt32 PriorityClass;
        public UInt32 SchedulingClass;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct SECURITY_ATTRIBUTES
    {
        public UInt32 nLength;
        public IntPtr lpSecurityDescriptor;
        public Int32 bInheritHandle;
    }

    [StructLayout(LayoutKind.Sequential)]
    struct JOBOBJECT_EXTENDED_LIMIT_INFORMATION
    {
        public JOBOBJECT_BASIC_LIMIT_INFORMATION BasicLimitInformation;
        public IO_COUNTERS IoInfo;
        public UIntPtr ProcessMemoryLimit;
        public UIntPtr JobMemoryLimit;
        public UIntPtr PeakProcessMemoryUsed;
        public UIntPtr PeakJobMemoryUsed;
    }

    public enum JobObjectInfoType
    {
        AssociateCompletionPortInformation = 7,
        BasicLimitInformation = 2,
        BasicUIRestrictions = 4,
        EndOfJobTimeInformation = 6,
        ExtendedLimitInformation = 9,
        SecurityLimitInformation = 5,
        GroupInformation = 11
    }

}