Working example of CreateJobObject/SetInformationJobObject pinvoke in .net?

Solution 1:

This can be little bit late, but still.

I tried all of the examples here, but no one was working for me in 32 and 64 bit mode simultaneously. Finally, I was required to examine all the signatures myself and create corresponding PInvoke routines. I think, somebody else could find this helpful.

Disclaimer: the solution is based on Matt Howells' answer.

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace JobManagement
{
    public 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)]
        [return: MarshalAs(UnmanagedType.Bool)]
        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
            };

            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);
            GC.SuppressFinalize(this);
        }

        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);
        }

    }

    #region Helper classes

    [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
    }

    #endregion

}

Solution 2:

Improving on Alexander's answer, here's a version that uses a SafeHandle. This is a CriticalFinalizerObject that makes working with handles much safer. .NET APIs (such as the Process class) always use SafeHandles with P/Invoke instead of IntPtrs.

internal sealed class ChildProcessManager : IDisposable
{
    private SafeJobHandle _handle;
    private bool _disposed;

    public ChildProcessManager()
    {
        _handle = new SafeJobHandle(CreateJobObject(IntPtr.Zero, null));

        var info = new JOBOBJECT_BASIC_LIMIT_INFORMATION
        {
            LimitFlags = 0x2000
        };

        var extendedInfo = new JOBOBJECT_EXTENDED_LIMIT_INFORMATION
        {
            BasicLimitInformation = info
        };

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

        if (!SetInformationJobObject(_handle, JobObjectInfoType.ExtendedLimitInformation, extendedInfoPtr,
                (uint)length))
        {
            throw new InvalidOperationException($"Unable to set information.  Error: {Marshal.GetLastWin32Error()}");
        }
    }

    public void Dispose()
    {
        if (_disposed) return;

        _handle.Dispose();
        _handle = null;
        _disposed = true;
    }

    private void ValidateDisposed()
    {
        if (_disposed) throw new ObjectDisposedException(nameof(ChildProcessManager));
    }

    public void AddProcess(SafeProcessHandle processHandle)
    {
        ValidateDisposed();
        if (!AssignProcessToJobObject(_handle, processHandle))
        {
            throw new InvalidOperationException("Unable to add the process");
        }
    }

    public void AddProcess(Process process)
    {
        AddProcess(process.SafeHandle);
    }

    public void AddProcess(int processId)
    {
        using (var process = Process.GetProcessById(processId))
        {
            AddProcess(process);
        }
    }

    #region Safe Handle

    // ReSharper disable once ClassNeverInstantiated.Local
    private sealed class SafeJobHandle : SafeHandleZeroOrMinusOneIsInvalid
    {
        public SafeJobHandle(IntPtr handle) : base(true)
        {
            SetHandle(handle);
        }

        protected override bool ReleaseHandle()
        {
            return CloseHandle(handle);
        }

        [DllImport("kernel32", SetLastError = true)]
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        private static extern bool CloseHandle(IntPtr hObject);
    }

    #endregion

    #region Win32
    // ReSharper disable InconsistentNaming

    [DllImport("kernel32", CharSet = CharSet.Unicode)]
    private static extern IntPtr CreateJobObject(IntPtr a, string lpName);

    [DllImport("kernel32")]
    private static extern bool SetInformationJobObject(SafeJobHandle hJob, JobObjectInfoType infoType, IntPtr lpJobObjectInfo, uint cbJobObjectInfoLength);

    [DllImport("kernel32", SetLastError = true)]
    private static extern bool AssignProcessToJobObject(SafeJobHandle job, SafeProcessHandle process);

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

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

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

    [StructLayout(LayoutKind.Sequential)]
    internal 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
    }

    // ReSharper restore InconsistentNaming
    #endregion
}

Solution 3:

To summarize, the signatures posed by Alexander Yezutov work under both x86 and x64. Matt Howells signatures use a number of UInt32's when UIntPtr should be used instead. I used the following P/Invoke signature for the CloseHandle which seems to work fine:

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

The following must be added to the app.manifest as posted by Mas:

<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
<application>
  <!-- A list of all Windows versions that this application is designed to work with. Windows will automatically select the most compatible environment.-->

    <!--The ID below indicates application support for Windows Vista -->
    <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>

    <!--The ID below indicates application support for Windows 7 -->
    <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>

</application>

and lastly, this won't work (at least under Win 7) when launched from Visual Studio. The parent process must be started from Windows Explorer.