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SYSTEM_MEMORY_LIST_INFORMATION (ntdll)
 
.
Summary
Structure returned by NtQuerySystemInformation in response to SYSTEM_INFORMATION_CLASS.SystemMemoryListInformation = 0x0050

C# Signature:

/// <summary>
/// This structure is defined at 88 bytes.  However on Windows 7 it is 168 bytes.
/// It seems there is more info added but we don't know what it is.  Be sure to
/// allocate at least 168 bytes to your buffer or it will likely fail.
/// </summary>
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct SYSTEM_MEMORY_LIST_INFORMATION // Size=88
{
    public UInt32 ZeroPageCount; // Size=4 Offset=0
    public UInt32 FreePageCount; // Size=4 Offset=4
    public UInt32 ModifiedPageCount; // Size=4 Offset=8
    public UInt32 ModifiedNoWritePageCount; // Size=4 Offset=12
    public UInt32 BadPageCount; // Size=4 Offset=16
    /// <summary>There are 8 priority levels, so array of 8</summary>
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
    public UInt32[] PageCountByPriority; // Size=32 Offset=20
    /// <summary>There are 8 priority levels, so array of 8</summary>
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
    public UInt32[] RepurposedPagesByPriority; // Size=32 Offset=52
    public UInt32 ModifiedPageCountPageFile; // Size=4 Offset=84
}

VB Signature:

Declare Function SYSTEM_MEMORY_LIST_INFORMATION Lib "ntdll.dll" (TODO) As TODO

User-Defined Types:

None.

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

public void Test()
{
    UInt32
        result = 0;

    NativeMethods.SYSTEM_MEMORY_LIST_INFORMATION
        MemoryList;

    UInt32
        returnSize;

    Int32[]
        arr = new Int32[] { (Int32)Commands.MEMORYLIST };

    IntPtr
        buff = Marshal.AllocHGlobal(1024); // should be more than adequate
    try
    {
        result = (UInt32)NativeMethods.NtQuerySystemInformation(NativeMethods.SYSTEM_INFORMATION_CLASS.SystemMemoryListInformation, buff, result, out returnSize);
        if (result != 0)
            // Most likely error is InfoLengthMismatch = 0xc0000004 -- meaning you need to make the buffer larger
            throw new System.ComponentModel.Win32Exception(((NativeMethods.NtStatus)result).ToString());
        MemoryList = (NativeMethods.SYSTEM_MEMORY_LIST_INFORMATION)Marshal.PtrToStructure(buff, typeof(NativeMethods.SYSTEM_MEMORY_LIST_INFORMATION));
    }
    finally
    {
        Marshal.FreeHGlobal(buff);
    }
}


Documentation

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