SetProcessWorkingSetSize (kernel32)
Last changed: -213.222.246.78

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Summary

C# Signature:

  //hint: nint - platform specific int for pointers (Int32 for x86 or Long for x64)
[DllImport("kernel32.dll")]
static extern bool SetProcessWorkingSetSize(IntPtr hProcess, nint dwMinimumWorkingSetSize, nint dwMaximumWorkingSetSize);

VB.NET Signature:

     'for x86
     Private Declare Function SetProcessWorkingSetSize Lib "kernel32.dll" (ByVal hProcess As IntPtr, ByVal dwMinimumWorkingSetSize As Int32, ByVal dwMaximumWorkingSetSize As Int32) As Int32

     'for x64
     Private Declare Function SetProcessWorkingSetSize Lib "kernel32.dll" (ByVal hProcess As IntPtr, ByVal dwMinimumWorkingSetSize As Long, ByVal dwMaximumWorkingSetSize As Long) As Int32

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Might be better written using int instead of UInt as -1 is a valid value for dwMaximumWorkingSetSize and dwMinimumWorkingSetSize. See Sample Code.

Sample Code:

//sample is probably a bad idea, but it will "trim down" the memory footprint of a .Net App (or at least the value reflected in Task Manager).

C#

   public class MemoryManagement{

        [DllImport("kernel32.dll")]
        public static extern bool SetProcessWorkingSetSize( IntPtr proc, nint min, nint max );

        public void FlushMemory() {
            GC.Collect() ;
            GC.WaitForPendingFinalizers() ;
            if(Environment.OSVersion.Platform == PlatformID.Win32NT) {
                SetProcessWorkingSetSize(System.Diagnostics.Process.GetCurrentProcess().Handle, -1, -1) ;
            }
        }
   }

VB.NET

     Friend Sub ReleaseMemory()
      Try
           GC.Collect()
           GC.WaitForPendingFinalizers()
           If Environment.OSVersion.Platform = PlatformID.Win32NT Then
            SetProcessWorkingSetSize(System.Diagnostics.Process.GetCurrentProcess().Handle, -1, -1)
           End If
      Catch
      End Try
     End Sub    

Alternative Managed API:

Do you know one? Please contribute it!

Documentation