type
  SIZE_T = Cardinal;
  {$EXTERNALSYM SIZE_T}
  DWORDLONG = Int64; // ULONGLONG
  {$EXTERNALSYM DWORDLONG}

type
  PMemoryStatus = ^TMemoryStatus;
  LPMEMORYSTATUS = PMemoryStatus;
  {$EXTERNALSYM LPMEMORYSTATUS}
  _MEMORYSTATUS = packed record
    dwLength : DWORD;
    dwMemoryLoad : DWORD;
    dwTotalPhys : SIZE_T;
    dwAvailPhys : SIZE_T;
    dwTotalPageFile: SIZE_T;
    dwAvailPageFile: SIZE_T;
    dwTotalVirtual : SIZE_T;
    dwAvailVirtual : SIZE_T;
  end;
  {$EXTERNALSYM _MEMORYSTATUS}
  TMemoryStatus = _MEMORYSTATUS;
  MEMORYSTATUS = _MEMORYSTATUS;
  {$EXTERNALSYM MEMORYSTATUS}

type
  PMemoryStatusEx = ^TMemoryStatusEx;
  LPMEMORYSTATUSEX = PMemoryStatusEx;
  {$EXTERNALSYM LPMEMORYSTATUSEX}
  _MEMORYSTATUSEX = packed record
    dwLength : DWORD;
    dwMemoryLoad : DWORD;
    ullTotalPhys : DWORDLONG;
    ullAvailPhys : DWORDLONG;
    ullTotalPageFile: DWORDLONG;
    ullAvailPageFile: DWORDLONG;
    ullTotalVirtual : DWORDLONG;
    ullAvailVirtual : DWORDLONG;
  end;
  {$EXTERNALSYM _MEMORYSTATUSEX}
  TMemoryStatusEx = _MEMORYSTATUSEX;
  MEMORYSTATUSEX = _MEMORYSTATUSEX;
  {$EXTERNALSYM MEMORYSTATUSEX}

//---

procedure GlobalMemoryStatus(var lpBuffer: TMemoryStatus); stdcall;
  external kernel32;
{$EXTERNALSYM GlobalMemoryStatus}

function GlobalMemoryStatusEx(var lpBuffer: TMemoryStatusEx): BOOL; stdcall;
type
  TFNGlobalMemoryStatusEx = function(var msx: TMemoryStatusEx): BOOL; stdcall;
var
  FNGlobalMemoryStatusEx: TFNGlobalMemoryStatusEx;
begin
  FNGlobalMemoryStatusEx := TFNGlobalMemoryStatusEx(
    GetProcAddress(GetModuleHandle(kernel32), 'GlobalMemoryStatusEx'));
  if not Assigned(FNGlobalMemoryStatusEx) then
  begin
    SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
    Result := False;
  end
  else
    Result := FNGlobalMemoryStatusEx(lpBuffer);
end;