library uuid;

{declare external function gen_uuid_sequential
returns char(16) character set octets free_it 
entry_point 'gen_uuid_sequential' module_name 'uuid.dll'}

function UuidCreateSequential(var guid: TGUID): HResult; stdcall; external 'RPCRT4.dll';
function ib_util_malloc(l: integer): pointer; cdecl; external 'ib_util.dll';

function gen_uuid_sequential: PAnsiChar; cdecl; export;
var
  uid: TGUID;
begin
  Result := ib_util_malloc(16);
  UuidCreateSequential(uid);
  Move(uid, Result^, SizeOf(uid));
end;

exports
  gen_uuid_sequential;

begin
  isMultiThread := True;
end.

procedure TForm1.Button1Click(Sender: TObject);
type
 PGuid= ^TGuid;
var
 gen_uuid_sequential: function(): PAnsiChar;
 LibHandle: THandle;
 FileName: string;
 Error: DWORD;
 g: PGuid;
begin
  FileName:= ExtractFilePath(Application.ExeName) + 'uuid.dll';
  @gen_uuid_sequential := nil;
  LibHandle := SafeLoadLibrary(FileName);
  if LibHandle >= 32 then
  begin
    @gen_uuid_sequential := GetProcAddress(LibHandle, 'gen_uuid_sequential');
    if @gen_uuid_sequential <> nil then
    begin
      g := PGuid(gen_uuid_sequential());
      ShowMessage(GuidToString(g^));
    end;
  end
  else
  begin
    Error:= GetLastError();
    ShowMessage('Error: ' + IntToStr(Error));
  end;
  FreeLibrary(LibHandle);
end;