How to implement the use of one dll library by two programs at the same time?

Question

Delphi

Hello!
I am writing a program to update another program.
How it all works:
1) In the main program, there is a "Check for Update" button, when clicked, a request is made to the server (site), where the text file is located (the current version is written in it) and the archive with the update. (The file is a temporary test solution).
2) The program compares the current version (a constant in the code or an entry in the registry) with the server's response, and if the versions differ, it launches another program - the updater. (!)
3) The updater downloads the archive from the server
4) If the archive was downloaded successfully, we complete the main program and unpack the archive
5) If the archive was unpacked successfully, run the main program and delete the archive, after which the updater closes (!)

Programs work with the server via https, so the main exe and the updater exe contain libeay32.dll and ssleay32.dll (all in one folder)
So one program does not work while another is running - and it seems to me that these libraries are already involved in the first one.
Separately, everything seems to work, but there is a gag at the moments when one program should start another.

The idea came to me to put an updater with copies of these libraries in a separate update folder, but it seems to me that this is not a solution that is not entirely correct.

What am I doing wrong and how should I do it right?
Thank you.

UPD: I'll attach the code
There is nothing on the form except a single progress bar to display the download progress (from non-visual components: IdSSLIOHandlerSocketOpenSSL1, IdHTTP1, IdAntiFreeze1)

updater code

//Сама программа (Project > View Source)
uses
  Vcl.Forms,
  Vcl.Dialogs,
  Windows,
  Registry,
  System.Classes,
  System.SysUtils,
  Unit1 in 'Unit1.pas' {Form1},
  IdMultipartFormData,
  IdBaseComponent,
  IdComponent,
  IdTCPConnection,
  IdTCPClient,
  IdHTTP,
  IdHashMessageDigest,
  IdSSLOpenSSL,
  IdSSL,
  IdIOHandler,
  IdIOHandlerSocket,
  IdIOHandlerStack;

{$R *.res}
Var HM :THandle;

function Check: boolean;
begin
  HM:=OpenMutex(MUTEX_ALL_ACCESS, false, 'Proj');
  Result:=(HM<>0);
  if HM=0 then HM:=CreateMutex(nil, false, 'Proj');
end;

function checkUpdate: boolean;
var
  Stream: TIdMultipartFormDataStream;
  HTTPClient: TidHTTP;
  response: WideString;
  cur_ver: string;
  Reg: TRegistry;
begin
  Reg:=TRegistry.Create;
  Reg.RootKey := HKEY_CURRENT_USER;
  Reg.OpenKey('\SOFTWARE\'+app_name_tech, true);
  result:=false;
  if reg.ValueExists('AppVer') then cur_ver := Reg.ReadString('AppVer');

  HTTPClient := TidHTTP.Create;
  try
    Stream := TIdMultipartFormDataStream.Create;
    Stream.AddFormField('query_type', 'update');
    Stream.AddFormField('v', cur_ver);
    response:= HTTPClient.Post(app_serv+'/updater.php  ', Stream); // Отправим запрос
    result:=StrToBool(response);
    HTTPClient.Disconnect;
    //FreeAndNil(response);
  finally
    Stream.Free;
    HTTPClient.Free;
  end;

end;

begin
  If Check then //проверка не запущена ли уже программа
    exit;
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  if CheckUpdate() then
  begin
    Application.CreateForm(TForm1, Form1);
    Application.Run;
  end
  else
  begin
    ShowMessage('Обновление не требуется');
  end;
end.

// далее Unit1

function UnZipFile(sourceFile, destPath: String): Boolean;
var
 ZipFile: TZipFile;
begin
  ZipFile := TZipFile.Create;
  try
    if ZipFile.IsValid(sourceFile) then begin
       ZipFile.ExtractZipFile(sourceFile, destPath);
       ZipFile.Close;
       result:= true;
    end;
  finally
    ZipFile.Free;
  end;
end;

procedure save_in_dir(dir, url: string; MyHTTP: TIdHTTP);
var
 MyStream: TMemoryStream;
 fname: string;
begin
 MyStream := TMemoryStream.Create;
 fname := url;
 // Получаем имя файла из url. Имя файла - текст за последним включением "/"
 while Pos('/', fname) <> 0 do
 begin
  Delete(fname, 1, Pos('/', fname));
 end;
 // Сам процесс сохранения файла
 MyHTTP.Get(url, MyStream);
 MyHTTP.Disconnect;
 MyStream.SaveToFile(dir + '\' + fname);
 MyStream.Free;
end;

procedure TForm1.FormActivate(Sender: TObject); 
// тут странный момент - форма "не успевает" отобразиться (я пробовал и OnCreate и OnShow), то есть за время работы программы появляются только всплывающие окна описанные ниже.
var
 Reg: TRegistry;
 Stream: TMemoryStream;
begin
  root_dir := ExtractFilePath(ParamStr(0));
  save_in_dir(root_dir, app_serv + '/update/update.zip', IdHTTP1);
  // когда скачалось
  if progressbar1.position=progressbar1.max then //(как по другому определить завершение загрузки не знаю)
  begin
    Application.Messagebox('Загрузка обновления прошла успешно.', 'Загрузка обновления..', mb_iconinformation or mb_ok);
    if FileExists(root_dir+'update.zip') then //есть ли файл
    begin
       try
        //вырубаем основную программу 
        KillProcess(root_dir+'main.exe');//KillTask('main.exe');  //этот момент проверить не могу, так как не получается запустить "одновременно 2 программы". При запуске в режиме отладки тут ошибок не возникало)
      except
        on e:Exception do ShowMessage('Не удалось вырубить основную программу');//ShowMessage(E.ClassName+' ошибка с сообщением : '+E.Message);
      end;
      //распаковать архив
      if UnZipFile(root_dir+'update.zip', root_dir) then
      begin
        //удалить архив
        DeleteFile(root_dir+'update.zip');
        //прописать новую версию
        Reg:=TRegistry.Create;
        Reg.RootKey := HKEY_CURRENT_USER;
        Reg.OpenKey('\SOFTWARE\'+app_name_tech, true);
        Reg.WriteString('app_ver', app_ver);
        ShowMessage('Обновление установлено!');
        //запустить основное приложение
        try
          ShellExecute(0, PChar('open'), PChar(root_dir+'main.exe'), nil, nil, SW_SHOWDEFAULT);
        except
          on e:Exception do ShowMessage(E.ClassName+' ошибка с сообщением : '+E.Message);
        end;
        //закрыть обновлятор
        //Application.Destroy;
        halt;
      end
      else
      begin
        ShowMessage('Не удалось обновиться! Не удалось распаковать архив');
      end;
    end
    else//если файла нет
    begin
      ShowMessage('Не удалось обновиться! Архив не найден');
    end;
  end;
end;

procedure TForm1.IdHTTP1Work(ASender: TObject; AWorkMode: TWorkMode;
  AWorkCount: Int64);
begin
  ProgressBar1.Position:=AWorkCount;
end;

procedure TForm1.IdHTTP1WorkBegin(ASender: TObject; AWorkMode: TWorkMode;
  AWorkCountMax: Int64);
begin
  ProgressBar1.Max:=AWorkCountMax;
end;

Answer 1

Libraries can and should be used by different programs at the same time, this is their purpose. The point is different.