[
  uuid(157EF74F-0CF2-4BD2-95D2-A11B394877E0),
  version(2.0),
]
library testole
{
  importlib("stdole2.tlb");

  [
    uuid(D1C67572-8795-4746-8CD4-050F9D500709),
    version(1.0),
    oleautomation,
    dual
  ]
   interface ITestOle: IDispatch
  {
    [id(0x0000010C)]
    HRESULT _stdcall UniMessage([in] VARIANT ParamIn1, [in] VARIANT ParamIn2, [out, retval] VARIANT* ParamOut);
  };

  [
    uuid(25358394-662E-432D-BAEE-C0500262498F),
    version(1.0),
  ]
  coclass TTestOle {
    [default] interface ITestOle;
  };

};

[/SRC]unit testole_TLB;

// ************************************************************************ //
// WARNING                                                                    
// -------                                                                    
// The types declared in this file were generated from data read from a       
// Type Library. If this type library is explicitly or indirectly (via        
// another type library referring to this type library) re-imported, or the   
// 'Refresh' command of the Type Library Editor activated while editing the   
// Type Library, the contents of this file will be regenerated and all        
// manual modifications will be lost.                                         
// ************************************************************************ //

// $Rev: 52393 $
// File generated on 16.08.2019 15:45:34 from Type Library described below.

// ************************************************************************  //
// Type Lib: testole.tlb (1)
// LIBID: {157EF74F-0CF2-4BD2-95D2-A11B394877E0}
// LCID: 0
// Helpfile: 
// HelpString: 
// DepndLst: 
//   (1) v2.0 stdole, (C:\Windows\SysWOW64\stdole2.tlb)
// SYS_KIND: SYS_WIN32
// Cmdline:
//   "C:\Program Files (x86)\Embarcadero\RAD Studio\10.0\bin\tlibimp.exe"  -P+ -R- "testole.tlb" -Ha- -Hs- -Hr- -O- -Yc- -Pt-
// ************************************************************************ //
{$TYPEDADDRESS OFF} // Unit must be compiled without type-checked pointers. 
{$WARN SYMBOL_PLATFORM OFF}
{$WRITEABLECONST ON}
{$VARPROPSETTER ON}
{$ALIGN 4}

interface

uses Winapi.Windows, System.Classes, System.Variants, System.Win.StdVCL, Vcl.Graphics, Vcl.OleServer, Winapi.ActiveX;
  

// *********************************************************************//
// GUIDS declared in the TypeLibrary. Following prefixes are used:        
//   Type Libraries     : LIBID_xxxx                                      
//   CoClasses          : CLASS_xxxx                                      
//   DISPInterfaces     : DIID_xxxx                                       
//   Non-DISP interfaces: IID_xxxx                                        
// *********************************************************************//
const
  // TypeLibrary Major and minor versions
  testoleMajorVersion = 2;
  testoleMinorVersion = 0;

  LIBID_testole: TGUID = '{157EF74F-0CF2-4BD2-95D2-A11B394877E0}';

  IID_ITestOle: TGUID = '{D1C67572-8795-4746-8CD4-050F9D500709}';
  CLASS_TTestOle: TGUID = '{25358394-662E-432D-BAEE-C0500262498F}';
type

// *********************************************************************//
// Forward declaration of types defined in TypeLibrary                    
// *********************************************************************//
  ITestOle = interface;
  ITestOleDisp = dispinterface;

// *********************************************************************//
// Declaration of CoClasses defined in Type Library                       
// (NOTE: Here we map each CoClass to its Default Interface)              
// *********************************************************************//
  TTestOle = ITestOle;


// *********************************************************************//
// Interface: ITestOle
// Flags:     (4416) Dual OleAutomation Dispatchable
// GUID:      {D1C67572-8795-4746-8CD4-050F9D500709}
// *********************************************************************//
  ITestOle = interface(IDispatch)
    ['{D1C67572-8795-4746-8CD4-050F9D500709}']
    function UniMessage(ParamIn1: OleVariant; ParamIn2: OleVariant): OleVariant; safecall;
  end;

// *********************************************************************//
// DispIntf:  ITestOleDisp
// Flags:     (4416) Dual OleAutomation Dispatchable
// GUID:      {D1C67572-8795-4746-8CD4-050F9D500709}
// *********************************************************************//
  ITestOleDisp = dispinterface
    ['{D1C67572-8795-4746-8CD4-050F9D500709}']
    function UniMessage(ParamIn1: OleVariant; ParamIn2: OleVariant): OleVariant; dispid 268;
  end;

implementation

uses System.Win.ComObj;

end.

library Server;

uses
  FastMM4,
  System.Win.ComServ, System.Win.ComObj,
  System.SysUtils, System.Variants,
  testole_tlb;

type
  TOleServerImpl = class(TAutoObject, ITestOle)
    function UniMessage(ParamIn1: OleVariant; ParamIn2: OleVariant): OleVariant; safecall;
  end;
  
{$R testole.tlb}

function TOleServerImpl.UniMessage(ParamIn1: OleVariant; ParamIn2: OleVariant): OleVariant; 
begin
  Result := Format(
    '%s, %s',
    [VarTypeAsText(VarType(ParamIn1)), VarTypeAsText(VarType(ParamIn2))]
  );
end;

exports
  DllGetClassObject,
  DllCanUnloadNow,
  DllRegisterServer,
  DllUnregisterServer;
 
begin
  TAutoObjectFactory.Create(
    ComServer,
    TOleServerImpl,
    CLASS_TTestOle,
    ciMultiInstance,
    tmBoth
  );
end.

program Client;

{$APPTYPE CONSOLE}

uses
  FastMM4,
  System.SysUtils,
  Winapi.Activex, System.Win.ComObj,
  testole_tlb;

var
  TestSrv: ITestOle;

function UniMessage(const Command: string; const Parameters: OleVariant): OleVariant;
begin
  Result:=TestSrv.UniMessage(Command,Parameters); // <-- тут
end;

procedure Call;
var
  Command: string;
  Buff: AnsiString;
begin
  Command:='qwerty';
  Buff:='1234567890';
  UniMessage(Command,Buff);
end;

procedure Test;
var
  Li: Integer;
begin
  TestSrv := CreateComObject(CLASS_TTestOle) as ITestOle;
  for Li := 0 to Round(1E+6) - 1 do
    Call;
  TestSrv := nil;
end;

begin
  Coinitialize(nil);
  Test;
  Writeln('Passed');
  Readln;
end.