TConnectionPoolManager = class(TObject)
 private
   fPools: TObjectList;
   fAllPoolSize: Integer;
   function GetPoolCount: Integer;
   function GetPool(aIndex: Integer): TConnectionPool;
 public
   constructor Create(aPoolSize: Integer);
   destructor Destroy; override;
   function AcquireConnection(aServer, aSchema, aUserName, aPassword: String): TConnectionItem;
   procedure ReleaseConnection(aConn: TConnectionItem);

   property AllPoolSize: Integer read fAllPoolSize;
   property PoolCount: Integer read GetPoolCount;
   property Pools[Index: Integer]: TConnectionPool read GetPool;
 end;
...
constructor TConnectionPoolManager.Create(aPoolSize: Integer);
begin
 fPools := TObjectList.Create;
 fPools.OwnsObjects := True;
end;

destructor TConnectionPoolManager.Destroy;
begin
 FreeAndNil(fPools);
 inherited;
end;
...
function TConnectionPoolManager.GetPoolCount: Integer;
begin
 Result := fPools.Count;
end;

function TConnectionPoolManager.GetPool(aIndex: Integer): TConnectionPool;
begin
 Result := TConnectionPool(fPools[aIndex]);
end;

IHRMDataService = interface(IUnknown)
   ['{C311580A-8AC5-4B69-834D-5B6DA89BD9DE}']
   function Get_PoolCount: Integer; stdcall;
   function Get_Servers(Index: Integer; out Value: PChar): HResult; stdcall;
   function Get_Schemas(Index: Integer; out Value: PChar): HResult; stdcall;
 end;

function THRMDataService.Get_PoolCount: Integer;
begin
 Result := -1;
 if Assigned(g_Manager) then
   Result := g_Manager.PoolCount;
end;

function THRMDataService.Get_Servers(Index: Integer;
 out Value: PChar): HResult;
begin
 Result := S_FALSE;
 Value := '';
 if Assigned(g_Manager) then
 begin
   Result := S_OK;
   Value := PChar(g_Manager.Pools[Index].Server);
 end;
end;

function THRMDataService.Get_Schemas(Index: Integer;
 out Value: PChar): HResult;
begin
 Result := S_FALSE;
 Value := '';
 if Assigned(g_Manager) then
 begin
   Result := S_OK;
   Value := PChar(g_Manager.Pools[Index].Schema);
 end;
end;

unit uGlobals;

interface
uses uConnectionPoolManager;

var
 g_Manager: TConnectionPoolManager;

implementation
uses SysUtils;

initialization
 g_Manager := TConnectionPoolManager.Create(3);

finalization
 FreeAndNil(g_Manager);

end.

procedure TForm1.Button1Click(Sender: TObject);
var
 s: IHRMDataService;
 c: PChar;
begin
 s := CreateComObject(CLASS_HRMDataService) as IHRMDataService;
 try
   Memo1.Lines.Add(Format('Pool count: %d',[s.Get_PoolCount])); // ВЫДАЕТ 0, хотя их точно не 0, потому что сервис работает
   s.Get_Servers(0, c);
   Memo1.Lines.Add(c); // пустая строка, что ГАРАНТИРОВАНО неправда, потому что сервис работает
 finally
   s := nil;
 end;
end;