Delphi 7 & Indy 10 OnCommand Event and VCL Components Thread Safe?

I have same problem experts, please help us. I will open other question to give you guys more 500 points. Please I'm waiting.

Tell me what vcl components you are updating, and what information you are passing to them, and i will show you how to do it in a thread safe manner.
Would also be handy if you could paste your main indy command method here.

Is that Safe???????

/////////////////////////////////////////////////////////////////////////////////////////////

procedure TFPrinc.IdCmdTCPServer1CommandHandlers5Command(
  ASender: TIdCommand);
var
  datetime, msg : string;
begin
    datetime := Asender.Context.Connection.IOHandler.ReadLn;
    msg := FindComp(ASender.Context.Connection.Socket.Binding.PeerIP) + ' - Nucleo Client ' +  datetime;
    HistoryAdd(msg,1);
    BD.SPSecurityAdd.ParamByName('@idfunc').AsString := FuncionarioID;
    BD.SPSecurityAdd.ParamByName('@idcaixa').AsString := StatusBar1.Panels[2].Text;
    BD.SPSecurityAdd.ParamByName('@data').AsString := FormatDateTime('MM/dd/yyyy hh:nn:ss AM/PM',now());
    BD.SPSecurityAdd.ParamByName('@mensagem').AsString := msg;
    Bd.SPSecurityAdd.ExecProc;

    FEMail_Send.Mensagem.Clear;
    FEMail_Send.Mensagem.Lines.Add('Security Email');
    FEMail_Send.Mensagem.Lines.Add('   ');
    FEMail_Send.Mensagem.Lines.Add(Msg);
    FEMail_Send.Mensagem.Lines.Add('   ');
    FEMail_Send.Mensagem.Lines.Add('   ');
    FEMail_Send.Mensagem.Lines.Add('Funcionario..........: ' + Funcionario);
    FEMail_Send.Mensagem.Lines.Add('Caixa................: ' + StatusBar1.Panels[2].Text);
    FEMail_Send.Send;

/////////////////////////////////////////////////////////////////////////////////////////////

well it's safe, but looking at your code, probably not the best solution for you.
I thought you meant things like a log (TMemo's etc).
If you are using SQL queries, etc. you should be defining them inside thread instead, as long as they do not update a component in the main vcl.

here's some of my code for doing this. It's from a IdTCPServer, but it should be the same for the CMD one

type
  TSpecificClientConnection = class(TServerClientWinSocket)
  public
      ID:          string; // just the unique id we create for each connection
      StatusBarText: string; // you could fill this when the client connects...
      ClientTimer: TTimer; // just an example of a component
      Constructor CreateWithSettings(ID_: string; statusbartext_: string);
      Destructor Destroy; override;
  end;

{ TClientSpecificData }

constructor TClientSpecificData.CreateWithSettings(ID_, statusbartext_: string);
    begin
        Inherited Create;
        ID := ID_;
        statusbartext := statusbartext_;
        ClientTimer := TTimer.create(nil); // just an example...
    end;

destructor TClientSpecificData.Destroy;
    begin
        ClientTimer.Free;
        inherited;
    end;


procedure TfServerMain.IdTCPServer1Connect(AThread: TIdPeerThread);
var
    ID_: string;
begin
    ID_ := AThread.Connection.Socket.Binding.PeerIP + ':' + IntToStr(AThread.Connection.Socket.Binding.PeerPort);
    AThread.Data := TClientSpecificData.CreateWithSettings(ID_);
    AThread.Connection.Tag := integer(AThread.Data); //can also store our data object here as long as we type cast it back
...
end;

procedure TfServerMain.IdTCPServer1Disconnect(AThread: TIdPeerThread);
begin
    if assigned(AThread.Data) then
    begin
        (AThread.Data as TClientSpecificData).Free;
        AThread.Data := nil;
    end;
end;

you can then access it in various places by typecasting it back
eg. (AThread.Data as TClientSpecificData).ClientTimer (or StatusBartext)


To access the StatusBar like you are doing is a bit different. This is one of the things you should not be doing in threads really.
However, you can get around it by using a TCriticalSection, or windows messages, or indys syncing methods (a little trickier actually)
for a simple, TCriticalSection, in a shared unit, declare the following
mycrit: TCriticalSection
crittext: string;

put the following in your form's create (or some other more relevent place)
mycrit := TCriticalSection.Create;
and in the form's destroy (or some other more relevent place)
mycrit.free;

then, EVERY TIME you want to change or read the value of "crittext" you must do it like this
mycrit.enter;
try
  s := crittext;
finally
  mycrit.Leave;
end;

note: you must do this in teh main vcl as well as in the threads.

hth, Loki

Forced accept.

Computer101
EE Admin