如何在 TIdTCPServer OnExecute 中同步线程

Question

Someone who knows Delhi Indy 10 Sockets ? the component TIdTCPServer. I have a service where instantiate multiple threads ( multithreading ) using TIdTCPServer to process requests from several clients ( tidTCPClient ) .

It's all working, no problem , but in the service ( the server) I have a screen where update a log and a list of connected users and log what they are doing and view this log in the memo main screen.

It turns out that being Multithreaded must use the Syncronize to update the memo that is in thread main . So far so ok right?

The memo will be updated in the event idTCPServerExecute component , only that what I have just as event argument is ( AContext : TIdContext ) where I caught the instance of the thread running to her can call the syncronize ?

wanted to do something like:

AContext.thread.Syncronize ( LogMemo ); // Will write in the memo on the main thread.

But I searched and not found the thread object. Does anyone know where is this object?

or how I could update the screen in this event without being in competition with other threads ?

procedure TfrmMainServer.TCPServerExecute(AContext: TIdContext);
var
     Cmd : String;
begin
     if AContext.Connection.IOHandler.Connected then
     begin
       If not AContext.Connection.IOHandler.InputBufferIsEmpty Then Begin
          Cmd  := AContext.Connection.IOHandler.ReadLn;

    // This is not acceptable in this way :

           memoFile.Lines.Add ('TESTING');
           txtInfoLabel.Caption := 'Arquivo enviado';
       End;
     end;
end;

Answer 1

You can derive a class from Indy's TIdSync or TIdNotify class and override the TIdSync.DoSynchronize() or TIdNotify.DoNotify() method to do what you need.

Or, in recent Delphi versions, you can use the anonymous procedure version of the static TThread.Synchronize() or TThread.Queue() methods.

Examples of both approaches have been posted many times before on Embarcadero's forum, Indy's forum, StackOverflow, etc. Search around.

Answer 2

I have a similar issue with TIdTCPServer.OnConnect(AContext: TIdContext) In my event handler I need to manipulate a TVirtualStringTree in the main thread. I googled this article:

http://www.delphigroups.info/2/4/211251.html

Code for me, running Delphi Rio 10.3 Indy 10, is:

uses IdSync;

procedure TMyClass.OnConnectFromClientChangedProc;
begin
  // Code to be executed in main thread
end;

procedure TMyClass.OnMyClientConnect(AContext: TIdContext);
begin
  TIdSync.SynchronizeMethod(OnConnectFromClientChangedProc);
end;

In a similar way can be managed the OnExecute event.