felixeckert

Hey, Im currently working on a Program in Delphi and have a "uLogAbstractor" unit tot handle logging across threads, this unit essentially just writes the log message and level to a global variable and the sends a Windows Message using the Winapi to the Main Form which has the logging components. Now I have noticed that regardless of the thread, the global variable containing the message seems to reset to its previous value after ive called PostMessage. Weirdly this doesn't occur if i output it using ShowMessage before calling PostMessage. Here is the log abstractor unit uLogAbstractor; interface uses SysUtils, Winapi.Windows, uConsts, Vcl.Dialogs; procedure Log(const lvl: Integer; const msg: String); procedure LogF(const lvl: Integer; const msg: String; const _format: array of const); var msghandle: Cardinal = 0; logmsg: String; loglvl: Integer; implementation procedure Log(const lvl: Integer; const msg: String); begin if msghandle = 0 then exit; loglvl := lvl; logmsg := msg; // ShowMessage(logmsg); PostMessage(msghandle, WM_LOG_MESSAGE, 0, 0); end; procedure LogF(const lvl: Integer; const msg: String; const _format: array of const); begin if msghandle = 0 then exit; loglvl := lvl; logmsg := Format(msg, _format); PostMessage(msghandle, WM_LOG_MESSAGE, 0, 0); end; end. And here is the procedure handling the message in the main form procedure TfrmMain.WMLogMessage(var msg: string); begin FLogger.Log(uLogAbstractor.loglvl, uLogAbstractor.logmsg); if uLogAbstractor.loglvl = LOG_LVL_DBG then begin if FLogger.FLogDebug then memoLog.Lines.Add(FLogger.FLastMsg); end else memoLog.Lines.Add(FLogger.FLastMsg); end; Does anyone know the reason for this behaviour? I'd be grateful for any help!

Thanks for the reply! An Object Queue where I would enqueue Records holding the message data would work fine? Im not too experienced with threading