[fpc-devel] daemonapp 100% cpu easting fix

[Alvise Nicoletti]

Steve Howe ha scritto:
> Hello all,
>
> While using the daemonapp.pp unit to code a daemon, I've found that 
> applications that it eat 100% of the CPU. After tracking and debugging, I've 
> found out that the problem is in the daemonapp's TDaemonThread.Execute() 
> method:
>
> procedure TDaemonThread.Execute;
>
> begin
>   If FDaemon.Start then
>     begin
>     FDaemon.Status:=csRunning;
>     StartServiceExecute;
>     if not FDaemon.Execute then
>       begin
>       While Not Terminated do
>         CheckControlMessage(True);
>       CheckControlMessage(False);
>       end;
>     end;
> end;
>
> The loop has no interval so it just consumes all free CPU. I think it should 
> be modified like this:
>
> procedure TDaemonThread.Execute;
>
> begin
>   If FDaemon.Start then
>     begin
>     FDaemon.Status:=csRunning;
>     StartServiceExecute;
>     if not FDaemon.Execute then
>       begin
>       While Not Terminated do
>       begin
>         CheckControlMessage(True);
>         Sleep(50);
>       end;
>       CheckControlMessage(False);
>       end;
>     end;
> end;
>
> Someone could argue that the damon's thread priority could be changed instead 
> to "idle", making the thread more cooperative, but since daemonapp.inc's 
> TDaemonController.Main() method also creates internally a TDaemonThread, and 
> that thread is not exposed, changing the daemon's thread wouldn't help 
> either.
>
> Does anyone have a better solution or comments ? Should I submit a patch ? If 
> the changed is accepted and someone could do it for me, it would be even 
> better.
>
>   
Don't know if that helps, but can this problem be related to the 
"strange behaviour" I notifyed in this mailing list with the topic:
"[lazarus] [fpc] strange behaviour (crash) in a closing linux daemon" 
the 07/11/2007

?