[fpc-devel] daemonapp 100% cpu easting fix

[Steve Howe]

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.

-- 
Best Regards,
Steve Howe