On 06/21/2012 03:04 PM, TS wrote:
1) Eg "time_settings 0 4 1" -> gnugo will play maybe 3 fast moves, then take 10 seconds for his next move. Any idea what might be causing this? I don't believe that this is just a "normal bug", since that would've surfaced a long time ago and been fixed by now.
GNU Go wasn't designed for time control from the start and when it was added it was very difficult to retrofit in a good way, not least because it does several local searches, where it's no good to have just half of them, and those are done depth first and thus not easily terminated with a meaningful result. The way time control was implemented was as a control loop around the level setting, which has a very non-linear and not easily predicted relation to the actual time needed for move generation. In this particular case it probably noticed it was way behind, reduced the level significantly, then after a few quick moves decided it could increase the level again but overcompensated to something too slow.
2) Also, easily reproducable: Try to change params while a game is in progress by just calling "level 10" and "time_settings 0 <whatever> 1" before calling the actual "genmove white" (assuming gnugo is w here) and gnugo will always just timeout and not generate any move anymore.
Doesn't sound surprising, it never gets a chance to tune in the level settings. I'm actually more surprised that the time control mechanisms do work reasonably robustly in many scenarios. They are kind of crude (and I'm only criticizing myself here) and could certainly be improved in various ways, although I don't think it's easy to do. The most sensible approach to get something significantly better is probably to try to keep the classical searches bounded by a good margin and let the time control mostly act on the Monte Carlo move generation, which is much more easily time controlled. But for that to make sense the Monte Carlo part needs to be much better and do meaningful work on boards larger than 9x9. /Gunnar _______________________________________________ gnugo-devel mailing list gnugo-devel@gnu.org https://lists.gnu.org/mailman/listinfo/gnugo-devel
