X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftimeman.cpp;h=da08f12d9692994355daf9a27130637b4b871d98;hp=0c5224642c191856bc458426597abdcee8e7edbb;hb=7fc47eeb6f6b5f3c5ff697e974093ff14413e42c;hpb=287e2e2f74332d59dae2bd01772a74b909b87d22 diff --git a/src/timeman.cpp b/src/timeman.cpp index 0c522464..da08f12d 100644 --- a/src/timeman.cpp +++ b/src/timeman.cpp @@ -1,8 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file) Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -19,6 +17,8 @@ */ #include +#include +#include #include "search.h" #include "timeman.h" @@ -26,90 +26,72 @@ TimeManagement Time; // Our global time management object -namespace { - enum TimeType { OptimumTime, MaxTime }; +/// TimeManagement::init() is called at the beginning of the search and calculates +/// the bounds of time allowed for the current game ply. We currently support: +// 1) x basetime (+ z increment) +// 2) x moves in y seconds (+ z increment) - int remaining(int myTime, int myInc, int moveOverhead, int movesToGo, - int moveNum, bool ponder, TimeType type) { +void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { - if (myTime <= 0) - return 0; + TimePoint moveOverhead = TimePoint(Options["Move Overhead"]); + TimePoint slowMover = TimePoint(Options["Slow Mover"]); + TimePoint npmsec = TimePoint(Options["nodestime"]); - double ratio; // Which ratio of myTime we are going to use - - // Usage of increment follows quadratic distribution with the maximum at move 25 - double inc = myInc * std::max(55.0, 120 - 0.12 * (moveNum - 25) * (moveNum - 25)); - - // In moves-to-go we distribute time according to a quadratic function with - // the maximum around move 20 for 40 moves in y time case. - if (movesToGo) - { - ratio = (type == OptimumTime ? 1.0 : 6.0) / std::min(50, movesToGo); - - if (moveNum <= 40) - ratio *= 1.1 - 0.001 * (moveNum - 20) * (moveNum - 20); - else - ratio *= 1.5; - - if (movesToGo > 1) - ratio = std::min(0.75, ratio); - - ratio *= 1 + inc / (myTime * 8.5); - } - // Otherwise we increase usage of remaining time as the game goes on - else - { - double k = 1 + 20 * moveNum / (500.0 + moveNum); - ratio = (type == OptimumTime ? 0.017 : 0.07) * (k + inc / myTime); - } - - int time = int(std::min(1.0, ratio) * std::max(0, myTime - moveOverhead)); - - if (type == OptimumTime && ponder) - time = 5 * time / 4; - - return time; - } - -} // namespace - - -/// init() is called at the beginning of the search and calculates the allowed -/// thinking time out of the time control and current game ply. We support four -/// different kinds of time controls, passed in 'limits': -/// -/// inc == 0 && movestogo == 0 means: x basetime [sudden death!] -/// inc == 0 && movestogo != 0 means: x moves in y minutes -/// inc > 0 && movestogo == 0 means: x basetime + z increment -/// inc > 0 && movestogo != 0 means: x moves in y minutes + z increment - -void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) -{ - int moveOverhead = Options["Move Overhead"]; - int npmsec = Options["nodestime"]; - bool ponder = Options["Ponder"]; + // optScale is a percentage of available time to use for the current move. + // maxScale is a multiplier applied to optimumTime. + double optScale, maxScale; // If we have to play in 'nodes as time' mode, then convert from time // to nodes, and use resulting values in time management formulas. - // WARNING: Given npms (nodes per millisecond) must be much lower then - // the real engine speed to avoid time losses. + // WARNING: to avoid time losses, the given npmsec (nodes per millisecond) + // must be much lower than the real engine speed. if (npmsec) { if (!availableNodes) // Only once at game start availableNodes = npmsec * limits.time[us]; // Time is in msec - // Convert from millisecs to nodes - limits.time[us] = (int)availableNodes; + // Convert from milliseconds to nodes + limits.time[us] = TimePoint(availableNodes); limits.inc[us] *= npmsec; limits.npmsec = npmsec; } - int moveNum = (ply + 1) / 2; - startTime = limits.startTime; - optimumTime = remaining(limits.time[us], limits.inc[us], moveOverhead, - limits.movestogo, moveNum, ponder, OptimumTime); - maximumTime = remaining(limits.time[us], limits.inc[us], moveOverhead, - limits.movestogo, moveNum, ponder, MaxTime); + + // Maximum move horizon of 50 moves + int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50; + + // Make sure timeLeft is > 0 since we may use it as a divisor + TimePoint timeLeft = std::max(TimePoint(1), + limits.time[us] + limits.inc[us] * (mtg - 1) - moveOverhead * (2 + mtg)); + + // A user may scale time usage by setting UCI option "Slow Mover" + // Default is 100 and changing this value will probably lose elo. + timeLeft = slowMover * timeLeft / 100; + + // x basetime (+ z increment) + // If there is a healthy increment, timeLeft can exceed actual available + // game time for the current move, so also cap to 20% of available game time. + if (limits.movestogo == 0) + { + optScale = std::min(0.0084 + std::pow(ply + 3.0, 0.5) * 0.0042, + 0.2 * limits.time[us] / double(timeLeft)); + maxScale = std::min(7.0, 4.0 + ply / 12.0); + } + + // x moves in y seconds (+ z increment) + else + { + optScale = std::min((0.8 + ply / 128.0) / mtg, + 0.8 * limits.time[us] / double(timeLeft)); + maxScale = std::min(6.3, 1.5 + 0.11 * mtg); + } + + // Never use more than 80% of the available time for this move + optimumTime = TimePoint(optScale * timeLeft); + maximumTime = TimePoint(std::min(0.8 * limits.time[us] - moveOverhead, maxScale * optimumTime)); + + if (Options["Ponder"]) + optimumTime += optimumTime / 4; }