X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftimeman.cpp;h=da08f12d9692994355daf9a27130637b4b871d98;hp=11405bb9a01c3b954428dd32b857bf8f0071f917;hb=7fc47eeb6f6b5f3c5ff697e974093ff14413e42c;hpb=b66552fc277ec6587bd93514a7a175d7905b2c6d diff --git a/src/timeman.cpp b/src/timeman.cpp index 11405bb9..da08f12d 100644 --- a/src/timeman.cpp +++ b/src/timeman.cpp @@ -1,7 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, 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 @@ -23,104 +22,76 @@ #include "search.h" #include "timeman.h" -#include "ucioption.h" +#include "uci.h" -namespace { +TimeManagement Time; // Our global time management object - enum TimeType { OptimumTime, MaxTime }; - const int MoveHorizon = 50; // Plan time management at most this many moves ahead - const double MaxRatio = 7.0; // When in trouble, we can step over reserved time with this ratio - const double StealRatio = 0.33; // However we must not steal time from remaining moves over this ratio +/// 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) - const double xscale = 9.3; - const double xshift = 59.8; - const double skewfactor = 0.172; +void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { + TimePoint moveOverhead = TimePoint(Options["Move Overhead"]); + TimePoint slowMover = TimePoint(Options["Slow Mover"]); + TimePoint npmsec = TimePoint(Options["nodestime"]); - // move_importance() is a skew-logistic function based on naive statistical - // analysis of "how many games are still undecided after n half-moves". Game - // is considered "undecided" as long as neither side has >275cp advantage. - // Data was extracted from CCRL game database with some simple filtering criteria. + // optScale is a percentage of available time to use for the current move. + // maxScale is a multiplier applied to optimumTime. + double optScale, maxScale; - double move_importance(int ply) { - - return pow((1 + exp((ply - xshift) / xscale)), -skewfactor) + DBL_MIN; // Ensure non-zero - } - - template - int remaining(int myTime, int movesToGo, int currentPly, int slowMover) + // 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: to avoid time losses, the given npmsec (nodes per millisecond) + // must be much lower than the real engine speed. + if (npmsec) { - const double TMaxRatio = (T == OptimumTime ? 1 : MaxRatio); - const double TStealRatio = (T == OptimumTime ? 0 : StealRatio); - - double thisMoveImportance = (move_importance(currentPly) * slowMover) / 100; - double otherMovesImportance = 0; - - for (int i = 1; i < movesToGo; ++i) - otherMovesImportance += move_importance(currentPly + 2 * i); + if (!availableNodes) // Only once at game start + availableNodes = npmsec * limits.time[us]; // Time is in msec - double ratio1 = (TMaxRatio * thisMoveImportance) / (TMaxRatio * thisMoveImportance + otherMovesImportance); - double ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / (thisMoveImportance + otherMovesImportance); - - return int(myTime * std::min(ratio1, ratio2)); + // Convert from milliseconds to nodes + limits.time[us] = TimePoint(availableNodes); + limits.inc[us] *= npmsec; + limits.npmsec = npmsec; } -} // namespace - - -void TimeManager::init(const Search::LimitsType& limits, int currentPly, Color us) -{ - /* We support four different kinds of time controls: - - increment == 0 && movesToGo == 0 means: x basetime [sudden death!] - increment == 0 && movesToGo != 0 means: x moves in y minutes - increment > 0 && movesToGo == 0 means: x basetime + z increment - increment > 0 && movesToGo != 0 means: x moves in y minutes + z increment + startTime = limits.startTime; - Time management is adjusted by following parameters: + // Maximum move horizon of 50 moves + int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50; - emergencyMoveHorizon: Be prepared to always play at least this many moves - emergencyBaseTime : Always attempt to keep at least this much time (in ms) at clock - emergencyMoveTime : Plus attempt to keep at least this much time for each remaining emergency move - minThinkingTime : No matter what, use at least this much thinking before doing the move - */ + // 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)); - int hypMTG, hypMyTime, t1, t2; + // 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; - // Read uci parameters - int emergencyMoveHorizon = 40; - int emergencyBaseTime = Options["Move Overhead"] * 2; - int emergencyMoveTime = Options["Move Overhead"]; - int minThinkingTime = Options["Minimum Thinking Time"]; - int slowMover = Options["Slow Mover"]; - - // Initialize unstablePvFactor to 1 and search times to maximum values - unstablePvFactor = 1; - optimumSearchTime = maximumSearchTime = std::max(limits.time[us], minThinkingTime); - - // We calculate optimum time usage for different hypothetical "moves to go"-values and choose the - // minimum of calculated search time values. Usually the greatest hypMTG gives the minimum values. - for (hypMTG = 1; hypMTG <= (limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon); ++hypMTG) + // 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) { - // Calculate thinking time for hypothetical "moves to go"-value - hypMyTime = limits.time[us] - + limits.inc[us] * (hypMTG - 1) - - emergencyBaseTime - - emergencyMoveTime * std::min(hypMTG, emergencyMoveHorizon); - - hypMyTime = std::max(hypMyTime, 0); - - t1 = minThinkingTime + remaining(hypMyTime, hypMTG, currentPly, slowMover); - t2 = minThinkingTime + remaining(hypMyTime, hypMTG, currentPly, slowMover); + 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); + } - optimumSearchTime = std::min(optimumSearchTime, t1); - maximumSearchTime = std::min(maximumSearchTime, t2); + // 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); } - if (Options["Ponder"]) - optimumSearchTime += optimumSearchTime / 4; + // 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)); - // Make sure that maxSearchTime is not over absoluteMaxSearchTime - optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime); + if (Options["Ponder"]) + optimumTime += optimumTime / 4; }