X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftimeman.cpp;h=da08f12d9692994355daf9a27130637b4b871d98;hp=81c2f39b77e4d40eaff30c57dadeeda6f4f2b1be;hb=HEAD;hpb=59a9bc93512138eca31ec38d36d8ddd7868ed708 diff --git a/src/timeman.cpp b/src/timeman.cpp index 81c2f39b..f404ee0c 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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2004-2023 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 @@ -17,128 +16,92 @@ along with this program. If not, see . */ +#include "timeman.h" + #include #include #include "search.h" -#include "timeman.h" -#include "ucioption.h" - -namespace { - - /// Constants - - 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 - - const double xscale = 9.3; - const double xshift = 59.8; - const double yscale = 7780; - const double yshift = 1e-3; // Larger than 0. Ensures a non-zero importance - const double skewfactor = 0.172; - - - /// 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. - - double move_importance(int ply) { - - return yscale / pow((1 + exp((ply - xshift) / xscale)), skewfactor) + yshift; - } - - - /// Function Prototypes - - enum TimeType { OptimumTime, MaxTime }; - - template - int remaining(int myTime, int movesToGo, int fullMoveNumber, int slowMover); -} - - -void TimeManager::pv_instability(double bestMoveChanges) { - - unstablePVExtraTime = int(bestMoveChanges * optimumSearchTime / 1.4); +#include "uci.h" + +namespace Stockfish { + +TimeManagement Time; // Our global time management object + + +// 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) +void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { + + // If we have no time, no need to initialize TM, except for the start time, + // which is used by movetime. + startTime = limits.startTime; + if (limits.time[us] == 0) + return; + + TimePoint moveOverhead = TimePoint(Options["Move Overhead"]); + TimePoint npmsec = TimePoint(Options["nodestime"]); + + // 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: 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 milliseconds to nodes + limits.time[us] = TimePoint(availableNodes); + limits.inc[us] *= npmsec; + limits.npmsec = npmsec; + } + + // 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)); + + // Use extra time with larger increments + double optExtra = std::clamp(1.0 + 12.5 * limits.inc[us] / limits.time[us], 1.0, 1.11); + + // Calculate time constants based on current time left. + double optConstant = std::min(0.00334 + 0.0003 * std::log10(limits.time[us] / 1000.0), 0.0049); + double maxConstant = std::max(3.4 + 3.0 * std::log10(limits.time[us] / 1000.0), 2.76); + + // 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(0.0120 + std::pow(ply + 3.1, 0.44) * optConstant, + 0.21 * limits.time[us] / double(timeLeft)) + * optExtra; + maxScale = std::min(6.9, maxConstant + ply / 12.2); + } + + // x moves in y seconds (+ z increment) + else + { + optScale = std::min((0.88 + ply / 116.4) / mtg, 0.88 * limits.time[us] / double(timeLeft)); + maxScale = std::min(6.3, 1.5 + 0.11 * mtg); + } + + // Limit the maximum possible time for this move + optimumTime = TimePoint(optScale * timeLeft); + maximumTime = + TimePoint(std::min(0.84 * limits.time[us] - moveOverhead, maxScale * optimumTime)) - 10; + + if (Options["Ponder"]) + optimumTime += optimumTime / 4; } - -void TimeManager::init(const Search::LimitsType& limits, int currentPly, Color us) -{ - /* We support four different kind 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 - - Time management is adjusted by following UCI parameters: - - 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 - */ - - int hypMTG, hypMyTime, t1, t2; - - // Read uci parameters - int emergencyMoveHorizon = Options["Emergency Move Horizon"]; - int emergencyBaseTime = Options["Emergency Base Time"]; - int emergencyMoveTime = Options["Emergency Move Time"]; - int minThinkingTime = Options["Minimum Thinking Time"]; - int slowMover = Options["Slow Mover"]; - - // Initialize all to maximum values but unstablePVExtraTime that is reset - unstablePVExtraTime = 0; - optimumSearchTime = maximumSearchTime = limits.time[us]; - - // 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) - { - // 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); - - optimumSearchTime = std::min(optimumSearchTime, t1); - maximumSearchTime = std::min(maximumSearchTime, t2); - } - - if (Options["Ponder"]) - optimumSearchTime += optimumSearchTime / 4; - - // Make sure that maxSearchTime is not over absoluteMaxSearchTime - optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime); -} - - -namespace { - - template - int remaining(int myTime, int movesToGo, int currentPly, int slowMover) - { - 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); - - double ratio1 = (TMaxRatio * thisMoveImportance) / (TMaxRatio * thisMoveImportance + otherMovesImportance); - double ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / (thisMoveImportance + otherMovesImportance); - - return int(floor(myTime * std::min(ratio1, ratio2))); - } -} +} // namespace Stockfish