/*
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) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "search.h"
#include "timeman.h"
-#include "ucioption.h"
+#include "uci.h"
+
+TimeManagement Time; // Our global time management object
namespace {
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
-
- const double xscale = 9.3;
- const double xshift = 59.8;
- const double skewfactor = 0.172;
+ constexpr int MoveHorizon = 50; // Plan time management at most this many moves ahead
+ constexpr double MaxRatio = 7.3; // When in trouble, we can step over reserved time with this ratio
+ constexpr double StealRatio = 0.34; // However we must not steal time from remaining moves over this ratio
// 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.
+ // Data was extracted from the CCRL game database with some simple filtering criteria.
double move_importance(int ply) {
- return pow((1 + exp((ply - xshift) / xscale)), -skewfactor) + DBL_MIN; // Ensure non-zero
+ constexpr double XScale = 6.85;
+ constexpr double XShift = 64.5;
+ constexpr double Skew = 0.171;
+
+ return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
}
template<TimeType T>
- int remaining(int myTime, int movesToGo, int currentPly, int slowMover)
- {
- const double TMaxRatio = (T == OptimumTime ? 1 : MaxRatio);
- const double TStealRatio = (T == OptimumTime ? 0 : StealRatio);
+ TimePoint remaining(TimePoint myTime, int movesToGo, int ply, TimePoint slowMover) {
+
+ constexpr double TMaxRatio = (T == OptimumTime ? 1.0 : MaxRatio);
+ constexpr double TStealRatio = (T == OptimumTime ? 0.0 : StealRatio);
- double thisMoveImportance = (move_importance(currentPly) * slowMover) / 100;
- double otherMovesImportance = 0;
+ double moveImportance = (move_importance(ply) * slowMover) / 100.0;
+ double otherMovesImportance = 0.0;
for (int i = 1; i < movesToGo; ++i)
- otherMovesImportance += move_importance(currentPly + 2 * i);
+ otherMovesImportance += move_importance(ply + 2 * i);
- double ratio1 = (TMaxRatio * thisMoveImportance) / (TMaxRatio * thisMoveImportance + otherMovesImportance);
- double ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / (thisMoveImportance + otherMovesImportance);
+ double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance);
+ double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance);
- return floor(myTime * std::min(ratio1, ratio2));
+ return TimePoint(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast
}
} // 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
-
- 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
- */
+/// 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) {
+
+ TimePoint minThinkingTime = Options["Minimum Thinking Time"];
+ TimePoint moveOverhead = Options["Move Overhead"];
+ TimePoint slowMover = Options["Slow Mover"];
+ TimePoint npmsec = Options["nodestime"];
+ TimePoint hypMyTime;
+
+ // 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
- int hypMTG, hypMyTime, t1, t2;
+ // Convert from milliseconds to nodes
+ limits.time[us] = TimePoint(availableNodes);
+ limits.inc[us] *= npmsec;
+ limits.npmsec = npmsec;
+ }
- // 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"];
+ startTime = limits.startTime;
+ optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime);
- // Initialize unstablePvFactor to 1 and search times to maximum values
- unstablePvFactor = 1;
- optimumSearchTime = maximumSearchTime = std::max(limits.time[us], minThinkingTime);
+ const int maxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
- // 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)
+ // 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 (int hypMTG = 1; hypMTG <= maxMTG; ++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);
+ - moveOverhead * (2 + std::min(hypMTG, 40));
- hypMyTime = std::max(hypMyTime, 0);
+ hypMyTime = std::max(hypMyTime, TimePoint(0));
- t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, currentPly, slowMover);
- t2 = minThinkingTime + remaining<MaxTime>(hypMyTime, hypMTG, currentPly, slowMover);
+ TimePoint t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
+ TimePoint t2 = minThinkingTime + remaining<MaxTime >(hypMyTime, hypMTG, ply, slowMover);
- optimumSearchTime = std::min(optimumSearchTime, t1);
- maximumSearchTime = std::min(maximumSearchTime, t2);
+ optimumTime = std::min(t1, optimumTime);
+ maximumTime = std::min(t2, maximumTime);
}
if (Options["Ponder"])
- optimumSearchTime += optimumSearchTime / 4;
-
- // Make sure that maxSearchTime is not over absoluteMaxSearchTime
- optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime);
+ optimumTime += optimumTime / 4;
}
projects / stockfish / blobdiff