Rev 169 | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
| Rev 169 | Rev 185 | ||
|---|---|---|---|
| Line 4... | Line 4... | ||
| 4 |   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad | 4 |   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad | 
| 5 |   Copyright (C) 2015- | 5 |   Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad | 
| 6 | 6 | ||
| 7 |   Stockfish is free software: you can redistribute it and/or modify | 7 |   Stockfish is free software: you can redistribute it and/or modify | 
| 8 |   it under the terms of the GNU General Public License as published by | 8 |   it under the terms of the GNU General Public License as published by | 
| 9 |   the Free Software Foundation, either version 3 of the License, or | 9 |   the Free Software Foundation, either version 3 of the License, or | 
| 10 |   (at your option) any later version. | 10 |   (at your option) any later version. | 
| Line 30... | Line 30... | ||
| 30 | 30 | ||
| 31 | namespace { | 31 | namespace { | 
| 32 | 32 | ||
| 33 | enum TimeType { OptimumTime, MaxTime }; | 33 | enum TimeType { OptimumTime, MaxTime }; | 
| 34 | 34 | ||
| 35 | 
 | 35 | constexpr int MoveHorizon = 50; // Plan time management at most this many moves ahead | 
| 36 | 
 | 36 | constexpr double MaxRatio = 7.3; // When in trouble, we can step over reserved time with this ratio | 
| 37 | 
 | 37 | constexpr double StealRatio = 0.34; // However we must not steal time from remaining moves over this ratio | 
| 38 | 38 | ||
| 39 | 39 | ||
| 40 |   // move_importance() is a skew-logistic function based on naive statistical | 40 |   // move_importance() is a skew-logistic function based on naive statistical | 
| 41 |   // analysis of "how many games are still undecided after n half-moves". Game | 41 |   // analysis of "how many games are still undecided after n half-moves". Game | 
| 42 |   // is considered "undecided" as long as neither side has >275cp advantage. | 42 |   // is considered "undecided" as long as neither side has >275cp advantage. | 
| 43 |   // Data was extracted from the CCRL game database with some simple filtering criteria. | 43 |   // Data was extracted from the CCRL game database with some simple filtering criteria. | 
| 44 | 44 | ||
| 45 | double move_importance(int ply) { | 45 | double move_importance(int ply) { | 
| 46 | 46 | ||
| 47 | 
 | 47 | constexpr double XScale = 6.85; | 
| 48 | 
 | 48 | constexpr double XShift = 64.5; | 
| 49 | 
 | 49 | constexpr double Skew = 0.171; | 
| 50 | 50 | ||
| 51 | return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero | 51 | return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero | 
| 52 |   } | 52 |   } | 
| 53 | 53 | ||
| 54 | template<TimeType T> | 54 | template<TimeType T> | 
| 55 | 
 | 55 | TimePoint remaining(TimePoint myTime, int movesToGo, int ply, TimePoint slowMover) { | 
| 56 | 56 | ||
| 57 | 
 | 57 | constexpr double TMaxRatio = (T == OptimumTime ? 1.0 : MaxRatio); | 
| 58 | 
 | 58 | constexpr double TStealRatio = (T == OptimumTime ? 0.0 : StealRatio); | 
| 59 | 59 | ||
| 60 | double moveImportance = (move_importance(ply) * slowMover) / | 60 | double moveImportance = (move_importance(ply) * slowMover) / 100.0; | 
| 61 | double otherMovesImportance = | 61 | double otherMovesImportance = 0.0; | 
| 62 | 62 | ||
| 63 | for (int i = 1; i < movesToGo; ++i) | 63 | for (int i = 1; i < movesToGo; ++i) | 
| 64 | otherMovesImportance += move_importance(ply + 2 * i); | 64 | otherMovesImportance += move_importance(ply + 2 * i); | 
| 65 | 65 | ||
| 66 | double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance); | 66 | double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance); | 
| 67 | double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance); | 67 | double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance); | 
| 68 | 68 | ||
| 69 | return | 69 | return TimePoint(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast | 
| 70 |   } | 70 |   } | 
| 71 | 71 | ||
| 72 | } // namespace | 72 | } // namespace | 
| 73 | 73 | ||
| 74 | 74 | ||
| Line 81... | Line 81... | ||
| 81 | ///  inc >  0 && movestogo == 0 means: x basetime + z increment | 81 | ///  inc >  0 && movestogo == 0 means: x basetime + z increment | 
| 82 | ///  inc >  0 && movestogo != 0 means: x moves in y minutes + z increment | 82 | ///  inc >  0 && movestogo != 0 means: x moves in y minutes + z increment | 
| 83 | 83 | ||
| 84 | void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { | 84 | void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { | 
| 85 | 85 | ||
| 86 | 
 | 86 | TimePoint minThinkingTime = Options["Minimum Thinking Time"]; | 
| 87 | 
 | 87 | TimePoint moveOverhead = Options["Move Overhead"]; | 
| 88 | 
 | 88 | TimePoint slowMover = Options["Slow Mover"]; | 
| 89 | 
 | 89 | TimePoint npmsec = Options["nodestime"]; | 
| - | 90 |   TimePoint hypMyTime; | |
| 90 | 91 | ||
| 91 |   // If we have to play in 'nodes as time' mode, then convert from time | 92 |   // If we have to play in 'nodes as time' mode, then convert from time | 
| 92 |   // to nodes, and use resulting values in time management formulas. | 93 |   // to nodes, and use resulting values in time management formulas. | 
| 93 |   // WARNING:  | 94 |   // WARNING: to avoid time losses, the given npmsec (nodes per millisecond) | 
| 94 |   //  | 95 |   // must be much lower than the real engine speed. | 
| 95 | if (npmsec) | 96 | if (npmsec) | 
| 96 |   { | 97 |   { | 
| 97 | if (!availableNodes) // Only once at game start | 98 | if (!availableNodes) // Only once at game start | 
| 98 | availableNodes = npmsec * limits.time[us]; // Time is in msec | 99 | availableNodes = npmsec * limits.time[us]; // Time is in msec | 
| 99 | 100 | ||
| 100 |       // Convert from  | 101 |       // Convert from milliseconds to nodes | 
| 101 | limits.time[us] = ( | 102 | limits.time[us] = TimePoint(availableNodes); | 
| 102 | limits.inc[us] *= npmsec; | 103 | limits.inc[us] *= npmsec; | 
| 103 | limits.npmsec = npmsec; | 104 | limits.npmsec = npmsec; | 
| 104 |   } | 105 |   } | 
| 105 | 106 | ||
| 106 | startTime = limits.startTime; | 107 | startTime = limits.startTime; | 
| 107 | optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime); | 108 | optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime); | 
| 108 | 109 | ||
| 109 | const int | 110 | const int maxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon; | 
| 110 | 111 | ||
| 111 |   // We calculate optimum time usage for different hypothetical "moves to go" | 112 |   // We calculate optimum time usage for different hypothetical "moves to go" values | 
| 112 |   // and choose the minimum of calculated search time values. Usually the greatest | 113 |   // and choose the minimum of calculated search time values. Usually the greatest | 
| 113 |   // hypMTG gives the minimum values. | 114 |   // hypMTG gives the minimum values. | 
| 114 | for (int hypMTG = 1; hypMTG <= | 115 | for (int hypMTG = 1; hypMTG <= maxMTG; ++hypMTG) | 
| 115 |   { | 116 |   { | 
| 116 |       // Calculate thinking time for hypothetical "moves to go"-value | 117 |       // Calculate thinking time for hypothetical "moves to go"-value | 
| 117 | 
 | 118 | hypMyTime = limits.time[us] | 
| 118 | 
 | 119 | + limits.inc[us] * (hypMTG - 1) | 
| 119 | 
 | 120 | - moveOverhead * (2 + std::min(hypMTG, 40)); | 
| 120 | 121 | ||
| 121 | hypMyTime = std::max(hypMyTime, 0); | 122 | hypMyTime = std::max(hypMyTime, TimePoint(0)); | 
| 122 | 123 | ||
| 123 | 
 | 124 | TimePoint t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover); | 
| 124 | 
 | 125 | TimePoint t2 = minThinkingTime + remaining<MaxTime >(hypMyTime, hypMTG, ply, slowMover); | 
| 125 | 126 | ||
| 126 | optimumTime = std::min(t1, optimumTime); | 127 | optimumTime = std::min(t1, optimumTime); | 
| 127 | maximumTime = std::min(t2, maximumTime); | 128 | maximumTime = std::min(t2, maximumTime); | 
| 128 |   } | 129 |   } | 
| 129 | 130 | ||