/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2016 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-#if !defined(SEARCH_H_INCLUDED)
+#ifndef SEARCH_H_INCLUDED
#define SEARCH_H_INCLUDED
-////
-//// Includes
-////
+#include <atomic>
+#include <memory> // For std::unique_ptr
+#include <stack>
+#include <vector>
+
+#include "misc.h"
+#include "position.h"
+#include "types.h"
-#include "depth.h"
-#include "move.h"
-#include "value.h"
+namespace Search {
+/// Stack struct keeps track of the information we need to remember from nodes
+/// shallower and deeper in the tree during the search. Each search thread has
+/// its own array of Stack objects, indexed by the current ply.
-////
-//// Constants
-////
+struct Stack {
+ Move* pv;
+ int ply;
+ Move currentMove;
+ Move excludedMove;
+ Move killers[2];
+ Value staticEval;
+ bool skipEarlyPruning;
+ int moveCount;
+};
-const int PLY_MAX = 100;
-const int PLY_MAX_PLUS_2 = PLY_MAX + 2;
+/// RootMove struct is used for moves at the root of the tree. For each root move
+/// we store a score and a PV (really a refutation in the case of moves which
+/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
+struct RootMove {
-////
-//// Types
-////
+ explicit RootMove(Move m) : pv(1, m) {}
-/// The SearchStack struct keeps track of the information we need to remember
-/// from nodes shallower and deeper in the tree during the search. Each
-/// search thread has its own array of SearchStack objects, indexed by the
-/// current ply.
-struct EvalInfo;
-struct SplitPoint;
+ bool operator<(const RootMove& m) const { return m.score < score; } // Descending sort
+ bool operator==(const Move& m) const { return pv[0] == m; }
+ void insert_pv_in_tt(Position& pos);
+ bool extract_ponder_from_tt(Position& pos);
-struct SearchStack {
- Move currentMove;
- Move mateKiller;
- Move excludedMove;
- Move bestMove;
- Move killers[2];
- Depth reduction;
- Value eval;
- Value evalMargin;
- bool skipNullMove;
- SplitPoint* sp;
+ Value score = -VALUE_INFINITE;
+ Value previousScore = -VALUE_INFINITE;
+ std::vector<Move> pv;
+};
+
+typedef std::vector<RootMove> RootMoveVector;
+
+/// LimitsType struct stores information sent by GUI about available time to
+/// search the current move, maximum depth/time, if we are in analysis mode or
+/// if we have to ponder while it's our opponent's turn to move.
+
+struct LimitsType {
+
+ LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
+ nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movestogo =
+ depth = movetime = mate = infinite = ponder = 0;
+ }
+
+ bool use_time_management() const {
+ return !(mate | movetime | depth | nodes | infinite);
+ }
+
+ std::vector<Move> searchmoves;
+ int time[COLOR_NB], inc[COLOR_NB], npmsec, movestogo, depth, movetime, mate, infinite, ponder;
+ int64_t nodes;
+ TimePoint startTime;
};
+/// The SignalsType struct stores atomic flags updated during the search
+/// typically in an async fashion e.g. to stop the search by the GUI.
+
+struct SignalsType {
+ std::atomic_bool stop, stopOnPonderhit;
+};
+
+typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
+
+extern SignalsType Signals;
+extern LimitsType Limits;
+extern StateStackPtr SetupStates;
-////
-//// Prototypes
-////
-class Position;
+void init();
+void clear();
+template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
-extern void init_search();
-extern void init_threads();
-extern void exit_threads();
-extern int64_t perft(Position& pos, Depth depth);
-extern bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[],
- int movesToGo, int maxDepth, int maxNodes, int maxTime, Move searchMoves[]);
+} // namespace Search
-#endif // !defined(SEARCH_H_INCLUDED)
+#endif // #ifndef SEARCH_H_INCLUDED