Simplify time management and fix 'ponder on' bug

[stockfish] / src / search.h

diff --git a/src/search.h b/src/search.h
index 4f98cc762fb041a0dac265a81cc9b1336b401150..2a9a37370af7b713bc730ece27ed47ae1de066c7 100644 (file)
--- a/src/search.h
+++ b/src/search.h
@@ -1,7 +1,7 @@
 /*
   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
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,63 +17,95 @@
   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
 
-#include "move.h"
-#include "types.h"
-
+#include <atomic>
+#include <memory>  // For std::unique_ptr
+#include <stack>
 #include <vector>
 
-class Position;
-struct SplitPoint;
+#include "misc.h"
+#include "position.h"
+#include "types.h"
+
+namespace Search {
 
-/// 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.
+/// 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.
 
-struct SearchStack {
-  SplitPoint* sp;
+struct Stack {
+  Move* pv;
   int ply;
   Move currentMove;
+  Move ttMove;
   Move excludedMove;
-  Move bestMove;
   Move killers[2];
   Depth reduction;
-  Value eval;
-  Value evalMargin;
-  int skipNullMove;
+  Value staticEval;
+  bool skipEarlyPruning;
+  int moveCount;
 };
 
-namespace Search {
+/// 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 {
+
+  explicit RootMove(Move m) : pv(1, m) {}
 
-/// The SearchLimits 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 is our opponent's side to move.
+  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);
+
+  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 {
 
-  bool useTimeManagement() const { return !(maxTime | maxDepth | maxNodes | infinite); }
+  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;
+  }
 
-  int time, increment, movesToGo, maxTime, maxDepth, maxNodes, infinite, ponder;
+  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 {
-  bool stopOnPonderhit, firstRootMove, stop, failedLowAtRoot;
+  std::atomic_bool stop, stopOnPonderhit;
 };
 
-extern volatile SignalsType Signals;
-extern LimitsType Limits;
-extern std::vector<Move> RootMoves;
-extern Position* RootPosition;
+typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
 
-extern void init();
-extern int64_t perft(Position& pos, Depth depth);
-extern void think();
+extern SignalsType Signals;
+extern LimitsType Limits;
+extern StateStackPtr SetupStates;
 
-}
+void init();
+void clear();
+template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
 
-extern void do_timer_event();
+} // namespace Search
 
-#endif // !defined(SEARCH_H_INCLUDED)
+#endif // #ifndef SEARCH_H_INCLUDED