Use atomics instead of volatile

[stockfish] / src / search.h

diff --git a/src/search.h b/src/search.h
index 1688534b59b0782ac0de81f59a63f49853e0a194..740063b9a59c5d4ff1c4db19bd18416ac4b32e58 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
@@ -17,55 +17,98 @@
   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 <cstring>
+#include <atomic>
+#include <memory>  // For std::unique_ptr
+#include <stack>
+#include <vector>
 
-#include "move.h"
+#include "misc.h"
+#include "position.h"
 #include "types.h"
 
-class Position;
 struct SplitPoint;
 
-/// 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.
+namespace Search {
 
-struct SearchStack {
-  SplitPoint* sp;
+/// 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 Stack {
+  SplitPoint* splitPoint;
+  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;
+};
+
+/// 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) {}
+
+  bool operator<(const RootMove& m) const { return score > m.score; } // Ascending 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.
 
-/// 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.
+struct LimitsType {
 
-struct SearchLimits {
+  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;
+  }
 
-  SearchLimits() { memset(this, 0, sizeof(SearchLimits)); }
+  bool use_time_management() const {
+    return !(mate | movetime | depth | nodes | infinite);
+  }
 
-  SearchLimits(int t, int i, int mtg, int mt, int md, int mn, bool inf, bool pon)
-              : time(t), increment(i), movesToGo(mtg), maxTime(mt), maxDepth(md),
-                maxNodes(mn), infinite(inf), ponder(pon) {}
+  std::vector<Move> searchmoves;
+  int time[COLOR_NB], inc[COLOR_NB], npmsec, movestogo, depth, movetime, mate, infinite, ponder;
+  int64_t nodes;
+  TimePoint startTime;
+};
 
-  bool useTimeManagement() const { return !(maxTime | maxDepth | maxNodes | infinite); }
+/// The SignalsType struct stores atomic flags updated during the search
+/// typically in an async fashion e.g. to stop the search by the GUI.
 
-  int time, increment, movesToGo, maxTime, maxDepth, maxNodes, infinite, ponder;
+struct SignalsType {
+  std::atomic<bool> stop, stopOnPonderhit, firstRootMove, failedLowAtRoot;
 };
 
-extern void init_search();
-extern int64_t perft(Position& pos, Depth depth);
-extern bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]);
+typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
+
+extern SignalsType Signals;
+extern LimitsType Limits;
+extern StateStackPtr SetupStates;
+
+void init();
+void reset();
+template<bool Root> uint64_t perft(Position& pos, Depth depth);
+
+} // namespace Search
 
-#endif // !defined(SEARCH_H_INCLUDED)
+#endif // #ifndef SEARCH_H_INCLUDED