Files
Stockfish/src/search.h
joergoster 8b15961349 Fix multiPV issue #502
In general, this patch handles the cases where we don't have a valid score for each PV line in a multiPV search. This can happen if the search has been stopped in an unfortunate moment while still in the aspiration loop. The patch consists of two parts.

Part 1: The new PVIdx was already part of the k-best pv's in the last iteration, and we therefore have a valid pv and score to output from the last iteration. This is taken care of with:

      bool updated = (i <= PVIdx && rootMoves[i].score != -VALUE_INFINITE);

Case 2: The new PVIdx was NOT part of the k-best pv's in the last iteration, and we have no valid pv and score to output. Not from the current nor from the previous iteration. To avoid this, we are now also considering the previous score when sorting, so that the PV lines with no actual but with a valid previous score are pushed up again, and the previous score can be displayed.

  bool operator<(const RootMove& m) const {
    return m.score != score ? m.score < score : m.previousScore < previousScore; } // Descending sort

I also added an assertion in UCI::value() to possibly catch similar issues earlier.

No functional change.

Closes #502
Closes #1074
2017-05-03 19:46:40 -07:00

112 lines
3.3 KiB
C++

/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
Copyright (C) 2015-2017 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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef SEARCH_H_INCLUDED
#define SEARCH_H_INCLUDED
#include <atomic>
#include <vector>
#include "misc.h"
#include "movepick.h"
#include "types.h"
class Position;
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.
struct Stack {
Move* pv;
CounterMoveStats* counterMoves;
int ply;
Move currentMove;
Move excludedMove;
Move killers[2];
Value staticEval;
int history;
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 m.score != score ? m.score < score : m.previousScore < previousScore; } // Descending sort
bool operator==(const Move& m) const { return pv[0] == m; }
bool extract_ponder_from_tt(Position& pos);
Value score = -VALUE_INFINITE;
Value previousScore = -VALUE_INFINITE;
std::vector<Move> pv;
};
typedef std::vector<RootMove> RootMoves;
/// 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;
};
/// 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;
};
extern SignalsType Signals;
extern LimitsType Limits;
void init();
void clear();
template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
} // namespace Search
#endif // #ifndef SEARCH_H_INCLUDED