Files
Stockfish/src/tt.h
T
Sami Kiminki beb327f910 Fix a Windows-only crash on exit without 'quit'
There was a bug in commit d4763424d2
(Add support for Windows large pages) that could result in trying to
free memory allocated with VirtualAlloc incorrectly with free().

Fix this by reverting the TT.resize(0) logic in the previous commit,
and instead, just call aligned_ttmem_free() in
TranspositionTable::~TranspositionTable().

fixes https://github.com/official-stockfish/Stockfish/issues/2677

closes https://github.com/official-stockfish/Stockfish/pull/2679

No functional change
2020-05-14 20:35:40 +02:00

102 lines
3.1 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) 2015-2020 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 TT_H_INCLUDED
#define TT_H_INCLUDED
#include "misc.h"
#include "types.h"
/// TTEntry struct is the 10 bytes transposition table entry, defined as below:
///
/// key 16 bit
/// move 16 bit
/// value 16 bit
/// eval value 16 bit
/// generation 5 bit
/// pv node 1 bit
/// bound type 2 bit
/// depth 8 bit
struct TTEntry {
Move move() const { return (Move )move16; }
Value value() const { return (Value)value16; }
Value eval() const { return (Value)eval16; }
Depth depth() const { return (Depth)depth8 + DEPTH_OFFSET; }
bool is_pv() const { return (bool)(genBound8 & 0x4); }
Bound bound() const { return (Bound)(genBound8 & 0x3); }
void save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev);
private:
friend class TranspositionTable;
uint16_t key16;
uint16_t move16;
int16_t value16;
int16_t eval16;
uint8_t genBound8;
uint8_t depth8;
};
/// A TranspositionTable is an array of Cluster, of size clusterCount. Each
/// cluster consists of ClusterSize number of TTEntry. Each non-empty TTEntry
/// contains information on exactly one position. The size of a Cluster should
/// divide the size of a cache line for best performance,
/// as the cacheline is prefetched when possible.
class TranspositionTable {
static constexpr int ClusterSize = 3;
struct Cluster {
TTEntry entry[ClusterSize];
char padding[2]; // Pad to 32 bytes
};
static_assert(sizeof(Cluster) == 32, "Unexpected Cluster size");
public:
~TranspositionTable() { aligned_ttmem_free(mem); }
void new_search() { generation8 += 8; } // Lower 3 bits are used by PV flag and Bound
TTEntry* probe(const Key key, bool& found) const;
int hashfull() const;
void resize(size_t mbSize);
void clear();
// The 32 lowest order bits of the key are used to get the index of the cluster
TTEntry* first_entry(const Key key) const {
return &table[(uint32_t(key) * uint64_t(clusterCount)) >> 32].entry[0];
}
private:
friend struct TTEntry;
size_t clusterCount;
Cluster* table;
void* mem;
uint8_t generation8; // Size must be not bigger than TTEntry::genBound8
};
extern TranspositionTable TT;
#endif // #ifndef TT_H_INCLUDED