internal static MList GetObject()
{
int slotID = System.Threading.Thread.CurrentThread.ManagedThreadId & Constants.BROKER_SLOT_MASK;
if (_cnt[slotID] == _pool[slotID].Length)
{
int poolLength = _pool[slotID].Length;
MList[] temp = new MList[poolLength + Constants.BrokerCapacity];
Array.Copy(_pool[slotID], temp, poolLength);
for (int i = 0; i < Constants.BrokerCapacity; i++)
{
temp[poolLength + i] = new MList();
}
_pool[slotID] = temp;
}
return(_pool[slotID][_cnt[slotID]++]);
}
/// Mate with KX vs K. This function is used to evaluate positions with
/// King and plenty of material vs a lone king. It simply gives the
/// attacking side a bonus for driving the defending king towards the edge
/// of the board, and for keeping the distance between the two kings small.
/// KXK
internal static Value Endgame_KXK(Color strongerSide, Position pos)
{
Color weakerSide = strongerSide ^ 1;
Debug.Assert(pos.non_pawn_material(weakerSide) == ValueC.VALUE_ZERO);
Debug.Assert(pos.piece_count(weakerSide, PieceTypeC.PAWN) == ValueC.VALUE_ZERO);
// Stalemate detection with lone king
MList mlist = MListBroker.GetObject(); mlist.pos = 0;
Movegen.generate_legal(pos, mlist.moves, ref mlist.pos);
bool any = mlist.pos > 0;
MListBroker.Free();
if (pos.sideToMove == weakerSide
&& !pos.in_check()
&& !any)
{
return ValueC.VALUE_DRAW;
}
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Value result = pos.non_pawn_material(strongerSide)
+ pos.piece_count(strongerSide, PieceTypeC.PAWN) * Constants.PawnValueEndgame
+ MateTable[loserKSq]
+ DistanceBonus[Utils.square_distance(winnerKSq, loserKSq)];
if (pos.piece_count(strongerSide, PieceTypeC.QUEEN)!=0
|| pos.piece_count(strongerSide, PieceTypeC.ROOK)!=0
|| pos.bishop_pair(strongerSide))
{
result += ValueC.VALUE_KNOWN_WIN;
}
return strongerSide == pos.sideToMove ? result : -result;
}
internal static void init()
{
for (int i = 0; i < Constants.BROKER_SLOTS; i++)
{
_pool[i] = new MList[0];
}
}
internal static MList GetObject()
{
int slotID = System.Threading.Thread.CurrentThread.ManagedThreadId & Constants.BROKER_SLOT_MASK;
if (_cnt[slotID] == _pool[slotID].Length)
{
int poolLength = _pool[slotID].Length;
MList[] temp = new MList[poolLength + Constants.BrokerCapacity];
Array.Copy(_pool[slotID], temp, poolLength);
for (int i = 0; i < Constants.BrokerCapacity; i++)
{
temp[poolLength + i] = new MList();
}
_pool[slotID] = temp;
}
return _pool[slotID][_cnt[slotID]++];
}
/// Book::probe() tries to find a book move for the given position. If no move
/// is found returns MOVE_NONE. If pickBest is true returns always the highest
/// rated move, otherwise randomly chooses one, based on the move score.
internal static Move probe(Position pos, string filename, bool pickBest)
{
#if PORTABLE
#region DLL book
if (bookNotExists)
{
return(MoveC.MOVE_NONE);
}
BookEntry e = new BookEntry();
UInt16 best = 0;
uint sum = 0;
Move move = MoveC.MOVE_NONE;
UInt64 key = book_key(pos);
try
{
System.Reflection.Assembly bookAssembly = System.Reflection.Assembly.Load("PortfishBook");
using (Stream fs = bookAssembly.GetManifestResourceStream("PortfishBook.book.bin"))
{
UInt64 size = (UInt64)(fs.Length / SIZE_OF_BOOKENTRY);
using (BinaryReader br = new BinaryReader(fs))
{
binary_search(key, size, br);
while (Read(ref e, br) && (e.key == key))
{
best = Math.Max(best, e.count);
sum += e.count;
// Choose book move according to its score. If a move has a very
// high score it has higher probability to be choosen than a move
// with lower score. Note that first entry is always chosen.
if ((RKiss.rand() % sum < e.count) ||
(pickBest && e.count == best))
{
move = e.move;
}
}
}
}
}
catch (System.IO.FileNotFoundException)
{
bookNotExists = true;
return(MoveC.MOVE_NONE);
}
#endregion
#else
#region File system read
if (!System.IO.File.Exists(filename))
{
return(MoveC.MOVE_NONE);
}
BookEntry e = new BookEntry();
UInt16 best = 0;
uint sum = 0;
Move move = MoveC.MOVE_NONE;
UInt64 key = book_key(pos);
using (FileStream fs = new FileStream(filename, FileMode.Open))
{
UInt64 size = (UInt64)(fs.Length / SIZE_OF_BOOKENTRY);
using (BinaryReader br = new BinaryReader(fs))
{
binary_search(key, size, br);
while (Read(ref e, br) && (e.key == key))
{
best = Math.Max(best, e.count);
sum += e.count;
// Choose book move according to its score. If a move has a very
// high score it has higher probability to be choosen than a move
// with lower score. Note that first entry is always chosen.
if (((sum != 0) && (RKiss.rand() % sum < e.count)) ||
(pickBest && e.count == best))
{
move = e.move;
}
}
br.Close();
}
fs.Close();
}
#endregion
#endif
if (move != 0)
{
// A PolyGlot book move is encoded as follows:
//
// bit 0- 5: destination square (from 0 to 63)
// bit 6-11: origin square (from 0 to 63)
// bit 12-14: promotion piece (from KNIGHT == 1 to QUEEN == 4)
//
// Castling moves follow "king captures rook" representation. So in case book
// move is a promotion we have to convert to our representation, in all the
// other cases we can directly compare with a Move after having masked out
// the special Move's flags (bit 14-15) that are not supported by PolyGlot.
int pt = (move >> 12) & 7;
if (pt != 0)
{
move = Utils.make_promotion(Utils.from_sq(move), Utils.to_sq(move), (pt + 1));
}
// Add 'special move' flags and verify it is legal
MList mlist = MListBroker.GetObject(); mlist.pos = 0;
Movegen.generate_legal(pos, mlist.moves, ref mlist.pos);
for (int i = 0; i < mlist.pos; i++)
{
if (move == (mlist.moves[i].move & 0x3FFF))
{
Move retval = mlist.moves[i].move;
MListBroker.Free();
return(retval);
}
}
MListBroker.Free();
}
return(MoveC.MOVE_NONE);
}