LimitsType Limits;
RootMoveVector RootMoves;
Position RootPos;
- Time::point SearchTime;
+ TimePoint SearchTime;
StateStackPtr SetupStates;
}
Move best = MOVE_NONE;
};
+ struct FastMove {
+ FastMove() { clear(); }
+
+ inline void clear() {
+ expectedPosKey = 0;
+ pv3[0] = pv3[1] = pv3[2] = MOVE_NONE;
+ stableCnt = 0;
+ }
+
+ void update(Position& pos) {
+ // Keep track how many times in a row the PV stays stable 3 ply deep.
+ const std::vector<Move>& RMpv = RootMoves[0].pv;
+ if (RMpv.size() >= 3)
+ {
+ if (pv3[2] == RMpv[2])
+ stableCnt++;
+ else
+ stableCnt = 0, pv3[2] = RMpv[2];
+
+ if (!expectedPosKey || pv3[0] != RMpv[0] || pv3[1] != RMpv[1])
+ {
+ pv3[0] = RMpv[0], pv3[1] = RMpv[1];
+ StateInfo st[2];
+ pos.do_move(RMpv[0], st[0], pos.gives_check(RMpv[0], CheckInfo(pos)));
+ pos.do_move(RMpv[1], st[1], pos.gives_check(RMpv[1], CheckInfo(pos)));
+ expectedPosKey = pos.key();
+ pos.undo_move(RMpv[1]);
+ pos.undo_move(RMpv[0]);
+ }
+ }
+ else
+ clear();
+ }
+
+ Key expectedPosKey;
+ Move pv3[3];
+ int stableCnt;
+ } FM;
+
size_t PVIdx;
TimeManager TimeMgr;
double BestMoveChanges;
Value DrawValue[COLOR_NB];
HistoryStats History;
+ CounterMovesHistoryStats CounterMovesHistory;
GainsStats Gains;
MovesStats Countermoves, Followupmoves;
Depth depth;
Value bestValue, alpha, beta, delta;
+ // Init fastMove if the previous search generated a candidate and we now got the predicted position.
+ const Move fastMove = (FM.expectedPosKey == pos.key()) ? FM.pv3[2] : MOVE_NONE;
+ FM.clear();
+
std::memset(ss-2, 0, 5 * sizeof(Stack));
depth = DEPTH_ZERO;
TT.new_search();
History.clear();
+ CounterMovesHistory.clear();
Gains.clear();
Countermoves.clear();
Followupmoves.clear();
// the UI) before a re-search.
if ( multiPV == 1
&& (bestValue <= alpha || bestValue >= beta)
- && Time::now() - SearchTime > 3000)
+ && now() - SearchTime > 3000)
sync_cout << UCI::pv(pos, depth, alpha, beta) << sync_endl;
// In case of failing low/high increase aspiration window and
if (Signals.stop)
sync_cout << "info nodes " << RootPos.nodes_searched()
- << " time " << Time::now() - SearchTime << sync_endl;
+ << " time " << now() - SearchTime << sync_endl;
- else if (PVIdx + 1 == multiPV || Time::now() - SearchTime > 3000)
+ else if (PVIdx + 1 == multiPV || now() - SearchTime > 3000)
sync_cout << UCI::pv(pos, depth, alpha, beta) << sync_endl;
}
Signals.stop = true;
// Do we have time for the next iteration? Can we stop searching now?
- if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit)
+ if (Limits.use_time_management())
{
- // Take some extra time if the best move has changed
- if (depth > 4 * ONE_PLY && multiPV == 1)
- TimeMgr.pv_instability(BestMoveChanges);
-
- // Stop the search if only one legal move is available or all
- // of the available time has been used.
- if ( RootMoves.size() == 1
- || Time::now() - SearchTime > TimeMgr.available_time())
+ if (!Signals.stop && !Signals.stopOnPonderhit)
{
- // If we are allowed to ponder do not stop the search now but
- // keep pondering until the GUI sends "ponderhit" or "stop".
- if (Limits.ponder)
- Signals.stopOnPonderhit = true;
- else
- Signals.stop = true;
+ // Take some extra time if the best move has changed
+ if (depth > 4 * ONE_PLY && multiPV == 1)
+ TimeMgr.pv_instability(BestMoveChanges);
+
+ // Stop the search if only one legal move is available or all
+ // of the available time has been used or we matched a fastMove
+ // from the previous search and just did a fast verification.
+ if ( RootMoves.size() == 1
+ || now() - SearchTime > TimeMgr.available_time()
+ || ( fastMove == RootMoves[0].pv[0]
+ && BestMoveChanges < 0.03
+ && 10 * (now() - SearchTime) > TimeMgr.available_time()))
+ {
+ // If we are allowed to ponder do not stop the search now but
+ // keep pondering until the GUI sends "ponderhit" or "stop".
+ if (Limits.ponder)
+ Signals.stopOnPonderhit = true;
+ else
+ Signals.stop = true;
+ }
}
+
+ // Update fast move stats.
+ FM.update(pos);
}
}
+ // Clear any candidate fast move that wasn't completely stable for at least
+ // the 6 final search iterations. (Independent of actual depth and thus TC.)
+ // Time condition prevents consecutive fast moves.
+ if (FM.stableCnt < 6 || now() - SearchTime < TimeMgr.available_time())
+ FM.clear();
+
// If skill level is enabled, swap best PV line with the sub-optimal one
if (skill.enabled())
std::swap(RootMoves[0], *std::find(RootMoves.begin(),
assert((ss-1)->currentMove != MOVE_NONE);
assert((ss-1)->currentMove != MOVE_NULL);
- MovePicker mp(pos, ttMove, History, pos.captured_piece_type());
+ MovePicker mp(pos, ttMove, History, CounterMovesHistory, pos.captured_piece_type());
CheckInfo ci(pos);
while ((move = mp.next_move<false>()) != MOVE_NONE)
Move followupmoves[] = { Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].first,
Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].second };
- MovePicker mp(pos, ttMove, depth, History, countermoves, followupmoves, ss);
+ MovePicker mp(pos, ttMove, depth, History, CounterMovesHistory, countermoves, followupmoves, ss);
CheckInfo ci(pos);
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
improving = ss->staticEval >= (ss-2)->staticEval
continue;
moveCount = ++splitPoint->moveCount;
- splitPoint->mutex.unlock();
+ splitPoint->spinlock.release();
}
else
++moveCount;
{
Signals.firstRootMove = (moveCount == 1);
- if (thisThread == Threads.main() && Time::now() - SearchTime > 3000)
+ if (thisThread == Threads.main() && now() - SearchTime > 3000)
sync_cout << "info depth " << depth / ONE_PLY
<< " currmove " << UCI::move(move, pos.is_chess960())
<< " currmovenumber " << moveCount + PVIdx << sync_endl;
&& moveCount >= FutilityMoveCounts[improving][depth])
{
if (SpNode)
- splitPoint->mutex.lock();
+ splitPoint->spinlock.acquire();
continue;
}
if (SpNode)
{
- splitPoint->mutex.lock();
+ splitPoint->spinlock.acquire();
if (bestValue > splitPoint->bestValue)
splitPoint->bestValue = bestValue;
}
if (predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < VALUE_ZERO)
{
if (SpNode)
- splitPoint->mutex.lock();
+ splitPoint->spinlock.acquire();
continue;
}
// Step 18. Check for new best move
if (SpNode)
{
- splitPoint->mutex.lock();
+ splitPoint->spinlock.acquire();
bestValue = splitPoint->bestValue;
alpha = splitPoint->alpha;
}
if (value > alpha)
{
+ // Clear fast move if unstable.
+ if (PvNode && pos.key() == FM.expectedPosKey && (move != FM.pv3[2] || moveCount > 1))
+ FM.clear();
+
bestMove = SpNode ? splitPoint->bestMove = move : move;
if (PvNode && !RootNode) // Update pv even in fail-high case
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
// be generated.
- MovePicker mp(pos, ttMove, depth, History, to_sq((ss-1)->currentMove));
+ MovePicker mp(pos, ttMove, depth, History, CounterMovesHistory, to_sq((ss-1)->currentMove));
CheckInfo ci(pos);
// Loop through the moves until no moves remain or a beta cutoff occurs
*pv = MOVE_NONE;
}
- // update_stats() updates killers, history, countermoves and followupmoves stats after a fail-high
- // of a quiet move.
+ // update_stats() updates killers, history, countermoves and followupmoves
+ // stats after a fail-high of a quiet move.
void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) {
ss->killers[0] = move;
}
- // Increase history value of the cut-off move and decrease all the other
- // played quiet moves.
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY));
+
+ Square prevSq = to_sq((ss-1)->currentMove);
+ HistoryStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
+
History.update(pos.moved_piece(move), to_sq(move), bonus);
- for (int i = 0; i < quietsCnt; ++i)
+ if (is_ok((ss-1)->currentMove))
{
- Move m = quiets[i];
- History.update(pos.moved_piece(m), to_sq(m), -bonus);
+ Countermoves.update(pos.piece_on(prevSq), prevSq, move);
+ cmh.update(pos.moved_piece(move), to_sq(move), bonus);
}
- if (is_ok((ss-1)->currentMove))
+ // Decrease all the other played quiet moves
+ for (int i = 0; i < quietsCnt; ++i)
{
- Square prevMoveSq = to_sq((ss-1)->currentMove);
- Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, move);
+ History.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+
+ if (is_ok((ss-1)->currentMove))
+ cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
}
if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove)
{
- Square prevOwnMoveSq = to_sq((ss-2)->currentMove);
- Followupmoves.update(pos.piece_on(prevOwnMoveSq), prevOwnMoveSq, move);
+ Square prevPrevSq = to_sq((ss-2)->currentMove);
+ Followupmoves.update(pos.piece_on(prevPrevSq), prevPrevSq, move);
}
}
Move Skill::pick_best(size_t multiPV) {
// PRNG sequence should be non-deterministic, so we seed it with the time at init
- static PRNG rng(Time::now());
+ static PRNG rng(now());
// RootMoves are already sorted by score in descending order
int variance = std::min(RootMoves[0].score - RootMoves[multiPV - 1].score, PawnValueMg);
string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) {
std::stringstream ss;
- Time::point elapsed = Time::now() - SearchTime + 1;
+ TimePoint elapsed = now() - SearchTime + 1;
size_t multiPV = std::min((size_t)Options["MultiPV"], RootMoves.size());
int selDepth = 0;
assert(!this_sp || (this_sp->master == this && searching));
- while (!exit)
+ while ( !exit
+ && !(this_sp && this_sp->slavesMask.none()))
{
+ // If there is nothing to do, sleep.
+ while( !exit
+ && !(this_sp && this_sp->slavesMask.none())
+ && !searching)
+ {
+ if ( !this_sp
+ && !Threads.main()->thinking)
+ {
+ std::unique_lock<Mutex> lk(mutex);
+ while (!exit && !Threads.main()->thinking)
+ sleepCondition.wait(lk);
+ }
+ else
+ std::this_thread::yield();
+ }
+
// If this thread has been assigned work, launch a search
while (searching)
{
- Threads.mutex.lock();
+ mutex.lock();
assert(activeSplitPoint);
-
SplitPoint* sp = activeSplitPoint;
- Threads.mutex.unlock();
+ mutex.unlock();
Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
Position pos(*sp->pos, this);
std::memcpy(ss-2, sp->ss-2, 5 * sizeof(Stack));
ss->splitPoint = sp;
- sp->mutex.lock();
+ sp->spinlock.acquire();
assert(activePosition == nullptr);
sp->allSlavesSearching = false;
sp->nodes += pos.nodes_searched();
- // Wake up the master thread so to allow it to return from the idle
- // loop in case we are the last slave of the split point.
- if (this != sp->master && sp->slavesMask.none())
- {
- assert(!sp->master->searching);
-
- sp->master->notify_one();
- }
-
// After releasing the lock we can't access any SplitPoint related data
// in a safe way because it could have been released under our feet by
// the sp master.
- sp->mutex.unlock();
+ sp->spinlock.release();
// Try to late join to another split point if none of its slaves has
// already finished.
SplitPoint* bestSp = NULL;
- int bestScore = INT_MAX;
+ int minLevel = INT_MAX;
for (Thread* th : Threads)
{
if ( sp
&& sp->allSlavesSearching
&& sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT
- && available_to(th))
+ && can_join(sp))
{
assert(this != th);
assert(!(this_sp && this_sp->slavesMask.none()));
// Prefer to join to SP with few parents to reduce the probability
// that a cut-off occurs above us, and hence we waste our work.
- int level = -1;
- for (SplitPoint* spp = th->activeSplitPoint; spp; spp = spp->parentSplitPoint)
+ int level = 0;
+ for (SplitPoint* p = th->activeSplitPoint; p; p = p->parentSplitPoint)
level++;
- int score = level * 256 * 256 + (int)sp->slavesMask.count() * 256 - sp->depth * 1;
-
- if (score < bestScore)
+ if (level < minLevel)
{
bestSp = sp;
- bestScore = score;
+ minLevel = level;
}
}
}
sp = bestSp;
// Recheck the conditions under lock protection
- Threads.mutex.lock();
- sp->mutex.lock();
+ sp->spinlock.acquire();
if ( sp->allSlavesSearching
- && sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT
- && available_to(sp->master))
+ && sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT)
{
- sp->slavesMask.set(idx);
- activeSplitPoint = sp;
- searching = true;
- }
+ spinlock.acquire();
- sp->mutex.unlock();
- Threads.mutex.unlock();
- }
- }
+ if (can_join(sp))
+ {
+ sp->slavesMask.set(idx);
+ activeSplitPoint = sp;
+ searching = true;
+ }
- // Avoid races with notify_one() fired from last slave of the split point
- std::unique_lock<std::mutex> lk(mutex);
+ spinlock.release();
+ }
- // If we are master and all slaves have finished then exit idle_loop
- if (this_sp && this_sp->slavesMask.none())
- {
- assert(!searching);
- break;
+ sp->spinlock.release();
+ }
}
-
- // If we are not searching, wait for a condition to be signaled instead of
- // wasting CPU time polling for work.
- if (!searching && !exit)
- sleepCondition.wait(lk);
}
}
void check_time() {
- static Time::point lastInfoTime = Time::now();
- Time::point elapsed = Time::now() - SearchTime;
+ static TimePoint lastInfoTime = now();
+ TimePoint elapsed = now() - SearchTime;
- if (Time::now() - lastInfoTime >= 1000)
+ if (now() - lastInfoTime >= 1000)
{
- lastInfoTime = Time::now();
+ lastInfoTime = now();
dbg_print();
}
else if (Limits.nodes)
{
- Threads.mutex.lock();
-
int64_t nodes = RootPos.nodes_searched();
// Loop across all split points and sum accumulated SplitPoint nodes plus
// all the currently active positions nodes.
+ // FIXME: Racy...
for (Thread* th : Threads)
for (size_t i = 0; i < th->splitPointsSize; ++i)
{
SplitPoint& sp = th->splitPoints[i];
- sp.mutex.lock();
+ sp.spinlock.acquire();
nodes += sp.nodes;
if (sp.slavesMask.test(idx) && Threads[idx]->activePosition)
nodes += Threads[idx]->activePosition->nodes_searched();
- sp.mutex.unlock();
+ sp.spinlock.release();
}
- Threads.mutex.unlock();
-
if (nodes >= Limits.nodes)
Signals.stop = true;
}
projects / stockfish / blobdiff