X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=4adcefa9464dcfb740dc6111d26cecbbae0e6e86;hp=002f0500ac8e21ce3c52179d59f414239eb5d69f;hb=b8c5ea869ca80338f8b2fa6815fc92349b889750;hpb=81cd7d787ef2b9d914c9c09ddbed59dffb78ec77 diff --git a/src/search.cpp b/src/search.cpp index 002f0500..4adcefa9 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -26,7 +26,6 @@ #include "book.h" #include "evaluate.h" -#include "history.h" #include "movegen.h" #include "movepick.h" #include "notation.h" @@ -87,7 +86,8 @@ namespace { TimeManager TimeMgr; int BestMoveChanges; Value DrawValue[COLOR_NB]; - History H; + History Hist; + Gains Gain; template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth); @@ -99,8 +99,8 @@ namespace { Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); bool check_is_dangerous(Position& pos, Move move, Value futilityBase, Value beta); - bool allows_move(const Position& pos, Move first, Move second); - bool prevents_move(const Position& pos, Move first, Move second); + bool allows(const Position& pos, Move first, Move second); + bool refutes(const Position& pos, Move first, Move second); string uci_pv(const Position& pos, int depth, Value alpha, Value beta); struct Skill { @@ -227,22 +227,25 @@ void Search::think() { << std::endl; } - Threads.wake_up(); + // Reset the threads, still sleeping: will be wake up at split time + for (size_t i = 0; i < Threads.size(); i++) + Threads[i].maxPly = 0; + + Threads.sleepWhileIdle = Options["Use Sleeping Threads"]; // Set best timer interval to avoid lagging under time pressure. Timer is // used to check for remaining available thinking time. - if (Limits.use_time_management()) - Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 16, - TimerResolution))); - else if (Limits.nodes) - Threads.set_timer(2 * TimerResolution); - else - Threads.set_timer(100); + Threads.timer_thread()->msec = + Limits.use_time_management() ? std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)) : + Limits.nodes ? 2 * TimerResolution + : 100; + + Threads.timer_thread()->notify_one(); // Wake up the recurring timer id_loop(RootPos); // Let's start searching ! - Threads.set_timer(0); // Stop timer - Threads.sleep(); + Threads.timer_thread()->msec = 0; // Stop the timer + Threads.sleepWhileIdle = true; // Send idle threads to sleep if (Options["Use Search Log"]) { @@ -262,12 +265,14 @@ void Search::think() { finalize: // When we reach max depth we arrive here even without Signals.stop is raised, - // but if we are pondering or in infinite search, we shouldn't print the best - // move before we are told to do so. + // but if we are pondering or in infinite search, according to UCI protocol, + // we shouldn't print the best move before the GUI sends a "stop" or "ponderhit" + // command. We simply wait here until GUI sends one of those commands (that + // raise Signals.stop). if (!Signals.stop && (Limits.ponder || Limits.infinite)) { Signals.stopOnPonderhit = true; - RootPos.this_thread()->wait_for_stop(); + RootPos.this_thread()->wait_for(Signals.stop); } // Best move could be MOVE_NONE when searching on a stalemate position @@ -295,7 +300,8 @@ namespace { bestValue = delta = -VALUE_INFINITE; ss->currentMove = MOVE_NULL; // Hack to skip update gains TT.new_search(); - H.clear(); + Hist.clear(); + Gain.clear(); PVSize = Options["MultiPV"]; Skill skill(Options["Skill Level"]); @@ -394,6 +400,7 @@ namespace { // Sort the PV lines searched so far and update the GUI sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1); + if (PVIdx + 1 == PVSize || Time::now() - SearchTime > 3000) sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; } @@ -494,13 +501,12 @@ namespace { Value bestValue, value, ttValue; Value eval, nullValue, futilityValue; bool inCheck, givesCheck, pvMove, singularExtensionNode; - bool captureOrPromotion, dangerous, doFullDepthSearch, threatExtension; + bool captureOrPromotion, dangerous, doFullDepthSearch; int moveCount, playedMoveCount; // Step 1. Initialize node Thread* thisThread = pos.this_thread(); moveCount = playedMoveCount = 0; - threatExtension = false; inCheck = pos.checkers(); if (SpNode) @@ -531,7 +537,7 @@ namespace { if (!RootNode) { // Step 2. Check for aborted search and immediate draw - if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) + if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) return DrawValue[pos.side_to_move()]; // Step 3. Mate distance pruning. Even if we mate at the next move our score @@ -614,7 +620,7 @@ namespace { && type_of(move) == NORMAL) { Square to = to_sq(move); - H.update_gain(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); + Gain.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); } // Step 6. Razoring (is omitted in PV nodes) @@ -664,12 +670,12 @@ namespace { if (eval - PawnValueMg > beta) R += ONE_PLY; - pos.do_null_move(st); + pos.do_null_move(st); (ss+1)->skipNullMove = true; nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : - search(pos, ss+1, -beta, -alpha, depth-R); (ss+1)->skipNullMove = false; - pos.do_null_move(st); + pos.undo_null_move(); if (nullValue >= beta) { @@ -693,15 +699,16 @@ namespace { // The null move failed low, which means that we may be faced with // some kind of threat. If the previous move was reduced, check if // the move that refuted the null move was somehow connected to the - // move which was reduced. If a connection is found extend moves that - // defend against threat. + // move which was reduced. If a connection is found, return a fail + // low score (which will cause the reduced move to fail high in the + // parent node, which will trigger a re-search with full depth). threatMove = (ss+1)->currentMove; if ( depth < 5 * ONE_PLY && (ss-1)->reduction && threatMove != MOVE_NONE - && allows_move(pos, (ss-1)->currentMove, threatMove)) - threatExtension = true; + && allows(pos, (ss-1)->currentMove, threatMove)) + return beta - 1; } } @@ -723,7 +730,7 @@ namespace { assert((ss-1)->currentMove != MOVE_NONE); assert((ss-1)->currentMove != MOVE_NULL); - MovePicker mp(pos, ttMove, H, pos.captured_piece_type()); + MovePicker mp(pos, ttMove, Hist, pos.captured_piece_type()); CheckInfo ci(pos); while ((move = mp.next_move()) != MOVE_NONE) @@ -755,7 +762,7 @@ namespace { split_point_start: // At split points actual search starts from here - MovePicker mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); + MovePicker mp(pos, ttMove, depth, Hist, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc singularExtensionNode = !RootNode @@ -819,9 +826,6 @@ split_point_start: // At split points actual search starts from here if (PvNode && dangerous) ext = ONE_PLY; - else if (threatExtension && prevents_move(pos, move, threatMove)) - ext = ONE_PLY; - else if (givesCheck && pos.see_sign(move) >= 0) ext = ONE_PLY / 2; @@ -846,7 +850,7 @@ split_point_start: // At split points actual search starts from here ss->excludedMove = MOVE_NONE; if (value < rBeta) - ext = rBeta >= beta ? ONE_PLY + ONE_PLY / 2 : ONE_PLY; + ext = ONE_PLY; } // Update current move (this must be done after singular extension search) @@ -864,7 +868,7 @@ split_point_start: // At split points actual search starts from here // Move count based pruning if ( depth < 16 * ONE_PLY && moveCount >= FutilityMoveCounts[depth] - && (!threatMove || !prevents_move(pos, move, threatMove))) + && (!threatMove || !refutes(pos, move, threatMove))) { if (SpNode) sp->mutex.lock(); @@ -877,7 +881,7 @@ split_point_start: // At split points actual search starts from here // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_moved(move), to_sq(move)); + + Gain[pos.piece_moved(move)][to_sq(move)]; if (futilityValue < beta) { @@ -919,8 +923,9 @@ split_point_start: // At split points actual search starts from here && !pvMove && !captureOrPromotion && !dangerous - && ss->killers[0] != move - && ss->killers[1] != move) + && move != ttMove + && move != ss->killers[0] + && move != ss->killers[1]) { ss->reduction = reduction(depth, moveCount); Depth d = std::max(newDepth - ss->reduction, ONE_PLY); @@ -1019,8 +1024,9 @@ split_point_start: // At split points actual search starts from here // Step 19. Check for splitting the search if ( !SpNode - && depth >= Threads.min_split_depth() - && Threads.available_slave_exists(thisThread)) + && depth >= Threads.minimumSplitDepth + && Threads.slave_available(thisThread) + && thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD) { assert(bestValue < beta); @@ -1068,13 +1074,13 @@ split_point_start: // At split points actual search starts from here // Increase history value of the cut-off move Value bonus = Value(int(depth) * int(depth)); - H.add(pos.piece_moved(bestMove), to_sq(bestMove), bonus); + Hist.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); // Decrease history of all the other played non-capture moves for (int i = 0; i < playedMoveCount - 1; i++) { Move m = movesSearched[i]; - H.add(pos.piece_moved(m), to_sq(m), -bonus); + Hist.update(pos.piece_moved(m), to_sq(m), -bonus); } } } @@ -1120,7 +1126,7 @@ split_point_start: // At split points actual search starts from here ss->ply = (ss-1)->ply + 1; // Check for an instant draw or maximum ply reached - if (pos.is_draw() || ss->ply > MAX_PLY) + if (pos.is_draw() || ss->ply > MAX_PLY) return DrawValue[pos.side_to_move()]; // Transposition table lookup. At PV nodes, we don't use the TT for @@ -1186,7 +1192,7 @@ split_point_start: // At split points actual search starts from here // 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, H, to_sq((ss-1)->currentMove)); + MovePicker mp(pos, ttMove, depth, Hist, to_sq((ss-1)->currentMove)); CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs @@ -1363,12 +1369,12 @@ split_point_start: // At split points actual search starts from here } - // allows_move() tests whether the move at previous ply (first) somehow makes a - // second move possible, for instance if the moving piece is the same in both - // moves. Normally the second move is the threat move (the best move returned + // allows() tests whether the 'first' move at previous ply somehow makes the + // 'second' move possible, for instance if the moving piece is the same in + // both moves. Normally the second move is the threat (the best move returned // from a null search that fails low). - bool allows_move(const Position& pos, Move first, Move second) { + bool allows(const Position& pos, Move first, Move second) { assert(is_ok(first)); assert(is_ok(second)); @@ -1404,12 +1410,11 @@ split_point_start: // At split points actual search starts from here } - // prevents_move() tests whether a move (first) is able to defend against an - // opponent's move (second). In this case will not be pruned. Normally the - // second move is the threat move (the best move returned from a null search - // that fails low). + // refutes() tests whether a 'first' move is able to defend against a 'second' + // opponent's move. In this case will not be pruned. Normally the second move + // is the threat (the best move returned from a null search that fails low). - bool prevents_move(const Position& pos, Move first, Move second) { + bool refutes(const Position& pos, Move first, Move second) { assert(is_ok(first)); assert(is_ok(second)); @@ -1569,7 +1574,7 @@ void RootMove::extract_pv_from_tt(Position& pos) { && pos.is_pseudo_legal(m = tte->move()) // Local copy, TT could change && pos.pl_move_is_legal(m, pos.pinned_pieces()) && ply < MAX_PLY - && (!pos.is_draw() || ply < 2)); + && (!pos.is_draw() || ply < 2)); pv.push_back(MOVE_NONE); // Must be zero-terminating @@ -1607,33 +1612,31 @@ void RootMove::insert_pv_in_tt(Position& pos) { void Thread::idle_loop() { - // Pointer 'sp_master', if non-NULL, points to the active SplitPoint - // object for which the thread is the master. - const SplitPoint* sp_master = splitPointsCnt ? curSplitPoint : NULL; + // Pointer 'this_sp' is not null only if we are called from split(), and not + // at the thread creation. So it means we are the split point's master. + const SplitPoint* this_sp = splitPointsSize ? activeSplitPoint : NULL; - assert(!sp_master || (sp_master->master == this && is_searching)); + assert(!this_sp || (this_sp->masterThread == this && searching)); - // If this thread is the master of a split point and all slaves have - // finished their work at this split point, return from the idle loop. - while (!sp_master || sp_master->slavesMask) + // If this thread is the master of a split point and all slaves have finished + // their work at this split point, return from the idle loop. + while (!this_sp || this_sp->slavesMask) { - // If we are not searching, wait for a condition to be signaled - // instead of wasting CPU time polling for work. - while ( do_sleep - || do_exit - || (!is_searching && Threads.use_sleeping_threads())) + // If we are not searching, wait for a condition to be signaled instead of + // wasting CPU time polling for work. + while ((!searching && Threads.sleepWhileIdle) || exit) { - if (do_exit) + if (exit) { - assert(!sp_master); + assert(!this_sp); return; } - // Grab the lock to avoid races with Thread::wake_up() + // Grab the lock to avoid races with Thread::notify_one() mutex.lock(); - // If we are master and all slaves have finished don't go to sleep - if (sp_master && !sp_master->slavesMask) + // If we are master and all slaves have finished then exit idle_loop + if (this_sp && !this_sp->slavesMask) { mutex.unlock(); break; @@ -1641,23 +1644,23 @@ void Thread::idle_loop() { // Do sleep after retesting sleep conditions under lock protection, in // particular we need to avoid a deadlock in case a master thread has, - // in the meanwhile, allocated us and sent the wake_up() call before we - // had the chance to grab the lock. - if (do_sleep || !is_searching) + // in the meanwhile, allocated us and sent the notify_one() call before + // we had the chance to grab the lock. + if (!searching && !exit) sleepCondition.wait(mutex); mutex.unlock(); } // If this thread has been assigned work, launch a search - if (is_searching) + if (searching) { - assert(!do_sleep && !do_exit); + assert(!exit); Threads.mutex.lock(); - assert(is_searching); - SplitPoint* sp = curSplitPoint; + assert(searching); + SplitPoint* sp = activeSplitPoint; Threads.mutex.unlock(); @@ -1669,34 +1672,39 @@ void Thread::idle_loop() { sp->mutex.lock(); - assert(sp->activePositions[idx] == NULL); + assert(sp->slavesPositions[idx] == NULL); - sp->activePositions[idx] = &pos; + sp->slavesPositions[idx] = &pos; - if (sp->nodeType == Root) + switch (sp->nodeType) { + case Root: search(pos, ss+1, sp->alpha, sp->beta, sp->depth); - else if (sp->nodeType == PV) + break; + case PV: search(pos, ss+1, sp->alpha, sp->beta, sp->depth); - else if (sp->nodeType == NonPV) + break; + case NonPV: search(pos, ss+1, sp->alpha, sp->beta, sp->depth); - else + break; + default: assert(false); + } - assert(is_searching); + assert(searching); - is_searching = false; - sp->activePositions[idx] = NULL; + searching = false; + sp->slavesPositions[idx] = NULL; sp->slavesMask &= ~(1ULL << idx); sp->nodes += pos.nodes_searched(); - // Wake up master thread so to allow it to return from the idle loop in - // case we are the last slave of the split point. - if ( Threads.use_sleeping_threads() - && this != sp->master + // Wake up master thread so to allow it to return from the idle loop + // in case we are the last slave of the split point. + if ( Threads.sleepWhileIdle + && this != sp->masterThread && !sp->slavesMask) { - assert(!sp->master->is_searching); - sp->master->notify_one(); + assert(!sp->masterThread->searching); + sp->masterThread->notify_one(); } // After releasing the lock we cannot access anymore any SplitPoint @@ -1736,7 +1744,7 @@ void check_time() { // Loop across all split points and sum accumulated SplitPoint nodes plus // all the currently active slaves positions. for (size_t i = 0; i < Threads.size(); i++) - for (int j = 0; j < Threads[i].splitPointsCnt; j++) + for (int j = 0; j < Threads[i].splitPointsSize; j++) { SplitPoint& sp = Threads[i].splitPoints[j]; @@ -1746,7 +1754,7 @@ void check_time() { Bitboard sm = sp.slavesMask; while (sm) { - Position* pos = sp.activePositions[pop_lsb(&sm)]; + Position* pos = sp.slavesPositions[pop_lsb(&sm)]; nodes += pos ? pos->nodes_searched() : 0; }