X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=681acb8141a0e1b5d7c8def9569ce28e8bb15ffc;hp=7f733a950f73bb0904fe8abaa35fd458f8c9044a;hb=e53774bc49dd0aaa1c129ee98c09e1a56ef974fb;hpb=0af24a14455bbcde181fff7632722ce55419991e diff --git a/src/search.cpp b/src/search.cpp index 7f733a95..681acb81 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -41,7 +41,7 @@ namespace Search { LimitsType Limits; RootMoveVector RootMoves; Position RootPos; - Time::point SearchTime; + TimePoint SearchTime; StateStackPtr SetupStates; } @@ -158,7 +158,7 @@ uint64_t Search::perft(Position& pos, Depth depth) { cnt = 1, nodes++; else { - pos.do_move(m, st, ci, pos.gives_check(m, ci)); + pos.do_move(m, st, pos.gives_check(m, ci)); cnt = leaf ? MoveList(pos).size() : perft(pos, depth - ONE_PLY); nodes += cnt; pos.undo_move(m); @@ -355,7 +355,7 @@ namespace { // 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 @@ -386,9 +386,9 @@ namespace { 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; } @@ -412,7 +412,7 @@ namespace { // 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()) + || 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". @@ -694,7 +694,7 @@ namespace { if (pos.legal(move, ci.pinned)) { ss->currentMove = move; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); pos.undo_move(move); if (value >= rbeta) @@ -765,7 +765,7 @@ moves_loop: // When in check and at SpNode search starts from here continue; moveCount = ++splitPoint->moveCount; - splitPoint->mutex.unlock(); + splitPoint->spinlock.release(); } else ++moveCount; @@ -774,7 +774,7 @@ moves_loop: // When in check and at SpNode search starts from here { 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; @@ -834,7 +834,7 @@ moves_loop: // When in check and at SpNode search starts from here && moveCount >= FutilityMoveCounts[improving][depth]) { if (SpNode) - splitPoint->mutex.lock(); + splitPoint->spinlock.acquire(); continue; } @@ -853,7 +853,7 @@ moves_loop: // When in check and at SpNode search starts from here if (SpNode) { - splitPoint->mutex.lock(); + splitPoint->spinlock.acquire(); if (bestValue > splitPoint->bestValue) splitPoint->bestValue = bestValue; } @@ -865,7 +865,7 @@ moves_loop: // When in check and at SpNode search starts from here if (predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < VALUE_ZERO) { if (SpNode) - splitPoint->mutex.lock(); + splitPoint->spinlock.acquire(); continue; } @@ -886,7 +886,7 @@ moves_loop: // When in check and at SpNode search starts from here quietsSearched[quietCount++] = move; // Step 14. Make the move - pos.do_move(move, st, ci, givesCheck); + pos.do_move(move, st, givesCheck); // Step 15. Reduced depth search (LMR). If the move fails high it will be // re-searched at full depth. @@ -965,7 +965,7 @@ moves_loop: // When in check and at SpNode search starts from here // Step 18. Check for new best move if (SpNode) { - splitPoint->mutex.lock(); + splitPoint->spinlock.acquire(); bestValue = splitPoint->bestValue; alpha = splitPoint->alpha; } @@ -1034,7 +1034,9 @@ moves_loop: // When in check and at SpNode search starts from here && Threads.size() >= 2 && depth >= Threads.minimumSplitDepth && ( !thisThread->activeSplitPoint - || !thisThread->activeSplitPoint->allSlavesSearching) + || !thisThread->activeSplitPoint->allSlavesSearching + || ( Threads.size() > MAX_SLAVES_PER_SPLITPOINT + && thisThread->activeSplitPoint->slavesMask.count() == MAX_SLAVES_PER_SPLITPOINT)) && thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD) { assert(bestValue > -VALUE_INFINITE && bestValue < beta); @@ -1247,7 +1249,7 @@ moves_loop: // When in check and at SpNode search starts from here ss->currentMove = move; // Make and search the move - pos.do_move(move, st, ci, givesCheck); + pos.do_move(move, st, givesCheck); value = givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY) : -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); pos.undo_move(move); @@ -1371,7 +1373,7 @@ moves_loop: // When in check and at SpNode search starts from here 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); @@ -1405,7 +1407,7 @@ moves_loop: // When in check and at SpNode search starts from here 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; @@ -1474,7 +1476,7 @@ void RootMove::insert_pv_in_tt(Position& pos) { if (!ttHit || tte->move() != m) // Don't overwrite correct entries tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, m, VALUE_NONE, TT.generation()); - pos.do_move(m, *st++); + pos.do_move(m, *st++, pos.gives_check(m, CheckInfo(pos))); } for (size_t i = pv.size(); i > 0; ) @@ -1494,7 +1496,7 @@ bool RootMove::extract_ponder_from_tt(Position& pos) assert(pv.size() == 1); - pos.do_move(pv[0], st); + pos.do_move(pv[0], st, pos.gives_check(pv[0], CheckInfo(pos))); TTEntry* tte = TT.probe(pos.key(), ttHit); pos.undo_move(pv[0]); @@ -1515,21 +1517,22 @@ void Thread::idle_loop() { // Pointer 'this_sp' is not null only if we are called from split(), and not // at the thread creation. This means we are the split point's master. - SplitPoint* this_sp = splitPointsSize ? activeSplitPoint : nullptr; + SplitPoint* this_sp = activeSplitPoint; - assert(!this_sp || (this_sp->masterThread == this && searching)); + assert(!this_sp || (this_sp->master == this && searching)); while (!exit) { // If this thread has been assigned work, launch a search while (searching) { - Threads.mutex.lock(); + Threads.spinlock.acquire(); assert(activeSplitPoint); + SplitPoint* sp = activeSplitPoint; - Threads.mutex.unlock(); + Threads.spinlock.release(); Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2) Position pos(*sp->pos, this); @@ -1537,7 +1540,7 @@ void Thread::idle_loop() { std::memcpy(ss-2, sp->ss-2, 5 * sizeof(Stack)); ss->splitPoint = sp; - sp->mutex.lock(); + sp->spinlock.acquire(); assert(activePosition == nullptr); @@ -1565,51 +1568,74 @@ void Thread::idle_loop() { // 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->masterThread - && sp->slavesMask.none()) + if (this != sp->master && sp->slavesMask.none()) { - assert(!sp->masterThread->searching); - sp->masterThread->notify_one(); + 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. - if (Threads.size() > 2) - for (size_t i = 0; i < Threads.size(); ++i) + SplitPoint* bestSp = NULL; + int minLevel = INT_MAX; + + for (Thread* th : Threads) + { + const size_t size = th->splitPointsSize; // Local copy + sp = size ? &th->splitPoints[size - 1] : nullptr; + + if ( sp + && sp->allSlavesSearching + && sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT + && can_join(sp)) { - const int size = Threads[i]->splitPointsSize; // Local copy - sp = size ? &Threads[i]->splitPoints[size - 1] : nullptr; + assert(this != th); + assert(!(this_sp && this_sp->slavesMask.none())); + assert(Threads.size() > 2); + + // 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 = 0; + for (SplitPoint* p = th->activeSplitPoint; p; p = p->parentSplitPoint) + level++; - if ( sp - && sp->allSlavesSearching - && available_to(Threads[i])) + if (level < minLevel) { - // Recheck the conditions under lock protection - Threads.mutex.lock(); - sp->mutex.lock(); - - if ( sp->allSlavesSearching - && available_to(Threads[i])) - { - sp->slavesMask.set(idx); - activeSplitPoint = sp; - searching = true; - } - - sp->mutex.unlock(); - Threads.mutex.unlock(); - - break; // Just a single attempt + bestSp = sp; + minLevel = level; } } + } + + if (bestSp) + { + sp = bestSp; + + // Recheck the conditions under lock protection + Threads.spinlock.acquire(); + sp->spinlock.acquire(); + + if ( sp->allSlavesSearching + && sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT + && can_join(sp)) + { + sp->slavesMask.set(idx); + activeSplitPoint = sp; + searching = true; + } + + sp->spinlock.release(); + Threads.spinlock.release(); + } } - // Grab the lock to avoid races with Thread::notify_one() + // Avoid races with notify_one() fired from last slave of the split point std::unique_lock lk(mutex); // If we are master and all slaves have finished then exit idle_loop @@ -1633,12 +1659,12 @@ void Thread::idle_loop() { 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(); } @@ -1661,18 +1687,18 @@ void check_time() { else if (Limits.nodes) { - Threads.mutex.lock(); + Threads.spinlock.acquire(); int64_t nodes = RootPos.nodes_searched(); // Loop across all split points and sum accumulated SplitPoint nodes plus // all the currently active positions nodes. for (Thread* th : Threads) - for (int i = 0; i < th->splitPointsSize; ++i) + for (size_t i = 0; i < th->splitPointsSize; ++i) { SplitPoint& sp = th->splitPoints[i]; - sp.mutex.lock(); + sp.spinlock.acquire(); nodes += sp.nodes; @@ -1680,10 +1706,10 @@ void check_time() { if (sp.slavesMask.test(idx) && Threads[idx]->activePosition) nodes += Threads[idx]->activePosition->nodes_searched(); - sp.mutex.unlock(); + sp.spinlock.release(); } - Threads.mutex.unlock(); + Threads.spinlock.release(); if (nodes >= Limits.nodes) Signals.stop = true;