void ThreadPool::start_thinking(const Position& pos, StateListPtr& states, const Search::LimitsType& limits) { main()->wait_for_search_finished(); Search::Signals.stopOnPonderhit = Search::Signals.stop = false; Search::Limits = limits; Search::RootMoves rootMoves; for (const auto& m : MoveList<LEGAL>(pos)) if ( limits.searchmoves.empty() || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), m)) rootMoves.push_back(Search::RootMove(m)); // After ownership transfer 'states' becomes empty, so if we stop the search // and call 'go' again without setting a new position states.get() == NULL. assert(states.get() || setupStates.get()); if (states.get()) setupStates = std::move(states); // Ownership transfer, states is now empty StateInfo tmp = setupStates->back(); for (Thread* th : Threads) { th->maxPly = 0; th->rootDepth = DEPTH_ZERO; th->rootMoves = rootMoves; th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th); } setupStates->back() = tmp; // Restore st->previous, cleared by Position::set() main()->start_searching(); }