using std::cout;
using std::endl;
using std::string;
+using Search::Signals;
+using Search::Limits;
-SearchLimits Limits;
-std::vector<Move> SearchMoves;
-Position* RootPosition;
+namespace Search {
+
+ volatile SignalsType Signals;
+ LimitsType Limits;
+ std::vector<Move> RootMoves;
+ Position RootPosition;
+}
namespace {
// RootMoveList struct is mainly a std::vector of RootMove objects
struct RootMoveList : public std::vector<RootMove> {
- void init(Position& pos, Move searchMoves[]);
+ void init(Position& pos, Move rootMoves[]);
RootMove* find(const Move& m, int startIndex = 0);
int bestMoveChanges;
int MultiPV, UCIMultiPV, MultiPVIdx;
// Time management variables
- volatile bool StopOnPonderhit, FirstRootMove, StopRequest, AspirationFailLow;
TimeManager TimeMgr;
// Skill level adjustment
/// Local functions
- Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove);
+ Move id_loop(Position& pos, Move rootMoves[], Move* ponderMove);
template <NodeType NT>
Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth);
void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
void do_skill_level(Move* best, Move* ponder);
- int elapsed_search_time(int set = 0);
+ int elapsed_time(bool reset = false);
string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
string speed_to_uci(int64_t nodes);
string pv_to_uci(const Move pv[], int pvNum, bool chess960);
/// init_search() is called during startup to initialize various lookup tables
-void init_search() {
+void Search::init() {
int d; // depth (ONE_PLY == 2)
int hd; // half depth (ONE_PLY == 1)
/// perft() is our utility to verify move generation. All the leaf nodes up to
/// the given depth are generated and counted and the sum returned.
-int64_t perft(Position& pos, Depth depth) {
+int64_t Search::perft(Position& pos, Depth depth) {
StateInfo st;
int64_t sum = 0;
/// variables, and calls id_loop(). It returns false when a "quit" command is
/// received during the search.
-void think() {
+void Search::think() {
static Book book; // Defined static to initialize the PRNG only once
- Position& pos = *RootPosition;
-
- // Save "search start" time and reset elapsed time to zero
- elapsed_search_time(get_system_time());
+ Position& pos = RootPosition;
- // Initialize global search-related variables
- StopOnPonderhit = StopRequest = AspirationFailLow = false;
+ // Reset elapsed search time
+ elapsed_time(true);
// Set output stream mode: normal or chess960. Castling notation is different
cout << set960(pos.is_chess960());
Move bookMove = book.probe(pos, Options["Best Book Move"].value<bool>());
if (bookMove != MOVE_NONE)
{
- if (!StopRequest && (Limits.ponder || Limits.infinite))
+ if (!Signals.stop && (Limits.ponder || Limits.infinite))
Threads.wait_for_stop_or_ponderhit();
cout << "bestmove " << bookMove << endl;
// We're ready to start thinking. Call the iterative deepening loop function
Move ponderMove = MOVE_NONE;
- Move bestMove = id_loop(pos, &SearchMoves[0], &ponderMove);
+ Move bestMove = id_loop(pos, &RootMoves[0], &ponderMove);
// Stop timer, no need to check for available time any more
Threads.set_timer(0);
// Write current search final statistics to log file
if (Options["Use Search Log"].value<bool>())
{
- int e = elapsed_search_time();
+ int e = elapsed_time();
Log log(Options["Search Log Filename"].value<string>());
log << "Nodes: " << pos.nodes_searched()
// When we reach max depth we arrive here even without a StopRequest, but if
// we are pondering or in infinite search, we shouldn't print the best move
// before we are told to do so.
- if (!StopRequest && (Limits.ponder || Limits.infinite))
+ if (!Signals.stop && (Limits.ponder || Limits.infinite))
Threads.wait_for_stop_or_ponderhit();
// Could be MOVE_NONE when searching on a stalemate position
// with increasing depth until the allocated thinking time has been consumed,
// user stops the search, or the maximum search depth is reached.
- Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove) {
+ Move id_loop(Position& pos, Move rootMoves[], Move* ponderMove) {
SearchStack ss[PLY_MAX_PLUS_2];
Value bestValues[PLY_MAX_PLUS_2];
ss->currentMove = MOVE_NULL; // Hack to skip update gains
// Moves to search are verified and copied
- Rml.init(pos, searchMoves);
+ Rml.init(pos, rootMoves);
// Handle special case of searching on a mate/stalemate position
if (!Rml.size())
}
// Iterative deepening loop until requested to stop or target depth reached
- while (!StopRequest && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth))
+ while (!Signals.stop && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth))
{
// Save now last iteration's scores, before Rml moves are reordered
for (size_t i = 0; i < Rml.size(); i++)
// If search has been stopped exit the aspiration window loop,
// note that sorting and writing PV back to TT is safe becuase
// Rml is still valid, although refers to the previous iteration.
- if (StopRequest)
+ if (Signals.stop)
break;
// Send full PV info to GUI if we are going to leave the loop or
// if we have a fail high/low and we are deep in the search. UCI
// protocol requires to send all the PV lines also if are still
// to be searched and so refer to the previous search's score.
- if ((bestValue > alpha && bestValue < beta) || elapsed_search_time() > 2000)
+ if ((bestValue > alpha && bestValue < beta) || elapsed_time() > 2000)
for (int i = 0; i < std::min(UCIMultiPV, (int)Rml.size()); i++)
{
bool updated = (i <= MultiPVIdx);
}
else if (bestValue <= alpha)
{
- AspirationFailLow = true;
- StopOnPonderhit = false;
+ Signals.failedLowAtRoot = true;
+ Signals.stopOnPonderhit = false;
alpha = std::max(alpha - aspirationDelta, -VALUE_INFINITE);
aspirationDelta += aspirationDelta / 2;
if (Options["Use Search Log"].value<bool>())
{
Log log(Options["Search Log Filename"].value<string>());
- log << pretty_pv(pos, depth, bestValue, elapsed_search_time(), &Rml[0].pv[0]) << endl;
+ log << pretty_pv(pos, depth, bestValue, elapsed_time(), &Rml[0].pv[0]) << endl;
}
// Filter out startup noise when monitoring best move stability
bestMoveNeverChanged = false;
// Do we have time for the next iteration? Can we stop searching now?
- if (!StopRequest && !StopOnPonderhit && Limits.useTimeManagement())
+ if (!Signals.stop && !Signals.stopOnPonderhit && Limits.useTimeManagement())
{
+ bool stop = false; // Local variable instead of the volatile Signals.stop
+
// Take in account some extra time if the best move has changed
if (depth > 4 && depth < 50)
TimeMgr.pv_instability(bestMoveChanges[depth], bestMoveChanges[depth - 1]);
// Stop search if most of available time is already consumed. We probably don't
// have enough time to search the first move at the next iteration anyway.
- if (elapsed_search_time() > (TimeMgr.available_time() * 62) / 100)
- StopRequest = true;
+ if (elapsed_time() > (TimeMgr.available_time() * 62) / 100)
+ stop = true;
// Stop search early if one move seems to be much better than others
if ( depth >= 10
- && !StopRequest
+ && !stop
&& ( bestMoveNeverChanged
- || elapsed_search_time() > (TimeMgr.available_time() * 40) / 100))
+ || elapsed_time() > (TimeMgr.available_time() * 40) / 100))
{
Value rBeta = bestValue - EasyMoveMargin;
(ss+1)->excludedMove = bestMove;
(ss+1)->excludedMove = MOVE_NONE;
if (v < rBeta)
- StopRequest = true;
+ stop = true;
}
- // If we are allowed to ponder do not stop the search now but keep pondering
- if (StopRequest && Limits.ponder) // FIXME Limits.ponder is racy
+ if (stop)
{
- StopRequest = false;
- StopOnPonderhit = true;
+ // If we are allowed to ponder do not stop the search now but
+ // keep pondering until GUI sends "ponderhit" or "stop".
+ if (Limits.ponder)
+ Signals.stopOnPonderhit = true;
+ else
+ Signals.stop = true;
}
}
}
}
// Step 2. Check for aborted search and immediate draw
- if (( StopRequest
+ if (( Signals.stop
|| pos.is_draw<false>()
|| ss->ply > PLY_MAX) && !RootNode)
return VALUE_DRAW;
if (RootNode)
{
// This is used by time management
- FirstRootMove = (moveCount == 1);
+ Signals.firstRootMove = (moveCount == 1);
// Save the current node count before the move is searched
nodes = pos.nodes_searched();
// For long searches send current move info to GUI
- if (pos.thread() == 0 && elapsed_search_time() > 2000)
+ if (pos.thread() == 0 && elapsed_time() > 2000)
cout << "info" << depth_to_uci(depth)
<< " currmove " << move
<< " currmovenumber " << moveCount + MultiPVIdx << endl;
// was aborted because the user interrupted the search or because we
// ran out of time. In this case, the return value of the search cannot
// be trusted, and we don't update the best move and/or PV.
- if (RootNode && !StopRequest)
+ if (RootNode && !Signals.stop)
{
// Remember searched nodes counts for this move
RootMove* rm = Rml.find(move);
&& depth >= Threads.min_split_depth()
&& bestValue < beta
&& Threads.available_slave_exists(pos.thread())
- && !StopRequest
+ && !Signals.stop
&& !thread.cutoff_occurred())
bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, depth,
threatMove, moveCount, &mp, NT);
// Step 21. Update tables
// If the search is not aborted, update the transposition table,
// history counters, and killer moves.
- if (!SpNode && !StopRequest && !thread.cutoff_occurred())
+ if (!SpNode && !Signals.stop && !thread.cutoff_occurred())
{
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
// current_search_time() returns the number of milliseconds which have passed
// since the beginning of the current search.
- int elapsed_search_time(int set) {
+ int elapsed_time(bool reset) {
static int searchStartTime;
- if (set)
- searchStartTime = set;
+ if (reset)
+ searchStartTime = get_system_time();
return get_system_time() - searchStartTime;
}
string speed_to_uci(int64_t nodes) {
std::stringstream s;
- int t = elapsed_search_time();
+ int t = elapsed_time();
s << " nodes " << nodes
<< " nps " << (t > 0 ? int(nodes * 1000 / t) : 0)
/// RootMove and RootMoveList method's definitions
- void RootMoveList::init(Position& pos, Move searchMoves[]) {
+ void RootMoveList::init(Position& pos, Move rootMoves[]) {
Move* sm;
bestMoveChanges = 0;
// Generate all legal moves and add them to RootMoveList
for (MoveList<MV_LEGAL> ml(pos); !ml.end(); ++ml)
{
- // If we have a searchMoves[] list then verify the move
+ // If we have a rootMoves[] list then verify the move
// is in the list before to add it.
- for (sm = searchMoves; *sm && *sm != ml.move(); sm++) {}
+ for (sm = rootMoves; *sm && *sm != ml.move(); sm++) {}
- if (sm != searchMoves && *sm != ml.move())
+ if (sm != rootMoves && *sm != ml.move())
continue;
RootMove rm;
}
-// ThreadsManager::wait_for_stop_or_ponderhit() is called when the maximum depth
-// is reached while the program is pondering. The point is to work around a wrinkle
-// in the UCI protocol: When pondering, the engine is not allowed to give a
-// "bestmove" before the GUI sends it a "stop" or "ponderhit" command.
-// We simply wait here until one of these commands (that raise StopRequest) is
-// sent, and return, after which the bestmove and pondermove will be printed.
-
-void ThreadsManager::wait_for_stop_or_ponderhit() {
-
- StopOnPonderhit = true;
-
- Thread& main = threads[0];
-
- lock_grab(&main.sleepLock);
-
- while (!StopRequest)
- cond_wait(&main.sleepCond, &main.sleepLock);
-
- lock_release(&main.sleepLock);
-}
-
-
-// uci_async_command() is called when a 'cmd' input line is received from the
-// GUI while searching.
-
-void uci_async_command(const std::string& cmd) {
-
- if (cmd == "quit" || cmd == "stop")
- StopRequest = true;
-
- else if (cmd == "ponderhit")
- {
- // The opponent has played the expected move. GUI sends "ponderhit" if
- // we were told to ponder on the same move the opponent has played. We
- // should continue searching but switching from pondering to normal search.
- Limits.ponder = false;
-
- if (StopOnPonderhit)
- StopRequest = true;
- }
-}
-
-
// do_timer_event() is called by the timer thread when the timer triggers
void do_timer_event() {
static int lastInfoTime;
- int e = elapsed_search_time();
+ int e = elapsed_time();
// Print debug information every one second
if (!lastInfoTime || get_system_time() - lastInfoTime >= 1000)
if (Limits.ponder)
return;
- bool stillAtFirstMove = FirstRootMove
- && !AspirationFailLow
+ bool stillAtFirstMove = Signals.firstRootMove
+ && !Signals.failedLowAtRoot
&& e > TimeMgr.available_time();
bool noMoreTime = e > TimeMgr.maximum_time()
if ( (Limits.useTimeManagement() && noMoreTime)
|| (Limits.maxTime && e >= Limits.maxTime)
/* missing nodes limit */ ) // FIXME
- StopRequest = true;
+ Signals.stop = true;
}