#include "move.h"
#include "movegen.h"
#include "movepick.h"
-#include "lock.h"
#include "search.h"
#include "timeman.h"
#include "thread.h"
const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 };
inline bool piece_is_slider(Piece p) { return Slidings[p]; }
- // ThreadsManager class is used to handle all the threads related stuff like init,
- // starting, parking and, the most important, launching a slave thread at a split
- // point. All the access to shared thread data is done through this class.
-
- class ThreadsManager {
- /* As long as the single ThreadsManager object is defined as a global we don't
- need to explicitly initialize to zero its data members because variables with
- static storage duration are automatically set to zero before enter main()
- */
- public:
- void init_threads();
- void exit_threads();
-
- int min_split_depth() const { return minimumSplitDepth; }
- int active_threads() const { return activeThreads; }
- void set_active_threads(int cnt) { activeThreads = cnt; }
-
- void read_uci_options();
- bool available_thread_exists(int master) const;
- bool thread_is_available(int slave, int master) const;
- bool cutoff_at_splitpoint(int threadID) const;
- void wake_sleeping_thread(int threadID);
- void idle_loop(int threadID, SplitPoint* sp);
-
- template <bool Fake>
- void split(Position& pos, SearchStack* ss, int ply, Value* alpha, const Value beta, Value* bestValue,
- Depth depth, Move threatMove, int moveCount, MovePicker* mp, bool pvNode);
-
- private:
- Depth minimumSplitDepth;
- int maxThreadsPerSplitPoint;
- bool useSleepingThreads;
- int activeThreads;
- volatile bool allThreadsShouldExit;
- Thread threads[MAX_THREADS];
- Lock mpLock, sleepLock[MAX_THREADS];
- WaitCondition sleepCond[MAX_THREADS];
- };
-
-
// RootMove struct is used for moves at the root of the tree. For each root
// move, we store two scores, a node count, and a PV (really a refutation
// in the case of moves which fail low). Value pv_score is normally set at
void extract_pv_from_tt(Position& pos);
void insert_pv_in_tt(Position& pos);
- std::string pv_info_to_uci(Position& pos, int depth, Value alpha, Value beta, int pvIdx);
-
+ std::string pv_info_to_uci(Position& pos, int depth, int selDepth,
+ Value alpha, Value beta, int pvIdx);
int64_t nodes;
Value pv_score;
Value non_pv_score;
};
- // RootMoveList struct is just a std::vector<> of RootMove objects,
+ // RootMoveList struct is just a vector of RootMove objects,
// with an handful of methods above the standard ones.
struct RootMoveList : public std::vector<RootMove> {
// Step 9. Internal iterative deepening
// Minimum depth for use of internal iterative deepening
- const Depth IIDDepth[2] = { 8 * ONE_PLY /* non-PV */, 5 * ONE_PLY /* PV */};
+ const Depth IIDDepth[] = { 8 * ONE_PLY, 5 * ONE_PLY };
// At Non-PV nodes we do an internal iterative deepening search
// when the static evaluation is bigger then beta - IIDMargin.
// Step 11. Decide the new search depth
- // Extensions. Configurable UCI options
- // Array index 0 is used at non-PV nodes, index 1 at PV nodes.
- Depth CheckExtension[2], PawnPushTo7thExtension[2];
- Depth PassedPawnExtension[2], PawnEndgameExtension[2];
+ // Extensions. Array index 0 is used for non-PV nodes, index 1 for PV nodes
+ const Depth CheckExtension[] = { ONE_PLY / 2, ONE_PLY / 1 };
+ const Depth PawnEndgameExtension[] = { ONE_PLY / 1, ONE_PLY / 1 };
+ const Depth PawnPushTo7thExtension[] = { ONE_PLY / 2, ONE_PLY / 2 };
+ const Depth PassedPawnExtension[] = { DEPTH_ZERO, ONE_PLY / 2 };
// Minimum depth for use of singular extension
- const Depth SingularExtensionDepth[2] = { 8 * ONE_PLY /* non-PV */, 6 * ONE_PLY /* PV */};
+ const Depth SingularExtensionDepth[] = { 8 * ONE_PLY, 6 * ONE_PLY };
// Step 12. Futility pruning
const Value FutilityMarginQS = Value(0x80);
// Futility lookup tables (initialized at startup) and their access functions
- Value FutilityMarginsMatrix[16][64]; // [depth][moveNumber]
- int FutilityMoveCountArray[32]; // [depth]
+ Value FutilityMargins[16][64]; // [depth][moveNumber]
+ int FutilityMoveCounts[32]; // [depth]
+
+ inline Value futility_margin(Depth d, int mn) {
- inline Value futility_margin(Depth d, int mn) { return d < 7 * ONE_PLY ? FutilityMarginsMatrix[Max(d, 1)][Min(mn, 63)] : 2 * VALUE_INFINITE; }
- inline int futility_move_count(Depth d) { return d < 16 * ONE_PLY ? FutilityMoveCountArray[d] : 512; }
+ return d < 7 * ONE_PLY ? FutilityMargins[Max(d, 1)][Min(mn, 63)]
+ : 2 * VALUE_INFINITE;
+ }
+
+ inline int futility_move_count(Depth d) {
+
+ return d < 16 * ONE_PLY ? FutilityMoveCounts[d] : MAX_MOVES;
+ }
// Step 14. Reduced search
- // Reduction lookup tables (initialized at startup) and their getter functions
- int8_t ReductionMatrix[2][64][64]; // [pv][depth][moveNumber]
+ // Reduction lookup tables (initialized at startup) and their access function
+ int8_t Reductions[2][64][64]; // [pv][depth][moveNumber]
+
+ template <NodeType PV> inline Depth reduction(Depth d, int mn) {
- template <NodeType PV>
- inline Depth reduction(Depth d, int mn) { return (Depth) ReductionMatrix[PV][Min(d / 2, 63)][Min(mn, 63)]; }
+ return (Depth) Reductions[PV][Min(d / ONE_PLY, 63)][Min(mn, 63)];
+ }
// Easy move margin. An easy move candidate must be at least this much
// better than the second best move.
int MultiPV, UCIMultiPV;
// Time management variables
- int SearchStartTime, MaxNodes, MaxDepth, ExactMaxTime;
- bool UseTimeManagement, InfiniteSearch, Pondering, StopOnPonderhit;
- bool FirstRootMove, StopRequest, QuitRequest, AspirationFailLow;
+ bool StopOnPonderhit, FirstRootMove, StopRequest, QuitRequest, AspirationFailLow;
TimeManager TimeMgr;
+ SearchLimits Limits;
// Log file
- bool UseLogFile;
std::ofstream LogFile;
// Skill level adjustment
bool SkillLevelEnabled;
RKISS RK;
- // Multi-threads manager
- ThreadsManager ThreadsMgr;
-
// Node counters, used only by thread[0] but try to keep in different cache
// lines (64 bytes each) from the heavy multi-thread read accessed variables.
bool SendSearchedNodes;
Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove);
template <NodeType PvNode, bool SpNode, bool Root>
- Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply);
+ Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth);
template <NodeType PvNode>
- Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply);
+ Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth);
template <NodeType PvNode>
- inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
+ inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) {
- return depth < ONE_PLY ? qsearch<PvNode>(pos, ss, alpha, beta, DEPTH_ZERO, ply)
- : search<PvNode, false, false>(pos, ss, alpha, beta, depth, ply);
+ return depth < ONE_PLY ? qsearch<PvNode>(pos, ss, alpha, beta, DEPTH_ZERO)
+ : search<PvNode, false, false>(pos, ss, alpha, beta, depth);
}
template <NodeType PvNode>
void update_gains(const Position& pos, Move move, Value before, Value after);
void do_skill_level(Move* best, Move* ponder);
- int current_search_time();
+ int current_search_time(int set = 0);
std::string value_to_uci(Value v);
std::string speed_to_uci(int64_t nodes);
void poll(const Position& pos);
void wait_for_stop_or_ponderhit();
-#if !defined(_MSC_VER)
- void* init_thread(void* threadID);
-#else
- DWORD WINAPI init_thread(LPVOID threadID);
-#endif
-
- // MovePickerExt is an extended MovePicker used to choose at compile time
+ // MovePickerExt is an extended MovePicker class used to choose at compile time
// the proper move source according to the type of node.
template<bool SpNode, bool Root> struct MovePickerExt;
} // namespace
-/// init_threads() is called during startup. It initializes various lookup tables
-/// and creates and launches search threads.
+/// init_search() is called during startup to initialize various lookup tables
-void init_threads() {
+void init_search() {
int d; // depth (ONE_PLY == 2)
int hd; // half depth (ONE_PLY == 1)
{
double pvRed = log(double(hd)) * log(double(mc)) / 3.0;
double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25;
- ReductionMatrix[PV][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0);
- ReductionMatrix[NonPV][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0);
+ Reductions[PV][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0);
+ Reductions[NonPV][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0);
}
// Init futility margins array
for (d = 1; d < 16; d++) for (mc = 0; mc < 64; mc++)
- FutilityMarginsMatrix[d][mc] = Value(112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45);
+ FutilityMargins[d][mc] = Value(112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45);
// Init futility move count array
for (d = 0; d < 32; d++)
- FutilityMoveCountArray[d] = int(3.001 + 0.25 * pow(d, 2.0));
-
- // Create and startup threads
- ThreadsMgr.init_threads();
+ FutilityMoveCounts[d] = int(3.001 + 0.25 * pow(d, 2.0));
}
-/// exit_threads() is a trampoline to access ThreadsMgr from outside of current file
-void exit_threads() { ThreadsMgr.exit_threads(); }
-
-
/// perft() is our utility to verify move generation. All the legal moves up to
/// given depth are generated and counted and the sum returned.
int64_t perft(Position& pos, Depth depth) {
- MoveStack mlist[MOVES_MAX];
+ MoveStack mlist[MAX_MOVES];
StateInfo st;
Move m;
int64_t sum = 0;
/// think() is the external interface to Stockfish's search, and is called when
/// the program receives the UCI 'go' command. It initializes various global
-/// variables, and calls id_loop(). It returns false when a quit command is
+/// variables, and calls id_loop(). It returns false when a "quit" command is
/// received during the search.
-bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[],
- int movesToGo, int maxDepth, int maxNodes, int maxTime, Move searchMoves[]) {
+bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) {
// Initialize global search-related variables
StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = SendSearchedNodes = false;
NodesSincePoll = 0;
- SearchStartTime = get_system_time();
- ExactMaxTime = maxTime;
- MaxDepth = maxDepth;
- MaxNodes = maxNodes;
- InfiniteSearch = infinite;
- Pondering = ponder;
- UseTimeManagement = !ExactMaxTime && !MaxDepth && !MaxNodes && !InfiniteSearch;
-
- // Look for a book move, only during games, not tests
- if (UseTimeManagement && Options["OwnBook"].value<bool>())
+ current_search_time(get_system_time());
+ Limits = limits;
+ TimeMgr.init(Limits, pos.startpos_ply_counter());
+
+ // Set best NodesBetweenPolls interval to avoid lagging under time pressure
+ if (Limits.maxNodes)
+ NodesBetweenPolls = Min(Limits.maxNodes, 30000);
+ else if (Limits.time && Limits.time < 1000)
+ NodesBetweenPolls = 1000;
+ else if (Limits.time && Limits.time < 5000)
+ NodesBetweenPolls = 5000;
+ else
+ NodesBetweenPolls = 30000;
+
+ // Look for a book move
+ if (Options["OwnBook"].value<bool>())
{
if (Options["Book File"].value<std::string>() != OpeningBook.name())
OpeningBook.open(Options["Book File"].value<std::string>());
Move bookMove = OpeningBook.get_move(pos, Options["Best Book Move"].value<bool>());
if (bookMove != MOVE_NONE)
{
- if (Pondering)
+ if (Limits.ponder)
wait_for_stop_or_ponderhit();
cout << "bestmove " << bookMove << endl;
}
// Read UCI options
- CheckExtension[1] = Options["Check Extension (PV nodes)"].value<Depth>();
- CheckExtension[0] = Options["Check Extension (non-PV nodes)"].value<Depth>();
- PawnPushTo7thExtension[1] = Options["Pawn Push to 7th Extension (PV nodes)"].value<Depth>();
- PawnPushTo7thExtension[0] = Options["Pawn Push to 7th Extension (non-PV nodes)"].value<Depth>();
- PassedPawnExtension[1] = Options["Passed Pawn Extension (PV nodes)"].value<Depth>();
- PassedPawnExtension[0] = Options["Passed Pawn Extension (non-PV nodes)"].value<Depth>();
- PawnEndgameExtension[1] = Options["Pawn Endgame Extension (PV nodes)"].value<Depth>();
- PawnEndgameExtension[0] = Options["Pawn Endgame Extension (non-PV nodes)"].value<Depth>();
- UCIMultiPV = Options["MultiPV"].value<int>();
- SkillLevel = Options["Skill level"].value<int>();
- UseLogFile = Options["Use Search Log"].value<bool>();
+ UCIMultiPV = Options["MultiPV"].value<int>();
+ SkillLevel = Options["Skill level"].value<int>();
read_evaluation_uci_options(pos.side_to_move());
+ Threads.read_uci_options();
+
+ // If needed allocate pawn and material hash tables and adjust TT size
+ Threads.init_hash_tables();
+ TT.set_size(Options["Hash"].value<int>());
if (Options["Clear Hash"].value<bool>())
{
Options["Clear Hash"].set_value("false");
TT.clear();
}
- TT.set_size(Options["Hash"].value<int>());
// Do we have to play with skill handicap? In this case enable MultiPV that
// we will use behind the scenes to retrieve a set of possible moves.
SkillLevelEnabled = (SkillLevel < 20);
MultiPV = (SkillLevelEnabled ? Max(UCIMultiPV, 4) : UCIMultiPV);
- // Set the number of active threads
- ThreadsMgr.read_uci_options();
- init_eval(ThreadsMgr.active_threads());
-
- // Wake up needed threads. Main thread, with threadID == 0, is always active
- for (int i = 1; i < ThreadsMgr.active_threads(); i++)
- ThreadsMgr.wake_sleeping_thread(i);
-
- // Set thinking time
- int myTime = time[pos.side_to_move()];
- int myIncrement = increment[pos.side_to_move()];
- if (UseTimeManagement)
- TimeMgr.init(myTime, myIncrement, movesToGo, pos.startpos_ply_counter());
-
- // Set best NodesBetweenPolls interval to avoid lagging under time pressure
- if (MaxNodes)
- NodesBetweenPolls = Min(MaxNodes, 30000);
- else if (myTime && myTime < 1000)
- NodesBetweenPolls = 1000;
- else if (myTime && myTime < 5000)
- NodesBetweenPolls = 5000;
- else
- NodesBetweenPolls = 30000;
+ // Wake up needed threads and reset maxPly counter
+ for (int i = 0; i < Threads.size(); i++)
+ {
+ Threads[i].wake_up();
+ Threads[i].maxPly = 0;
+ }
- // Write search information to log file
- if (UseLogFile)
+ // Write to log file and keep it open to be accessed during the search
+ if (Options["Use Search Log"].value<bool>())
{
std::string name = Options["Search Log Filename"].value<std::string>();
LogFile.open(name.c_str(), std::ios::out | std::ios::app);
- LogFile << "\nSearching: " << pos.to_fen()
- << "\ninfinite: " << infinite
- << " ponder: " << ponder
- << " time: " << myTime
- << " increment: " << myIncrement
- << " moves to go: " << movesToGo
- << endl;
+ if (LogFile.is_open())
+ LogFile << "\nSearching: " << pos.to_fen()
+ << "\ninfinite: " << Limits.infinite
+ << " ponder: " << Limits.ponder
+ << " time: " << Limits.time
+ << " increment: " << Limits.increment
+ << " moves to go: " << Limits.movesToGo
+ << endl;
}
// We're ready to start thinking. Call the iterative deepening loop function
Move ponderMove = MOVE_NONE;
Move bestMove = id_loop(pos, searchMoves, &ponderMove);
- // Print final search statistics
cout << "info" << speed_to_uci(pos.nodes_searched()) << endl;
- if (UseLogFile)
+ // Write final search statistics and close log file
+ if (LogFile.is_open())
{
int t = current_search_time();
LogFile << "Nodes: " << pos.nodes_searched()
- << "\nNodes/second: " << (t > 0 ? int(pos.nodes_searched() * 1000 / t) : 0)
+ << "\nNodes/second: " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0)
<< "\nBest move: " << move_to_san(pos, bestMove);
StateInfo st;
}
// This makes all the threads to go to sleep
- ThreadsMgr.set_active_threads(1);
+ Threads.set_size(1);
// If we are pondering or in infinite search, we shouldn't print the
// best move before we are told to do so.
- if (!StopRequest && (Pondering || InfiniteSearch))
+ if (!StopRequest && (Limits.ponder || Limits.infinite))
wait_for_stop_or_ponderhit();
// Could be MOVE_NONE when searching on a stalemate position
SearchStack ss[PLY_MAX_PLUS_2];
Value bestValues[PLY_MAX_PLUS_2];
int bestMoveChanges[PLY_MAX_PLUS_2];
- int depth, aspirationDelta, skillSamplingDepth;
+ int depth, selDepth, aspirationDelta;
Value value, alpha, beta;
Move bestMove, easyMove, skillBest, skillPonder;
TT.new_search();
H.clear();
*ponderMove = bestMove = easyMove = skillBest = skillPonder = MOVE_NONE;
- depth = aspirationDelta = skillSamplingDepth = 0;
+ depth = aspirationDelta = 0;
alpha = -VALUE_INFINITE, beta = VALUE_INFINITE;
ss->currentMove = MOVE_NULL; // Hack to skip update_gains()
return MOVE_NONE;
}
- // Choose a random sampling depth according to SkillLevel so that at low
- // skills there is an higher risk to pick up a blunder.
- if (SkillLevelEnabled)
- skillSamplingDepth = 4 + SkillLevel + (RK.rand<unsigned>() % 4);
-
- // Iterative deepening loop
- while (++depth <= PLY_MAX && (!MaxDepth || depth <= MaxDepth) && !StopRequest)
+ // Iterative deepening loop until requested to stop or target depth reached
+ while (!StopRequest && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth))
{
Rml.bestMoveChanges = 0;
cout << set960(pos.is_chess960()) << "info depth " << depth << endl;
// research with bigger window until not failing high/low anymore.
do {
// Search starting from ss+1 to allow calling update_gains()
- value = search<PV, false, true>(pos, ss+1, alpha, beta, depth * ONE_PLY, 0);
+ value = search<PV, false, true>(pos, ss+1, alpha, beta, depth * ONE_PLY);
// Write PV back to transposition table in case the relevant entries
// have been overwritten during the search.
bestMoveChanges[depth] = Rml.bestMoveChanges;
// Do we need to pick now the best and the ponder moves ?
- if (SkillLevelEnabled && depth == skillSamplingDepth)
+ if (SkillLevelEnabled && depth == 1 + SkillLevel)
do_skill_level(&skillBest, &skillPonder);
+ // Retrieve max searched depth among threads
+ selDepth = 0;
+ for (int i = 0; i < Threads.size(); i++)
+ if (Threads[i].maxPly > selDepth)
+ selDepth = Threads[i].maxPly;
+
// Send PV line to GUI and to log file
for (int i = 0; i < Min(UCIMultiPV, (int)Rml.size()); i++)
- cout << Rml[i].pv_info_to_uci(pos, depth, alpha, beta, i) << endl;
+ cout << Rml[i].pv_info_to_uci(pos, depth, selDepth, alpha, beta, i) << endl;
- if (UseLogFile)
+ if (LogFile.is_open())
LogFile << pretty_pv(pos, depth, value, current_search_time(), Rml[0].pv) << endl;
// Init easyMove after first iteration or drop if differs from the best move
else if (bestMove != easyMove)
easyMove = MOVE_NONE;
- if (UseTimeManagement && !StopRequest)
+ // Check for some early stop condition
+ if (!StopRequest && Limits.useTimeManagement())
{
- // Time to stop?
- bool noMoreTime = false;
-
// Stop search early when the last two iterations returned a mate score
if ( depth >= 5
- && abs(bestValues[depth]) >= abs(VALUE_MATE) - 100
- && abs(bestValues[depth - 1]) >= abs(VALUE_MATE) - 100)
- noMoreTime = true;
+ && abs(bestValues[depth]) >= VALUE_MATE_IN_PLY_MAX
+ && abs(bestValues[depth - 1]) >= VALUE_MATE_IN_PLY_MAX)
+ StopRequest = true;
// Stop search early if one move seems to be much better than the
- // others or if there is only a single legal move. In this latter
- // case we search up to Iteration 8 anyway to get a proper score.
+ // others or if there is only a single legal move. Also in the latter
+ // case we search up to some depth anyway to get a proper score.
if ( depth >= 7
&& easyMove == bestMove
&& ( Rml.size() == 1
&& current_search_time() > TimeMgr.available_time() / 16)
||( Rml[0].nodes > (pos.nodes_searched() * 98) / 100
&& current_search_time() > TimeMgr.available_time() / 32)))
- noMoreTime = true;
+ StopRequest = true;
- // Add some extra time if the best move has changed during the last two iterations
+ // 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]);
+ TimeMgr.pv_instability(bestMoveChanges[depth], bestMoveChanges[depth - 1]);
- // Stop search if most of MaxSearchTime is consumed at the end of the
- // iteration. We probably don't have enough time to search the first
- // move at the next iteration anyway.
- if (current_search_time() > (TimeMgr.available_time() * 80) / 128)
- noMoreTime = true;
+ // 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 (current_search_time() > (TimeMgr.available_time() * 62) / 100)
+ StopRequest = true;
- if (noMoreTime)
+ // If we are allowed to ponder do not stop the search now but keep pondering
+ if (StopRequest && Limits.ponder)
{
- if (Pondering)
- StopOnPonderhit = true;
- else
- break;
+ StopRequest = false;
+ StopOnPonderhit = true;
}
}
}
- // When using skills fake best and ponder moves with the sub-optimal ones
+ // When using skills overwrite best and ponder moves with the sub-optimal ones
if (SkillLevelEnabled)
{
if (skillBest == MOVE_NONE) // Still unassigned ?
// here: This is taken care of after we return from the split point.
template <NodeType PvNode, bool SpNode, bool Root>
- Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
+ Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta > alpha && beta <= VALUE_INFINITE);
assert(PvNode || alpha == beta - 1);
- assert((Root || ply > 0) && ply < PLY_MAX);
- assert(pos.thread() >= 0 && pos.thread() < ThreadsMgr.active_threads());
+ assert(pos.thread() >= 0 && pos.thread() < Threads.size());
- Move movesSearched[MOVES_MAX];
+ Move movesSearched[MAX_MOVES];
int64_t nodes;
StateInfo st;
const TTEntry *tte;
refinedValue = bestValue = value = -VALUE_INFINITE;
oldAlpha = alpha;
isCheck = pos.is_check();
+ ss->ply = (ss-1)->ply + 1;
+
+ // Used to send selDepth info to GUI
+ if (PvNode && Threads[threadID].maxPly < ss->ply)
+ Threads[threadID].maxPly = ss->ply;
if (SpNode)
{
// Step 2. Check for aborted search and immediate draw
if (( StopRequest
- || ThreadsMgr.cutoff_at_splitpoint(threadID)
+ || Threads[threadID].cutoff_occurred()
|| pos.is_draw()
- || ply >= PLY_MAX - 1) && !Root)
+ || ss->ply > PLY_MAX) && !Root)
return VALUE_DRAW;
// Step 3. Mate distance pruning
- alpha = Max(value_mated_in(ply), alpha);
- beta = Min(value_mate_in(ply+1), beta);
+ alpha = Max(value_mated_in(ss->ply), alpha);
+ beta = Min(value_mate_in(ss->ply+1), beta);
if (alpha >= beta)
return alpha;
if ( !Root
&& tte
&& (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT
- : ok_to_use_TT(tte, depth, beta, ply)))
+ : ok_to_use_TT(tte, depth, beta, ss->ply)))
{
TT.refresh(tte);
ss->bestMove = ttMove; // Can be MOVE_NONE
- return value_from_tt(tte->value(), ply);
+ return value_from_tt(tte->value(), ss->ply);
}
// Step 5. Evaluate the position statically and update parent's gain statistics
ss->eval = tte->static_value();
ss->evalMargin = tte->static_value_margin();
- refinedValue = refine_eval(tte, ss->eval, ply);
+ refinedValue = refine_eval(tte, ss->eval, ss->ply);
}
else
{
&& !pos.has_pawn_on_7th(pos.side_to_move()))
{
Value rbeta = beta - razor_margin(depth);
- Value v = qsearch<NonPV>(pos, ss, rbeta-1, rbeta, DEPTH_ZERO, ply);
+ Value v = qsearch<NonPV>(pos, ss, rbeta-1, rbeta, DEPTH_ZERO);
if (v < rbeta)
// Logically we should return (v + razor_margin(depth)), but
// surprisingly this did slightly weaker in tests.
pos.do_null_move(st);
(ss+1)->skipNullMove = true;
- nullValue = -search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY, ply+1);
+ nullValue = -search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY);
(ss+1)->skipNullMove = false;
pos.undo_null_move();
// Do verification search at high depths
ss->skipNullMove = true;
- Value v = search<NonPV>(pos, ss, alpha, beta, depth-R*ONE_PLY, ply);
+ Value v = search<NonPV>(pos, ss, alpha, beta, depth-R*ONE_PLY);
ss->skipNullMove = false;
if (v >= beta)
Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2);
ss->skipNullMove = true;
- search<PvNode>(pos, ss, alpha, beta, d, ply);
+ search<PvNode>(pos, ss, alpha, beta, d);
ss->skipNullMove = false;
ttMove = ss->bestMove;
// Loop through all legal moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
&& (move = mp.get_next_move()) != MOVE_NONE
- && !ThreadsMgr.cutoff_at_splitpoint(threadID))
+ && !Threads[threadID].cutoff_occurred())
{
assert(move_is_ok(move));
&& move == tte->move()
&& ext < ONE_PLY)
{
- Value ttValue = value_from_tt(tte->value(), ply);
+ Value ttValue = value_from_tt(tte->value(), ss->ply);
if (abs(ttValue) < VALUE_KNOWN_WIN)
{
Value rBeta = ttValue - int(depth);
ss->excludedMove = move;
ss->skipNullMove = true;
- Value v = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2, ply);
+ Value v = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
ss->bestMove = MOVE_NONE;
if (Root && MultiPV > 1)
alpha = -VALUE_INFINITE;
- value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, ply+1);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth);
}
else
{
{
alpha = SpNode ? sp->alpha : alpha;
Depth d = newDepth - ss->reduction;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, ply+1);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
doFullDepthSearch = (value > alpha);
}
ss->reduction = 3 * ONE_PLY;
Value rAlpha = alpha - 300;
Depth d = newDepth - ss->reduction;
- value = -search<NonPV>(pos, ss+1, -(rAlpha+1), -rAlpha, d, ply+1);
+ value = -search<NonPV>(pos, ss+1, -(rAlpha+1), -rAlpha, d);
doFullDepthSearch = (value > rAlpha);
ss->reduction = DEPTH_ZERO; // Restore original reduction
}
if (doFullDepthSearch)
{
alpha = SpNode ? sp->alpha : alpha;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, ply+1);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth);
// Step extra. pv search (only in PV nodes)
// Search only for possible new PV nodes, if instead value >= beta then
// parent node fails low with value <= alpha and tries another move.
if (PvNode && value > alpha && (Root || value < beta))
- value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, ply+1);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth);
}
}
alpha = sp->alpha;
}
- if (value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID)))
+ if (value > bestValue && !(SpNode && Threads[threadID].cutoff_occurred()))
{
bestValue = value;
sp->alpha = value;
}
else if (SpNode)
- sp->betaCutoff = true;
+ sp->is_betaCutoff = true;
- if (value == value_mate_in(ply + 1))
+ if (value == value_mate_in(ss->ply + 1))
ss->mateKiller = move;
ss->bestMove = move;
// Step 18. Check for split
if ( !Root
&& !SpNode
- && depth >= ThreadsMgr.min_split_depth()
- && ThreadsMgr.active_threads() > 1
+ && depth >= Threads.min_split_depth()
&& bestValue < beta
- && ThreadsMgr.available_thread_exists(threadID)
+ && Threads.available_slave_exists(threadID)
&& !StopRequest
- && !ThreadsMgr.cutoff_at_splitpoint(threadID))
- ThreadsMgr.split<FakeSplit>(pos, ss, ply, &alpha, beta, &bestValue, depth,
- threatMove, moveCount, &mp, PvNode);
+ && !Threads[threadID].cutoff_occurred())
+ Threads.split<FakeSplit>(pos, ss, &alpha, beta, &bestValue, depth,
+ threatMove, moveCount, &mp, PvNode);
}
// Step 19. Check for mate and stalemate
// no legal moves, it must be mate or stalemate.
// If one move was excluded return fail low score.
if (!SpNode && !moveCount)
- return excludedMove ? oldAlpha : isCheck ? value_mated_in(ply) : VALUE_DRAW;
+ return excludedMove ? oldAlpha : isCheck ? value_mated_in(ss->ply) : VALUE_DRAW;
// Step 20. Update tables
// If the search is not aborted, update the transposition table,
// history counters, and killer moves.
- if (!SpNode && !StopRequest && !ThreadsMgr.cutoff_at_splitpoint(threadID))
+ if (!SpNode && !StopRequest && !Threads[threadID].cutoff_occurred())
{
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
: bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT;
- TT.store(posKey, value_to_tt(bestValue, ply), vt, depth, move, ss->eval, ss->evalMargin);
+ TT.store(posKey, value_to_tt(bestValue, ss->ply), vt, depth, move, ss->eval, ss->evalMargin);
// Update killers and history only for non capture moves that fails high
if ( bestValue >= beta
if (SpNode)
{
// Here we have the lock still grabbed
- sp->slaves[threadID] = 0;
+ sp->is_slave[threadID] = false;
sp->nodes += pos.nodes_searched();
lock_release(&(sp->lock));
}
// less than ONE_PLY).
template <NodeType PvNode>
- Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
+ Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
assert(PvNode || alpha == beta - 1);
assert(depth <= 0);
- assert(ply > 0 && ply < PLY_MAX);
- assert(pos.thread() >= 0 && pos.thread() < ThreadsMgr.active_threads());
+ assert(pos.thread() >= 0 && pos.thread() < Threads.size());
StateInfo st;
Move ttMove, move;
Value oldAlpha = alpha;
ss->bestMove = ss->currentMove = MOVE_NONE;
+ ss->ply = (ss-1)->ply + 1;
// Check for an instant draw or maximum ply reached
- if (pos.is_draw() || ply >= PLY_MAX - 1)
+ if (ss->ply > PLY_MAX || pos.is_draw())
return VALUE_DRAW;
// Decide whether or not to include checks, this fixes also the type of
tte = TT.retrieve(pos.get_key());
ttMove = (tte ? tte->move() : MOVE_NONE);
- if (!PvNode && tte && ok_to_use_TT(tte, ttDepth, beta, ply))
+ if (!PvNode && tte && ok_to_use_TT(tte, ttDepth, beta, ss->ply))
{
ss->bestMove = ttMove; // Can be MOVE_NONE
- return value_from_tt(tte->value(), ply);
+ return value_from_tt(tte->value(), ss->ply);
}
// Evaluate the position statically
if (bestValue >= beta)
{
if (!tte)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
return bestValue;
}
// Make and search the move
pos.do_move(move, st, ci, moveIsCheck);
- value = -qsearch<PvNode>(pos, ss+1, -beta, -alpha, depth-ONE_PLY, ply+1);
+ value = -qsearch<PvNode>(pos, ss+1, -beta, -alpha, depth-ONE_PLY);
pos.undo_move(move);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
// All legal moves have been searched. A special case: If we're in check
// and no legal moves were found, it is checkmate.
if (isCheck && bestValue == -VALUE_INFINITE)
- return value_mated_in(ply);
+ return value_mated_in(ss->ply);
// Update transposition table
ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), vt, ttDepth, ss->bestMove, ss->eval, evalMargin);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, ss->bestMove, ss->eval, evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
&& pos.type_of_piece_on(move_to(m)) != PAWN
&& ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
- pos.midgame_value_of_piece_on(move_to(m)) == VALUE_ZERO)
- && !move_is_promotion(m)
- && !move_is_ep(m))
+ && !move_is_special(m))
{
result += PawnEndgameExtension[PvNode];
*dangerous = true;
// current_search_time() returns the number of milliseconds which have passed
// since the beginning of the current search.
- int current_search_time() {
+ int current_search_time(int set) {
- return get_system_time() - SearchStartTime;
+ static int searchStartTime;
+
+ if (set)
+ searchStartTime = set;
+
+ return get_system_time() - searchStartTime;
}
std::stringstream s;
if (abs(v) < VALUE_MATE - PLY_MAX * ONE_PLY)
- s << "cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to centipawns
+ s << "cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to centipawns
else
- s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
+ s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
return s.str();
}
if (!std::getline(std::cin, command) || command == "quit")
{
// Quit the program as soon as possible
- Pondering = false;
+ Limits.ponder = false;
QuitRequest = StopRequest = true;
return;
}
{
// Stop calculating as soon as possible, but still send the "bestmove"
// and possibly the "ponder" token when finishing the search.
- Pondering = false;
+ Limits.ponder = false;
StopRequest = true;
}
else if (command == "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.
- Pondering = false;
+ Limits.ponder = false;
if (StopOnPonderhit)
StopRequest = true;
}
// Should we stop the search?
- if (Pondering)
+ if (Limits.ponder)
return;
bool stillAtFirstMove = FirstRootMove
bool noMoreTime = t > TimeMgr.maximum_time()
|| stillAtFirstMove;
- if ( (UseTimeManagement && noMoreTime)
- || (ExactMaxTime && t >= ExactMaxTime)
- || (MaxNodes && pos.nodes_searched() >= MaxNodes)) // FIXME
+ if ( (Limits.useTimeManagement() && noMoreTime)
+ || (Limits.maxTime && t >= Limits.maxTime)
+ || (Limits.maxNodes && pos.nodes_searched() >= Limits.maxNodes)) // FIXME
StopRequest = true;
}
}
- // init_thread() is the function which is called when a new thread is
- // launched. It simply calls the idle_loop() function with the supplied
- // threadID. There are two versions of this function; one for POSIX
- // threads and one for Windows threads.
-
-#if !defined(_MSC_VER)
-
- void* init_thread(void* threadID) {
-
- ThreadsMgr.idle_loop(*(int*)threadID, NULL);
- return NULL;
- }
-
-#else
-
- DWORD WINAPI init_thread(LPVOID threadID) {
-
- ThreadsMgr.idle_loop(*(int*)threadID, NULL);
- return 0;
- }
-
-#endif
-
-
- /// The ThreadsManager class
-
-
- // read_uci_options() updates number of active threads and other internal
- // parameters according to the UCI options values. It is called before
- // to start a new search.
-
- void ThreadsManager::read_uci_options() {
-
- maxThreadsPerSplitPoint = Options["Maximum Number of Threads per Split Point"].value<int>();
- minimumSplitDepth = Options["Minimum Split Depth"].value<int>() * ONE_PLY;
- useSleepingThreads = Options["Use Sleeping Threads"].value<bool>();
- activeThreads = Options["Threads"].value<int>();
- }
-
-
- // idle_loop() is where the threads are parked when they have no work to do.
- // The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint
- // object for which the current thread is the master.
-
- void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) {
-
- assert(threadID >= 0 && threadID < MAX_THREADS);
-
- int i;
- bool allFinished = false;
-
- while (true)
- {
- // Slave threads can exit as soon as AllThreadsShouldExit raises,
- // master should exit as last one.
- if (allThreadsShouldExit)
- {
- assert(!sp);
- threads[threadID].state = THREAD_TERMINATED;
- return;
- }
-
- // If we are not thinking, wait for a condition to be signaled
- // instead of wasting CPU time polling for work.
- while ( threadID >= activeThreads || threads[threadID].state == THREAD_INITIALIZING
- || (useSleepingThreads && threads[threadID].state == THREAD_AVAILABLE))
- {
- assert(!sp || useSleepingThreads);
- assert(threadID != 0 || useSleepingThreads);
-
- if (threads[threadID].state == THREAD_INITIALIZING)
- threads[threadID].state = THREAD_AVAILABLE;
-
- // Grab the lock to avoid races with wake_sleeping_thread()
- lock_grab(&sleepLock[threadID]);
-
- // If we are master and all slaves have finished do not go to sleep
- for (i = 0; sp && i < activeThreads && !sp->slaves[i]; i++) {}
- allFinished = (i == activeThreads);
-
- if (allFinished || allThreadsShouldExit)
- {
- lock_release(&sleepLock[threadID]);
- break;
- }
-
- // Do sleep here after retesting sleep conditions
- if (threadID >= activeThreads || threads[threadID].state == THREAD_AVAILABLE)
- cond_wait(&sleepCond[threadID], &sleepLock[threadID]);
-
- lock_release(&sleepLock[threadID]);
- }
-
- // If this thread has been assigned work, launch a search
- if (threads[threadID].state == THREAD_WORKISWAITING)
- {
- assert(!allThreadsShouldExit);
-
- threads[threadID].state = THREAD_SEARCHING;
-
- // Copy SplitPoint position and search stack and call search()
- // with SplitPoint template parameter set to true.
- SearchStack ss[PLY_MAX_PLUS_2];
- SplitPoint* tsp = threads[threadID].splitPoint;
- Position pos(*tsp->pos, threadID);
-
- memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack));
- (ss+1)->sp = tsp;
-
- if (tsp->pvNode)
- search<PV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth, tsp->ply);
- else
- search<NonPV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth, tsp->ply);
-
- assert(threads[threadID].state == THREAD_SEARCHING);
-
- threads[threadID].state = THREAD_AVAILABLE;
-
- // 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 (useSleepingThreads && threadID != tsp->master && threads[tsp->master].state == THREAD_AVAILABLE)
- wake_sleeping_thread(tsp->master);
- }
-
- // 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.
- for (i = 0; sp && i < activeThreads && !sp->slaves[i]; i++) {}
- allFinished = (i == activeThreads);
-
- if (allFinished)
- {
- // Because sp->slaves[] is reset under lock protection,
- // be sure sp->lock has been released before to return.
- lock_grab(&(sp->lock));
- lock_release(&(sp->lock));
-
- // In helpful master concept a master can help only a sub-tree, and
- // because here is all finished is not possible master is booked.
- assert(threads[threadID].state == THREAD_AVAILABLE);
-
- threads[threadID].state = THREAD_SEARCHING;
- return;
- }
- }
- }
-
-
- // init_threads() is called during startup. It launches all helper threads,
- // and initializes the split point stack and the global locks and condition
- // objects.
+ // When playing with strength handicap choose best move among the MultiPV set
+ // using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen.
+ void do_skill_level(Move* best, Move* ponder) {
- void ThreadsManager::init_threads() {
+ assert(MultiPV > 1);
- int i, arg[MAX_THREADS];
- bool ok;
+ // Rml list is already sorted by pv_score in descending order
+ int s;
+ int max_s = -VALUE_INFINITE;
+ int size = Min(MultiPV, (int)Rml.size());
+ int max = Rml[0].pv_score;
+ int var = Min(max - Rml[size - 1].pv_score, PawnValueMidgame);
+ int wk = 120 - 2 * SkillLevel;
- // Initialize global locks
- lock_init(&mpLock);
+ // PRNG sequence should be non deterministic
+ for (int i = abs(get_system_time() % 50); i > 0; i--)
+ RK.rand<unsigned>();
- for (i = 0; i < MAX_THREADS; i++)
+ // Choose best move. For each move's score we add two terms both dependent
+ // on wk, one deterministic and bigger for weaker moves, and one random,
+ // then we choose the move with the resulting highest score.
+ for (int i = 0; i < size; i++)
{
- lock_init(&sleepLock[i]);
- cond_init(&sleepCond[i]);
- }
-
- // Initialize splitPoints[] locks
- for (i = 0; i < MAX_THREADS; i++)
- for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
- lock_init(&(threads[i].splitPoints[j].lock));
-
- // Will be set just before program exits to properly end the threads
- allThreadsShouldExit = false;
+ s = Rml[i].pv_score;
- // Threads will be put all threads to sleep as soon as created
- activeThreads = 1;
+ // Don't allow crazy blunders even at very low skills
+ if (i > 0 && Rml[i-1].pv_score > s + EasyMoveMargin)
+ break;
- // All threads except the main thread should be initialized to THREAD_INITIALIZING
- threads[0].state = THREAD_SEARCHING;
- for (i = 1; i < MAX_THREADS; i++)
- threads[i].state = THREAD_INITIALIZING;
+ // This is our magical formula
+ s += ((max - s) * wk + var * (RK.rand<unsigned>() % wk)) / 128;
- // Launch the helper threads
- for (i = 1; i < MAX_THREADS; i++)
- {
- arg[i] = i;
-
-#if !defined(_MSC_VER)
- pthread_t pthread[1];
- ok = (pthread_create(pthread, NULL, init_thread, (void*)(&arg[i])) == 0);
- pthread_detach(pthread[0]);
-#else
- ok = (CreateThread(NULL, 0, init_thread, (LPVOID)(&arg[i]), 0, NULL) != NULL);
-#endif
- if (!ok)
+ if (s > max_s)
{
- cout << "Failed to create thread number " << i << endl;
- exit(EXIT_FAILURE);
+ max_s = s;
+ *best = Rml[i].pv[0];
+ *ponder = Rml[i].pv[1];
}
-
- // Wait until the thread has finished launching and is gone to sleep
- while (threads[i].state == THREAD_INITIALIZING) {}
}
}
- // exit_threads() is called when the program exits. It makes all the
- // helper threads exit cleanly.
-
- void ThreadsManager::exit_threads() {
-
- allThreadsShouldExit = true; // Let the woken up threads to exit idle_loop()
-
- // Wake up all the threads and waits for termination
- for (int i = 1; i < MAX_THREADS; i++)
- {
- wake_sleeping_thread(i);
- while (threads[i].state != THREAD_TERMINATED) {}
- }
-
- // Now we can safely destroy the locks
- for (int i = 0; i < MAX_THREADS; i++)
- for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
- lock_destroy(&(threads[i].splitPoints[j].lock));
-
- lock_destroy(&mpLock);
-
- // Now we can safely destroy the wait conditions
- for (int i = 0; i < MAX_THREADS; i++)
- {
- lock_destroy(&sleepLock[i]);
- cond_destroy(&sleepCond[i]);
- }
- }
-
-
- // cutoff_at_splitpoint() checks whether a beta cutoff has occurred in
- // the thread's currently active split point, or in some ancestor of
- // the current split point.
-
- bool ThreadsManager::cutoff_at_splitpoint(int threadID) const {
-
- assert(threadID >= 0 && threadID < activeThreads);
-
- SplitPoint* sp = threads[threadID].splitPoint;
-
- for ( ; sp && !sp->betaCutoff; sp = sp->parent) {}
- return sp != NULL;
- }
-
-
- // thread_is_available() checks whether the thread with threadID "slave" is
- // available to help the thread with threadID "master" at a split point. An
- // obvious requirement is that "slave" must be idle. With more than two
- // threads, this is not by itself sufficient: If "slave" is the master of
- // some active split point, it is only available as a slave to the other
- // threads which are busy searching the split point at the top of "slave"'s
- // split point stack (the "helpful master concept" in YBWC terminology).
-
- bool ThreadsManager::thread_is_available(int slave, int master) const {
-
- assert(slave >= 0 && slave < activeThreads);
- assert(master >= 0 && master < activeThreads);
- assert(activeThreads > 1);
-
- if (threads[slave].state != THREAD_AVAILABLE || slave == master)
- return false;
-
- // Make a local copy to be sure doesn't change under our feet
- int localActiveSplitPoints = threads[slave].activeSplitPoints;
-
- // No active split points means that the thread is available as
- // a slave for any other thread.
- if (localActiveSplitPoints == 0 || activeThreads == 2)
- return true;
-
- // Apply the "helpful master" concept if possible. Use localActiveSplitPoints
- // that is known to be > 0, instead of threads[slave].activeSplitPoints that
- // could have been set to 0 by another thread leading to an out of bound access.
- if (threads[slave].splitPoints[localActiveSplitPoints - 1].slaves[master])
- return true;
-
- return false;
- }
-
-
- // available_thread_exists() tries to find an idle thread which is available as
- // a slave for the thread with threadID "master".
-
- bool ThreadsManager::available_thread_exists(int master) const {
-
- assert(master >= 0 && master < activeThreads);
- assert(activeThreads > 1);
-
- for (int i = 0; i < activeThreads; i++)
- if (thread_is_available(i, master))
- return true;
-
- return false;
- }
-
-
- // split() does the actual work of distributing the work at a node between
- // several available threads. If it does not succeed in splitting the
- // node (because no idle threads are available, or because we have no unused
- // split point objects), the function immediately returns. If splitting is
- // possible, a SplitPoint object is initialized with all the data that must be
- // copied to the helper threads and we tell our helper threads that they have
- // been assigned work. This will cause them to instantly leave their idle loops and
- // call search().When all threads have returned from search() then split() returns.
-
- template <bool Fake>
- void ThreadsManager::split(Position& pos, SearchStack* ss, int ply, Value* alpha,
- const Value beta, Value* bestValue, Depth depth, Move threatMove,
- int moveCount, MovePicker* mp, bool pvNode) {
- assert(pos.is_ok());
- assert(ply > 0 && ply < PLY_MAX);
- assert(*bestValue >= -VALUE_INFINITE);
- assert(*bestValue <= *alpha);
- assert(*alpha < beta);
- assert(beta <= VALUE_INFINITE);
- assert(depth > DEPTH_ZERO);
- assert(pos.thread() >= 0 && pos.thread() < activeThreads);
- assert(activeThreads > 1);
-
- int i, master = pos.thread();
- Thread& masterThread = threads[master];
-
- lock_grab(&mpLock);
-
- // If no other thread is available to help us, or if we have too many
- // active split points, don't split.
- if ( !available_thread_exists(master)
- || masterThread.activeSplitPoints >= MAX_ACTIVE_SPLIT_POINTS)
- {
- lock_release(&mpLock);
- return;
- }
-
- // Pick the next available split point object from the split point stack
- SplitPoint& splitPoint = masterThread.splitPoints[masterThread.activeSplitPoints++];
-
- // Initialize the split point object
- splitPoint.parent = masterThread.splitPoint;
- splitPoint.master = master;
- splitPoint.betaCutoff = false;
- splitPoint.ply = ply;
- splitPoint.depth = depth;
- splitPoint.threatMove = threatMove;
- splitPoint.alpha = *alpha;
- splitPoint.beta = beta;
- splitPoint.pvNode = pvNode;
- splitPoint.bestValue = *bestValue;
- splitPoint.mp = mp;
- splitPoint.moveCount = moveCount;
- splitPoint.pos = &pos;
- splitPoint.nodes = 0;
- splitPoint.ss = ss;
- for (i = 0; i < activeThreads; i++)
- splitPoint.slaves[i] = 0;
-
- masterThread.splitPoint = &splitPoint;
-
- // If we are here it means we are not available
- assert(masterThread.state != THREAD_AVAILABLE);
-
- int workersCnt = 1; // At least the master is included
-
- // Allocate available threads setting state to THREAD_BOOKED
- for (i = 0; !Fake && i < activeThreads && workersCnt < maxThreadsPerSplitPoint; i++)
- if (thread_is_available(i, master))
- {
- threads[i].state = THREAD_BOOKED;
- threads[i].splitPoint = &splitPoint;
- splitPoint.slaves[i] = 1;
- workersCnt++;
- }
-
- assert(Fake || workersCnt > 1);
-
- // We can release the lock because slave threads are already booked and master is not available
- lock_release(&mpLock);
-
- // Tell the threads that they have work to do. This will make them leave
- // their idle loop.
- for (i = 0; i < activeThreads; i++)
- if (i == master || splitPoint.slaves[i])
- {
- assert(i == master || threads[i].state == THREAD_BOOKED);
-
- threads[i].state = THREAD_WORKISWAITING; // This makes the slave to exit from idle_loop()
-
- if (useSleepingThreads && i != master)
- wake_sleeping_thread(i);
- }
-
- // Everything is set up. The master thread enters the idle loop, from
- // which it will instantly launch a search, because its state is
- // THREAD_WORKISWAITING. We send the split point as a second parameter to the
- // idle loop, which means that the main thread will return from the idle
- // loop when all threads have finished their work at this split point.
- idle_loop(master, &splitPoint);
-
- // We have returned from the idle loop, which means that all threads are
- // finished. Update alpha and bestValue, and return.
- lock_grab(&mpLock);
-
- *alpha = splitPoint.alpha;
- *bestValue = splitPoint.bestValue;
- masterThread.activeSplitPoints--;
- masterThread.splitPoint = splitPoint.parent;
- pos.set_nodes_searched(pos.nodes_searched() + splitPoint.nodes);
-
- lock_release(&mpLock);
- }
-
-
- // wake_sleeping_thread() wakes up the thread with the given threadID
- // when it is time to start a new search.
-
- void ThreadsManager::wake_sleeping_thread(int threadID) {
-
- lock_grab(&sleepLock[threadID]);
- cond_signal(&sleepCond[threadID]);
- lock_release(&sleepLock[threadID]);
- }
-
-
/// RootMove and RootMoveList method's definitions
RootMove::RootMove() {
return *this;
}
+ void RootMoveList::init(Position& pos, Move searchMoves[]) {
+
+ MoveStack mlist[MAX_MOVES];
+ Move* sm;
+
+ clear();
+ bestMoveChanges = 0;
+
+ // Generate all legal moves and add them to RootMoveList
+ MoveStack* last = generate<MV_LEGAL>(pos, mlist);
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ {
+ // If we have a searchMoves[] list then verify cur->move
+ // is in the list before to add it.
+ for (sm = searchMoves; *sm && *sm != cur->move; sm++) {}
+
+ if (searchMoves[0] && *sm != cur->move)
+ continue;
+
+ RootMove rm;
+ rm.pv[0] = cur->move;
+ rm.pv[1] = MOVE_NONE;
+ rm.pv_score = -VALUE_INFINITE;
+ push_back(rm);
+ }
+ }
+
// extract_pv_from_tt() builds a PV by adding moves from the transposition table.
// We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This
// allow to always have a ponder move even when we fail high at root and also a
// pv_info_to_uci() returns a string with information on the current PV line
// formatted according to UCI specification.
- std::string RootMove::pv_info_to_uci(Position& pos, int depth, Value alpha,
+ std::string RootMove::pv_info_to_uci(Position& pos, int depth, int selDepth, Value alpha,
Value beta, int pvIdx) {
- std::stringstream s, l;
- Move* m = pv;
-
- while (*m != MOVE_NONE)
- l << *m++ << " ";
+ std::stringstream s;
s << "info depth " << depth
- << " seldepth " << int(m - pv)
+ << " seldepth " << selDepth
<< " multipv " << pvIdx + 1
<< " score " << value_to_uci(pv_score)
<< (pv_score >= beta ? " lowerbound" : pv_score <= alpha ? " upperbound" : "")
<< speed_to_uci(pos.nodes_searched())
- << " pv " << l.str();
+ << " pv ";
+
+ for (Move* m = pv; *m != MOVE_NONE; m++)
+ s << *m << " ";
return s.str();
}
+} // namespace
- void RootMoveList::init(Position& pos, Move searchMoves[]) {
- MoveStack mlist[MOVES_MAX];
- Move* sm;
+// ThreadsManager::idle_loop() is where the threads are parked when they have no work
+// to do. The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint
+// object for which the current thread is the master.
- clear();
- bestMoveChanges = 0;
+void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) {
- // Generate all legal moves and add them to RootMoveList
- MoveStack* last = generate<MV_LEGAL>(pos, mlist);
- for (MoveStack* cur = mlist; cur != last; cur++)
- {
- // If we have a searchMoves[] list then verify cur->move
- // is in the list before to add it.
- for (sm = searchMoves; *sm && *sm != cur->move; sm++) {}
+ assert(threadID >= 0 && threadID < MAX_THREADS);
- if (searchMoves[0] && *sm != cur->move)
- continue;
+ int i;
+ bool allFinished;
- RootMove rm;
- rm.pv[0] = cur->move;
- rm.pv[1] = MOVE_NONE;
- rm.pv_score = -VALUE_INFINITE;
- push_back(rm);
- }
- }
+ while (true)
+ {
+ // Slave threads can exit as soon as AllThreadsShouldExit raises,
+ // master should exit as last one.
+ if (allThreadsShouldExit)
+ {
+ assert(!sp);
+ threads[threadID].state = Thread::TERMINATED;
+ return;
+ }
+ // If we are not thinking, wait for a condition to be signaled
+ // instead of wasting CPU time polling for work.
+ while ( threadID >= activeThreads
+ || threads[threadID].state == Thread::INITIALIZING
+ || (useSleepingThreads && threads[threadID].state == Thread::AVAILABLE))
+ {
+ assert(!sp || useSleepingThreads);
+ assert(threadID != 0 || useSleepingThreads);
- // When playing with strength handicap choose best move among the MultiPV set
- // using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen.
- void do_skill_level(Move* best, Move* ponder) {
+ if (threads[threadID].state == Thread::INITIALIZING)
+ threads[threadID].state = Thread::AVAILABLE;
- assert(MultiPV > 1);
+ // Grab the lock to avoid races with Thread::wake_up()
+ lock_grab(&threads[threadID].sleepLock);
- // Rml list is already sorted by pv_score in descending order
- int s;
- int max_s = -VALUE_INFINITE;
- int size = Min(MultiPV, (int)Rml.size());
- int max = Rml[0].pv_score;
- int var = Min(max - Rml[size - 1].pv_score, PawnValueMidgame);
- int wk = 120 - 2 * SkillLevel;
+ // If we are master and all slaves have finished do not go to sleep
+ for (i = 0; sp && i < activeThreads && !sp->is_slave[i]; i++) {}
+ allFinished = (i == activeThreads);
- // PRNG sequence should be non deterministic
- for (int i = abs(get_system_time() % 50); i > 0; i--)
- RK.rand<unsigned>();
+ if (allFinished || allThreadsShouldExit)
+ {
+ lock_release(&threads[threadID].sleepLock);
+ break;
+ }
- // Choose best move. For each move's score we add two terms both dependent
- // on wk, one deterministic and bigger for weaker moves, and one random,
- // then we choose the move with the resulting highest score.
- for (int i = 0; i < size; i++)
- {
- s = Rml[i].pv_score;
+ // Do sleep here after retesting sleep conditions
+ if (threadID >= activeThreads || threads[threadID].state == Thread::AVAILABLE)
+ cond_wait(&threads[threadID].sleepCond, &threads[threadID].sleepLock);
- // Don't allow crazy blunders even at very low skills
- if (i > 0 && Rml[i-1].pv_score > s + EasyMoveMargin)
- break;
+ lock_release(&threads[threadID].sleepLock);
+ }
- // This is our magical formula
- s += ((max - s) * wk + var * (RK.rand<unsigned>() % wk)) / 128;
+ // If this thread has been assigned work, launch a search
+ if (threads[threadID].state == Thread::WORKISWAITING)
+ {
+ assert(!allThreadsShouldExit);
- if (s > max_s)
- {
- max_s = s;
- *best = Rml[i].pv[0];
- *ponder = Rml[i].pv[1];
- }
- }
- }
+ threads[threadID].state = Thread::SEARCHING;
-} // namespace
+ // Copy split point position and search stack and call search()
+ // with SplitPoint template parameter set to true.
+ SearchStack ss[PLY_MAX_PLUS_2];
+ SplitPoint* tsp = threads[threadID].splitPoint;
+ Position pos(*tsp->pos, threadID);
+
+ memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack));
+ (ss+1)->sp = tsp;
+
+ if (tsp->pvNode)
+ search<PV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
+ else
+ search<NonPV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
+
+ assert(threads[threadID].state == Thread::SEARCHING);
+
+ threads[threadID].state = Thread::AVAILABLE;
+
+ // 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 ( useSleepingThreads
+ && threadID != tsp->master
+ && threads[tsp->master].state == Thread::AVAILABLE)
+ threads[tsp->master].wake_up();
+ }
+
+ // 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.
+ for (i = 0; sp && i < activeThreads && !sp->is_slave[i]; i++) {}
+ allFinished = (i == activeThreads);
+
+ if (allFinished)
+ {
+ // Because sp->slaves[] is reset under lock protection,
+ // be sure sp->lock has been released before to return.
+ lock_grab(&(sp->lock));
+ lock_release(&(sp->lock));
+
+ // In helpful master concept a master can help only a sub-tree, and
+ // because here is all finished is not possible master is booked.
+ assert(threads[threadID].state == Thread::AVAILABLE);
+
+ threads[threadID].state = Thread::SEARCHING;
+ return;
+ }
+ }
+}
projects / stockfish / blobdiff