/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#if !defined(THREAD_H_INCLUDED)
+#ifndef THREAD_H_INCLUDED
#define THREAD_H_INCLUDED
-#include <set>
+#include <atomic>
+#include <condition_variable>
+#include <cstddef>
+#include <cstdint>
+#include <mutex>
+#include <vector>
-#include "material.h"
#include "movepick.h"
-#include "pawns.h"
#include "position.h"
#include "search.h"
-
-const int MAX_THREADS = 32;
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
-
-struct SplitPoint {
-
- // Const data after split point has been setup
- const Position* pos;
- const Search::Stack* ss;
- Depth depth;
- Value beta;
- int nodeType;
- int master;
- Move threatMove;
-
- // Const pointers to shared data
- MovePicker* mp;
- SplitPoint* parent;
-
-
- // Shared data
- Lock lock;
- volatile uint64_t slavesMask;
- volatile int64_t nodes;
- volatile Value alpha;
- volatile Value bestValue;
- volatile Move bestMove;
- volatile int moveCount;
- volatile bool cutoff;
+#include "thread_win32_osx.h"
+#include "types.h"
+
+namespace Stockfish {
+
+// Thread class keeps together all the thread-related stuff.
+class Thread {
+
+ std::mutex mutex;
+ std::condition_variable cv;
+ size_t idx;
+ bool exit = false, searching = true; // Set before starting std::thread
+ NativeThread stdThread;
+
+ public:
+ explicit Thread(size_t);
+ virtual ~Thread();
+ virtual void search();
+ void clear();
+ void idle_loop();
+ void start_searching();
+ void wait_for_search_finished();
+ size_t id() const { return idx; }
+
+ size_t pvIdx, pvLast;
+ std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
+ int selDepth, nmpMinPly;
+ Value bestValue, optimism[COLOR_NB];
+
+ Position rootPos;
+ StateInfo rootState;
+ Search::RootMoves rootMoves;
+ Depth rootDepth, completedDepth;
+ Value rootDelta;
+ Value rootSimpleEval;
+ CounterMoveHistory counterMoves;
+ ButterflyHistory mainHistory;
+ CapturePieceToHistory captureHistory;
+ ContinuationHistory continuationHistory[2][2];
+ PawnHistory pawnHistory;
};
-/// Thread struct keeps together all the thread related stuff like locks, state
-/// and especially split points. We also use per-thread pawn and material hash
-/// tables so that once we get a pointer to an entry its life time is unlimited
-/// and we don't have to care about someone changing the entry under our feet.
-
-struct Thread {
-
- Thread(int id);
- ~Thread();
-
- void wake_up();
- bool cutoff_occurred() const;
- bool is_available_to(int master) const;
- void idle_loop(SplitPoint* sp_master);
- void main_loop();
- void timer_loop();
- void wait_for_stop_or_ponderhit();
-
- SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
- MaterialInfoTable materialTable;
- PawnInfoTable pawnTable;
- int threadID;
- int maxPly;
- Lock sleepLock;
- WaitCondition sleepCond;
- ThreadHandle handle;
- SplitPoint* volatile curSplitPoint;
- volatile int splitPointsCnt;
- volatile bool is_searching;
- volatile bool do_sleep;
- volatile bool do_exit;
+// MainThread is a derived class specific for main thread
+struct MainThread: public Thread {
+
+ using Thread::Thread;
+
+ void search() override;
+ void check_time();
+
+ double previousTimeReduction;
+ Value bestPreviousScore;
+ Value bestPreviousAverageScore;
+ Value iterValue[4];
+ int callsCnt;
+ bool stopOnPonderhit;
+ std::atomic_bool ponder;
};
-/// ThreadsManager class handles 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:
- Thread& operator[](int threadID) { return *threads[threadID]; }
- void init();
- void exit();
-
- bool use_sleeping_threads() const { return useSleepingThreads; }
- int min_split_depth() const { return minimumSplitDepth; }
- int size() const { return activeThreads; }
-
- void wake_up();
- void sleep();
- void read_uci_options();
- bool available_slave_exists(int master) const;
- void set_timer(int msec);
- void stop_thinking();
- void start_thinking(const Position& pos, const Search::LimitsType& limits,
- const std::set<Move>& = std::set<Move>(), bool async = false);
-
- template <bool Fake>
- Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
- Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
-private:
- friend struct Thread;
-
- Thread* timer;
- Thread* threads[MAX_THREADS];
- Lock splitLock;
- WaitCondition sleepCond;
- Depth minimumSplitDepth;
- int maxThreadsPerSplitPoint;
- int activeThreads;
- bool useSleepingThreads;
+// ThreadPool struct handles all the threads-related stuff like init, starting,
+// parking and, most importantly, launching a thread. All the access to threads
+// is done through this class.
+struct ThreadPool {
+
+ void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false);
+ void clear();
+ void set(size_t);
+
+ MainThread* main() const { return static_cast<MainThread*>(threads.front()); }
+ uint64_t nodes_searched() const { return accumulate(&Thread::nodes); }
+ uint64_t tb_hits() const { return accumulate(&Thread::tbHits); }
+ Thread* get_best_thread() const;
+ void start_searching();
+ void wait_for_search_finished() const;
+
+ std::atomic_bool stop, increaseDepth;
+
+ auto cbegin() const noexcept { return threads.cbegin(); }
+ auto begin() noexcept { return threads.begin(); }
+ auto end() noexcept { return threads.end(); }
+ auto cend() const noexcept { return threads.cend(); }
+ auto size() const noexcept { return threads.size(); }
+ auto empty() const noexcept { return threads.empty(); }
+
+ private:
+ StateListPtr setupStates;
+ std::vector<Thread*> threads;
+
+ uint64_t accumulate(std::atomic<uint64_t> Thread::*member) const {
+
+ uint64_t sum = 0;
+ for (Thread* th : threads)
+ sum += (th->*member).load(std::memory_order_relaxed);
+ return sum;
+ }
};
-extern ThreadsManager Threads;
+extern ThreadPool Threads;
+
+} // namespace Stockfish
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED
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