/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2004-2021 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 <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+#include <vector>
-////
-//// Includes
-////
-
-#include "lock.h"
+#include "material.h"
#include "movepick.h"
+#include "pawns.h"
#include "position.h"
#include "search.h"
+#include "thread_win32_osx.h"
+
+namespace Stockfish {
+
+/// Thread class keeps together all the thread-related stuff. We 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.
+
+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; }
+
+ Pawns::Table pawnsTable;
+ Material::Table materialTable;
+ size_t pvIdx, pvLast;
+ uint64_t ttHitAverage;
+ int selDepth, nmpMinPly;
+ Color nmpColor;
+ std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
+
+ Position rootPos;
+ StateInfo rootState;
+ Search::RootMoves rootMoves;
+ Depth rootDepth, completedDepth;
+ CounterMoveHistory counterMoves;
+ ButterflyHistory mainHistory;
+ LowPlyHistory lowPlyHistory;
+ CapturePieceToHistory captureHistory;
+ ContinuationHistory continuationHistory[2][2];
+ Score trend;
+};
+
+/// MainThread is a derived class specific for main thread
-////
-//// Constants and variables
-////
-
-const int THREAD_MAX = 8;
-
-
-////
-//// Types
-////
-
-struct SplitPoint {
- SplitPoint *parent;
- Position pos;
- SearchStack sstack[THREAD_MAX][PLY_MAX];
- SearchStack *parentSstack;
- int ply;
- Depth depth;
- volatile Value alpha, beta, bestValue;
- bool pvNode;
- Bitboard dcCandidates;
- int master, slaves[THREAD_MAX];
- Lock lock;
- MovePicker *mp;
- volatile int moves;
- volatile int cpus;
- bool finished;
+struct MainThread : public Thread {
+
+ using Thread::Thread;
+
+ void search() override;
+ void check_time();
+
+ double previousTimeReduction;
+ Value bestPreviousScore;
+ Value iterValue[4];
+ int callsCnt;
+ bool stopOnPonderhit;
+ std::atomic_bool ponder;
};
-struct Thread {
- SplitPoint *splitPoint;
- int activeSplitPoints;
- uint64_t nodes;
- bool failHighPly1;
- volatile bool stop;
- volatile bool running;
- volatile bool idle;
- volatile bool workIsWaiting;
- volatile bool printCurrentLine;
- unsigned char pad[64];
+/// 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 : public std::vector<Thread*> {
+
+ void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false);
+ void clear();
+ void set(size_t);
+
+ MainThread* main() const { return static_cast<MainThread*>(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;
+
+private:
+ StateListPtr setupStates;
+
+ uint64_t accumulate(std::atomic<uint64_t> Thread::* member) const {
+
+ uint64_t sum = 0;
+ for (Thread* th : *this)
+ sum += (th->*member).load(std::memory_order_relaxed);
+ return sum;
+ }
};
+extern ThreadPool Threads;
+
+} // namespace Stockfish
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED