/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 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 <cstring>
+#include <atomic>
+#include <condition_variable>
+#include <cstddef>
+#include <cstdint>
+#include <mutex>
+#include <vector>
-#include "lock.h"
#include "movepick.h"
#include "position.h"
#include "search.h"
+#include "thread_win32_osx.h"
+#include "types.h"
-const int MAX_THREADS = 32;
-const int MAX_ACTIVE_SPLIT_POINTS = 8;
-
-struct SplitPoint {
-
- // Const data after splitPoint has been setup
- SplitPoint* parent;
- const Position* pos;
- Depth depth;
- bool pvNode;
- Value beta;
- int ply;
- int master;
- Move threatMove;
-
- // Const pointers to shared data
- MovePicker* mp;
- SearchStack* ss;
-
- // Shared data
- Lock lock;
- volatile int64_t nodes;
- volatile Value alpha;
- volatile Value bestValue;
- volatile int moveCount;
- volatile bool betaCutoff;
- volatile int slaves[MAX_THREADS];
+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;
};
-// ThreadState type is used to represent thread's current state
-enum ThreadState
-{
- THREAD_INITIALIZING, // thread is initializing itself
- THREAD_SEARCHING, // thread is performing work
- THREAD_AVAILABLE, // thread is waiting for work
- THREAD_BOOKED, // other thread (master) has booked us as a slave
- THREAD_WORKISWAITING, // master has ordered us to start
- THREAD_TERMINATED // we are quitting and thread is terminated
+
+// 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;
};
-struct Thread {
- int maxPly;
- Lock sleepLock;
- WaitCondition sleepCond;
- volatile ThreadState state;
- SplitPoint* volatile splitPoint;
- volatile int activeSplitPoints;
- SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
-
- void wake_up() {
- lock_grab(&sleepLock);
- cond_signal(&sleepCond);
- lock_release(&sleepLock);
- }
+
+// 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;
+ }
};
-#endif // !defined(THREAD_H_INCLUDED)
+extern ThreadPool Threads;
+
+} // namespace Stockfish
+
+#endif // #ifndef THREAD_H_INCLUDED
projects / stockfish / blobdiff