2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
5 Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
7 Stockfish is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 Stockfish is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #ifndef THREAD_H_INCLUDED
22 #define THREAD_H_INCLUDED
25 #include <condition_variable>
35 #include "thread_win32_osx.h"
38 /// Thread class keeps together all the thread-related stuff. We use
39 /// per-thread pawn and material hash tables so that once we get a
40 /// pointer to an entry its life time is unlimited and we don't have
41 /// to care about someone changing the entry under our feet.
46 std::condition_variable cv;
48 bool exit = false, searching = true; // Set before starting std::thread
49 NativeThread stdThread;
52 explicit Thread(size_t);
54 virtual void search();
57 void start_searching();
58 void wait_for_search_finished();
59 int best_move_count(Move move);
61 Pawns::Table pawnsTable;
62 Material::Table materialTable;
63 size_t pvIdx, pvLast, shuffleExts;
64 int selDepth, nmpMinPly;
66 std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
69 Search::RootMoves rootMoves;
70 Depth rootDepth, completedDepth;
71 CounterMoveHistory counterMoves;
72 ButterflyHistory mainHistory;
73 CapturePieceToHistory captureHistory;
74 ContinuationHistory continuationHistory[2][2];
79 /// MainThread is a derived class specific for main thread
81 struct MainThread : public Thread {
85 void search() override;
88 double previousTimeReduction;
92 std::atomic_bool ponder;
96 /// ThreadPool struct handles all the threads-related stuff like init, starting,
97 /// parking and, most importantly, launching a thread. All the access to threads
98 /// is done through this class.
100 struct ThreadPool : public std::vector<Thread*> {
102 void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false);
106 MainThread* main() const { return static_cast<MainThread*>(front()); }
107 uint64_t nodes_searched() const { return accumulate(&Thread::nodes); }
108 uint64_t tb_hits() const { return accumulate(&Thread::tbHits); }
110 std::atomic_bool stop;
113 StateListPtr setupStates;
115 uint64_t accumulate(std::atomic<uint64_t> Thread::* member) const {
118 for (Thread* th : *this)
119 sum += (th->*member).load(std::memory_order_relaxed);
124 extern ThreadPool Threads;
126 #endif // #ifndef THREAD_H_INCLUDED