1 /* 2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1 3 Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file) 4 5 Stockfish is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation, either version 3 of the License, or 8 (at your option) any later version. 9 10 Stockfish is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #ifndef THREAD_H_INCLUDED 20 #define THREAD_H_INCLUDED 21 22 #include <atomic> 23 #include <condition_variable> 24 #include <mutex> 25 #include <thread> 26 #include <vector> 27 28 #include "material.h" 29 #include "movepick.h" 30 #include "pawns.h" 31 #include "position.h" 32 #include "search.h" 33 #include "thread_win32_osx.h" 34 35 namespace Stockfish { 36 37 /// Thread class keeps together all the thread-related stuff. We use 38 /// per-thread pawn and material hash tables so that once we get a 39 /// pointer to an entry its life time is unlimited and we don't have 40 /// to care about someone changing the entry under our feet. 41 42 class Thread { 43 44 std::mutex mutex; 45 std::condition_variable cv; 46 size_t idx; 47 bool exit = false, searching = true; // Set before starting std::thread 48 NativeThread stdThread; 49 50 public: 51 explicit Thread(size_t); 52 virtual ~Thread(); 53 virtual void search(); 54 void clear(); 55 void idle_loop(); 56 void start_searching(); 57 void wait_for_search_finished(); id()58 size_t id() const { return idx; } 59 60 Pawns::Table pawnsTable; 61 Material::Table materialTable; 62 size_t pvIdx, pvLast; 63 uint64_t ttHitAverage; 64 int selDepth, nmpMinPly; 65 Color nmpColor; 66 std::atomic<uint64_t> nodes, tbHits, bestMoveChanges; 67 68 Position rootPos; 69 StateInfo rootState; 70 Search::RootMoves rootMoves; 71 Depth rootDepth, completedDepth; 72 CounterMoveHistory counterMoves; 73 ButterflyHistory mainHistory; 74 LowPlyHistory lowPlyHistory; 75 CapturePieceToHistory captureHistory; 76 ContinuationHistory continuationHistory[2][2]; 77 Score trend; 78 }; 79 80 81 /// MainThread is a derived class specific for main thread 82 83 struct MainThread : public Thread { 84 85 using Thread::Thread; 86 87 void search() override; 88 void check_time(); 89 90 double previousTimeReduction; 91 Value bestPreviousScore; 92 Value iterValue[4]; 93 int callsCnt; 94 bool stopOnPonderhit; 95 std::atomic_bool ponder; 96 }; 97 98 99 /// ThreadPool struct handles all the threads-related stuff like init, starting, 100 /// parking and, most importantly, launching a thread. All the access to threads 101 /// is done through this class. 102 103 struct ThreadPool : public std::vector<Thread*> { 104 105 void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false); 106 void clear(); 107 void set(size_t); 108 mainThreadPool109 MainThread* main() const { return static_cast<MainThread*>(front()); } nodes_searchedThreadPool110 uint64_t nodes_searched() const { return accumulate(&Thread::nodes); } tb_hitsThreadPool111 uint64_t tb_hits() const { return accumulate(&Thread::tbHits); } 112 Thread* get_best_thread() const; 113 void start_searching(); 114 void wait_for_search_finished() const; 115 116 std::atomic_bool stop, increaseDepth; 117 118 private: 119 StateListPtr setupStates; 120 accumulateThreadPool121 uint64_t accumulate(std::atomic<uint64_t> Thread::* member) const { 122 123 uint64_t sum = 0; 124 for (Thread* th : *this) 125 sum += (th->*member).load(std::memory_order_relaxed); 126 return sum; 127 } 128 }; 129 130 extern ThreadPool Threads; 131 132 } // namespace Stockfish 133 134 #endif // #ifndef THREAD_H_INCLUDED 135