2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #if !defined(THREAD_H_INCLUDED)
21 #define THREAD_H_INCLUDED
32 const int MAX_THREADS = 32;
33 const int MAX_SPLITPOINTS_PER_THREAD = 8;
37 // Const data after split point has been setup
39 const Search::Stack* ss;
46 // Const pointers to shared data
53 volatile uint64_t slavesMask;
54 volatile int64_t nodes;
56 volatile Value bestValue;
57 volatile Move bestMove;
58 volatile int moveCount;
63 /// Thread struct keeps together all the thread related stuff like locks, state
64 /// and especially split points. We also use per-thread pawn and material hash
65 /// tables so that once we get a pointer to an entry its life time is unlimited
66 /// and we don't have to care about someone changing the entry under our feet.
71 bool cutoff_occurred() const;
72 bool is_available_to(int master) const;
73 void idle_loop(SplitPoint* sp_master);
76 void wait_for_stop_or_ponderhit();
78 SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
79 MaterialInfoTable materialTable;
80 PawnInfoTable pawnTable;
84 WaitCondition sleepCond;
86 SplitPoint* volatile curSplitPoint;
87 volatile int splitPointsCnt;
88 volatile bool is_searching;
89 volatile bool do_sleep;
90 volatile bool do_exit;
94 /// ThreadsManager class handles all the threads related stuff like init, starting,
95 /// parking and, the most important, launching a slave thread at a split point.
96 /// All the access to shared thread data is done through this class.
98 class ThreadsManager {
99 /* As long as the single ThreadsManager object is defined as a global we don't
100 need to explicitly initialize to zero its data members because variables with
101 static storage duration are automatically set to zero before enter main()
104 Thread& operator[](int threadID) { return threads[threadID]; }
108 bool use_sleeping_threads() const { return useSleepingThreads; }
109 int min_split_depth() const { return minimumSplitDepth; }
110 int size() const { return activeThreads; }
112 void set_size(int cnt);
113 void read_uci_options();
114 bool available_slave_exists(int master) const;
115 void set_timer(int msec);
116 void stop_thinking();
117 void start_thinking(const Position& pos, const Search::LimitsType& limits,
118 const std::set<Move>& = std::set<Move>(), bool async = false);
121 Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
122 Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
124 friend struct Thread;
126 Thread threads[MAX_THREADS + 1]; // Last one is used as a timer
128 WaitCondition sleepCond;
129 Depth minimumSplitDepth;
130 int maxThreadsPerSplitPoint;
132 bool useSleepingThreads;
135 extern ThreadsManager Threads;
137 #endif // !defined(THREAD_H_INCLUDED)