2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 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_ACTIVE_SPLIT_POINTS = 8;
37 // Const data after splitPoint has been setup
47 // Const pointers to shared data
53 volatile int64_t nodes;
55 volatile Value bestValue;
56 volatile int moveCount;
57 volatile bool is_betaCutoff;
58 volatile bool is_slave[MAX_THREADS];
62 /// Thread struct keeps together all the thread related stuff like locks, state
63 /// and especially split points. We also use per-thread pawn and material hash
64 /// tables so that once we get a pointer to an entry its life time is unlimited
65 /// and we don't have to care about someone changing the entry under our feet.
70 bool cutoff_occurred() const;
71 bool is_available_to(int master) const;
72 void idle_loop(SplitPoint* sp);
76 SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
77 MaterialInfoTable materialTable;
78 PawnInfoTable pawnTable;
82 WaitCondition sleepCond;
83 SplitPoint* volatile splitPoint;
84 volatile int activeSplitPoints;
85 volatile bool is_searching;
86 volatile bool do_sleep;
87 volatile bool do_terminate;
97 /// ThreadsManager class handles all the threads related stuff like init, starting,
98 /// parking and, the most important, launching a slave thread at a split point.
99 /// All the access to shared thread data is done through this class.
101 class ThreadsManager {
102 /* As long as the single ThreadsManager object is defined as a global we don't
103 need to explicitly initialize to zero its data members because variables with
104 static storage duration are automatically set to zero before enter main()
107 Thread& operator[](int threadID) { return threads[threadID]; }
111 bool use_sleeping_threads() const { return useSleepingThreads; }
112 int min_split_depth() const { return minimumSplitDepth; }
113 int size() const { return activeThreads; }
115 void set_size(int cnt);
116 void read_uci_options();
117 bool available_slave_exists(int master) const;
118 bool split_point_finished(SplitPoint* sp) const;
119 void set_timer(int msec);
120 void wait_for_stop_or_ponderhit();
121 void start_thinking(const Position& pos, const Search::LimitsType& limits,
122 const std::vector<Move>& searchMoves, bool asyncMode);
125 Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue,
126 Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
128 friend struct Thread;
130 Thread threads[MAX_THREADS + 1]; // Last one is used as a timer
132 Depth minimumSplitDepth;
133 int maxThreadsPerSplitPoint;
135 bool useSleepingThreads;
136 WaitCondition sleepCond;
139 extern ThreadsManager Threads;
141 #endif // !defined(THREAD_H_INCLUDED)