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 = 64; // Because SplitPoint::slavesMask is a uint64_t
33 const int MAX_SPLITPOINTS_PER_THREAD = 8;
36 Mutex() { lock_init(l); }
37 ~Mutex() { lock_destroy(l); }
39 void lock() { lock_grab(l); }
40 void unlock() { lock_release(l); }
43 friend struct ConditionVariable;
48 struct ConditionVariable {
49 ConditionVariable() { cond_init(c); }
50 ~ConditionVariable() { cond_destroy(c); }
52 void wait(Mutex& m) { cond_wait(c, m.l); }
53 void wait_for(Mutex& m, int ms) { timed_wait(c, m.l, ms); }
54 void notify_one() { cond_signal(c); }
64 // Const data after split point has been setup
66 const Search::Stack* ss;
73 // Const pointers to shared data
79 Position* activePositions[MAX_THREADS];
80 volatile uint64_t slavesMask;
81 volatile int64_t nodes;
83 volatile Value bestValue;
84 volatile Move bestMove;
85 volatile int moveCount;
90 /// Thread struct keeps together all the thread related stuff like locks, state
91 /// and especially split points. We also use per-thread pawn and material hash
92 /// tables so that once we get a pointer to an entry its life time is unlimited
93 /// and we don't have to care about someone changing the entry under our feet.
97 typedef void (Thread::* Fn) (); // Pointer to member function
104 bool cutoff_occurred() const;
105 bool is_available_to(Thread* master) const;
109 void wait_for_stop_or_ponderhit();
111 SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
112 Eval::Table evalTable;
113 Material::Table materialTable;
119 ConditionVariable sleepCondition;
122 SplitPoint* volatile curSplitPoint;
123 volatile int splitPointsCnt;
124 volatile bool is_searching;
125 volatile bool do_sleep;
126 volatile bool do_exit;
130 /// ThreadPool class handles all the threads related stuff like init, starting,
131 /// parking and, the most important, launching a slave thread at a split point.
132 /// All the access to shared thread data is done through this class.
137 void init(); // No c'tor and d'tor, threads rely on globals that should
138 void exit(); // be initialized and valid during the whole thread lifetime.
140 Thread& operator[](size_t id) { return *threads[id]; }
141 bool use_sleeping_threads() const { return useSleepingThreads; }
142 int min_split_depth() const { return minimumSplitDepth; }
143 size_t size() const { return threads.size(); }
144 Thread* main_thread() { return threads[0]; }
146 void wake_up() const;
148 void read_uci_options();
149 bool available_slave_exists(Thread* master) const;
150 void set_timer(int msec);
151 void wait_for_search_finished();
152 void start_searching(const Position&, const Search::LimitsType&,
153 const std::vector<Move>&, Search::StateStackPtr&);
156 Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
157 Depth depth, Move threatMove, int moveCount, MovePicker& mp, int nodeType);
160 friend void check_time();
162 std::vector<Thread*> threads;
165 ConditionVariable sleepCondition;
166 Depth minimumSplitDepth;
167 int maxThreadsPerSplitPoint;
168 bool useSleepingThreads;
171 extern ThreadPool Threads;
173 #endif // !defined(THREAD_H_INCLUDED)