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
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 #ifndef THREAD_H_INCLUDED
21 #define THREAD_H_INCLUDED
25 #include <condition_variable>
35 #include "thread_win32.h"
39 const size_t MAX_THREADS = 128;
42 /// ThreadBase struct is the base of the hierarchy from where we derive all the
43 /// specialized thread classes.
45 struct ThreadBase : public std::thread {
47 virtual ~ThreadBase() = default;
48 virtual void idle_loop() = 0;
50 void wait(volatile const bool& b);
51 void wait_while(volatile const bool& b);
54 ConditionVariable sleepCondition;
55 volatile bool exit = false;
59 /// Thread struct keeps together all the thread related stuff like locks, state
60 /// and especially split points. We also use per-thread pawn and material hash
61 /// tables so that once we get a pointer to an entry its life time is unlimited
62 /// and we don't have to care about someone changing the entry under our feet.
64 struct Thread : public ThreadBase {
67 virtual void idle_loop();
68 void search(bool isMainThread = false);
70 Pawns::Table pawnsTable;
71 Material::Table materialTable;
75 volatile bool searching;
78 Search::RootMoveVector rootMoves;
80 Search::Stack stack[MAX_PLY+4];
82 MovesStats counterMoves;
86 /// MainThread and TimerThread are derived classes used to characterize the two
87 /// special threads: the main one and the recurring timer.
89 struct MainThread : public Thread {
90 virtual void idle_loop();
93 volatile bool thinking = true; // Avoid a race with start_thinking()
96 struct TimerThread : public ThreadBase {
98 static const int Resolution = 5; // Millisec between two check_time() calls
100 virtual void idle_loop();
106 /// ThreadPool struct handles all the threads related stuff like init, starting,
107 /// parking and, most importantly, launching a slave thread at a split point.
108 /// All the access to shared thread data is done through this class.
110 struct ThreadPool : public std::vector<Thread*> {
112 void init(); // No c'tor and d'tor, threads rely on globals that should be
113 void exit(); // initialized and are valid during the whole thread lifetime.
115 MainThread* main() { return static_cast<MainThread*>(at(0)); }
116 void read_uci_options();
117 void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
118 int64_t nodes_searched();
122 extern ThreadPool Threads;
124 #endif // #ifndef THREAD_H_INCLUDED