/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#if !defined(THREAD_H_INCLUDED)
+#ifndef THREAD_H_INCLUDED
#define THREAD_H_INCLUDED
+#include <atomic>
+#include <bitset>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
#include <vector>
#include "material.h"
#include "pawns.h"
#include "position.h"
#include "search.h"
+#include "thread_win32.h"
-const int MAX_THREADS = 64; // Because SplitPoint::slavesMask is a uint64_t
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
-struct Mutex {
- Mutex() { lock_init(l); }
- ~Mutex() { lock_destroy(l); }
+/// ThreadBase struct is the base of the hierarchy from where we derive all the
+/// specialized thread classes.
- void lock() { lock_grab(l); }
- void unlock() { lock_release(l); }
+struct ThreadBase : public std::thread {
-private:
- friend struct ConditionVariable;
+ ThreadBase() { exit = false; }
+ virtual ~ThreadBase() = default;
+ virtual void idle_loop() = 0;
+ void notify_one();
+ void wait(std::atomic<bool>& b);
+ void wait_while(std::atomic<bool>& b);
- Lock l;
-};
-
-struct ConditionVariable {
- ConditionVariable() { cond_init(c); }
- ~ConditionVariable() { cond_destroy(c); }
-
- void wait(Mutex& m) { cond_wait(c, m.l); }
- void wait_for(Mutex& m, int ms) { timed_wait(c, m.l, ms); }
- void notify_one() { cond_signal(c); }
-
-private:
- WaitCondition c;
+ Mutex mutex;
+ ConditionVariable sleepCondition;
+ std::atomic<bool> exit;
};
-class Thread;
-struct SplitPoint {
+/// Thread struct keeps together all the thread related stuff like locks, state,
+/// history and countermoves tables. We also use per-thread pawn and material hash
+/// tables so that once we get a pointer to an entry its life time is unlimited
+/// and we don't have to care about someone changing the entry under our feet.
- // Const data after split point has been setup
- const Position* pos;
- const Search::Stack* ss;
- Depth depth;
- Value beta;
- int nodeType;
- Thread* master;
- Move threatMove;
+struct Thread : public ThreadBase {
- // Const pointers to shared data
- MovePicker* mp;
- SplitPoint* parent;
+ Thread();
+ virtual void idle_loop();
+ void search(bool isMainThread = false);
- // Shared data
- Mutex mutex;
- Position* activePositions[MAX_THREADS];
- volatile uint64_t slavesMask;
- volatile int64_t nodes;
- volatile Value alpha;
- volatile Value bestValue;
- volatile Move bestMove;
- volatile int moveCount;
- volatile bool cutoff;
+ Pawns::Table pawnsTable;
+ Material::Table materialTable;
+ Endgames endgames;
+ size_t idx, PVIdx;
+ int maxPly;
+ std::atomic<bool> searching;
+
+ Position rootPos;
+ Search::RootMoveVector rootMoves;
+ Depth rootDepth;
+ HistoryStats history;
+ MovesStats counterMoves;
+ Depth completedDepth;
};
-/// Thread struct keeps together all the thread related stuff like locks, state
-/// and especially split points. We also use per-thread pawn and material hash
-/// tables so that once we get a pointer to an entry its life time is unlimited
-/// and we don't have to care about someone changing the entry under our feet.
+/// MainThread and TimerThread are derived classes used to characterize the two
+/// special threads: the main one and the recurring timer.
-class Thread {
+struct MainThread : public Thread {
+ MainThread() { thinking = true; } // Avoid a race with start_thinking()
+ virtual void idle_loop();
+ void join();
+ void think();
+ std::atomic<bool> thinking;
+};
- typedef void (Thread::* Fn) (); // Pointer to member function
+struct TimerThread : public ThreadBase {
-public:
- Thread(Fn fn);
- ~Thread();
+ static const int Resolution = 5; // Millisec between two check_time() calls
- void wake_up();
- bool cutoff_occurred() const;
- bool is_available_to(Thread* master) const;
- void idle_loop();
- void main_loop();
- void timer_loop();
- void wait_for_stop();
+ virtual void idle_loop();
+ void check_time();
- SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
- Material::Table materialTable;
- Endgames endgames;
- Pawns::Table pawnsTable;
- size_t idx;
- int maxPly;
- Mutex mutex;
- ConditionVariable sleepCondition;
- NativeHandle handle;
- Fn start_fn;
- SplitPoint* volatile curSplitPoint;
- volatile int splitPointsCnt;
- volatile bool is_searching;
- volatile bool do_sleep;
- volatile bool do_exit;
+ bool run = false;
};
-/// ThreadPool class handles all the threads related stuff like init, starting,
-/// parking and, the most important, launching a slave thread at a split point.
+/// ThreadPool struct handles all the threads related stuff like init, starting,
+/// parking and, most importantly, launching a thread.
/// All the access to shared thread data is done through this class.
-class ThreadPool {
+struct ThreadPool : public std::vector<Thread*> {
-public:
- void init(); // No c'tor and d'tor, threads rely on globals that should
+ void init(); // No constructor and destructor, threads rely on globals that should
void exit(); // be initialized and valid during the whole thread lifetime.
- Thread& operator[](size_t id) { return *threads[id]; }
- bool use_sleeping_threads() const { return useSleepingThreads; }
- int min_split_depth() const { return minimumSplitDepth; }
- size_t size() const { return threads.size(); }
- Thread* main_thread() { return threads[0]; }
-
- void wake_up() const;
- void sleep() const;
+ MainThread* main() { return static_cast<MainThread*>(at(0)); }
void read_uci_options();
- bool available_slave_exists(Thread* master) const;
- void set_timer(int msec);
- void wait_for_search_finished();
- void start_searching(const Position&, const Search::LimitsType&,
- const std::vector<Move>&, Search::StateStackPtr&);
-
- template <bool Fake>
- Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
- Depth depth, Move threatMove, int moveCount, MovePicker& mp, int nodeType);
-private:
- friend class Thread;
- friend void check_time();
-
- std::vector<Thread*> threads;
- Thread* timer;
- Mutex mutex;
- ConditionVariable sleepCondition;
- Depth minimumSplitDepth;
- int maxThreadsPerSplitPoint;
- bool useSleepingThreads;
+ void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
+ int64_t nodes_searched();
+ TimerThread* timer;
};
extern ThreadPool Threads;
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED
projects / stockfish / blobdiff