/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2013 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 <cstring>
+#include <vector>
-#include "lock.h"
#include "material.h"
#include "movepick.h"
#include "pawns.h"
#include "position.h"
+#include "search.h"
-const int MAX_THREADS = 32;
-const int MAX_ACTIVE_SPLIT_POINTS = 8;
+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); }
+
+ void lock() { lock_grab(l); }
+ void unlock() { lock_release(l); }
+
+private:
+ friend struct ConditionVariable;
+
+ 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;
+};
+
+struct Thread;
struct SplitPoint {
- // Const data after splitPoint has been setup
- SplitPoint* parent;
+ // Const data after split point has been setup
const Position* pos;
+ const Search::Stack* ss;
+ Thread* masterThread;
Depth depth;
Value beta;
int nodeType;
- int ply;
- int master;
Move threatMove;
+ bool cutNode;
// Const pointers to shared data
- MovePicker* mp;
- SearchStack* ss;
+ MovePicker* movePicker;
+ SplitPoint* parentSplitPoint;
// Shared data
- Lock lock;
+ Mutex mutex;
+ volatile uint64_t slavesMask;
volatile int64_t nodes;
volatile Value alpha;
volatile Value bestValue;
+ volatile Move bestMove;
volatile int moveCount;
- volatile bool is_betaCutoff;
- volatile bool is_slave[MAX_THREADS];
+ volatile bool cutoff;
};
-/// Thread struct is used to keep 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.
+/// ThreadBase struct is the base of the hierarchy from where we derive all the
+/// specialized thread classes.
+
+struct ThreadBase {
-struct Thread {
+ ThreadBase() : exit(false) {}
+ virtual ~ThreadBase() {}
+ virtual void idle_loop() = 0;
+ void notify_one();
+ void wait_for(volatile const bool& b);
- enum ThreadState
- {
- AVAILABLE, // Thread is waiting for work
- WORKISWAITING, // Master has ordered us to start searching
- SEARCHING // Thread is performing work
- };
+ Mutex mutex;
+ ConditionVariable sleepCondition;
+ NativeHandle handle;
+ volatile bool exit;
+};
+
+
+/// 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.
+
+struct Thread : public ThreadBase {
- void wake_up();
+ Thread();
+ virtual void idle_loop();
bool cutoff_occurred() const;
- bool is_available_to(int master) const;
- void idle_loop(SplitPoint* sp);
+ bool is_available_to(const Thread* master) const;
- SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
- MaterialInfoTable materialTable;
- PawnInfoTable pawnTable;
- int threadID;
+ template <bool Fake>
+ void split(Position& pos, const Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove,
+ Depth depth, Move threatMove, int moveCount, MovePicker* movePicker, int nodeType, bool cutNode);
+
+ SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
+ Material::Table materialTable;
+ Endgames endgames;
+ Pawns::Table pawnsTable;
+ Position* activePosition;
+ size_t idx;
int maxPly;
- Lock sleepLock;
- WaitCondition sleepCond;
- volatile ThreadState state;
- SplitPoint* volatile splitPoint;
- volatile int activeSplitPoints;
- volatile bool do_sleep;
- volatile bool do_terminate;
-
-#if defined(_MSC_VER)
- HANDLE handle;
-#else
- pthread_t handle;
-#endif
+ SplitPoint* volatile activeSplitPoint;
+ volatile int splitPointsSize;
+ volatile bool searching;
};
-/// ThreadsManager class is used to handle all the threads related stuff like init,
-/// starting, parking and, the most important, launching a slave thread at a split
-/// point. All the access to shared thread data is done through this class.
+/// MainThread and TimerThread are derived classes used to characterize the two
+/// special threads: the main one and the recurring timer.
-class ThreadsManager {
- /* As long as the single ThreadsManager object is defined as a global we don't
- need to explicitly initialize to zero its data members because variables with
- static storage duration are automatically set to zero before enter main()
- */
-public:
- Thread& operator[](int threadID) { return threads[threadID]; }
- void init();
- void exit();
+struct MainThread : public Thread {
+ MainThread() : thinking(true) {} // Avoid a race with start_thinking()
+ virtual void idle_loop();
+ volatile bool thinking;
+};
- bool use_sleeping_threads() const { return useSleepingThreads; }
- int min_split_depth() const { return minimumSplitDepth; }
- int size() const { return activeThreads; }
+struct TimerThread : public ThreadBase {
+ TimerThread() : msec(0) {}
+ virtual void idle_loop();
+ int msec;
+};
- void set_size(int cnt);
+
+/// ThreadPool struct handles all the threads related stuff like init, starting,
+/// parking and, the most important, launching a slave thread at a split point.
+/// All the access to shared thread data is done through this class.
+
+struct ThreadPool : public std::vector<Thread*> {
+
+ void init(); // No c'tor and d'tor, threads rely on globals that should
+ void exit(); // be initialized and valid during the whole thread lifetime.
+
+ MainThread* main() { return static_cast<MainThread*>((*this)[0]); }
void read_uci_options();
- bool available_slave_exists(int master) const;
+ Thread* available_slave(const Thread* master) const;
+ void wait_for_think_finished();
+ void start_thinking(const Position&, const Search::LimitsType&,
+ const std::vector<Move>&, Search::StateStackPtr&);
- template <bool Fake>
- Value split(Position& pos, SearchStack* ss, Value alpha, Value beta, Value bestValue,
- Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
-private:
- Thread threads[MAX_THREADS];
- Lock threadsLock;
+ bool sleepWhileIdle;
Depth minimumSplitDepth;
- int maxThreadsPerSplitPoint;
- int activeThreads;
- bool useSleepingThreads;
+ size_t maxThreadsPerSplitPoint;
+ Mutex mutex;
+ ConditionVariable sleepCondition;
+ TimerThread* timer;
};
-extern ThreadsManager Threads;
+extern ThreadPool Threads;
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED
projects / stockfish / blobdiff