/*
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) 2008-2012 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)
#define THREAD_H_INCLUDED
+#include <vector>
-////
-//// Includes
-////
-
-#include <cstring>
-
-#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_SPLITPOINTS_PER_THREAD = 8;
-////
-//// Constants and variables
-////
-
-const int MAX_THREADS = 16;
-const int MAX_ACTIVE_SPLIT_POINTS = 8;
-
-
-////
-//// Types
-////
+class 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;
Depth depth;
- bool pvNode, mateThreat;
Value beta;
- int ply;
- int master;
+ int nodeType;
+ Thread* master;
Move threatMove;
// Const pointers to shared data
MovePicker* mp;
- SearchStack* parentSstack;
+ SplitPoint* parent;
// Shared data
Lock lock;
+ volatile uint64_t slavesMask;
volatile int64_t nodes;
volatile Value alpha;
volatile Value bestValue;
+ volatile Move bestMove;
volatile int moveCount;
- volatile bool betaCutoff;
- volatile int slaves[MAX_THREADS];
+ volatile bool cutoff;
};
-// ThreadState type is used to represent thread's current state
-enum ThreadState
-{
- THREAD_INITIALIZING, // thread is initializing itself
- THREAD_SEARCHING, // thread is performing work
- THREAD_AVAILABLE, // thread is waiting for work
- THREAD_BOOKED, // other thread (master) has booked us as a slave
- THREAD_WORKISWAITING, // master has ordered us to start
- THREAD_TERMINATED // we are quitting and thread is terminated
+/// 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.
+
+class Thread {
+
+ Thread(const Thread&); // Only declared to disable the default ones
+ Thread& operator=(const Thread&); // that are not suitable in this case.
+
+ typedef void (Thread::* Fn) ();
+
+public:
+ Thread(Fn fn);
+ ~Thread();
+
+ void wake_up();
+ bool cutoff_occurred() const;
+ bool is_available_to(const Thread& master) const;
+ void idle_loop(SplitPoint* sp_master);
+ void idle_loop() { idle_loop(NULL); } // Hack to allow storing in start_fn
+ void main_loop();
+ void timer_loop();
+ void wait_for_stop_or_ponderhit();
+
+ SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
+ MaterialTable materialTable;
+ PawnTable pawnTable;
+ int idx;
+ int maxPly;
+ Lock sleepLock;
+ WaitCondition sleepCond;
+ NativeHandle handle;
+ Fn start_fn;
+ SplitPoint* volatile curSplitPoint;
+ volatile int splitPointsCnt;
+ volatile bool is_searching;
+ volatile bool do_sleep;
+ volatile bool do_exit;
};
-struct Thread {
- volatile ThreadState state;
- SplitPoint* volatile splitPoint;
- volatile int activeSplitPoints;
- SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
+
+/// ThreadsManager class 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.
+
+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:
+ void init(); // No c'tor becuase Threads is static and we need engine initialized
+ ~ThreadsManager();
+
+ Thread& operator[](int id) { return *threads[id]; }
+ bool use_sleeping_threads() const { return useSleepingThreads; }
+ int min_split_depth() const { return minimumSplitDepth; }
+ int size() const { return (int)threads.size(); }
+ Thread* main_thread() const { return threads[0]; }
+ Thread* this_thread() const { return (Thread*)tls_get(tlsKey); }
+ void set_this_thread(Thread* th) const { tls_set(tlsKey, th); }
+
+ void wake_up() const;
+ void sleep() const;
+ void read_uci_options();
+ bool available_slave_exists(const Thread& master) const;
+ void set_timer(int msec);
+ void wait_for_search_finished();
+ void start_searching(const Position& pos, const Search::LimitsType& limits,
+ const std::vector<Move>& searchMoves);
+
+ 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;
+
+ std::vector<Thread*> threads;
+ Thread* timer;
+ ThreadLocalStorageKey tlsKey;
+ Lock splitLock;
+ WaitCondition sleepCond;
+ Depth minimumSplitDepth;
+ int maxThreadsPerSplitPoint;
+ bool useSleepingThreads;
};
+extern ThreadsManager Threads;
#endif // !defined(THREAD_H_INCLUDED)
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