/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 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
-
-////
-//// Includes
-////
-
#include <cstring>
#include "lock.h"
+#include "material.h"
#include "movepick.h"
+#include "pawns.h"
#include "position.h"
-#include "search.h"
-
-
-////
-//// Constants and variables
-////
-const int MAX_THREADS = 8;
-const int ACTIVE_SPLIT_POINTS_MAX = 8;
-
-
-////
-//// Types
-////
+const int MAX_THREADS = 32;
+const int MAX_ACTIVE_SPLIT_POINTS = 8;
struct SplitPoint {
- SplitPoint *parent;
+
+ // Const data after splitPoint has been setup
+ SplitPoint* parent;
const Position* pos;
- SearchStack sstack[MAX_THREADS][PLY_MAX_PLUS_2];
- SearchStack *parentSstack;
- int ply;
Depth depth;
- volatile Value alpha, beta, bestValue;
- Value futilityValue;
bool pvNode;
- int master, slaves[MAX_THREADS];
+ Value beta;
+ int ply;
+ int master;
+ Move threatMove;
+
+ // Const pointers to shared data
+ MovePicker* mp;
+ SearchStack* ss;
+
+ // Shared data
Lock lock;
- MovePicker *mp;
- volatile int moves;
- volatile int cpus;
- bool finished;
+ volatile int64_t nodes;
+ volatile Value alpha;
+ volatile Value bestValue;
+ volatile int moveCount;
+ volatile bool betaCutoff;
+ volatile int slaves[MAX_THREADS];
};
+// 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
+};
+
+
+// We 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 {
- SplitPoint *splitPoint;
+ MaterialInfoTable materialTable;
+ PawnInfoTable pawnTable;
+ int maxPly;
+ Lock sleepLock;
+ WaitCondition sleepCond;
+ volatile ThreadState state;
+ SplitPoint* volatile splitPoint;
volatile int activeSplitPoints;
- uint64_t nodes;
- uint64_t betaCutOffs[2];
- volatile bool stopRequest;
- volatile bool running;
- volatile bool idle;
- volatile bool sleeping;
- volatile bool workIsWaiting;
- volatile bool printCurrentLineRequest;
- unsigned char pad[64]; // set some distance among local data for each thread
+ SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
+
+ void wake_up() {
+ lock_grab(&sleepLock);
+ cond_signal(&sleepCond);
+ lock_release(&sleepLock);
+ }
+};
+
+
+// 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.
+
+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_threads();
+ void exit_threads();
+
+ int min_split_depth() const { return minimumSplitDepth; }
+ int active_threads() const { return activeThreads; }
+ void set_active_threads(int cnt) { activeThreads = cnt; }
+
+ void read_uci_options();
+ bool available_thread_exists(int master) const;
+ bool thread_is_available(int slave, int master) const;
+ bool cutoff_at_splitpoint(int threadID) const;
+ void idle_loop(int threadID, SplitPoint* sp);
+
+ template <bool Fake>
+ void split(Position& pos, SearchStack* ss, Value* alpha, const Value beta, Value* bestValue,
+ Depth depth, Move threatMove, int moveCount, MovePicker* mp, bool pvNode);
+private:
+ Lock mpLock;
+ Depth minimumSplitDepth;
+ int maxThreadsPerSplitPoint;
+ bool useSleepingThreads;
+ int activeThreads;
+ volatile bool allThreadsShouldExit;
+ Thread threads[MAX_THREADS];
};
+extern ThreadsManager ThreadsMgr;
#endif // !defined(THREAD_H_INCLUDED)