/*
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
#if !defined(THREAD_H_INCLUDED)
#define THREAD_H_INCLUDED
-#include <cstring>
+#include <vector>
-#include "lock.h"
+#include "evaluate.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_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;
+};
+
+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;
Value beta;
- int ply;
- int master;
+ int nodeType;
+ Thread* master;
Move threatMove;
// Const pointers to shared data
MovePicker* mp;
- SearchStack* ss;
+ SplitPoint* parent;
// Shared data
- Lock lock;
+ 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 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.
-// 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.
+class Thread {
-struct Thread {
- MaterialInfoTable materialTable;
- PawnInfoTable pawnTable;
+ typedef void (Thread::* Fn) (); // Pointer to member function
+
+public:
+ Thread(Fn fn);
+ ~Thread();
+
+ 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_or_ponderhit();
+
+ SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
+ Eval::Table evalTable;
+ MaterialTable materialTable;
+ PawnTable pawnTable;
+ size_t idx;
int maxPly;
- Lock sleepLock;
- WaitCondition sleepCond;
- volatile ThreadState state;
- SplitPoint* volatile splitPoint;
- volatile int activeSplitPoints;
- SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
-
- void wake_up() {
- lock_grab(&sleepLock);
- cond_signal(&sleepCond);
- lock_release(&sleepLock);
- }
+ 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;
};
-// 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.
+/// ThreadPool 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 ThreadPool {
-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();
- void init_hash_tables();
+ 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.
+ Thread& operator[](size_t id) { return *threads[id]; }
+ bool use_sleeping_threads() const { return useSleepingThreads; }
int min_split_depth() const { return minimumSplitDepth; }
- int active_threads() const { return activeThreads; }
- void set_active_threads(int cnt) { activeThreads = cnt; }
+ size_t size() const { return threads.size(); }
+ Thread* main_thread() { return threads[0]; }
+ void wake_up() const;
+ void sleep() const;
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);
+ 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>
- void split(Position& pos, SearchStack* ss, Value* alpha, const Value beta, Value* bestValue,
- Depth depth, Move threatMove, int moveCount, MovePicker* mp, bool pvNode);
+ 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:
- Lock mpLock;
+ friend class Thread;
+ friend void check_time();
+
+ std::vector<Thread*> threads;
+ Thread* timer;
+ Mutex mutex;
+ ConditionVariable sleepCondition;
Depth minimumSplitDepth;
int maxThreadsPerSplitPoint;
bool useSleepingThreads;
- int activeThreads;
- volatile bool allThreadsShouldExit;
- Thread threads[MAX_THREADS];
};
-extern ThreadsManager ThreadsMgr;
+extern ThreadPool Threads;
#endif // !defined(THREAD_H_INCLUDED)