X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=793a3c606797c573131fe5f59cbc4e6c915c4b6e;hp=17354773b1fd9cb05f471c49c7293a806d118215;hb=588670e8d2ed5735300c5549ef754ceb09f1f461;hpb=04e1ba8aa2dd0a7dbf4110503d71494df91b4ef5 diff --git a/src/thread.h b/src/thread.h index 17354773..793a3c60 100644 --- a/src/thread.h +++ b/src/thread.h @@ -1,7 +1,7 @@ /* 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 @@ -17,79 +17,163 @@ along with this program. If not, see . */ - #if !defined(THREAD_H_INCLUDED) #define THREAD_H_INCLUDED +#include -//// -//// Includes -//// - -#include - -#include "lock.h" +#include "material.h" #include "movepick.h" +#include "pawns.h" #include "position.h" #include "search.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); } -//// -//// Constants and variables -//// + void lock() { lock_grab(l); } + void unlock() { lock_release(l); } -const int MAX_THREADS = 8; -const int MAX_ACTIVE_SPLIT_POINTS = 8; +private: + friend struct ConditionVariable; + Lock l; +}; + +struct ConditionVariable { + ConditionVariable() { cond_init(c); } + ~ConditionVariable() { cond_destroy(c); } -//// -//// Types -//// + 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; Depth depth; - bool pvNode, mateThreat; Value beta; - int ply; - SearchStack sstack[MAX_THREADS][PLY_MAX_PLUS_2]; + int nodeType; + Thread* master; + Move threatMove; // Const pointers to shared data MovePicker* mp; - SearchStack* parentSstack; + 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 stopRequest; - volatile int slaves[MAX_THREADS]; + volatile bool cutoff; }; -// ThreadState type is used to represent thread's current state -enum ThreadState -{ - THREAD_SEARCHING, // thread is performing work - THREAD_AVAILABLE, // thread is polling for work - THREAD_SLEEPING, // we are not thinking, so thread is sleeping - 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. struct Thread { - uint64_t nodes; - uint64_t betaCutOffs[2]; - volatile ThreadState state; - SplitPoint* volatile splitPoint; - volatile int activeSplitPoints; - SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS]; + + Thread(); + virtual ~Thread(); + + virtual void idle_loop(); + void notify_one(); + bool cutoff_occurred() const; + bool is_available_to(Thread* master) const; + void wait_for(volatile const bool& b); + + 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; + SplitPoint* volatile curSplitPoint; + volatile int splitPointsCnt; + volatile bool searching; + volatile bool exit; +}; + + +/// MainThread and TimerThread are sublassed from Thread to charaterize the two +/// special threads: the main one and the recurring timer. + +struct MainThread : public Thread { + MainThread() : thinking(true) {} // Avoid a race with start_thinking() + virtual void idle_loop(); + volatile bool thinking; +}; + +struct TimerThread : public Thread { + TimerThread() : msec(0) {} + virtual void idle_loop(); + int msec; +}; + + +/// 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 { + +public: + 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]; } + size_t size() const { return threads.size(); } + MainThread* main_thread() { return static_cast(threads[0]); } + TimerThread* timer_thread() { return timer; } + + void read_uci_options(); + bool available_slave_exists(Thread* master) const; + void wait_for_think_finished(); + void start_thinking(const Position&, const Search::LimitsType&, + const std::vector&, Search::StateStackPtr&); + + template + 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); + + bool sleepWhileIdle; + Depth minimumSplitDepth; + +private: + friend struct Thread; + friend struct MainThread; + friend void check_time(); + + std::vector threads; + TimerThread* timer; + Mutex mutex; + ConditionVariable sleepCondition; + int maxThreadsPerSplitPoint; }; +extern ThreadPool Threads; #endif // !defined(THREAD_H_INCLUDED)