X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=0265ee670b2ea9e84765a8b6208f8b1f8ccb2e9c;hp=04e023067999c63fefb432cfa67cfcda1b1787f5;hb=dccaa145d2b57999aa3e368c7c9203731b4e9685;hpb=32d3a07c6710e84d78999cb69c6a866b0bfff482 diff --git a/src/thread.h b/src/thread.h index 04e02306..0265ee67 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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 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 @@ -17,10 +17,10 @@ along with this program. If not, see . */ -#if !defined(THREAD_H_INCLUDED) +#ifndef THREAD_H_INCLUDED #define THREAD_H_INCLUDED -#include +#include #include #include "material.h" @@ -29,29 +29,65 @@ #include "position.h" #include "search.h" -const int MAX_THREADS = 32; +struct Thread; + +const int MAX_THREADS = 128; const int MAX_SPLITPOINTS_PER_THREAD = 8; +const int MAX_SLAVES_PER_SPLITPOINT = 4; + +/// Mutex and ConditionVariable struct are wrappers of the low level locking +/// machinery and are modeled after the corresponding C++11 classes. + +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; +}; + + +/// SplitPoint struct stores information shared by the threads searching in +/// parallel below the same split point. It is populated at splitting time. struct SplitPoint { // Const data after split point has been setup const Position* pos; - const Search::Stack* ss; + Search::Stack* ss; + Thread* masterThread; Depth depth; Value beta; int nodeType; - int master; - Move threatMove; + bool cutNode; // Const pointers to shared data - MovePicker* mp; - SplitPoint* parent; - - - // Shared data - Lock lock; - volatile uint64_t slavesMask; - volatile int64_t nodes; + MovePicker* movePicker; + SplitPoint* parentSplitPoint; + + // Shared variable data + Mutex mutex; + std::bitset slavesMask; + int slavesCount; + volatile bool allSlavesSearching; + volatile uint64_t nodes; volatile Value alpha; volatile Value bestValue; volatile Move bestMove; @@ -60,90 +96,93 @@ struct SplitPoint { }; +/// ThreadBase struct is the base of the hierarchy from where we derive all the +/// specialized thread classes. + +struct ThreadBase { + + ThreadBase() : handle(NativeHandle()), exit(false) {} + virtual ~ThreadBase() {} + virtual void idle_loop() = 0; + void notify_one(); + void wait_for(volatile const bool& b); + + 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. -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) (); +struct Thread : public ThreadBase { -public: - Thread(Fn fn); - ~Thread(); - - void wake_up(); + Thread(); + virtual void idle_loop(); bool cutoff_occurred() const; - bool is_available_to(int 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(); + bool available_to(const Thread* master) const; + + void split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove, + Depth depth, int moveCount, MovePicker* movePicker, int nodeType, bool cutNode); SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD]; - MaterialInfoTable materialTable; - PawnInfoTable pawnTable; - int threadID; + Pawns::Table pawnsTable; + Material::Table materialTable; + Endgames endgames; + Position* activePosition; + size_t 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; + SplitPoint* volatile activeSplitPoint; + volatile int splitPointsSize; + volatile bool searching; +}; + + +/// MainThread and TimerThread are derived classes used to characterize 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 ThreadBase { + + static const int Resolution = 5; // Millisec between two check_time() calls + + TimerThread() : run(false) {} + virtual void idle_loop(); + + bool run; }; -/// ThreadsManager class handles all the threads related stuff like init, starting, -/// parking and, the most important, launching a slave thread at a split point. +/// ThreadPool struct handles all the threads related stuff like init, starting, +/// parking and, most importantly, 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 stuff 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(); } - - void wake_up() const; - void sleep() const; +struct ThreadPool : public std::vector { + + void init(); // No c'tor and d'tor, threads rely on globals that should be + void exit(); // initialized and are valid during the whole thread lifetime. + + MainThread* main() { return static_cast(at(0)); } void read_uci_options(); - bool available_slave_exists(int master) const; - void set_timer(int msec); - void stop_thinking(); - void start_thinking(const Position& pos, const Search::LimitsType& limits, - const std::set& = std::set(), bool async = false); - - 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); -private: - friend class Thread; + Thread* available_slave(const Thread* master) const; + void wait_for_think_finished(); + void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&); - std::vector threads; - Thread* timer; - Lock splitLock; - WaitCondition sleepCond; Depth minimumSplitDepth; - int maxThreadsPerSplitPoint; - bool useSleepingThreads; + Mutex mutex; + ConditionVariable sleepCondition; + TimerThread* timer; }; -extern ThreadsManager Threads; +extern ThreadPool Threads; -#endif // !defined(THREAD_H_INCLUDED) +#endif // #ifndef THREAD_H_INCLUDED