X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=215b27c688b2823b11112a56e862645cd7c726d0;hp=92f5ed33a168b9742c176055759b01cb78c2c6e7;hb=26dabb1e6bcd8035f0f3516c4358a73f2b041a1c;hpb=a3a0df92a3ed5ce7c98ff596e687d3d6533590c8 diff --git a/src/thread.h b/src/thread.h index 92f5ed33..215b27c6 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) 2008-2013 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 @@ -20,6 +20,11 @@ #ifndef THREAD_H_INCLUDED #define THREAD_H_INCLUDED +#include +#include +#include +#include +#include #include #include "material.h" @@ -27,57 +32,52 @@ #include "pawns.h" #include "position.h" #include "search.h" +#include "thread_win32.h" -const int MAX_THREADS = 64; // Because SplitPoint::slavesMask is a uint64_t -const int MAX_SPLITPOINTS_PER_THREAD = 8; +struct Thread; -struct Mutex { - Mutex() { lock_init(l); } - ~Mutex() { lock_destroy(l); } +const size_t MAX_THREADS = 128; +const size_t MAX_SPLITPOINTS_PER_THREAD = 8; +const size_t MAX_SLAVES_PER_SPLITPOINT = 4; - void lock() { lock_grab(l); } - void unlock() { lock_release(l); } +class Spinlock { -private: - friend struct ConditionVariable; + std::atomic_int lock; - Lock l; +public: + Spinlock() { lock = 1; } // Init here to workaround a bug with MSVC 2013 + void acquire() { + while (lock.fetch_sub(1, std::memory_order_acquire) != 1) + for (int cnt = 0; lock.load(std::memory_order_relaxed) <= 0; ++cnt) + if (cnt >= 10000) std::this_thread::yield(); // Be nice to hyperthreading + } + void release() { lock.store(1, std::memory_order_release); } }; -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; -}; - -struct Thread; +/// 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; - Thread* masterThread; + Search::Stack* ss; + Thread* master; Depth depth; Value beta; int nodeType; - Move threatMove; bool cutNode; // Const pointers to shared data MovePicker* movePicker; SplitPoint* parentSplitPoint; - // Shared data - Mutex mutex; - volatile uint64_t slavesMask; - volatile int64_t nodes; + // Shared variable data + Spinlock spinlock; + std::bitset slavesMask; + volatile bool allSlavesSearching; + volatile uint64_t nodes; volatile Value alpha; volatile Value bestValue; volatile Move bestMove; @@ -91,16 +91,16 @@ struct SplitPoint { struct ThreadBase { - ThreadBase() : exit(false) {} - virtual ~ThreadBase() {} + virtual ~ThreadBase() = default; virtual void idle_loop() = 0; void notify_one(); void wait_for(volatile const bool& b); + std::thread nativeThread; Mutex mutex; + Spinlock spinlock; ConditionVariable sleepCondition; - NativeHandle handle; - volatile bool exit; + volatile bool exit = false; }; @@ -114,21 +114,20 @@ struct Thread : public ThreadBase { Thread(); virtual void idle_loop(); bool cutoff_occurred() const; - bool available_to(const Thread* master) const; + bool can_join(const SplitPoint* sp) const; - template - void split(Position& pos, const Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove, - Depth depth, Move threatMove, int moveCount, MovePicker* movePicker, int nodeType, bool cutNode); + 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]; + Pawns::Table pawnsTable; Material::Table materialTable; Endgames endgames; - Pawns::Table pawnsTable; Position* activePosition; size_t idx; int maxPly; SplitPoint* volatile activeSplitPoint; - volatile int splitPointsSize; + volatile size_t splitPointsSize; volatile bool searching; }; @@ -137,40 +136,36 @@ struct Thread : public ThreadBase { /// 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; + void join(); + volatile bool thinking = true; // Avoid a race with start_thinking() }; struct TimerThread : public ThreadBase { - TimerThread() : run(false) {} + + static const int Resolution = 5; // Millisec between two check_time() calls + virtual void idle_loop(); - bool run; - static const int Resolution = 5; // msec between two check_time() calls + + bool run = false; }; /// ThreadPool struct handles all the threads related stuff like init, starting, -/// parking and, the most important, launching a slave thread at a split point. +/// parking and, most importantly, launching a slave thread at a split point. /// All the access to shared thread data is done through this class. struct ThreadPool : public std::vector { - 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. + 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((*this)[0]); } + MainThread* main() { return static_cast(at(0)); } void read_uci_options(); - Thread* available_slave(const Thread* master) const; - void wait_for_think_finished(); - void start_thinking(const Position&, const Search::LimitsType&, - const std::vector&, Search::StateStackPtr&); + Thread* available_slave(const SplitPoint* sp) const; + void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&); - bool sleepWhileIdle; Depth minimumSplitDepth; - size_t maxThreadsPerSplitPoint; - Mutex mutex; - ConditionVariable sleepCondition; TimerThread* timer; };