X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=41d2b8f6d271769df032888d7c633bb7c20a6581;hp=f530913cf22017f21fa49a2ca812dc6861b5439c;hb=b8c00efa2767ebf74545d2ba4bd344ef7c963319;hpb=5fd5453e594ee6cadf4a3c502bc53d28cfe5aa8b diff --git a/src/thread.h b/src/thread.h index f530913c..41d2b8f6 100644 --- a/src/thread.h +++ b/src/thread.h @@ -2,6 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, 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 @@ -20,7 +21,10 @@ #ifndef THREAD_H_INCLUDED #define THREAD_H_INCLUDED -#include +#include +#include +#include +#include #include #include "material.h" @@ -28,158 +32,96 @@ #include "pawns.h" #include "position.h" #include "search.h" +#include "thread_win32_osx.h" -struct Thread; -const size_t MAX_THREADS = 128; -const size_t MAX_SPLITPOINTS_PER_THREAD = 8; -const size_t MAX_SLAVES_PER_SPLITPOINT = 4; +/// Thread class keeps together all the thread-related stuff. 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. -/// Mutex and ConditionVariable struct are wrappers of the low level locking -/// machinery and are modeled after the corresponding C++11 classes. +class Thread { -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; - Search::Stack* ss; - Thread* master; - Depth depth; - Value beta; - int nodeType; - bool cutNode; - - // Const pointers to shared data - MovePicker* movePicker; - SplitPoint* parentSplitPoint; - - // Shared variable data - Mutex mutex; - std::bitset slavesMask; - volatile bool allSlavesSearching; - volatile uint64_t nodes; - volatile Value alpha; - volatile Value bestValue; - volatile Move bestMove; - volatile int moveCount; - volatile bool cutoff; -}; - - -/// 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. - -struct Thread : public ThreadBase { - - Thread(); - virtual void idle_loop(); - bool cutoff_occurred() const; - 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); + std::mutex mutex; + std::condition_variable cv; + size_t idx; + bool exit = false, searching = true; // Set before starting std::thread + NativeThread stdThread; + +public: + explicit Thread(size_t); + virtual ~Thread(); + virtual void search(); + void clear(); + void idle_loop(); + void start_searching(); + void wait_for_search_finished(); + int best_move_count(Move move) const; - SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD]; Pawns::Table pawnsTable; Material::Table materialTable; - Endgames endgames; - Position* activePosition; - size_t idx; - int maxPly; - SplitPoint* volatile activeSplitPoint; - volatile size_t splitPointsSize; - volatile bool searching; + size_t pvIdx, pvLast; + uint64_t ttHitAverage; + int selDepth, nmpMinPly; + Color nmpColor; + std::atomic nodes, tbHits, bestMoveChanges; + + Position rootPos; + Search::RootMoves rootMoves; + Depth rootDepth, completedDepth; + CounterMoveHistory counterMoves; + ButterflyHistory mainHistory; + LowPlyHistory lowPlyHistory; + CapturePieceToHistory captureHistory; + ContinuationHistory continuationHistory[2][2]; + Score contempt; }; -/// MainThread and TimerThread are derived classes used to characterize the two -/// special threads: the main one and the recurring timer. +/// MainThread is a derived class specific for main thread 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 + using Thread::Thread; - TimerThread() : run(false) {} - virtual void idle_loop(); + void search() override; + void check_time(); - bool run; + double previousTimeReduction; + Value previousScore; + Value iterValue[4]; + int callsCnt; + bool stopOnPonderhit; + std::atomic_bool ponder; }; -/// 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. +/// ThreadPool struct handles all the threads-related stuff like init, starting, +/// parking and, most importantly, launching a thread. All the access to threads +/// is done through this class. 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. + void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false); + void clear(); + void set(size_t); + + MainThread* main() const { return static_cast(front()); } + uint64_t nodes_searched() const { return accumulate(&Thread::nodes); } + uint64_t tb_hits() const { return accumulate(&Thread::tbHits); } + + std::atomic_bool stop, increaseDepth; + +private: + StateListPtr setupStates; - 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&, Search::StateStackPtr&); + uint64_t accumulate(std::atomic Thread::* member) const { - Depth minimumSplitDepth; - Mutex mutex; - ConditionVariable sleepCondition; - TimerThread* timer; + uint64_t sum = 0; + for (Thread* th : *this) + sum += (th->*member).load(std::memory_order_relaxed); + return sum; + } }; extern ThreadPool Threads;