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) 2015-2017 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
#ifndef THREAD_H_INCLUDED
#define THREAD_H_INCLUDED
-#include <bitset>
+#include <atomic>
#include <condition_variable>
#include <mutex>
#include <thread>
#include "pawns.h"
#include "position.h"
#include "search.h"
-
-struct Thread;
-
-const int MAX_THREADS = 128;
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
-
-/// 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* masterThread;
- Depth depth;
- Value beta;
- int nodeType;
- bool cutNode;
-
- // Const pointers to shared data
- MovePicker* movePicker;
- SplitPoint* parentSplitPoint;
-
- // Shared variable data
- std::mutex mutex;
- std::bitset<MAX_THREADS> slavesMask;
- volatile bool allSlavesSearching;
- volatile uint64_t nodes;
- volatile Value alpha;
- volatile Value bestValue;
- volatile Move bestMove;
- volatile int moveCount;
- volatile bool cutoff;
-};
+#include "thread_win32.h"
-/// ThreadBase struct is the base of the hierarchy from where we derive all the
-/// specialized thread classes.
+/// Thread struct keeps together all the thread-related stuff. 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 ThreadBase {
-
- ThreadBase() : exit(false) {}
- virtual ~ThreadBase() {}
- virtual void idle_loop() = 0;
- void notify_one();
- void wait_for(volatile const bool& b);
+class Thread {
std::thread nativeThread;
- std::mutex mutex;
- std::condition_variable sleepCondition;
- 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 {
+ Mutex mutex;
+ ConditionVariable sleepCondition;
+ bool exit, searching;
+public:
Thread();
- virtual void idle_loop();
- bool cutoff_occurred() const;
- bool available_to(const Thread* master) const;
+ virtual ~Thread();
+ virtual void search();
+ void idle_loop();
+ void start_searching(bool resume = false);
+ void wait_for_search_finished();
+ void wait(std::atomic_bool& condition);
- 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;
- Position* activePosition;
- size_t idx;
- int maxPly;
- SplitPoint* volatile activeSplitPoint;
- volatile int splitPointsSize;
- volatile bool searching;
+ size_t idx, PVIdx;
+ int maxPly, callsCnt;
+ uint64_t tbHits;
+
+ Position rootPos;
+ Search::RootMoves rootMoves;
+ Depth rootDepth;
+ Depth completedDepth;
+ std::atomic_bool resetCalls;
+ CounterMoveStat counterMoves;
+ ButterflyHistory history;
+ CounterMoveHistoryStat counterMoveHistory;
};
-/// 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 with a specific overload for the 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 {
+ virtual void search();
- static const int Resolution = 5; // Millisec between two check_time() calls
-
- TimerThread() : run(false) {}
- virtual void idle_loop();
-
- bool run;
+ bool easyMovePlayed, failedLow;
+ double bestMoveChanges;
+ Value previousScore;
};
-/// 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
+/// data is done through this class.
struct ThreadPool : public std::vector<Thread*> {
- 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 init(); // No constructor and destructor, threads rely on globals that should
+ void exit(); // be initialized and valid during the whole thread lifetime.
MainThread* main() { return static_cast<MainThread*>(at(0)); }
+ void start_thinking(Position&, StateListPtr&, const Search::LimitsType&);
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&);
-
- Depth minimumSplitDepth;
- std::mutex mutex;
- std::condition_variable sleepCondition;
- TimerThread* timer;
+ uint64_t nodes_searched() const;
+ uint64_t tb_hits() const;
+
+private:
+ StateListPtr setupStates;
};
extern ThreadPool Threads;
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