/*
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) 2008-2015 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#if !defined(THREAD_H_INCLUDED)
+#ifndef THREAD_H_INCLUDED
#define THREAD_H_INCLUDED
-#include <cstring>
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+#include <vector>
-#include "lock.h"
#include "material.h"
#include "movepick.h"
#include "pawns.h"
#include "position.h"
+#include "search.h"
+#include "thread_win32.h"
-const int MAX_THREADS = 32;
-const int MAX_ACTIVE_SPLIT_POINTS = 8;
-
-struct SplitPoint {
-
- // Const data after splitPoint has been setup
- SplitPoint* parent;
- const Position* pos;
- Depth depth;
- Value beta;
- int nodeType;
- int ply;
- int master;
- Move threatMove;
-
- // Const pointers to shared data
- MovePicker* mp;
- SearchStack* ss;
-
- // Shared data
- Lock lock;
- volatile int64_t nodes;
- volatile Value alpha;
- volatile Value bestValue;
- volatile int moveCount;
- volatile bool is_betaCutoff;
- volatile bool is_slave[MAX_THREADS];
-};
+/// 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.
+
+class Thread {
-/// Thread struct is used to keep 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.
+ std::thread nativeThread;
+ Mutex mutex;
+ ConditionVariable sleepCondition;
+ bool exit, searching;
+
+public:
+ Thread();
+ 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);
+
+ Pawns::Table pawnsTable;
+ Material::Table materialTable;
+ Endgames endgames;
+ size_t idx, PVIdx;
+ int maxPly;
+ std::atomic<uint64_t> nodes, tbHits;
+
+ Position rootPos;
+ Search::RootMoves rootMoves;
+ Depth rootDepth;
+ Depth completedDepth;
+ CounterMoveStat counterMoves;
+ ButterflyHistory history;
+ CounterMoveHistoryStat counterMoveHistory;
+};
-struct Thread {
- enum ThreadState
- {
- INITIALIZING, // Thread is initializing itself
- SEARCHING, // Thread is performing work
- AVAILABLE, // Thread is waiting for work
- WORKISWAITING, // Master has ordered us to start searching
- TERMINATED // We are quitting and thread is terminated
- };
+/// MainThread is a derived class with a specific overload for the main thread
- void wake_up();
- bool cutoff_occurred() const;
- bool is_available_to(int master) const;
+struct MainThread : public Thread {
+ virtual void search();
+ void check_time();
- SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
- MaterialInfoTable materialTable;
- PawnInfoTable pawnTable;
- int maxPly;
- Lock sleepLock;
- WaitCondition sleepCond;
- volatile ThreadState state;
- SplitPoint* volatile splitPoint;
- volatile int activeSplitPoints;
+ bool easyMovePlayed, failedLow;
+ double bestMoveChanges;
+ Value previousScore;
+ int callsCnt = 0;
};
-/// ThreadsManager class is used to handle 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.
+/// 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.
-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:
- Thread& operator[](int threadID) { return threads[threadID]; }
- void init();
- void exit();
- void init_hash_tables();
+struct ThreadPool : public std::vector<Thread*> {
- int min_split_depth() const { return minimumSplitDepth; }
- int size() const { return activeThreads; }
- void set_size(int cnt) { activeThreads = cnt; }
+ 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();
- bool available_slave_exists(int master) const;
- void idle_loop(int threadID, SplitPoint* sp);
+ uint64_t nodes_searched() const;
+ uint64_t tb_hits() const;
- template <bool Fake>
- Value split(Position& pos, SearchStack* ss, Value alpha, Value beta, Value bestValue,
- Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
private:
- Thread threads[MAX_THREADS];
- Lock threadsLock;
- Depth minimumSplitDepth;
- int maxThreadsPerSplitPoint;
- int activeThreads;
- bool useSleepingThreads;
- volatile bool allThreadsShouldExit;
+ StateListPtr setupStates;
};
-extern ThreadsManager Threads;
+extern ThreadPool Threads;
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED