/*
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
#ifndef THREAD_H_INCLUDED
#define THREAD_H_INCLUDED
+#include <atomic>
+#include <bitset>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
#include <vector>
#include "material.h"
#include "pawns.h"
#include "position.h"
#include "search.h"
-
-const int MAX_THREADS = 64; // Because SplitPoint::slavesMask is a uint64_t
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
-
-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;
-};
-
-struct Thread;
-
-struct SplitPoint {
-
- // Const data after split point has been setup
- const Position* pos;
- const Search::Stack* ss;
- Thread* masterThread;
- 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;
- 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.
-struct ThreadBase {
+struct ThreadBase : public std::thread {
- ThreadBase() : exit(false) {}
- virtual ~ThreadBase() {}
+ ThreadBase() { exit = false; }
+ virtual ~ThreadBase() = default;
virtual void idle_loop() = 0;
void notify_one();
- void wait_for(volatile const bool& b);
+ void wait(std::atomic<bool>& b);
+ void wait_while(std::atomic<bool>& b);
Mutex mutex;
ConditionVariable sleepCondition;
- NativeHandle handle;
- volatile bool exit;
+ std::atomic<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
+/// Thread struct keeps together all the thread related stuff like locks, state,
+/// history and countermoves tables. 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.
Thread();
virtual void idle_loop();
- bool cutoff_occurred() const;
- bool available_to(const Thread* master) const;
-
- template <bool Fake>
- 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 search(bool isMainThread = false);
- SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
+ Pawns::Table pawnsTable;
Material::Table materialTable;
Endgames endgames;
- Pawns::Table pawnsTable;
- Position* activePosition;
- size_t idx;
+ size_t idx, PVIdx;
int maxPly;
- SplitPoint* volatile activeSplitPoint;
- volatile int splitPointsSize;
- volatile bool searching;
+ std::atomic<bool> searching;
+
+ Position rootPos;
+ Search::RootMoveVector rootMoves;
+ Depth rootDepth;
+ HistoryStats history;
+ MovesStats counterMoves;
+ Depth completedDepth;
};
/// special threads: the main one and the recurring timer.
struct MainThread : public Thread {
- MainThread() : thinking(true) {} // Avoid a race with start_thinking()
+ MainThread() { thinking = true; } // Avoid a race with start_thinking()
virtual void idle_loop();
- volatile bool thinking;
+ void join();
+ void think();
+ std::atomic<bool> thinking;
};
struct TimerThread : public ThreadBase {
- TimerThread() : msec(0) {}
+
+ static const int Resolution = 5; // Millisec between two check_time() calls
+
virtual void idle_loop();
- int msec;
+ void check_time();
+
+ 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 thread.
/// All the access to shared thread 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
+ 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*>((*this)[0]); }
+ MainThread* main() { return static_cast<MainThread*>(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<Move>&, Search::StateStackPtr&);
-
- bool sleepWhileIdle;
- Depth minimumSplitDepth;
- size_t maxThreadsPerSplitPoint;
- Mutex mutex;
- ConditionVariable sleepCondition;
+ void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
+ int64_t nodes_searched();
TimerThread* timer;
};
projects / stockfish / blobdiff