X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fthread.h;h=3f902dc17b794a35250f87759e932dd9f0607bd4;hb=21120288a385cb2eabb9d32f6dc6007a03adf382;hp=14924bf2280662be82523e81e94d09a7136d1c16;hpb=093dd8fe88d278db6cd5c956a771a45a295e1de3;p=stockfish

diff --git a/src/thread.h b/src/thread.h
index 14924bf2..3f902dc1 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) 2008-2009 Marco Costalba
+  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
@@ -17,70 +17,141 @@
   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 <bitset>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+#include <vector>
 
-////
-//// Includes
-////
-
-#include <cstring>
-
-#include "lock.h"
+#include "material.h"
 #include "movepick.h"
+#include "pawns.h"
 #include "position.h"
 #include "search.h"
 
+struct Thread;
 
-////
-//// Constants and variables
-////
-
-const int THREAD_MAX = 8;
-const int ACTIVE_SPLIT_POINTS_MAX = 8;
+const int MAX_THREADS = 128;
+const int MAX_SPLITPOINTS_PER_THREAD = 8;
 
-
-////
-//// Types
-////
+/// SplitPoint struct stores information shared by the threads searching in
+/// parallel below the same split point. It is populated at splitting time.
 
 struct SplitPoint {
-  SplitPoint *parent;
+
+  // Const data after split point has been setup
   const Position* pos;
-  SearchStack sstack[THREAD_MAX][PLY_MAX_PLUS_2];
-  SearchStack *parentSstack;
-  int ply;
+  Search::Stack* ss;
+  Thread* masterThread;
   Depth depth;
-  volatile Value alpha, beta, bestValue;
-  Value futilityValue;
-  bool pvNode;
-  int master, slaves[THREAD_MAX];
-  Lock lock;
-  MovePicker *mp;
-  volatile int moves;
-  volatile int cpus;
-  bool finished;
+  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;
+};
+
+
+/// ThreadBase struct is the base of the hierarchy from where we derive all the
+/// specialized thread classes.
+
+struct ThreadBase {
+
+  virtual ~ThreadBase() = default;
+  virtual void idle_loop() = 0;
+  void notify_one();
+  void wait_for(volatile const bool& b);
+
+  std::thread nativeThread;
+  std::mutex mutex;
+  std::condition_variable sleepCondition;
+  volatile bool exit = false;
+};
+
+
+/// 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);
+
+  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;
+};
+
+
+/// MainThread and TimerThread are derived classes used to characterize the two
+/// special threads: the main one and the recurring timer.
+
+struct MainThread : public Thread {
+  virtual void idle_loop();
+  volatile bool thinking = true; // Avoid a race with start_thinking()
 };
 
+struct TimerThread : public ThreadBase {
+
+  static const int Resolution = 5; // Millisec between two check_time() calls
+
+  virtual void idle_loop();
+
+  bool run = false;
+};
+
+
+/// 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.
+
+struct ThreadPool : public std::vector<Thread*> {
 
-struct 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.
 
-  Thread() { memset(this, 0, sizeof(Thread)); }
+  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&, Search::StateStackPtr&);
 
-  SplitPoint *splitPoint;
-  volatile int activeSplitPoints;
-  uint64_t nodes;
-  uint64_t betaCutOffs[2];
-  volatile bool stop;
-  volatile bool running;
-  volatile bool idle;
-  volatile bool sleeping;
-  volatile bool workIsWaiting;
-  volatile bool printCurrentLine;
-  unsigned char pad[64]; // set some distance among local data for each thread
+  Depth minimumSplitDepth;
+  std::mutex mutex;
+  std::condition_variable sleepCondition;
+  TimerThread* timer;
 };
 
+extern ThreadPool Threads;
 
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED