X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=f69012aeb0a3053130b85abada02704b7781d531;hp=46ce03aa318c07ea1d66a29a6439b886d4e496c0;hb=27c5cb59127101d834636d4faa0062d4e7bd05ce;hpb=d58176bfead421088bb3543b3cb6d1c359a3c91b

diff --git a/src/thread.h b/src/thread.h
index 46ce03aa..fd7343a8 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) 2008-2010 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
@@ -17,125 +17,107 @@
   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 <bitset>
+#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];
+
+/// ThreadBase struct is the base of the hierarchy from where we derive all the
+/// specialized thread classes.
+
+struct ThreadBase : public std::thread {
+
+  ThreadBase() { exit = false; }
+  virtual ~ThreadBase() = default;
+  virtual void idle_loop() = 0;
+  void notify_one();
+  void wait(std::atomic<bool>& b);
+  void wait_while(std::atomic<bool>& b);
+
+  Mutex mutex;
+  ConditionVariable sleepCondition;
+  std::atomic<bool> exit;
 };
 
 
-/// 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.
+/// 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.
 
-struct Thread {
+struct Thread : public ThreadBase {
 
-  void wake_up();
-  bool cutoff_occurred() const;
-  bool is_available_to(int master) const;
-  void idle_loop(SplitPoint* sp);
-  void listener_loop();
-  void timer_loop();
+  Thread();
+  virtual void idle_loop();
+  void search(bool isMainThread = false);
 
-  SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
-  MaterialInfoTable materialTable;
-  PawnInfoTable pawnTable;
-  int threadID;
+  Pawns::Table pawnsTable;
+  Material::Table materialTable;
+  Endgames endgames;
+  size_t idx, PVIdx;
   int maxPly;
-  Lock sleepLock;
-  WaitCondition sleepCond;
-  SplitPoint* volatile splitPoint;
-  volatile int activeSplitPoints;
-  volatile bool is_searching;
-  volatile bool do_sleep;
-  volatile bool do_terminate;
-
-#if defined(_MSC_VER)
-  HANDLE handle;
-#else
-  pthread_t handle;
-#endif
+  std::atomic<bool> searching;
+
+  Position rootPos;
+  Search::RootMoveVector rootMoves;
+  Depth rootDepth;
+  HistoryStats history;
+  MovesStats counterMoves;
+  Depth completedDepth;
+};
+
+
+/// MainThread and TimerThread are derived classes used to characterize the two
+/// special threads: the main one and the recurring timer.
+
+struct MainThread : public Thread {
+  MainThread() { thinking = true; } // Avoid a race with start_thinking()
+  virtual void idle_loop();
+  void join();
+  void think();
+  std::atomic<bool> thinking;
+};
+
+struct TimerThread : public ThreadBase {
+
+  static const int Resolution = 5; // Millisec between two check_time() calls
+
+  virtual void idle_loop();
+  void check_time();
+
+  bool run = false;
 };
 
 
-/// 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 shared thread 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();
+struct ThreadPool : public std::vector<Thread*> {
 
-  bool use_sleeping_threads() const { return useSleepingThreads; }
-  int min_split_depth() const { return minimumSplitDepth; }
-  int size() const { return activeThreads; }
+  void init(); // No constructor and destructor, threads rely on globals that should 
+  void exit(); // be initialized and valid during the whole thread lifetime.
 
-  void set_size(int cnt);
+  MainThread* main() { return static_cast<MainThread*>(at(0)); }
   void read_uci_options();
-  bool available_slave_exists(int master) const;
-
-  void getline(std::string& cmd);
-  void start_listener();
-  void stop_listener();
-  void set_timer(int msec);
-
-  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:
-  friend struct Thread;
-
-  Thread threads[MAX_THREADS + 2]; // Last 2 are the listener and the timer
-  Lock threadsLock;
-  Depth minimumSplitDepth;
-  int maxThreadsPerSplitPoint;
-  int activeThreads;
-  bool useSleepingThreads;
-  WaitCondition sleepCond;
-  std::string inputLine;
+  void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
+  int64_t nodes_searched();
+  TimerThread* timer;
 };
 
-extern ThreadsManager Threads;
+extern ThreadPool Threads;
 
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED