X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=fd7343a8f57a1d9d2bc0f1c40f27c94ad1148098;hp=92be3a22985572303fae5c669386daf25a6919a8;hb=27c5cb59127101d834636d4faa0062d4e7bd05ce;hpb=89a89eb60535a72139730ecd60b6e1257db269d4

diff --git a/src/thread.h b/src/thread.h
index 92be3a22..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) 2008-2012 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
@@ -17,9 +17,14 @@
   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 <atomic>
+#include <bitset>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
 #include <vector>
 
 #include "material.h"
@@ -27,145 +32,92 @@
 #include "pawns.h"
 #include "position.h"
 #include "search.h"
+#include "thread_win32.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); }
+/// ThreadBase struct is the base of the hierarchy from where we derive all the
+/// specialized thread classes.
 
-  void lock() { lock_grab(l); }
-  void unlock() { lock_release(l); }
+struct ThreadBase : public std::thread {
 
-private:
-  friend struct ConditionVariable;
+  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);
 
-  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;
+  Mutex mutex;
+  ConditionVariable sleepCondition;
+  std::atomic<bool> exit;
 };
 
-class Thread;
 
-struct SplitPoint {
+/// 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.
 
-  // Const data after split point has been setup
-  const Position* pos;
-  const Search::Stack* ss;
-  Depth depth;
-  Value beta;
-  int nodeType;
-  Thread* master;
-  Move threatMove;
+struct Thread : public ThreadBase {
 
-  // Const pointers to shared data
-  MovePicker* mp;
-  SplitPoint* parent;
+  Thread();
+  virtual void idle_loop();
+  void search(bool isMainThread = false);
 
-  // Shared data
-  Mutex mutex;
-  Position* activePositions[MAX_THREADS];
-  volatile uint64_t slavesMask;
-  volatile int64_t nodes;
-  volatile Value alpha;
-  volatile Value bestValue;
-  volatile Move bestMove;
-  volatile int moveCount;
-  volatile bool cutoff;
+  Pawns::Table pawnsTable;
+  Material::Table materialTable;
+  Endgames endgames;
+  size_t idx, PVIdx;
+  int maxPly;
+  std::atomic<bool> searching;
+
+  Position rootPos;
+  Search::RootMoveVector rootMoves;
+  Depth rootDepth;
+  HistoryStats history;
+  MovesStats counterMoves;
+  Depth completedDepth;
 };
 
 
-/// 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.
+/// MainThread and TimerThread are derived classes used to characterize the two
+/// special threads: the main one and the recurring timer.
 
-class Thread {
+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;
+};
 
-  typedef void (Thread::* Fn) (); // Pointer to member function
+struct TimerThread : public ThreadBase {
 
-public:
-  Thread(Fn fn);
- ~Thread();
+  static const int Resolution = 5; // Millisec between two check_time() calls
 
-  void wake_up();
-  bool cutoff_occurred() const;
-  bool is_available_to(Thread* master) const;
-  void idle_loop();
-  void main_loop();
-  void timer_loop();
-  void wait_for_stop();
+  virtual void idle_loop();
+  void check_time();
 
-  SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
-  Material::Table materialTable;
-  Endgames endgames;
-  Pawns::Table pawnsTable;
-  size_t idx;
-  int maxPly;
-  Mutex mutex;
-  ConditionVariable sleepCondition;
-  NativeHandle handle;
-  Fn start_fn;
-  SplitPoint* volatile curSplitPoint;
-  volatile int splitPointsCnt;
-  volatile bool is_searching;
-  volatile bool do_sleep;
-  volatile bool do_exit;
+  bool run = false;
 };
 
 
-/// ThreadPool class handles all the threads related stuff like init, starting,
-/// parking and, the most important, launching a slave thread at a split point.
+/// 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 ThreadPool {
+struct ThreadPool : public std::vector<Thread*> {
 
-public:
-  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.
 
-  Thread& operator[](size_t id) { return *threads[id]; }
-  bool use_sleeping_threads() const { return useSleepingThreads; }
-  int min_split_depth() const { return minimumSplitDepth; }
-  size_t size() const { return threads.size(); }
-  Thread* main_thread() { return threads[0]; }
-
-  void wake_up() const;
-  void sleep() const;
+  MainThread* main() { return static_cast<MainThread*>(at(0)); }
   void read_uci_options();
-  bool available_slave_exists(Thread* master) const;
-  void set_timer(int msec);
-  void wait_for_search_finished();
-  void start_searching(const Position&, const Search::LimitsType&,
-                       const std::vector<Move>&, Search::StateStackPtr&);
-
-  template <bool Fake>
-  Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
-              Depth depth, Move threatMove, int moveCount, MovePicker& mp, int nodeType);
-private:
-  friend class Thread;
-  friend void check_time();
-
-  std::vector<Thread*> threads;
-  Thread* timer;
-  Mutex mutex;
-  ConditionVariable sleepCondition;
-  Depth minimumSplitDepth;
-  int maxThreadsPerSplitPoint;
-  bool useSleepingThreads;
+  void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
+  int64_t nodes_searched();
+  TimerThread* timer;
 };
 
 extern ThreadPool Threads;
 
-#endif // !defined(THREAD_H_INCLUDED)
+#endif // #ifndef THREAD_H_INCLUDED