X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=6817e20e53e78fb0d9be02d2031ab3439d10d13d;hp=372d4da362e50db09f6e317cf9912d90c825328d;hb=55bd27b8f08a151128d7065fa2819aa3e9605299;hpb=13d8231746686118f0175111c769b55f48a6592e

diff --git a/src/thread.h b/src/thread.h
index 372d4da3..6817e20e 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) 2008-2012 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
@@ -17,79 +17,154 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
 #if !defined(THREAD_H_INCLUDED)
 #define THREAD_H_INCLUDED
 
+#include <vector>
 
-////
-//// Includes
-////
-
-#include <cstring>
-
-#include "lock.h"
+#include "material.h"
 #include "movepick.h"
+#include "pawns.h"
 #include "position.h"
 #include "search.h"
 
+const int MAX_THREADS = 32;
+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;
 
-////
-//// Constants and variables
-////
+  Lock l;
+};
+
+struct ConditionVariable {
+  ConditionVariable() { cond_init(c); }
+ ~ConditionVariable() { cond_destroy(c); }
 
-const int MAX_THREADS = 8;
-const int MAX_ACTIVE_SPLIT_POINTS = 8;
+  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;
+};
 
-////
-//// Types
-////
+class Thread;
 
 struct SplitPoint {
 
-  // Const data after splitPoint has been setup
-  SplitPoint* parent;
+  // Const data after split point has been setup
   const Position* pos;
+  const Search::Stack* ss;
   Depth depth;
-  bool pvNode, mateThreat;
   Value beta;
-  int ply;
+  int nodeType;
+  Thread* master;
   Move threatMove;
-  SearchStack sstack[MAX_THREADS][PLY_MAX_PLUS_2];
 
   // Const pointers to shared data
   MovePicker* mp;
-  SearchStack* parentSstack;
+  SplitPoint* parent;
 
   // Shared data
-  Lock lock;
+  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 stopRequest;
-  volatile int slaves[MAX_THREADS];
+  volatile bool cutoff;
 };
 
-// ThreadState type is used to represent thread's current state
 
-enum ThreadState
-{
-  THREAD_INITIALIZING,  // thread is initializing itself
-  THREAD_SEARCHING,     // thread is performing work
-  THREAD_AVAILABLE,     // thread is waiting for work
-  THREAD_BOOKED,        // other thread (master) has booked us as a slave
-  THREAD_WORKISWAITING, // master has ordered us to start
-  THREAD_TERMINATED     // we are quitting and thread is terminated
+/// 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.
+
+class Thread {
+
+  typedef void (Thread::* Fn) (); // Pointer to member function
+
+public:
+  Thread(Fn fn);
+ ~Thread();
+
+  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_or_ponderhit();
+
+  SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
+  MaterialTable materialTable;
+  PawnTable pawnTable;
+  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;
 };
 
-struct Thread {
-  uint64_t nodes;
-  volatile ThreadState state;
-  SplitPoint* volatile splitPoint;
-  volatile int activeSplitPoints;
-  SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
+
+/// ThreadPool class handles 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.
+
+class ThreadPool {
+
+public:
+  void init(); // No c'tor and d'tor, 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;
+  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;
 };
 
+extern ThreadPool Threads;
 
 #endif // !defined(THREAD_H_INCLUDED)