X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fthread.h;h=d6a48eca73d14937f19212d462d9a120398d21d0;hb=HEAD;hp=64804d45e19f9b882010ff1a0751a53cc3fade31;hpb=8e71ee7ec6c1634af5d17f8ba43049f85ef42c53;p=stockfish

diff --git a/src/thread.h b/src/thread.h
index 64804d45..cb2f6db1 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -1,7 +1,6 @@
 /*
   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) 2004-2023 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,61 +16,120 @@
   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 <condition_variable>
+#include <cstddef>
+#include <cstdint>
+#include <mutex>
+#include <vector>
 
-#include "lock.h"
 #include "movepick.h"
 #include "position.h"
 #include "search.h"
+#include "thread_win32_osx.h"
+#include "types.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;
-  bool pvNode;
-  Value beta;
-  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 betaCutoff;
-  volatile int slaves[MAX_THREADS];
+namespace Stockfish {
+
+// Thread class keeps together all the thread-related stuff.
+class Thread {
+
+    std::mutex              mutex;
+    std::condition_variable cv;
+    size_t                  idx;
+    bool                    exit = false, searching = true;  // Set before starting std::thread
+    NativeThread            stdThread;
+
+   public:
+    explicit Thread(size_t);
+    virtual ~Thread();
+    virtual void search();
+    void         clear();
+    void         idle_loop();
+    void         start_searching();
+    void         wait_for_search_finished();
+    size_t       id() const { return idx; }
+
+    size_t                pvIdx, pvLast;
+    std::atomic<uint64_t> nodes, tbHits, bestMoveChanges;
+    int                   selDepth, nmpMinPly;
+    Value                 bestValue, optimism[COLOR_NB];
+
+    Position              rootPos;
+    StateInfo             rootState;
+    Search::RootMoves     rootMoves;
+    Depth                 rootDepth, completedDepth;
+    Value                 rootDelta;
+    Value                 rootSimpleEval;
+    CounterMoveHistory    counterMoves;
+    ButterflyHistory      mainHistory;
+    CapturePieceToHistory captureHistory;
+    ContinuationHistory   continuationHistory[2][2];
+    PawnHistory           pawnHistory;
 };
 
-// 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
+
+// MainThread is a derived class specific for main thread
+struct MainThread: public Thread {
+
+    using Thread::Thread;
+
+    void search() override;
+    void check_time();
+
+    double           previousTimeReduction;
+    Value            bestPreviousScore;
+    Value            bestPreviousAverageScore;
+    Value            iterValue[4];
+    int              callsCnt;
+    bool             stopOnPonderhit;
+    std::atomic_bool ponder;
 };
 
-struct Thread {
-  volatile ThreadState state;
-  SplitPoint* volatile splitPoint;
-  volatile int activeSplitPoints;
-  SplitPoint splitPoints[MAX_ACTIVE_SPLIT_POINTS];
+
+// ThreadPool struct handles all the threads-related stuff like init, starting,
+// parking and, most importantly, launching a thread. All the access to threads
+// is done through this class.
+struct ThreadPool {
+
+    void start_thinking(Position&, StateListPtr&, const Search::LimitsType&, bool = false);
+    void clear();
+    void set(size_t);
+
+    MainThread* main() const { return static_cast<MainThread*>(threads.front()); }
+    uint64_t    nodes_searched() const { return accumulate(&Thread::nodes); }
+    uint64_t    tb_hits() const { return accumulate(&Thread::tbHits); }
+    Thread*     get_best_thread() const;
+    void        start_searching();
+    void        wait_for_search_finished() const;
+
+    std::atomic_bool stop, increaseDepth;
+
+    auto cbegin() const noexcept { return threads.cbegin(); }
+    auto begin() noexcept { return threads.begin(); }
+    auto end() noexcept { return threads.end(); }
+    auto cend() const noexcept { return threads.cend(); }
+    auto size() const noexcept { return threads.size(); }
+    auto empty() const noexcept { return threads.empty(); }
+
+   private:
+    StateListPtr         setupStates;
+    std::vector<Thread*> threads;
+
+    uint64_t accumulate(std::atomic<uint64_t> Thread::*member) const {
+
+        uint64_t sum = 0;
+        for (Thread* th : threads)
+            sum += (th->*member).load(std::memory_order_relaxed);
+        return sum;
+    }
 };
 
-#endif // !defined(THREAD_H_INCLUDED)
+extern ThreadPool Threads;
+
+}  // namespace Stockfish
+
+#endif  // #ifndef THREAD_H_INCLUDED