X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=34307297dead0fa04a8c21b30f3045d588076f5c;hp=f8e65941f0d6beefa96a95aecc6195117978cca5;hb=6fa6da3ee13d2b7bdbec3cd24ff8ca43233c74fb;hpb=38112060dc2da351c6dde8f12d0ee5cfaeac5084

diff --git a/src/thread.h b/src/thread.h
index f8e65941..34307297 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -39,18 +39,34 @@ const size_t MAX_THREADS = 128;
 const size_t MAX_SPLITPOINTS_PER_THREAD = 8;
 const size_t MAX_SLAVES_PER_SPLITPOINT = 4;
 
-/// Spinlock class wraps low level atomic operations to provide spin lock functionality
+#if 0
+/// Spinlock class wraps low level atomic operations to provide a spin lock
 
 class Spinlock {
 
-  std::atomic_flag lock;
+  std::atomic_int lock;
 
 public:
-  Spinlock() { std::atomic_flag_clear(&lock); }
-  void acquire() { while (lock.test_and_set(std::memory_order_acquire)) {} }
-  void release() { lock.clear(std::memory_order_release); }
+  Spinlock() { lock = 1; } // Init here to workaround a bug with MSVC 2013
+  void acquire() {
+    while (lock.fetch_sub(1, std::memory_order_acquire) != 1)
+        while (lock.load(std::memory_order_relaxed) <= 0) {}
+  }
+  void release() { lock.store(1, std::memory_order_release); }
 };
 
+#else
+
+class Spinlock {
+
+  std::mutex mutex;
+
+public:
+  void acquire() { mutex.lock(); }
+  void release() { mutex.unlock(); }
+};
+
+#endif
 
 /// SplitPoint struct stores information shared by the threads searching in
 /// parallel below the same split point. It is populated at splitting time.
@@ -110,7 +126,7 @@ struct Thread : public ThreadBase {
   Thread();
   virtual void idle_loop();
   bool cutoff_occurred() const;
-  bool available_to(const Thread* master) const;
+  bool can_join(const SplitPoint* sp) 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);
@@ -157,7 +173,7 @@ struct ThreadPool : public std::vector<Thread*> {
 
   MainThread* main() { return static_cast<MainThread*>(at(0)); }
   void read_uci_options();
-  Thread* available_slave(const Thread* master) const;
+  Thread* available_slave(const SplitPoint* sp) const;
   void wait_for_think_finished();
   void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);