X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fthread.h;h=8f930149f333e764d3525fc9d93fd8f4dba3798b;hb=e5da0e4b79b405da5bdc42f6fb4c2ba49afba00a;hp=231443dbba0d9f9c521b085ec2837c20587b2973;hpb=4b59347194f027e597040cb0c35835c688408e18;p=stockfish

diff --git a/src/thread.h b/src/thread.h
index 231443db..8f930149 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -40,6 +40,19 @@ const size_t MAX_THREADS = 128;
 const size_t MAX_SPLITPOINTS_PER_THREAD = 8;
 const size_t MAX_SLAVES_PER_SPLITPOINT = 4;
 
+class Spinlock {
+  std::atomic_int _lock;
+
+public:
+  Spinlock() { _lock = 1; } // Init here to workaround a bug with MSVC 2013
+  void lock() {
+      while (_lock.fetch_sub(1, std::memory_order_acquire) != 1)
+          for (int cnt = 0; _lock.load(std::memory_order_relaxed) <= 0; ++cnt)
+              if (cnt >= 10000) std::this_thread::yield(); // Be nice to hyperthreading
+  }
+  void unlock() { _lock.store(1, std::memory_order_release); }
+};
+
 
 /// SplitPoint struct stores information shared by the threads searching in
 /// parallel below the same split point. It is populated at splitting time.
@@ -60,7 +73,7 @@ struct SplitPoint {
   SplitPoint* parentSplitPoint;
 
   // Shared variable data
-  Mutex mutex;
+  Spinlock mutex;
   std::bitset<MAX_THREADS> slavesMask;
   volatile bool allSlavesSearching;
   volatile uint64_t nodes;
@@ -114,6 +127,7 @@ struct Thread : public ThreadBase {
   SplitPoint* volatile activeSplitPoint;
   volatile size_t splitPointsSize;
   volatile bool searching;
+  Spinlock allocMutex;
 };
 
 
@@ -151,7 +165,6 @@ struct ThreadPool : public std::vector<Thread*> {
   void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
 
   Depth minimumSplitDepth;
-  Mutex mutex;
   ConditionVariable sleepCondition;
   TimerThread* timer;
 };