X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=ee7fb061229e0288ce163eda0ac944bda6118cb6;hp=4d70bf2fbd038a9da98971c04c1bada7ba523743;hb=be77406a55d1840862237cffe153dc08a83108d3;hpb=81c7975dcdf37ec96d308f800c2a40f6cb08907e

diff --git a/src/thread.h b/src/thread.h
index 4d70bf2f..ee7fb061 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -40,6 +40,20 @@ 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 acquire() {
+      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 release() { 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 +74,7 @@ struct SplitPoint {
   SplitPoint* parentSplitPoint;
 
   // Shared variable data
-  Mutex mutex;
+  Spinlock spinlock;
   std::bitset<MAX_THREADS> slavesMask;
   volatile bool allSlavesSearching;
   volatile uint64_t nodes;
@@ -75,15 +89,15 @@ struct SplitPoint {
 /// ThreadBase struct is the base of the hierarchy from where we derive all the
 /// specialized thread classes.
 
-struct ThreadBase {
+struct ThreadBase : public std::thread {
 
   virtual ~ThreadBase() = default;
   virtual void idle_loop() = 0;
   void notify_one();
   void wait_for(volatile const bool& b);
 
-  std::thread nativeThread;
   Mutex mutex;
+  Spinlock spinlock;
   ConditionVariable sleepCondition;
   volatile bool exit = false;
 };
@@ -122,6 +136,7 @@ struct Thread : public ThreadBase {
 
 struct MainThread : public Thread {
   virtual void idle_loop();
+  void join();
   volatile bool thinking = true; // Avoid a race with start_thinking()
 };
 
@@ -147,11 +162,9 @@ struct ThreadPool : public std::vector<Thread*> {
   MainThread* main() { return static_cast<MainThread*>(at(0)); }
   void read_uci_options();
   Thread* available_slave(const SplitPoint* sp) const;
-  void wait_for_think_finished();
   void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
 
   Depth minimumSplitDepth;
-  ConditionVariable sleepCondition;
   TimerThread* timer;
 };