Use atomics instead of volatile

[stockfish] / src / thread.h

diff --git a/src/thread.h b/src/thread.h
index 459b1ddde9fe11daadd308bb5f717abfcc86dbd8..abb7a22333800f4aa2d648290640f71261e749ab 100644 (file)
--- a/src/thread.h
+++ b/src/thread.h
@@ -44,15 +44,16 @@ const size_t MAX_THREADS = 128;
 
 struct ThreadBase : public std::thread {
 
 
 struct ThreadBase : public std::thread {
 

+  ThreadBase() { exit = false; }

   virtual ~ThreadBase() = default;
   virtual void idle_loop() = 0;
   void notify_one();
   virtual ~ThreadBase() = default;
   virtual void idle_loop() = 0;
   void notify_one();

-  void wait(volatile const bool& b);
-  void wait_while(volatile const bool& b);
+  void wait(std::atomic<bool>& b);
+  void wait_while(std::atomic<bool>& b);

 
   Mutex mutex;
   ConditionVariable sleepCondition;
 
   Mutex mutex;
   ConditionVariable sleepCondition;

-  volatile bool exit = false;
+  std::atomic<bool> exit;

 };
 
 
 };
 
 


@@ -72,7 +73,7 @@ struct Thread : public ThreadBase {
   Endgames endgames;
   size_t idx, PVIdx;
   int maxPly;
   Endgames endgames;
   size_t idx, PVIdx;
   int maxPly;

-  volatile bool searching;
+  std::atomic<bool> searching;

 
   Position rootPos;
   Search::RootMoveVector rootMoves;
 
   Position rootPos;
   Search::RootMoveVector rootMoves;


@@ -87,10 +88,11 @@ struct Thread : public ThreadBase {
 /// special threads: the main one and the recurring timer.
 
 struct MainThread : public Thread {
 /// special threads: the main one and the recurring timer.
 
 struct MainThread : public Thread {

+  MainThread() { thinking = true; } // Avoid a race with start_thinking()

   virtual void idle_loop();
   void join();
   void think();
   virtual void idle_loop();
   void join();
   void think();

-  volatile bool thinking = true; // Avoid a race with start_thinking()
+  std::atomic<bool> thinking;

 };
 
 struct TimerThread : public ThreadBase {
 };
 
 struct TimerThread : public ThreadBase {