Implement spin lock using std::atomic

shogun-toolbox · Jan 25, 2017 · 91c79df · 91c79df
1 parent 0f5a975
commit 91c79df
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Showing 2 changed files with 21 additions and 5 deletions.
diff --git a/src/shogun/lib/Lock.cpp b/src/shogun/lib/Lock.cpp
@@ -26,15 +26,15 @@
 	#define PTHREAD_LOCK_DESTROY(lock) pthread_spin_destroy(lock)
 	#define PTHREAD_LOCK(lock) pthread_spin_lock(lock)
 	#define PTHREAD_UNLOCK(lock) pthread_spin_unlock(lock)
-#endif
+#endif // DARWIN
 #else
 	#define PTHREAD_LOCK_T pthread_mutex_t
 	#define PTHREAD_LOCK_INIT(lock) pthread_mutex_init(lock, NULL)
 	#define PTHREAD_LOCK_DESTROY(lock) pthread_mutex_destroy(lock)
 	#define PTHREAD_LOCK(lock) pthread_mutex_lock(lock)
 	#define PTHREAD_UNLOCK(lock) pthread_mutex_unlock(lock)
-#endif
-#endif
+#endif // USE_SPINLOCKS
+#endif // HAVE_PTHREAD
 
 using namespace shogun;
 
@@ -56,14 +56,22 @@ CLock::~CLock()
 
 void CLock::lock()
 {
-#ifdef HAVE_PTHREAD
+#ifdef HAVE_CXX11_ATOMIC
+	while(m_flag.test_and_set(std::memory_order_acquire));
+#elif HAVE_PTHREAD
 	PTHREAD_LOCK((PTHREAD_LOCK_T*) lock_object);
+#else
+	SG_NOTIMPLEMENTED
 #endif
 }
 
 void CLock::unlock()
 {
-#ifdef HAVE_PTHREAD
+#ifdef HAVE_CXX11_ATOMIC
+	m_flag.clear(std::memory_order_release);
+#elif HAVE_PTHREAD
 	PTHREAD_UNLOCK((PTHREAD_LOCK_T*) lock_object);
+#else
+	SG_NOTIMPLEMENTED
 #endif
 }
diff --git a/src/shogun/lib/Lock.h b/src/shogun/lib/Lock.h
@@ -11,6 +11,10 @@
 
 #include <shogun/lib/config.h>
 
+#ifdef HAVE_CXX11_ATOMIC
+#include <atomic>
+#endif
+
 namespace shogun
 {
 /** @brief Class Lock used for synchronization in concurrent programs. */
@@ -29,7 +33,11 @@ class CLock
 
 private:
 	/** lock object */
+#ifdef HAVE_CXX11_ATOMIC
+	std::atomic_flag m_flag = ATOMIC_FLAG_INIT;
+#else
 	void* lock_object;
+#endif	
 };
 }
 #endif // __LOCK_H__