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[pintos-anon] / src / threads / synch.h

diff --git a/src/threads/synch.h b/src/threads/synch.h
index 53a5ee488cf07c83f68a7b136bc6506136180ac9..a19e88b181dff1208839ff890154aa69b299ce91 100644 (file)
--- a/src/threads/synch.h
+++ b/src/threads/synch.h
@@ -41,10 +41,11 @@ void cond_wait (struct condition *, struct lock *);
 void cond_signal (struct condition *, struct lock *);
 void cond_broadcast (struct condition *, struct lock *);
 
-/* Memory barrier.
+/* Optimization barrier.
 
-   The compiler will not reorder operations that access memory
-   across a memory barrier. */
-#define barrier() asm volatile ("")
+   The compiler will not reorder operations across an
+   optimization barrier.  See "Optimization Barriers" in the
+   reference guide for more information.*/
+#define barrier() asm volatile ("" : : : "memory")
 
 #endif /* threads/synch.h */