X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=inline;f=src%2Fthreads%2Fsynch.h;h=a19e88b181dff1208839ff890154aa69b299ce91;hb=8b801a69f8e0c2c4ef7e32a2476786f80f433b8e;hp=53a5ee488cf07c83f68a7b136bc6506136180ac9;hpb=615bf3b3d2a8573ed6fb9ddc0055745e163ac999;p=pintos-anon

diff --git a/src/threads/synch.h b/src/threads/synch.h
index 53a5ee4..a19e88b 100644
--- 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 */