From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 13 Jul 2012 20:33:41 +0000 (-0400)
Subject: Support dependency barriers.
X-Git-Url: http://git.postgresql.org/gitweb/static/developers.postgresql.org?a=commitdiff_plain;h=24d58d7e64ec9c81f4d2daf0ed4bc01a5086ec8f;p=users%2Frhaas%2Fpostgres.git

Support dependency barriers.
---

diff --git a/src/include/storage/barrier.h b/src/include/storage/barrier.h
index cd85633c13..dbcc0f8a64 100644
--- a/src/include/storage/barrier.h
+++ b/src/include/storage/barrier.h
@@ -20,4 +20,12 @@
  */
 #include "port/atomics.h"
 
+/*
+ * If dependency barriers are undefined, we define them as a no-op.  The only
+ * known platform where anything more is required is DEC Alpha.
+ */
+#if !defined(pg_read_barrier_depends)
+#define pg_read_barrier_depends()
+#endif
+
 #endif   /* BARRIER_H */