From: Michael Lee <mzlee@fb.com>
Date: Tue, 19 Jul 2016 20:26:37 +0000 (-0700)
Subject: Fix macro check in SysMembarrier
X-Git-Tag: 2016.07.26~30
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7dd33144a64c45dfce872842679f7cba71f64c98;p=folly.git

Fix macro check in SysMembarrier

Summary:
FOLLY_X64 is usually defined, so check whehter it is defined
to 0 or 1.  In addition, memory barriers are not necessarily widely
available on the mobile platforms. What leads me to believe this is
that, at least for older ndk's, atomics are not guaranteed to work for
multicore platforms.

Reviewed By: andriigrynenko

Differential Revision: D3586806

fbshipit-source-id: 3ac8c4b74cac09e41bc3cb65c8adc2732b8b2256
---

diff --git a/folly/portability/SysMembarrier.cpp b/folly/portability/SysMembarrier.cpp
index 923bece7..16fa5fb0 100644
--- a/folly/portability/SysMembarrier.cpp
+++ b/folly/portability/SysMembarrier.cpp
@@ -21,7 +21,7 @@
 #include <folly/Portability.h>
 #include <folly/portability/Unistd.h>
 
-#if !defined(__NR_membarrier) && defined(FOLLY_X64)
+#if !defined(__NR_membarrier) && FOLLY_X64 && !FOLLY_MOBILE
 #define __NR_membarrier 324
 #define MEMBARRIER_CMD_QUERY 0
 #define MEMBARRIER_CMD_SHARED 1