From ba05fb4d0cdf397d6dd77a40dfa986bc4b465b22 Mon Sep 17 00:00:00 2001
From: Milian Wolff <mail@milianw.de>
Date: Wed, 17 Dec 2014 13:40:27 +0100
Subject: [PATCH] Use acquire semantics after all... ;-)

According to this page, the relaxed semantics are a useless
optimization and might in fact degrade performance on some systems:

http://www.boost.org/doc/libs/master/doc/html/atomic/usage_examples.html#boost_atomic.usage_examples.example_spinlock
---
 libheaptrack.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libheaptrack.cpp b/libheaptrack.cpp
index b581bc9..bf33593 100644
--- a/libheaptrack.cpp
+++ b/libheaptrack.cpp
@@ -416,7 +416,7 @@ private:
     HeapTrack(AdditionalLockCheck lockCheck)
     {
         debugLog<VeryVerboseOutput>("%s", "acquiring lock");
-        while (s_locked.exchange(true, std::memory_order_relaxed) && lockCheck()) {
+        while (s_locked.exchange(true, std::memory_order_acquire) && lockCheck()) {
             std::this_thread::yield();
         }
         debugLog<VeryVerboseOutput>("%s", "lock acquired");
-- 
2.7.4