commit ab00be9c6e2706be3499bd189637e27edf7f2168
author Hans Boehm <hboehm@google.com> Fri Jan 29 20:40:09 2016 +0000
committer Gerrit Code Review <noreply-gerritcodereview@google.com> Fri Jan 29 20:40:09 2016 +0000
tree 2e842a13fbc2b7e8f25473f9afb1dc6f7e32d1ca
parent 2624ffcdbafd0d89cb92f688d4c264bb08a2522c
parent b0171b9573c446724c10c86d41887d0133590b6c

Merge "Do not use atomic increment in allocation as fence."

runtime/atomic.h

diff --git a/runtime/atomic.h b/runtime/atomic.h
index 0faa3c6..d4a7f37 100644
--- a/runtime/atomic.h
+++ b/runtime/atomic.h
@@ -278,6 +278,10 @@
     return this->fetch_add(value, std::memory_order_seq_cst);  // Return old_value.
   }
 
+  T FetchAndAddRelaxed(const T value) {
+    return this->fetch_add(value, std::memory_order_relaxed);  // Return old_value.
+  }
+
   T FetchAndSubSequentiallyConsistent(const T value) {
     return this->fetch_sub(value, std::memory_order_seq_cst);  // Return old value.
   }

runtime/gc/heap-inl.h

diff --git a/runtime/gc/heap-inl.h b/runtime/gc/heap-inl.h
index d1ab587..f437830 100644
--- a/runtime/gc/heap-inl.h
+++ b/runtime/gc/heap-inl.h
@@ -145,9 +145,9 @@
       WriteBarrierField(obj, mirror::Object::ClassOffset(), klass);
     }
     pre_fence_visitor(obj, usable_size);
+    QuasiAtomic::ThreadFenceForConstructor();
     new_num_bytes_allocated = static_cast<size_t>(
-        num_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes_tl_bulk_allocated))
-        + bytes_tl_bulk_allocated;
+        num_bytes_allocated_.FetchAndAddRelaxed(bytes_tl_bulk_allocated)) + bytes_tl_bulk_allocated;
   }
   if (kIsDebugBuild && Runtime::Current()->IsStarted()) {
     CHECK_LE(obj->SizeOf(), usable_size);