# HG changeset patch
# User tschatzl
# Date 1382516586 -7200
# Node ID 1b422ef5288ad4da7c36f1953331201128d1e2f0
# Parent  0823c8bac468b45c42f05814f430ece8d06291d7
8025728: Missing volatile specifier for field G1AllocRegion::_alloc_region
Summary: The field G1AllocRegion::_alloc_region needs to be declared volatile as it is used with that intention. Otherwise the compiler may generate the code that reloads the value which might have changed in the meantime, leading to spurious crashes.
Reviewed-by: iveresov, simonis, tschatzl
Contributed-by: Axel Siebenborn <axel.siebenborn@sap.com>

diff -r 0823c8bac468 -r 1b422ef5288a src/share/vm/gc_implementation/g1/g1AllocRegion.hpp
--- a/src/share/vm/gc_implementation/g1/g1AllocRegion.hpp	Tue Oct 22 12:03:50 2013 -0700
+++ b/src/share/vm/gc_implementation/g1/g1AllocRegion.hpp	Wed Oct 23 10:23:06 2013 +0200
@@ -55,7 +55,7 @@
   // then _alloc_region is NULL and this object should not be used to
   // satisfy allocation requests (it was done this way to force the
   // correct use of init() and release()).
-  HeapRegion* _alloc_region;
+  HeapRegion* volatile _alloc_region;
 
   // It keeps track of the distinct number of regions that are used
   // for allocation in the active interval of this object, i.e.,
@@ -132,8 +132,9 @@
   static void setup(G1CollectedHeap* g1h, HeapRegion* dummy_region);
 
   HeapRegion* get() const {
+    HeapRegion * hr = _alloc_region;
     // Make sure that the dummy region does not escape this class.
-    return (_alloc_region == _dummy_region) ? NULL : _alloc_region;
+    return (hr == _dummy_region) ? NULL : hr;
   }
 
   uint count() { return _count; }