7023069: G1: Introduce symmetric locking in the slow allocation path 7023151: G1: refactor the code that operates on _cur_alloc_region to be re-used for allocs by the GC threads 7018286: G1: humongous allocation attempts should take the GC locker into account Summary: First, this change replaces the asymmetric locking scheme in the G1 slow alloc path by a summetric one. Second, it factors out the code that operates on _cur_alloc_region so that it can be re-used for allocations by the GC threads in the future. Reviewed-by: stefank, brutisso, johnc

--- a/src/share/vm/memory/cardTableModRefBS.hpp	Tue Mar 29 22:36:16 2011 -0400
+++ b/src/share/vm/memory/cardTableModRefBS.hpp	Wed Mar 30 10:26:59 2011 -0400
@@ -382,6 +382,11 @@
     return (addr_for(pcard) == p);
   }
 
+  HeapWord* align_to_card_boundary(HeapWord* p) {
+    jbyte* pcard = byte_for(p + card_size_in_words - 1);
+    return addr_for(pcard);
+  }
+
   // The kinds of precision a CardTableModRefBS may offer.
   enum PrecisionStyle {
     Precise,