--- a/src/share/vm/memory/allocation.hpp	Mon Feb 11 10:31:56 2013 -0800
+++ b/src/share/vm/memory/allocation.hpp	Mon Apr 08 07:49:28 2013 +0200
@@ -611,4 +611,23 @@
   void check()    PRODUCT_RETURN;
 };
 
+// Helper class to allocate arrays that may become large.
+// Uses the OS malloc for allocations smaller than ArrayAllocatorMallocLimit
+// and uses mapped memory for larger allocations.
+// Most OS mallocs do something similar but Solaris malloc does not revert
+// to mapped memory for large allocations. By default ArrayAllocatorMallocLimit
+// is set so that we always use malloc except for Solaris where we set the
+// limit to get mapped memory.
+template <class E, MEMFLAGS F>
+class ArrayAllocator : StackObj {
+  char* _addr;
+  bool _use_malloc;
+  size_t _size;
+ public:
+  ArrayAllocator() : _addr(NULL), _use_malloc(false), _size(0) { }
+  ~ArrayAllocator() { free(); }
+  E* allocate(size_t length);
+  void free();
+};
+
 #endif // SHARE_VM_MEMORY_ALLOCATION_HPP