--- /dev/null	2015-10-06 23:29:51.451421828 +0200
+++ new/src/share/vm/gc/shenandoah/brooksPointer.cpp	2015-10-14 13:54:45.845124722 +0200
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "memory/universe.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "gc/shenandoah/brooksPointer.hpp"
+#include "gc/shenandoah/shenandoahBarrierSet.hpp"
+
+BrooksPointer::BrooksPointer(HeapWord** hw) : _heap_word(hw) {}
+
+BrooksPointer BrooksPointer::get(oop obj) {
+  HeapWord* hw_obj = (HeapWord*) obj;
+  HeapWord* brooks_ptr = hw_obj - 1;
+  // We know that the value in that memory location is a pointer to another
+  // heapword/oop.
+  return BrooksPointer((HeapWord**) brooks_ptr);
+}
+
+void BrooksPointer::set_forwardee(oop forwardee) {
+  assert(ShenandoahHeap::heap()->is_in(forwardee), "forwardee must be valid oop in the heap");
+  *_heap_word = (HeapWord*) forwardee;
+#ifdef ASSERT
+  if (ShenandoahTraceBrooksPointers) {
+    tty->print_cr("setting_forwardee to "PTR_FORMAT" = "PTR_FORMAT, p2i((HeapWord*) forwardee), p2i(*_heap_word));
+  }
+#endif
+}
+
+HeapWord* BrooksPointer::cas_forwardee(HeapWord* old, HeapWord* forwardee) {
+  assert(ShenandoahHeap::heap()->is_in(forwardee), "forwardee must point to a heap address");
+
+
+
+  HeapWord* o = old;
+  HeapWord* n = forwardee;
+  HeapWord* result;
+
+#ifdef ASSERT
+  if (ShenandoahTraceBrooksPointers) {
+    tty->print_cr("Attempting to CAS "PTR_FORMAT" value "PTR_FORMAT" from "PTR_FORMAT" to "PTR_FORMAT, p2i(_heap_word), p2i(*_heap_word), p2i(o), p2i(n));
+  }
+#endif
+
+#ifdef ASSERT
+  if (ShenandoahVerifyWritesToFromSpace || ShenandoahVerifyReadsToFromSpace) {
+    ShenandoahHeap* sh = (ShenandoahHeap*) Universe::heap();
+    ShenandoahHeapRegion* hr = sh->heap_region_containing(old);
+
+    {
+      hr->memProtectionOff();
+      result =  (HeapWord*) (HeapWord*) Atomic::cmpxchg_ptr(n, _heap_word, o);
+      hr->memProtectionOn();
+    }
+  } else {
+    result =  (HeapWord*) (HeapWord*) Atomic::cmpxchg_ptr(n, _heap_word, o);
+  }
+#else
+  result =  (HeapWord*) (HeapWord*) Atomic::cmpxchg_ptr(n, _heap_word, o);
+#endif
+
+#ifdef ASSERT
+  if (ShenandoahTraceBrooksPointers) {
+    tty->print_cr("Result of CAS from "PTR_FORMAT" to "PTR_FORMAT" was "PTR_FORMAT" read value was "PTR_FORMAT, p2i(o), p2i(n), p2i(result), p2i(*_heap_word));
+  }
+#endif
+
+  return result;
+}
+
+bool BrooksPointer::check_forwardee_is_in_heap(oop forwardee) {
+   return Universe::heap()->is_in(forwardee);
+}