--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/genRemSet.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,121 @@
+/*
+ * Copyright 2001-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// A GenRemSet provides ways of iterating over pointers accross generations.
+// (This is especially useful for older-to-younger.)
+
+class Generation;
+class BarrierSet;
+class OopsInGenClosure;
+class CardTableRS;
+
+class GenRemSet: public CHeapObj {
+  friend class Generation;
+
+  BarrierSet* _bs;
+
+public:
+  enum Name {
+    CardTable,
+    Other
+  };
+
+  GenRemSet(BarrierSet * bs) : _bs(bs) {}
+
+  virtual Name rs_kind() = 0;
+
+  // These are for dynamic downcasts.  Unfortunately that it names the
+  // possible subtypes (but not that they are subtypes!)  Return NULL if
+  // the cast is invalide.
+  virtual CardTableRS* as_CardTableRS() { return NULL; }
+
+  // Return the barrier set associated with "this."
+  BarrierSet* bs() { return _bs; }
+
+  // Do any (sequential) processing necessary to prepare for (possibly
+  // "parallel", if that arg is true) calls to younger_refs_iterate.
+  virtual void prepare_for_younger_refs_iterate(bool parallel) = 0;
+
+  // Apply the "do_oop" method of "blk" to (exactly) all oop locations
+  //  1) that are in objects allocated in "g" at the time of the last call
+  //     to "save_Marks", and
+  //  2) that point to objects in younger generations.
+  virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0;
+
+  virtual void younger_refs_in_space_iterate(Space* sp,
+                                             OopsInGenClosure* cl) = 0;
+
+  // This method is used to notify the remembered set that "new_val" has
+  // been written into "field" by the garbage collector.
+  void write_ref_field_gc(oop* field, oop new_val);
+protected:
+  virtual void write_ref_field_gc_work(oop* field, oop new_val) = 0;
+public:
+
+  // A version of the above suitable for use by parallel collectors.
+  virtual void write_ref_field_gc_par(oop* field, oop new_val) = 0;
+
+  // Resize one of the regions covered by the remembered set.
+  virtual void resize_covered_region(MemRegion new_region) = 0;
+
+  // If the rem set imposes any alignment restrictions on boundaries
+  // within the heap, this function tells whether they are met.
+  virtual bool is_aligned(HeapWord* addr) = 0;
+
+  // If the RS (or BS) imposes an aligment constraint on maximum heap size.
+  // (This must be static, and dispatch on "nm", because it is called
+  // before an RS is created.)
+  static uintx max_alignment_constraint(Name nm);
+
+  virtual void verify() = 0;
+
+  // Verify that the remembered set has no entries for
+  // the heap interval denoted by mr.
+  virtual void verify_empty(MemRegion mr) = 0;
+
+  // If appropriate, print some information about the remset on "tty".
+  virtual void print() {}
+
+  // Informs the RS that the given memregion contains no references to
+  // younger generations.
+  virtual void clear(MemRegion mr) = 0;
+
+  // Informs the RS that there are no references to generations
+  // younger than gen from generations gen and older.
+  // The parameter clear_perm indicates if the perm_gen's
+  // remembered set should also be processed/cleared.
+  virtual void clear_into_younger(Generation* gen, bool clear_perm) = 0;
+
+  // Informs the RS that refs in the given "mr" may have changed
+  // arbitrarily, and therefore may contain old-to-young pointers.
+  virtual void invalidate(MemRegion mr) = 0;
+
+  // Informs the RS that refs in this generation
+  // may have changed arbitrarily, and therefore may contain
+  // old-to-young pointers in arbitrary locations. The parameter
+  // younger indicates if the same should be done for younger generations
+  // as well. The parameter perm indicates if the same should be done for
+  // perm gen as well.
+  virtual void invalidate_or_clear(Generation* gen, bool younger, bool perm) = 0;
+};