--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/genOopClosures.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,149 @@
+/*
+ * Copyright 2001-2007 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.
+ *
+ */
+
+class Generation;
+class HeapWord;
+class CardTableRS;
+class CardTableModRefBS;
+class DefNewGeneration;
+
+// Closure for iterating roots from a particular generation
+// Note: all classes deriving from this MUST call this do_barrier
+// method at the end of their own do_oop method!
+// Note: no do_oop defined, this is an abstract class.
+
+class OopsInGenClosure : public OopClosure {
+ private:
+  Generation*         _orig_gen;     // generation originally set in ctor
+  Generation*         _gen;          // generation being scanned
+
+ protected:
+  // Some subtypes need access.
+  HeapWord*           _gen_boundary; // start of generation
+  CardTableRS*        _rs;           // remembered set
+
+  // For assertions
+  Generation* generation() { return _gen; }
+  CardTableRS* rs() { return _rs; }
+
+  // Derived classes that modify oops so that they might be old-to-young
+  // pointers must call the method below.
+  void do_barrier(oop* p);
+
+ public:
+  OopsInGenClosure() : OopClosure(NULL),
+    _orig_gen(NULL), _gen(NULL), _gen_boundary(NULL), _rs(NULL) {};
+
+  OopsInGenClosure(Generation* gen);
+  void set_generation(Generation* gen);
+
+  void reset_generation() { _gen = _orig_gen; }
+
+  // Problem with static closures: must have _gen_boundary set at some point,
+  // but cannot do this until after the heap is initialized.
+  void set_orig_generation(Generation* gen) {
+    _orig_gen = gen;
+    set_generation(gen);
+  }
+
+  HeapWord* gen_boundary() { return _gen_boundary; }
+};
+
+// Closure for scanning DefNewGeneration.
+//
+// This closure will perform barrier store calls for ALL
+// pointers in scanned oops.
+class ScanClosure: public OopsInGenClosure {
+protected:
+  DefNewGeneration* _g;
+  HeapWord* _boundary;
+  bool _gc_barrier;
+public:
+  ScanClosure(DefNewGeneration* g, bool gc_barrier);
+  void do_oop(oop* p);
+  void do_oop_nv(oop* p);
+  bool do_header() { return false; }
+  Prefetch::style prefetch_style() {
+    return Prefetch::do_write;
+  }
+};
+
+// Closure for scanning DefNewGeneration.
+//
+// This closure only performs barrier store calls on
+// pointers into the DefNewGeneration. This is less
+// precise, but faster, than a ScanClosure
+class FastScanClosure: public OopsInGenClosure {
+protected:
+  DefNewGeneration* _g;
+  HeapWord* _boundary;
+  bool _gc_barrier;
+public:
+  FastScanClosure(DefNewGeneration* g, bool gc_barrier);
+  void do_oop(oop* p);
+  void do_oop_nv(oop* p);
+  bool do_header() { return false; }
+  Prefetch::style prefetch_style() {
+    return Prefetch::do_write;
+  }
+};
+
+class FilteringClosure: public OopClosure {
+  HeapWord* _boundary;
+  OopClosure* _cl;
+public:
+  FilteringClosure(HeapWord* boundary, OopClosure* cl) :
+    OopClosure(cl->_ref_processor), _boundary(boundary),
+    _cl(cl) {}
+  void do_oop(oop* p);
+  void do_oop_nv(oop* p) {
+    oop obj = *p;
+    if ((HeapWord*)obj < _boundary && obj != NULL) {
+      _cl->do_oop(p);
+    }
+  }
+  bool do_header() { return false; }
+};
+
+// Closure for scanning DefNewGeneration's weak references.
+// NOTE: very much like ScanClosure but not derived from
+//  OopsInGenClosure -- weak references are processed all
+//  at once, with no notion of which generation they were in.
+class ScanWeakRefClosure: public OopClosure {
+protected:
+  DefNewGeneration*  _g;
+  HeapWord*          _boundary;
+public:
+  ScanWeakRefClosure(DefNewGeneration* g);
+  void do_oop(oop* p);
+  void do_oop_nv(oop* p);
+};
+
+class VerifyOopClosure: public OopClosure {
+public:
+  void do_oop(oop* p) {
+    guarantee((*p)->is_oop_or_null(), "invalid oop");
+  }
+  static VerifyOopClosure verify_oop;
+};