instanceRefKlass.hpp revision 342:37f87013dfd8 
1/*
2 * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25// An instanceRefKlass is a specialized instanceKlass for Java
26// classes that are subclasses of java/lang/ref/Reference.
27//
28// These classes are used to implement soft/weak/final/phantom
29// references and finalization, and need special treatment by the
30// garbage collector.
31//
32// During GC discovered reference objects are added (chained) to one
33// of the four lists below, depending on the type of reference.
34// The linked occurs through the next field in class java/lang/ref/Reference.
35//
36// Afterwards, the discovered references are processed in decreasing
37// order of reachability. Reference objects eligible for notification
38// are linked to the static pending_list in class java/lang/ref/Reference,
39// and the pending list lock object in the same class is notified.
40
41
42class instanceRefKlass: public instanceKlass {
43 public:
44  // Type testing
45  bool oop_is_instanceRef() const             { return true; }
46
47  // Casting from klassOop
48  static instanceRefKlass* cast(klassOop k) {
49    assert(k->klass_part()->oop_is_instanceRef(), "cast to instanceRefKlass");
50    return (instanceRefKlass*) k->klass_part();
51  }
52
53  // allocation
54  DEFINE_ALLOCATE_PERMANENT(instanceRefKlass);
55
56  // Garbage collection
57  int  oop_adjust_pointers(oop obj);
58  void oop_follow_contents(oop obj);
59
60  // Parallel Scavenge and Parallel Old
61  PARALLEL_GC_DECLS
62
63  int oop_oop_iterate(oop obj, OopClosure* blk) {
64    return oop_oop_iterate_v(obj, blk);
65  }
66  int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
67    return oop_oop_iterate_v_m(obj, blk, mr);
68  }
69
70#define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                \
71  int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);                         \
72  int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr);
73
74  ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
75  ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
76
77#ifndef SERIALGC
78#define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)      \
79  int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
80
81  ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
82  ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
83#endif // !SERIALGC
84
85  static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
86  static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
87
88  // Update non-static oop maps so 'referent', 'nextPending' and
89  // 'discovered' will look like non-oops
90  static void update_nonstatic_oop_maps(klassOop k);
91
92 public:
93  // Verification
94  void oop_verify_on(oop obj, outputStream* st);
95};
96