1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_OOPS_INSTANCEREFKLASS_HPP
26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP
27
28 #include "gc/shared/specialized_oop_closures.hpp"
29 #include "oops/instanceKlass.hpp"
30 #include "utilities/macros.hpp"
31
32 class ClassFileParser;
33
34 // An InstanceRefKlass is a specialized InstanceKlass for Java
35 // classes that are subclasses of java/lang/ref/Reference.
36 //
37 // These classes are used to implement soft/weak/final/phantom
38 // references and finalization, and need special treatment by the
39 // garbage collector.
40 //
41 // During GC discovered reference objects are added (chained) to one
42 // of the four lists below, depending on the type of reference.
43 // The linked occurs through the next field in class java/lang/ref/Reference.
44 //
45 // Afterwards, the discovered references are processed in decreasing
46 // order of reachability. Reference objects eligible for notification
47 // are linked to the static pending_list in class java/lang/ref/Reference,
48 // and the pending list lock object in the same class is notified.
49
50
51 class InstanceRefKlass: public InstanceKlass {
52 friend class InstanceKlass;
53 private:
54 InstanceRefKlass(const ClassFileParser& parser) : InstanceKlass(parser, InstanceKlass::_misc_kind_reference) {}
55
56 public:
57 InstanceRefKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
58
59 // GC specific object visitors
60 //
61 // Mark Sweep
62 int oop_ms_adjust_pointers(oop obj);
63 #if INCLUDE_ALL_GCS
64 // Parallel Scavenge
65 void oop_ps_push_contents( oop obj, PSPromotionManager* pm);
66 // Parallel Compact
67 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
68 void oop_pc_update_pointers(oop obj);
69 #endif
70
71 // Oop fields (and metadata) iterators
72 // [nv = true] Use non-virtual calls to do_oop_nv.
73 // [nv = false] Use virtual calls to do_oop.
74 //
75 // The InstanceRefKlass iterators also support reference processing.
76
77
78 // Forward iteration
79 private:
80 // Iterate over all oop fields and metadata.
81 template <bool nv, class OopClosureType>
82 inline void oop_oop_iterate(oop obj, OopClosureType* closure);
83
84 // Reverse iteration
85 #if INCLUDE_ALL_GCS
86 // Iterate over all oop fields and metadata.
87 template <bool nv, class OopClosureType>
88 inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
89 #endif // INCLUDE_ALL_GCS
90
91 // Bounded range iteration
92 // Iterate over all oop fields and metadata.
93 template <bool nv, class OopClosureType>
94 inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
95
96 // Reference processing part of the iterators.
97
98 // Specialized for [T = oop] or [T = narrowOop].
99 template <bool nv, typename T, class OopClosureType, class Contains>
100 inline void oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains);
101
102 // Only perform reference processing if the referent object is within mr.
103 template <bool nv, class OopClosureType>
104 inline void oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr);
105
106 // Reference processing
107 template <bool nv, class OopClosureType>
108 inline void oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure);
109
110
111 public:
112
113 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL)
114 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL)
115
116 #if INCLUDE_ALL_GCS
117 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS)
118 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS)
119 #endif // INCLUDE_ALL_GCS
120
121 static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
122 static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
123 static bool owns_pending_list_lock(JavaThread* thread);
124
125 // Update non-static oop maps so 'referent', 'nextPending' and
126 // 'discovered' will look like non-oops
127 static void update_nonstatic_oop_maps(Klass* k);
128
129 public:
130 // Verification
131 void oop_verify_on(oop obj, outputStream* st);
132 };
133
134 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP