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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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 // An InstanceRefKlass is a specialized InstanceKlass for Java
33 // classes that are subclasses of java/lang/ref/Reference.
34 //
35 // These classes are used to implement soft/weak/final/phantom
36 // references and finalization, and need special treatment by the
37 // garbage collector.
38 //
39 // During GC discovered reference objects are added (chained) to one
40 // of the four lists below, depending on the type of reference.
41 // The linked occurs through the next field in class java/lang/ref/Reference.
42 //
43 // Afterwards, the discovered references are processed in decreasing
44 // order of reachability. Reference objects eligible for notification
45 // are linked to the static pending_list in class java/lang/ref/Reference,
46 // and the pending list lock object in the same class is notified.
47
48
49 class InstanceRefKlass: public InstanceKlass {
50 friend class InstanceKlass;
51
52 // Constructor
53 InstanceRefKlass(int vtable_len, int itable_len, int static_field_size, int nonstatic_oop_map_size, ReferenceType rt, AccessFlags access_flags, bool is_anonymous)
54 : InstanceKlass(vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt, access_flags, is_anonymous) {}
55
56 public:
57 InstanceRefKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
58 // Type testing
59 bool oop_is_instanceRef() const { return true; }
60
61 // Casting from Klass*
62 static InstanceRefKlass* cast(Klass* k) {
63 assert(k->oop_is_instanceRef(), "cast to InstanceRefKlass");
64 return (InstanceRefKlass*) k;
65 }
66
67 // GC specific object visitors
68 //
69 // Mark Sweep
70 void oop_ms_follow_contents(oop obj);
71 int oop_ms_adjust_pointers(oop obj);
72 #if INCLUDE_ALL_GCS
73 // Parallel Scavenge
74 void oop_ps_push_contents( oop obj, PSPromotionManager* pm);
75 // Parallel Compact
76 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
77 void oop_pc_update_pointers(oop obj);
78 #endif
79
80 // Oop fields (and metadata) iterators
81 // [nv = true] Use non-virtual calls to do_oop_nv.
82 // [nv = false] Use virtual calls to do_oop.
83 //
84 // The InstanceRefKlass iterators also support reference processing.
85
86
87 // Forward iteration
88 private:
89 // Iterate over all oop fields and metadata.
90 template <bool nv, class OopClosureType>
91 inline int oop_oop_iterate(oop obj, OopClosureType* closure);
92
93 // Reverse iteration
94 #if INCLUDE_ALL_GCS
95 // Iterate over all oop fields and metadata.
96 template <bool nv, class OopClosureType>
97 inline int oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
98 #endif // INCLUDE_ALL_GCS
99
100 // Bounded range iteration
101 // Iterate over all oop fields and metadata.
102 template <bool nv, class OopClosureType>
103 inline int oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
104
105 // Reference processing part of the iterators.
106
107 // Specialized for [T = oop] or [T = narrowOop].
108 template <bool nv, typename T, class OopClosureType, class Contains>
109 inline void oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains);
110
111 // Only perform reference processing if the referent object is within mr.
112 template <bool nv, class OopClosureType>
113 inline void oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr);
114
115 // Reference processing
116 template <bool nv, class OopClosureType>
117 inline void oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure);
118
119
120 public:
121
122 #define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
123 int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure); \
124 int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* closure, MemRegion mr);
125
126 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
127 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
128
129 #if INCLUDE_ALL_GCS
130 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
131 int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
132
133 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
134 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
135 #endif // INCLUDE_ALL_GCS
136
137 static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
138 static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
139 static bool owns_pending_list_lock(JavaThread* thread);
140
141 // Update non-static oop maps so 'referent', 'nextPending' and
142 // 'discovered' will look like non-oops
143 static void update_nonstatic_oop_maps(Klass* k);
144
145 public:
146 // Verification
147 void oop_verify_on(oop obj, outputStream* st);
148 };
149
150 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP