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.
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5 * This code is free software; you can redistribute it and/or modify it
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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,
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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 int oop_ms_adjust_pointers(oop obj);
71 #if INCLUDE_ALL_GCS
72 // Parallel Scavenge
73 void oop_ps_push_contents( oop obj, PSPromotionManager* pm);
74 // Parallel Compact
75 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
76 void oop_pc_update_pointers(oop obj);
77 #endif
78
79 // Oop fields (and metadata) iterators
80 // [nv = true] Use non-virtual calls to do_oop_nv.
81 // [nv = false] Use virtual calls to do_oop.
82 //
83 // The InstanceRefKlass iterators also support reference processing.
84
85
86 // Forward iteration
87 private:
88 // Iterate over all oop fields and metadata.
89 template <bool nv, class OopClosureType>
90 inline int oop_oop_iterate(oop obj, OopClosureType* closure);
91
92 // Reverse iteration
93 #if INCLUDE_ALL_GCS
94 // Iterate over all oop fields and metadata.
95 template <bool nv, class OopClosureType>
96 inline int oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
97 #endif // INCLUDE_ALL_GCS
98
99 // Bounded range iteration
100 // Iterate over all oop fields and metadata.
101 template <bool nv, class OopClosureType>
102 inline int oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
103
104 // Reference processing part of the iterators.
105
106 // Specialized for [T = oop] or [T = narrowOop].
107 template <bool nv, typename T, class OopClosureType, class Contains>
108 inline void oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains);
109
110 // Only perform reference processing if the referent object is within mr.
111 template <bool nv, class OopClosureType>
112 inline void oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr);
113
114 // Reference processing
115 template <bool nv, class OopClosureType>
116 inline void oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure);
117
118
119 public:
120
121 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL)
122 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL)
123
124 #if INCLUDE_ALL_GCS
125 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS)
126 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS)
127 #endif // INCLUDE_ALL_GCS
128
129 static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
130 static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
131 static bool owns_pending_list_lock(JavaThread* thread);
132
133 // Update non-static oop maps so 'referent', 'nextPending' and
134 // 'discovered' will look like non-oops
135 static void update_nonstatic_oop_maps(Klass* k);
136
137 public:
138 // Verification
139 void oop_verify_on(oop obj, outputStream* st);
140 };
141
142 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP