1 /*
2 * Copyright (c) 1997, 2025, 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_OOPS_ARRAYKLASS_HPP
26 #define SHARE_OOPS_ARRAYKLASS_HPP
27
28 #include "oops/klass.hpp"
29 #include "oops/layoutKind.hpp"
30
31 class fieldDescriptor;
32 class klassVtable;
33 class ObjArrayKlass;
34
35 // ArrayKlass is the abstract baseclass for all array classes
36
37 class ArrayKlass: public Klass {
38 friend class VMStructs;
39
40 public:
41 enum ArrayProperties : uint32_t {
42 DEFAULT = 0, // NULLABLE and ATOMIC
43 NULL_RESTRICTED = 1 << 0,
44 NON_ATOMIC = 1 << 1,
45 // FINAL = 1 << 2,
46 // VOLATILE = 1 << 3
47 INVALID = 1 << 4,
48 DUMMY = 1 << 5 // Just to transition the code, to be removed ASAP
49 };
50
51 static bool is_null_restricted(ArrayProperties props) { return (props & NULL_RESTRICTED) != 0; }
52 static bool is_non_atomic(ArrayProperties props) { return (props & NON_ATOMIC) != 0; }
53
54 static ArrayProperties array_properties_from_layout(LayoutKind lk);
55
56 private:
57 // If you add a new field that points to any metaspace object, you
58 // must add this field to ArrayKlass::metaspace_pointers_do().
59 int _dimension; // This is n'th-dimensional array.
60 ArrayProperties _properties;
61 ObjArrayKlass* volatile _higher_dimension; // Refers the (n+1)'th-dimensional array (if present).
62 ArrayKlass* volatile _lower_dimension; // Refers the (n-1)'th-dimensional array (if present).
63
64 protected:
65 // Constructors
66 // The constructor with the Symbol argument does the real array
67 // initialization, the other is a dummy
68 ArrayKlass(Symbol* name, KlassKind kind, ArrayProperties props, markWord prototype_header = markWord::prototype());
69 ArrayKlass();
70
71 // Create array_name for element klass
72 static Symbol* create_element_klass_array_name(Klass* element_klass, TRAPS);
73
74 public:
75
76 // Testing operation
77 DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
78
79 // Returns the ObjArrayKlass for n'th dimension.
80 ArrayKlass* array_klass(int n, TRAPS);
81 ArrayKlass* array_klass_or_null(int n);
82
83 // Returns the array class with this class as element type.
84 ArrayKlass* array_klass(TRAPS);
85 ArrayKlass* array_klass_or_null();
86
87 // Instance variables
88 int dimension() const { return _dimension; }
89 void set_dimension(int dimension) { _dimension = dimension; }
90
91 ArrayProperties properties() const { return _properties; }
92 void set_properties(ArrayProperties props) { _properties = props; }
93 static ByteSize properties_offset() { return byte_offset_of(ArrayKlass, _properties); }
94
95 ObjArrayKlass* higher_dimension() const { return _higher_dimension; }
96 inline ObjArrayKlass* higher_dimension_acquire() const; // load with acquire semantics
97 void set_higher_dimension(ObjArrayKlass* k) { _higher_dimension = k; }
98 inline void release_set_higher_dimension(ObjArrayKlass* k); // store with release semantics
99
100 ArrayKlass* lower_dimension() const { return _lower_dimension; }
101 void set_lower_dimension(ArrayKlass* k) { _lower_dimension = k; }
102
103 // offset of first element, including any padding for the sake of alignment
104 int array_header_in_bytes() const { return layout_helper_header_size(layout_helper()); }
105 int log2_element_size() const { return layout_helper_log2_element_size(layout_helper()); }
106 // type of elements (T_OBJECT for both oop arrays and array-arrays)
107 BasicType element_type() const { return layout_helper_element_type(layout_helper()); }
108
109 virtual InstanceKlass* java_super() const;
110
111 // Allocation
112 // Sizes points to the first dimension of the array, subsequent dimensions
113 // are always in higher memory. The callers of these set that up.
114 virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
115
116 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
117 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
118
119 // Lookup operations
120 Method* uncached_lookup_method(const Symbol* name,
121 const Symbol* signature,
122 OverpassLookupMode overpass_mode,
123 PrivateLookupMode private_mode = PrivateLookupMode::find) const;
124
125 static ArrayKlass* cast(Klass* k) {
126 return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
127 }
128
129 static const ArrayKlass* cast(const Klass* k) {
130 assert(k->is_array_klass(), "cast to ArrayKlass");
131 return static_cast<const ArrayKlass*>(k);
132 }
133
134 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
135 Array<InstanceKlass*>* transitive_interfaces);
136
137 oop component_mirror() const;
138
139 // Sizing
140 static int static_size(int header_size);
141
142 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
143
144 // Return a handle.
145 static void complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
146
147 // JVMTI support
148 jint jvmti_class_status() const;
149
150 #if INCLUDE_CDS
151 // CDS support - remove and restore oops from metadata. Oops are not shared.
152 virtual void remove_unshareable_info();
153 virtual void remove_java_mirror();
154 void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
155 void cds_print_value_on(outputStream* st) const;
156 #endif
157
158 void log_array_class_load(Klass* k);
159 // Printing
160 void print_on(outputStream* st) const;
161 void print_value_on(outputStream* st) const;
162
163 void oop_print_on(oop obj, outputStream* st);
164
165 // Verification
166 void verify_on(outputStream* st);
167
168 void oop_verify_on(oop obj, outputStream* st);
169 };
170
171 class ArrayDescription : public StackObj {
172 public:
173 Klass::KlassKind _kind;
174 ArrayKlass::ArrayProperties _properties;
175 LayoutKind _layout_kind;
176 ArrayDescription(Klass::KlassKind k, ArrayKlass::ArrayProperties p, LayoutKind lk) { _kind = k; _properties = p; _layout_kind = lk; }
177 };
178
179 #endif // SHARE_OOPS_ARRAYKLASS_HPP