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