1 /*
2 * Copyright (c) 1997, 2024, 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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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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24
25 #ifndef SHARE_OOPS_ARRAYKLASS_HPP
26 #define SHARE_OOPS_ARRAYKLASS_HPP
27
28 #include "oops/klass.hpp"
29
30 class fieldDescriptor;
31 class klassVtable;
32 class ObjArrayKlass;
33
34 // ArrayKlass is the abstract baseclass for all array classes
35
36 class ArrayKlass: public Klass {
37 friend class VMStructs;
38 private:
39 // If you add a new field that points to any metaspace object, you
40 // must add this field to ArrayKlass::metaspace_pointers_do().
41 int _dimension; // This is n'th-dimensional array.
42 ObjArrayKlass* volatile _higher_dimension; // Refers the (n+1)'th-dimensional array (if present).
43 ArrayKlass* volatile _lower_dimension; // Refers the (n-1)'th-dimensional array (if present).
44
45 protected:
46 Klass* _element_klass; // The klass of the elements of this array type
47 // The element type must be registered for both object arrays
48 // (incl. object arrays with value type elements) and value type
49 // arrays containing flat value types. However, the element
50 // type must not be registered for arrays of primitive types.
51 // TODO: Update the class hierarchy so that element klass appears
52 // only in array that contain non-primitive types.
53 // Constructors
54 // The constructor with the Symbol argument does the real array
55 // initialization, the other is a dummy
56 ArrayKlass(Symbol* name, KlassKind kind);
57 ArrayKlass();
58
59 // Create array_name for element klass
60 static Symbol* create_element_klass_array_name(Klass* element_klass, TRAPS);
61
62 void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
63
64 public:
65 // Instance variables
66 virtual Klass* element_klass() const { return _element_klass; }
67 virtual void set_element_klass(Klass* k) { _element_klass = k; }
68
69 // Compiler/Interpreter offset
70 static ByteSize element_klass_offset() { return in_ByteSize(offset_of(ArrayKlass, _element_klass)); }
71
72 // Are loads and stores to this concrete array type atomic?
73 // Note that Object[] is naturally atomic, but its subtypes may not be.
74 virtual bool element_access_must_be_atomic() { return true; }
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 ObjArrayKlass* higher_dimension() const { return _higher_dimension; }
92 inline ObjArrayKlass* higher_dimension_acquire() const; // load with acquire semantics
93 void set_higher_dimension(ObjArrayKlass* k) { _higher_dimension = k; }
94 inline void release_set_higher_dimension(ObjArrayKlass* k); // store with release semantics
95
96 ArrayKlass* lower_dimension() const { return _lower_dimension; }
97 void set_lower_dimension(ArrayKlass* k) { _lower_dimension = k; }
98
99 // offset of first element, including any padding for the sake of alignment
100 int array_header_in_bytes() const { return layout_helper_header_size(layout_helper()); }
101 int log2_element_size() const { return layout_helper_log2_element_size(layout_helper()); }
102 // type of elements (T_OBJECT for both oop arrays and array-arrays)
103 BasicType element_type() const { return layout_helper_element_type(layout_helper()); }
104
105 virtual InstanceKlass* java_super() const;
106
107 // Allocation
108 // Sizes points to the first dimension of the array, subsequent dimensions
109 // are always in higher memory. The callers of these set that up.
110 virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
111 objArrayOop allocate_arrayArray(int n, int length, TRAPS);
112
113 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
114 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
115
116 // Lookup operations
117 Method* uncached_lookup_method(const Symbol* name,
118 const Symbol* signature,
119 OverpassLookupMode overpass_mode,
120 PrivateLookupMode private_mode = PrivateLookupMode::find) const;
121
122 static ArrayKlass* cast(Klass* k) {
123 return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
124 }
125
126 static const ArrayKlass* cast(const Klass* k) {
127 assert(k->is_array_klass(), "cast to ArrayKlass");
128 return static_cast<const ArrayKlass*>(k);
129 }
130
131 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
132 Array<InstanceKlass*>* transitive_interfaces);
133
134 oop component_mirror() const;
135
136 // Sizing
137 static int static_size(int header_size);
138
139 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
140
141 // Return a handle.
142 static void complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
143
144
145 // jvm support
146 jint compute_modifier_flags() const;
147
148 // JVMTI support
149 jint jvmti_class_status() const;
150
151 #if INCLUDE_CDS
152 // CDS support - remove and restore oops from metadata. Oops are not shared.
153 virtual void remove_unshareable_info();
154 virtual void remove_java_mirror();
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;
162 void print_value_on(outputStream* st) const;
163
164 void oop_print_on(oop obj, outputStream* st);
165
166 // Verification
167 void verify_on(outputStream* st);
168
169 void oop_verify_on(oop obj, outputStream* st);
170 };
171
172 #endif // SHARE_OOPS_ARRAYKLASS_HPP