1 /*
2 * Copyright (c) 1997, 2020, 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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12 * version 2 for more details (a copy is included in the LICENSE file that
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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
33 // ArrayKlass is the abstract baseclass for all array classes
34
35 class ArrayKlass: public Klass {
36 friend class VMStructs;
37 private:
38 // If you add a new field that points to any metaspace object, you
39 // must add this field to ArrayKlass::metaspace_pointers_do().
40 int _dimension; // This is n'th-dimensional array.
41 Klass* volatile _higher_dimension; // Refers the (n+1)'th-dimensional array (if present).
42 Klass* volatile _lower_dimension; // Refers the (n-1)'th-dimensional array (if present).
43
44 protected:
45 Klass* _element_klass; // The klass of the elements of this array type
46 // The element type must be registered for both object arrays
47 // (incl. object arrays with value type elements) and value type
48 // arrays containing flattened value types. However, the element
49 // type must not be registered for arrays of primitive types.
50 // TODO: Update the class hierarchy so that element klass appears
51 // only in array that contain non-primitive types.
52 // Constructors
53 // The constructor with the Symbol argument does the real array
54 // initialization, the other is a dummy
55 ArrayKlass(Symbol* name, KlassID id);
56 ArrayKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
57
58 // Create array_name for element klass, creates a permanent symbol, returns result
59 static Symbol* create_element_klass_array_name(bool is_qtype, Klass* element_klass, TRAPS);
60
61 public:
62 // Instance variables
63 virtual Klass* element_klass() const { return _element_klass; }
64 virtual void set_element_klass(Klass* k) { _element_klass = k; }
65
66 // Compiler/Interpreter offset
67 static ByteSize element_klass_offset() { return in_ByteSize(offset_of(ArrayKlass, _element_klass)); }
68
69 // Presented with an ArrayKlass, which storage_properties should be encoded into arrayOop
70 virtual ArrayStorageProperties storage_properties() { return ArrayStorageProperties::empty; }
71
72 // Testing operation
73 DEBUG_ONLY(bool is_array_klass_slow() const { return true; })
74
75 // Instance variables
76 int dimension() const { return _dimension; }
77 void set_dimension(int dimension) { _dimension = dimension; }
78
79 Klass* higher_dimension() const { return _higher_dimension; }
80 inline Klass* higher_dimension_acquire() const; // load with acquire semantics
81 void set_higher_dimension(Klass* k) { _higher_dimension = k; }
82 inline void release_set_higher_dimension(Klass* k); // store with release semantics
83
84 Klass* lower_dimension() const { return _lower_dimension; }
85 void set_lower_dimension(Klass* k) { _lower_dimension = k; }
86
87 // offset of first element, including any padding for the sake of alignment
88 int array_header_in_bytes() const { return layout_helper_header_size(layout_helper()); }
89 int log2_element_size() const { return layout_helper_log2_element_size(layout_helper()); }
90 // type of elements (T_OBJECT for both oop arrays and array-arrays)
91 BasicType element_type() const { return layout_helper_element_type(layout_helper()); }
92
93 virtual InstanceKlass* java_super() const;//{ return SystemDictionary::Object_klass(); }
94
95 // Allocation
96 // Sizes points to the first dimension of the array, subsequent dimensions
97 // are always in higher memory. The callers of these set that up.
98 virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
99 objArrayOop allocate_arrayArray(int n, int length, TRAPS);
100
101 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
102 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
103
104 // Lookup operations
105 Method* uncached_lookup_method(const Symbol* name,
106 const Symbol* signature,
107 OverpassLookupMode overpass_mode,
108 PrivateLookupMode private_mode = find_private) const;
109
110 static ArrayKlass* cast(Klass* k) {
111 return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k)));
112 }
113
114 static const ArrayKlass* cast(const Klass* k) {
115 assert(k->is_array_klass(), "cast to ArrayKlass");
116 return static_cast<const ArrayKlass*>(k);
117 }
118
119 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
120 Array<InstanceKlass*>* transitive_interfaces);
121
122 oop component_mirror() const;
123
124 // Sizing
125 static int static_size(int header_size);
126
127 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
128
129 // Iterators
130 void array_klasses_do(void f(Klass* k));
131
132 // Return a handle.
133 static void complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS);
134
135
136 // jvm support
137 jint compute_modifier_flags(TRAPS) const;
138
139 // JVMTI support
140 jint jvmti_class_status() const;
141
142 // CDS support - remove and restore oops from metadata. Oops are not shared.
143 virtual void remove_unshareable_info();
144 virtual void remove_java_mirror();
145 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
146
147 // Printing
148 void print_on(outputStream* st) const;
149 void print_value_on(outputStream* st) const;
150
151 void oop_print_on(oop obj, outputStream* st);
152
153 // Verification
154 void verify_on(outputStream* st);
155
156 void oop_verify_on(oop obj, outputStream* st);
157 };
158
159 #endif // SHARE_OOPS_ARRAYKLASS_HPP