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. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 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, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 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 // 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_is_atomic() { return true; } 75 76 // Testing operation 77 DEBUG_ONLY(bool is_array_klass_slow() const { return true; }) 78 79 // Instance variables 80 int dimension() const { return _dimension; } 81 void set_dimension(int dimension) { _dimension = dimension; } 82 83 Klass* higher_dimension() const { return _higher_dimension; } 84 inline Klass* higher_dimension_acquire() const; // load with acquire semantics 85 void set_higher_dimension(Klass* k) { _higher_dimension = k; } 86 inline void release_set_higher_dimension(Klass* k); // store with release semantics 87 88 Klass* lower_dimension() const { return _lower_dimension; } 89 void set_lower_dimension(Klass* k) { _lower_dimension = k; } 90 91 // offset of first element, including any padding for the sake of alignment 92 int array_header_in_bytes() const { return layout_helper_header_size(layout_helper()); } 93 int log2_element_size() const { return layout_helper_log2_element_size(layout_helper()); } 94 // type of elements (T_OBJECT for both oop arrays and array-arrays) 95 BasicType element_type() const { return layout_helper_element_type(layout_helper()); } 96 97 virtual InstanceKlass* java_super() const;//{ return SystemDictionary::Object_klass(); } 98 99 // Allocation 100 // Sizes points to the first dimension of the array, subsequent dimensions 101 // are always in higher memory. The callers of these set that up. 102 virtual oop multi_allocate(int rank, jint* sizes, TRAPS); 103 objArrayOop allocate_arrayArray(int n, int length, TRAPS); 104 105 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 106 Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const; 107 108 // Lookup operations 109 Method* uncached_lookup_method(const Symbol* name, 110 const Symbol* signature, 111 OverpassLookupMode overpass_mode, 112 PrivateLookupMode private_mode = find_private) const; 113 114 static ArrayKlass* cast(Klass* k) { 115 return const_cast<ArrayKlass*>(cast(const_cast<const Klass*>(k))); 116 } 117 118 static const ArrayKlass* cast(const Klass* k) { 119 assert(k->is_array_klass(), "cast to ArrayKlass"); 120 return static_cast<const ArrayKlass*>(k); 121 } 122 123 GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots, 124 Array<InstanceKlass*>* transitive_interfaces); 125 126 oop component_mirror() const; 127 128 // Sizing 129 static int static_size(int header_size); 130 131 virtual void metaspace_pointers_do(MetaspaceClosure* iter); 132 133 // Iterators 134 void array_klasses_do(void f(Klass* k)); 135 136 // Return a handle. 137 static void complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module, TRAPS); 138 139 140 // jvm support 141 jint compute_modifier_flags(TRAPS) const; 142 143 // JVMTI support 144 jint jvmti_class_status() const; 145 146 // CDS support - remove and restore oops from metadata. Oops are not shared. 147 virtual void remove_unshareable_info(); 148 virtual void remove_java_mirror(); 149 virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS); 150 151 // Printing 152 void print_on(outputStream* st) const; 153 void print_value_on(outputStream* st) const; 154 155 void oop_print_on(oop obj, outputStream* st); 156 157 // Verification 158 void verify_on(outputStream* st); 159 160 void oop_verify_on(oop obj, outputStream* st); 161 }; 162 163 #endif // SHARE_OOPS_ARRAYKLASS_HPP