1/*
2 * Copyright (c) 1997, 2017, 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#include "precompiled.hpp"
26#include "classfile/javaClasses.hpp"
27#include "classfile/systemDictionary.hpp"
28#include "classfile/vmSymbols.hpp"
29#include "gc/shared/collectedHeap.inline.hpp"
30#include "gc/shared/gcLocker.hpp"
31#include "jvmtifiles/jvmti.h"
32#include "memory/metaspaceClosure.hpp"
33#include "memory/resourceArea.hpp"
34#include "memory/universe.inline.hpp"
35#include "oops/arrayKlass.hpp"
36#include "oops/arrayOop.hpp"
37#include "oops/instanceKlass.hpp"
38#include "oops/objArrayOop.hpp"
39#include "oops/oop.inline.hpp"
40
41int ArrayKlass::static_size(int header_size) {
42  // size of an array klass object
43  assert(header_size <= InstanceKlass::header_size(), "bad header size");
44  // If this assert fails, see comments in base_create_array_klass.
45  header_size = InstanceKlass::header_size();
46  int vtable_len = Universe::base_vtable_size();
47  int size = header_size + vtable_len;
48  return align_metadata_size(size);
49}
50
51
52Klass* ArrayKlass::java_super() const {
53  if (super() == NULL)  return NULL;  // bootstrap case
54  // Array klasses have primary supertypes which are not reported to Java.
55  // Example super chain:  String[][] -> Object[][] -> Object[] -> Object
56  return SystemDictionary::Object_klass();
57}
58
59
60oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
61  ShouldNotReachHere();
62  return NULL;
63}
64
65// find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
66Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
67  // There are no fields in an array klass but look to the super class (Object)
68  assert(super(), "super klass must be present");
69  return super()->find_field(name, sig, fd);
70}
71
72Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
73                                           const Symbol* signature,
74                                           OverpassLookupMode overpass_mode) const {
75  // There are no methods in an array klass but the super class (Object) has some
76  assert(super(), "super klass must be present");
77  // Always ignore overpass methods in superclasses, although technically the
78  // super klass of an array, (j.l.Object) should not have
79  // any overpass methods present.
80  return super()->uncached_lookup_method(name, signature, Klass::skip_overpass);
81}
82
83ArrayKlass::ArrayKlass(Symbol* name) :
84  _dimension(1),
85  _higher_dimension(NULL),
86  _lower_dimension(NULL) {
87    // Arrays don't add any new methods, so their vtable is the same size as
88    // the vtable of klass Object.
89    set_vtable_length(Universe::base_vtable_size());
90    set_name(name);
91    set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass());
92    set_layout_helper(Klass::_lh_neutral_value);
93    set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
94    TRACE_INIT_ID(this);
95}
96
97
98// Initialization of vtables and mirror object is done separatly from base_create_array_klass,
99// since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
100void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
101  ResourceMark rm(THREAD);
102  k->initialize_supers(super_klass, CHECK);
103  k->vtable().initialize_vtable(false, CHECK);
104
105  // During bootstrapping, before java.base is defined, the module_entry may not be present yet.
106  // These classes will be put on a fixup list and their module fields will be patched once
107  // java.base is defined.
108  assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()),
109         "module entry not available post " JAVA_BASE_NAME " definition");
110  oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL;
111  java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), CHECK);
112}
113
114GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) {
115  // interfaces = { cloneable_klass, serializable_klass };
116  assert(num_extra_slots == 0, "sanity of primitive array type");
117  // Must share this for correct bootstrapping!
118  set_secondary_supers(Universe::the_array_interfaces_array());
119  return NULL;
120}
121
122bool ArrayKlass::compute_is_subtype_of(Klass* k) {
123  // An array is a subtype of Serializable, Clonable, and Object
124  return    k == SystemDictionary::Object_klass()
125         || k == SystemDictionary::Cloneable_klass()
126         || k == SystemDictionary::Serializable_klass();
127}
128
129objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
130  if (length < 0) {
131    THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
132  }
133  if (length > arrayOopDesc::max_array_length(T_ARRAY)) {
134    report_java_out_of_memory("Requested array size exceeds VM limit");
135    JvmtiExport::post_array_size_exhausted();
136    THROW_OOP_0(Universe::out_of_memory_error_array_size());
137  }
138  int size = objArrayOopDesc::object_size(length);
139  Klass* k = array_klass(n+dimension(), CHECK_0);
140  ArrayKlass* ak = ArrayKlass::cast(k);
141  objArrayOop o =
142    (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0);
143  // initialization to NULL not necessary, area already cleared
144  return o;
145}
146
147void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
148  Klass* k = this;
149  // Iterate over this array klass and all higher dimensions
150  while (k != NULL) {
151    f(k, CHECK);
152    k = ArrayKlass::cast(k)->higher_dimension();
153  }
154}
155
156void ArrayKlass::array_klasses_do(void f(Klass* k)) {
157  Klass* k = this;
158  // Iterate over this array klass and all higher dimensions
159  while (k != NULL) {
160    f(k);
161    k = ArrayKlass::cast(k)->higher_dimension();
162  }
163}
164
165// JVM support
166
167jint ArrayKlass::compute_modifier_flags(TRAPS) const {
168  return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
169}
170
171// JVMTI support
172
173jint ArrayKlass::jvmti_class_status() const {
174  return JVMTI_CLASS_STATUS_ARRAY;
175}
176
177void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
178  Klass::metaspace_pointers_do(it);
179
180  ResourceMark rm;
181  log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name());
182
183  // need to cast away volatile
184  it->push((Klass**)&_higher_dimension);
185  it->push((Klass**)&_lower_dimension);
186}
187
188void ArrayKlass::remove_unshareable_info() {
189  Klass::remove_unshareable_info();
190  if (_higher_dimension != NULL) {
191    ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
192    ak->remove_unshareable_info();
193  }
194}
195
196void ArrayKlass::remove_java_mirror() {
197  Klass::remove_java_mirror();
198  if (_higher_dimension != NULL) {
199    ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
200    ak->remove_java_mirror();
201  }
202}
203
204void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
205  assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
206  Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
207  // Klass recreates the component mirror also
208
209  if (_higher_dimension != NULL) {
210    ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
211    ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
212  }
213}
214
215// Printing
216
217void ArrayKlass::print_on(outputStream* st) const {
218  assert(is_klass(), "must be klass");
219  Klass::print_on(st);
220}
221
222void ArrayKlass::print_value_on(outputStream* st) const {
223  assert(is_klass(), "must be klass");
224  for(int index = 0; index < dimension(); index++) {
225    st->print("[]");
226  }
227}
228
229void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
230  assert(obj->is_array(), "must be array");
231  Klass::oop_print_on(obj, st);
232  st->print_cr(" - length: %d", arrayOop(obj)->length());
233}
234
235
236// Verification
237
238void ArrayKlass::verify_on(outputStream* st) {
239  Klass::verify_on(st);
240}
241
242void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
243  guarantee(obj->is_array(), "must be array");
244  arrayOop a = arrayOop(obj);
245  guarantee(a->length() >= 0, "array with negative length?");
246}
247