src/share/vm/oops/arrayKlass.cpp

Thu, 04 Apr 2019 17:56:29 +0800

author
aoqi
date
Thu, 04 Apr 2019 17:56:29 +0800
changeset 9572
624a0741915c
parent 8856
ac27a9c85bea
child 9931
fd44df5e3bc3
permissions
-rw-r--r--

Merge

     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  */
    25 #include "precompiled.hpp"
    26 #include "classfile/javaClasses.hpp"
    27 #include "classfile/systemDictionary.hpp"
    28 #include "classfile/vmSymbols.hpp"
    29 #include "gc_interface/collectedHeap.inline.hpp"
    30 #include "jvmtifiles/jvmti.h"
    31 #include "memory/gcLocker.hpp"
    32 #include "memory/universe.inline.hpp"
    33 #include "oops/arrayKlass.hpp"
    34 #include "oops/arrayOop.hpp"
    35 #include "oops/instanceKlass.hpp"
    36 #include "oops/objArrayOop.hpp"
    37 #include "oops/oop.inline.hpp"
    39 int ArrayKlass::static_size(int header_size) {
    40   // size of an array klass object
    41   assert(header_size <= InstanceKlass::header_size(), "bad header size");
    42   // If this assert fails, see comments in base_create_array_klass.
    43   header_size = InstanceKlass::header_size();
    44   int vtable_len = Universe::base_vtable_size();
    45 #ifdef _LP64
    46   int size = header_size + align_object_offset(vtable_len);
    47 #else
    48   int size = header_size + vtable_len;
    49 #endif
    50   return align_object_size(size);
    51 }
    54 Klass* ArrayKlass::java_super() const {
    55   if (super() == NULL)  return NULL;  // bootstrap case
    56   // Array klasses have primary supertypes which are not reported to Java.
    57   // Example super chain:  String[][] -> Object[][] -> Object[] -> Object
    58   return SystemDictionary::Object_klass();
    59 }
    62 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
    63   ShouldNotReachHere();
    64   return NULL;
    65 }
    67 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
    68 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
    69   // There are no fields in an array klass but look to the super class (Object)
    70   assert(super(), "super klass must be present");
    71   return super()->find_field(name, sig, fd);
    72 }
    74 Method* ArrayKlass::uncached_lookup_method(Symbol* name, Symbol* signature, 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 }
    83 ArrayKlass::ArrayKlass(Symbol* name) {
    84   set_name(name);
    86   set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass());
    87   set_layout_helper(Klass::_lh_neutral_value);
    88   set_dimension(1);
    89   set_higher_dimension(NULL);
    90   set_lower_dimension(NULL);
    91   set_component_mirror(NULL);
    92   // Arrays don't add any new methods, so their vtable is the same size as
    93   // the vtable of klass Object.
    94   int vtable_size = Universe::base_vtable_size();
    95   set_vtable_length(vtable_size);
    96   set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
    97 }
   100 // Initialization of vtables and mirror object is done separatly from base_create_array_klass,
   101 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
   102 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, KlassHandle super_klass, TRAPS) {
   103   ResourceMark rm(THREAD);
   104   k->initialize_supers(super_klass(), CHECK);
   105   k->vtable()->initialize_vtable(false, CHECK);
   106   java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(NULL), CHECK);
   107 }
   109 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) {
   110   // interfaces = { cloneable_klass, serializable_klass };
   111   assert(num_extra_slots == 0, "sanity of primitive array type");
   112   // Must share this for correct bootstrapping!
   113   set_secondary_supers(Universe::the_array_interfaces_array());
   114   return NULL;
   115 }
   117 bool ArrayKlass::compute_is_subtype_of(Klass* k) {
   118   // An array is a subtype of Serializable, Clonable, and Object
   119   return    k == SystemDictionary::Object_klass()
   120          || k == SystemDictionary::Cloneable_klass()
   121          || k == SystemDictionary::Serializable_klass();
   122 }
   125 inline intptr_t* ArrayKlass::start_of_vtable() const {
   126   // all vtables start at the same place, that's why we use InstanceKlass::header_size here
   127   return ((intptr_t*)this) + InstanceKlass::header_size();
   128 }
   131 klassVtable* ArrayKlass::vtable() const {
   132   KlassHandle kh(Thread::current(), this);
   133   return new klassVtable(kh, start_of_vtable(), vtable_length() / vtableEntry::size());
   134 }
   137 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
   138   if (length < 0) {
   139     THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
   140   }
   141   if (length > arrayOopDesc::max_array_length(T_ARRAY)) {
   142     report_java_out_of_memory("Requested array size exceeds VM limit");
   143     JvmtiExport::post_array_size_exhausted();
   144     THROW_OOP_0(Universe::out_of_memory_error_array_size());
   145   }
   146   int size = objArrayOopDesc::object_size(length);
   147   Klass* k = array_klass(n+dimension(), CHECK_0);
   148   ArrayKlass* ak = ArrayKlass::cast(k);
   149   objArrayOop o =
   150     (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0);
   151   // initialization to NULL not necessary, area already cleared
   152   return o;
   153 }
   155 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
   156   Klass* k = this;
   157   // Iterate over this array klass and all higher dimensions
   158   while (k != NULL) {
   159     f(k, CHECK);
   160     k = ArrayKlass::cast(k)->higher_dimension();
   161   }
   162 }
   164 void ArrayKlass::array_klasses_do(void f(Klass* k)) {
   165   Klass* k = this;
   166   // Iterate over this array klass and all higher dimensions
   167   while (k != NULL) {
   168     f(k);
   169     k = ArrayKlass::cast(k)->higher_dimension();
   170   }
   171 }
   173 // GC support
   175 void ArrayKlass::oops_do(OopClosure* cl) {
   176   Klass::oops_do(cl);
   178   cl->do_oop(adr_component_mirror());
   179 }
   181 // JVM support
   183 jint ArrayKlass::compute_modifier_flags(TRAPS) const {
   184   return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
   185 }
   187 // JVMTI support
   189 jint ArrayKlass::jvmti_class_status() const {
   190   return JVMTI_CLASS_STATUS_ARRAY;
   191 }
   193 void ArrayKlass::remove_unshareable_info() {
   194   Klass::remove_unshareable_info();
   195   // Clear the java mirror
   196   set_component_mirror(NULL);
   197 }
   199 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
   200   assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
   201   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
   202   // Klass recreates the component mirror also
   203 }
   205 // Printing
   207 void ArrayKlass::print_on(outputStream* st) const {
   208   assert(is_klass(), "must be klass");
   209   Klass::print_on(st);
   210 }
   212 void ArrayKlass::print_value_on(outputStream* st) const {
   213   assert(is_klass(), "must be klass");
   214   for(int index = 0; index < dimension(); index++) {
   215     st->print("[]");
   216   }
   217 }
   219 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
   220   assert(obj->is_array(), "must be array");
   221   Klass::oop_print_on(obj, st);
   222   st->print_cr(" - length: %d", arrayOop(obj)->length());
   223 }
   226 // Verification
   228 void ArrayKlass::verify_on(outputStream* st) {
   229   Klass::verify_on(st);
   231   if (component_mirror() != NULL) {
   232     guarantee(component_mirror()->klass() != NULL, "should have a class");
   233   }
   234 }
   236 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
   237   guarantee(obj->is_array(), "must be array");
   238   arrayOop a = arrayOop(obj);
   239   guarantee(a->length() >= 0, "array with negative length?");
   240 }

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