1 /*
   2  * Copyright (c) 1997, 2011, 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 "gc_implementation/shared/markSweep.inline.hpp"
  29 #include "gc_interface/collectedHeap.inline.hpp"
  30 #include "oops/instanceKlass.hpp"
  31 #include "oops/objArrayKlassKlass.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "oops/oop.inline2.hpp"
  34 #ifndef SERIALGC
  35 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
  36 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
  37 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
  38 #include "memory/cardTableRS.hpp"
  39 #include "oops/oop.pcgc.inline.hpp"
  40 #endif
  41 
  42 klassOop objArrayKlassKlass::create_klass(TRAPS) {
  43   objArrayKlassKlass o;
  44   KlassHandle h_this_klass(THREAD, Universe::klassKlassObj());
  45   KlassHandle k = base_create_klass(h_this_klass, header_size(), o.vtbl_value(), CHECK_0);
  46   assert(k()->size() == align_object_size(header_size()), "wrong size for object");
  47   java_lang_Class::create_mirror(k, CHECK_0); // Allocate mirror
  48   return k();
  49 }
  50 
  51 klassOop objArrayKlassKlass::allocate_system_objArray_klass(TRAPS) {
  52   // system_objArrays have no instance klass, so allocate with fake class, then reset to NULL
  53   KlassHandle kk(THREAD, Universe::intArrayKlassObj());
  54   klassOop k = allocate_objArray_klass(1, kk, CHECK_0);
  55   objArrayKlass* tk = (objArrayKlass*) k->klass_part();
  56   tk->set_element_klass(NULL);
  57   tk->set_bottom_klass(NULL);
  58   return k;
  59 }
  60 
  61 
  62 klassOop objArrayKlassKlass::allocate_objArray_klass(int n, KlassHandle element_klass, TRAPS) {
  63   objArrayKlassKlassHandle this_oop(THREAD, as_klassOop());
  64   return allocate_objArray_klass_impl(this_oop, n, element_klass, THREAD);
  65 }
  66 
  67 klassOop objArrayKlassKlass::allocate_objArray_klass_impl(objArrayKlassKlassHandle this_oop,
  68                                                           int n, KlassHandle element_klass, TRAPS) {
  69 
  70   // Eagerly allocate the direct array supertype.
  71   KlassHandle super_klass = KlassHandle();
  72   if (!Universe::is_bootstrapping()) {
  73     KlassHandle element_super (THREAD, element_klass->super());
  74     if (element_super.not_null()) {
  75       // The element type has a direct super.  E.g., String[] has direct super of Object[].
  76       super_klass = KlassHandle(THREAD, element_super->array_klass_or_null());
  77       bool supers_exist = super_klass.not_null();
  78       // Also, see if the element has secondary supertypes.
  79       // We need an array type for each.
  80       objArrayHandle element_supers = objArrayHandle(THREAD,
  81                                             element_klass->secondary_supers());
  82       for( int i = element_supers->length()-1; i >= 0; i-- ) {
  83         klassOop elem_super = (klassOop) element_supers->obj_at(i);
  84         if (Klass::cast(elem_super)->array_klass_or_null() == NULL) {
  85           supers_exist = false;
  86           break;
  87         }
  88       }
  89       if (!supers_exist) {
  90         // Oops.  Not allocated yet.  Back out, allocate it, and retry.
  91 #ifndef PRODUCT
  92         if (WizardMode) {
  93           tty->print_cr("Must retry array klass creation for depth %d",n);
  94         }
  95 #endif
  96         KlassHandle ek;
  97         {
  98           MutexUnlocker mu(MultiArray_lock);
  99           MutexUnlocker mc(Compile_lock);   // for vtables
 100           klassOop sk = element_super->array_klass(CHECK_0);
 101           super_klass = KlassHandle(THREAD, sk);
 102           for( int i = element_supers->length()-1; i >= 0; i-- ) {
 103             KlassHandle elem_super (THREAD, element_supers->obj_at(i));
 104             elem_super->array_klass(CHECK_0);
 105           }
 106           // Now retry from the beginning
 107           klassOop klass_oop = element_klass->array_klass(n, CHECK_0);
 108           // Create a handle because the enclosing brace, when locking
 109           // can cause a gc.  Better to have this function return a Handle.
 110           ek = KlassHandle(THREAD, klass_oop);
 111         }  // re-lock
 112         return ek();
 113       }
 114     } else {
 115       // The element type is already Object.  Object[] has direct super of Object.
 116       super_klass = KlassHandle(THREAD, SystemDictionary::Object_klass());
 117     }
 118   }
 119 
 120   // Create type name for klass.
 121   Symbol* name = NULL;
 122   if (!element_klass->oop_is_instance() ||
 123       (name = instanceKlass::cast(element_klass())->array_name()) == NULL) {
 124 
 125     ResourceMark rm(THREAD);
 126     char *name_str = element_klass->name()->as_C_string();
 127     int len = element_klass->name()->utf8_length();
 128     char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
 129     int idx = 0;
 130     new_str[idx++] = '[';
 131     if (element_klass->oop_is_instance()) { // it could be an array or simple type
 132       new_str[idx++] = 'L';
 133     }
 134     memcpy(&new_str[idx], name_str, len * sizeof(char));
 135     idx += len;
 136     if (element_klass->oop_is_instance()) {
 137       new_str[idx++] = ';';
 138     }
 139     new_str[idx++] = '\0';
 140     name = SymbolTable::new_symbol(new_str, CHECK_0);
 141     if (element_klass->oop_is_instance()) {
 142       instanceKlass* ik = instanceKlass::cast(element_klass());
 143       ik->set_array_name(name);
 144     }
 145   }
 146 
 147   objArrayKlass o;
 148   arrayKlassHandle k = arrayKlass::base_create_array_klass(o.vtbl_value(),
 149                                                            objArrayKlass::header_size(),
 150                                                           this_oop,
 151                                                            CHECK_0);
 152 
 153   // Initialize instance variables
 154   objArrayKlass* oak = objArrayKlass::cast(k());
 155   oak->set_dimension(n);
 156   oak->set_element_klass(element_klass());
 157   oak->set_name(name);
 158   // decrement refcount because object arrays are not explicitly freed.  The
 159   // instanceKlass array_name() keeps the name counted while the klass is
 160   // loaded.
 161   name->decrement_refcount();
 162 
 163   klassOop bk;
 164   if (element_klass->oop_is_objArray()) {
 165     bk = objArrayKlass::cast(element_klass())->bottom_klass();
 166   } else {
 167     bk = element_klass();
 168   }
 169   assert(bk != NULL && (Klass::cast(bk)->oop_is_instance() || Klass::cast(bk)->oop_is_typeArray()), "invalid bottom klass");
 170   oak->set_bottom_klass(bk);
 171 
 172   oak->set_layout_helper(array_layout_helper(T_OBJECT));
 173   assert(oak->oop_is_javaArray(), "sanity");
 174   assert(oak->oop_is_objArray(), "sanity");
 175 
 176   // Call complete_create_array_klass after all instance variables has been initialized.
 177   arrayKlass::complete_create_array_klass(k, super_klass, CHECK_0);
 178 
 179   return k();
 180 }
 181 
 182 
 183 void objArrayKlassKlass::oop_follow_contents(oop obj) {
 184   assert(obj->is_klass(), "must be klass");
 185   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
 186 
 187   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 188   MarkSweep::mark_and_push(oak->element_klass_addr());
 189   MarkSweep::mark_and_push(oak->bottom_klass_addr());
 190 
 191   arrayKlassKlass::oop_follow_contents(obj);
 192 }
 193 
 194 #ifndef SERIALGC
 195 void objArrayKlassKlass::oop_follow_contents(ParCompactionManager* cm,
 196                                              oop obj) {
 197   assert(obj->is_klass(), "must be klass");
 198   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
 199 
 200   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 201   PSParallelCompact::mark_and_push(cm, oak->element_klass_addr());
 202   PSParallelCompact::mark_and_push(cm, oak->bottom_klass_addr());
 203 
 204   arrayKlassKlass::oop_follow_contents(cm, obj);
 205 }
 206 #endif // SERIALGC
 207 
 208 
 209 int objArrayKlassKlass::oop_adjust_pointers(oop obj) {
 210   assert(obj->is_klass(), "must be klass");
 211   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
 212 
 213   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 214   MarkSweep::adjust_pointer(oak->element_klass_addr());
 215   MarkSweep::adjust_pointer(oak->bottom_klass_addr());
 216 
 217   return arrayKlassKlass::oop_adjust_pointers(obj);
 218 }
 219 
 220 
 221 
 222 int objArrayKlassKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
 223   assert(obj->is_klass(), "must be klass");
 224   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
 225 
 226   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 227   blk->do_oop(oak->element_klass_addr());
 228   blk->do_oop(oak->bottom_klass_addr());
 229 
 230   return arrayKlassKlass::oop_oop_iterate(obj, blk);
 231 }
 232 
 233 
 234 int
 235 objArrayKlassKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
 236   assert(obj->is_klass(), "must be klass");
 237   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
 238 
 239   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 240   oop* addr;
 241   addr = oak->element_klass_addr();
 242   if (mr.contains(addr)) blk->do_oop(addr);
 243   addr = oak->bottom_klass_addr();
 244   if (mr.contains(addr)) blk->do_oop(addr);
 245 
 246   return arrayKlassKlass::oop_oop_iterate_m(obj, blk, mr);
 247 }
 248 
 249 #ifndef SERIALGC
 250 void objArrayKlassKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
 251   assert(obj->blueprint()->oop_is_objArrayKlass(),"must be an obj array klass");
 252   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 253   oop* p = oak->element_klass_addr();
 254   if (PSScavenge::should_scavenge(p)) {
 255     pm->claim_or_forward_depth(p);
 256   }
 257   p = oak->bottom_klass_addr();
 258   if (PSScavenge::should_scavenge(p)) {
 259     pm->claim_or_forward_depth(p);
 260   }
 261 
 262   arrayKlassKlass::oop_push_contents(pm, obj);
 263 }
 264 
 265 int objArrayKlassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
 266   assert(obj->is_klass(), "must be klass");
 267   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
 268 
 269   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 270   PSParallelCompact::adjust_pointer(oak->element_klass_addr());
 271   PSParallelCompact::adjust_pointer(oak->bottom_klass_addr());
 272 
 273   return arrayKlassKlass::oop_update_pointers(cm, obj);
 274 }
 275 #endif // SERIALGC
 276 
 277 #ifndef PRODUCT
 278 
 279 // Printing
 280 
 281 void objArrayKlassKlass::oop_print_on(oop obj, outputStream* st) {
 282   assert(obj->is_klass(), "must be klass");
 283   objArrayKlass* oak = (objArrayKlass*) klassOop(obj)->klass_part();
 284   klassKlass::oop_print_on(obj, st);
 285   st->print(" - instance klass: ");
 286   oak->element_klass()->print_value_on(st);
 287   st->cr();
 288 }
 289 
 290 #endif //PRODUCT
 291 
 292 void objArrayKlassKlass::oop_print_value_on(oop obj, outputStream* st) {
 293   assert(obj->is_klass(), "must be klass");
 294   objArrayKlass* oak = (objArrayKlass*) klassOop(obj)->klass_part();
 295 
 296   oak->element_klass()->print_value_on(st);
 297   st->print("[]");
 298 }
 299 
 300 const char* objArrayKlassKlass::internal_name() const {
 301   return "{object array class}";
 302 }
 303 
 304 
 305 // Verification
 306 
 307 void objArrayKlassKlass::oop_verify_on(oop obj, outputStream* st) {
 308   arrayKlassKlass::oop_verify_on(obj, st);
 309   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
 310   guarantee(oak->element_klass()->is_perm(),  "should be in permspace");
 311   guarantee(oak->element_klass()->is_klass(), "should be klass");
 312   guarantee(oak->bottom_klass()->is_perm(),   "should be in permspace");
 313   guarantee(oak->bottom_klass()->is_klass(),  "should be klass");
 314   Klass* bk = Klass::cast(oak->bottom_klass());
 315   guarantee(bk->oop_is_instance() || bk->oop_is_typeArray(),  "invalid bottom klass");
 316 }