1 /*
   2  * Copyright (c) 1997, 2010, 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/classLoader.hpp"
  27 #include "classfile/javaClasses.hpp"
  28 #include "classfile/symbolTable.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "classfile/vmSymbols.hpp"
  31 #include "code/codeCache.hpp"
  32 #include "code/dependencies.hpp"
  33 #include "gc_interface/collectedHeap.inline.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "memory/cardTableModRefBS.hpp"
  36 #include "memory/filemap.hpp"
  37 #include "memory/gcLocker.inline.hpp"
  38 #include "memory/genCollectedHeap.hpp"
  39 #include "memory/genRemSet.hpp"
  40 #include "memory/generation.hpp"
  41 #include "memory/oopFactory.hpp"
  42 #include "memory/permGen.hpp"
  43 #include "memory/space.hpp"
  44 #include "memory/universe.hpp"
  45 #include "memory/universe.inline.hpp"
  46 #include "oops/arrayKlassKlass.hpp"
  47 #include "oops/compiledICHolderKlass.hpp"
  48 #include "oops/constMethodKlass.hpp"
  49 #include "oops/constantPoolKlass.hpp"
  50 #include "oops/constantPoolOop.hpp"
  51 #include "oops/cpCacheKlass.hpp"
  52 #include "oops/cpCacheOop.hpp"
  53 #include "oops/instanceKlass.hpp"
  54 #include "oops/instanceMirrorKlass.hpp"
  55 #include "oops/instanceKlassKlass.hpp"
  56 #include "oops/instanceRefKlass.hpp"
  57 #include "oops/klassKlass.hpp"
  58 #include "oops/klassOop.hpp"
  59 #include "oops/methodDataKlass.hpp"
  60 #include "oops/methodKlass.hpp"
  61 #include "oops/objArrayKlassKlass.hpp"
  62 #include "oops/oop.inline.hpp"
  63 #include "oops/typeArrayKlass.hpp"
  64 #include "oops/typeArrayKlassKlass.hpp"
  65 #include "prims/jvmtiRedefineClassesTrace.hpp"
  66 #include "runtime/aprofiler.hpp"
  67 #include "runtime/arguments.hpp"
  68 #include "runtime/deoptimization.hpp"
  69 #include "runtime/fprofiler.hpp"
  70 #include "runtime/handles.inline.hpp"
  71 #include "runtime/init.hpp"
  72 #include "runtime/java.hpp"
  73 #include "runtime/javaCalls.hpp"
  74 #include "runtime/sharedRuntime.hpp"
  75 #include "runtime/synchronizer.hpp"
  76 #include "runtime/timer.hpp"
  77 #include "runtime/vm_operations.hpp"
  78 #include "services/memoryService.hpp"
  79 #include "utilities/copy.hpp"
  80 #include "utilities/events.hpp"
  81 #include "utilities/hashtable.inline.hpp"
  82 #include "utilities/preserveException.hpp"
  83 #ifdef TARGET_OS_FAMILY_linux
  84 # include "thread_linux.inline.hpp"
  85 #endif
  86 #ifdef TARGET_OS_FAMILY_solaris
  87 # include "thread_solaris.inline.hpp"
  88 #endif
  89 #ifdef TARGET_OS_FAMILY_windows
  90 # include "thread_windows.inline.hpp"
  91 #endif
  92 #ifndef SERIALGC
  93 #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
  94 #include "gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp"
  95 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  96 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
  97 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
  98 #endif
  99 
 100 // Known objects
 101 klassOop Universe::_boolArrayKlassObj                 = NULL;
 102 klassOop Universe::_byteArrayKlassObj                 = NULL;
 103 klassOop Universe::_charArrayKlassObj                 = NULL;
 104 klassOop Universe::_intArrayKlassObj                  = NULL;
 105 klassOop Universe::_shortArrayKlassObj                = NULL;
 106 klassOop Universe::_longArrayKlassObj                 = NULL;
 107 klassOop Universe::_singleArrayKlassObj               = NULL;
 108 klassOop Universe::_doubleArrayKlassObj               = NULL;
 109 klassOop Universe::_typeArrayKlassObjs[T_VOID+1]      = { NULL /*, NULL...*/ };
 110 klassOop Universe::_objectArrayKlassObj               = NULL;
 111 klassOop Universe::_methodKlassObj                    = NULL;
 112 klassOop Universe::_constMethodKlassObj               = NULL;
 113 klassOop Universe::_methodDataKlassObj                = NULL;
 114 klassOop Universe::_klassKlassObj                     = NULL;
 115 klassOop Universe::_arrayKlassKlassObj                = NULL;
 116 klassOop Universe::_objArrayKlassKlassObj             = NULL;
 117 klassOop Universe::_typeArrayKlassKlassObj            = NULL;
 118 klassOop Universe::_instanceKlassKlassObj             = NULL;
 119 klassOop Universe::_constantPoolKlassObj              = NULL;
 120 klassOop Universe::_constantPoolCacheKlassObj         = NULL;
 121 klassOop Universe::_compiledICHolderKlassObj          = NULL;
 122 klassOop Universe::_systemObjArrayKlassObj            = NULL;
 123 oop Universe::_int_mirror                             = NULL;
 124 oop Universe::_float_mirror                           = NULL;
 125 oop Universe::_double_mirror                          = NULL;
 126 oop Universe::_byte_mirror                            = NULL;
 127 oop Universe::_bool_mirror                            = NULL;
 128 oop Universe::_char_mirror                            = NULL;
 129 oop Universe::_long_mirror                            = NULL;
 130 oop Universe::_short_mirror                           = NULL;
 131 oop Universe::_void_mirror                            = NULL;
 132 oop Universe::_mirrors[T_VOID+1]                      = { NULL /*, NULL...*/ };
 133 oop Universe::_main_thread_group                      = NULL;
 134 oop Universe::_system_thread_group                    = NULL;
 135 typeArrayOop Universe::_the_empty_byte_array          = NULL;
 136 typeArrayOop Universe::_the_empty_short_array         = NULL;
 137 typeArrayOop Universe::_the_empty_int_array           = NULL;
 138 objArrayOop Universe::_the_empty_system_obj_array     = NULL;
 139 objArrayOop Universe::_the_empty_class_klass_array    = NULL;
 140 objArrayOop Universe::_the_array_interfaces_array     = NULL;
 141 oop Universe::_the_null_string                        = NULL;
 142 oop Universe::_the_min_jint_string                   = NULL;
 143 LatestMethodOopCache* Universe::_finalizer_register_cache = NULL;
 144 LatestMethodOopCache* Universe::_loader_addClass_cache    = NULL;
 145 ActiveMethodOopsCache* Universe::_reflect_invoke_cache    = NULL;
 146 oop Universe::_out_of_memory_error_java_heap          = NULL;
 147 oop Universe::_out_of_memory_error_perm_gen           = NULL;
 148 oop Universe::_out_of_memory_error_array_size         = NULL;
 149 oop Universe::_out_of_memory_error_gc_overhead_limit  = NULL;
 150 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
 151 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 152 bool Universe::_verify_in_progress                    = false;
 153 oop Universe::_null_ptr_exception_instance            = NULL;
 154 oop Universe::_arithmetic_exception_instance          = NULL;
 155 oop Universe::_virtual_machine_error_instance         = NULL;
 156 oop Universe::_vm_exception                           = NULL;
 157 
 158 // These variables are guarded by FullGCALot_lock.
 159 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;)
 160 debug_only(int Universe::_fullgc_alot_dummy_next      = 0;)
 161 
 162 
 163 // Heap
 164 int             Universe::_verify_count = 0;
 165 
 166 int             Universe::_base_vtable_size = 0;
 167 bool            Universe::_bootstrapping = false;
 168 bool            Universe::_fully_initialized = false;
 169 
 170 size_t          Universe::_heap_capacity_at_last_gc;
 171 size_t          Universe::_heap_used_at_last_gc = 0;
 172 
 173 CollectedHeap*  Universe::_collectedHeap = NULL;
 174 
 175 NarrowOopStruct Universe::_narrow_oop = { NULL, 0, true };
 176 
 177 
 178 void Universe::basic_type_classes_do(void f(klassOop)) {
 179   f(boolArrayKlassObj());
 180   f(byteArrayKlassObj());
 181   f(charArrayKlassObj());
 182   f(intArrayKlassObj());
 183   f(shortArrayKlassObj());
 184   f(longArrayKlassObj());
 185   f(singleArrayKlassObj());
 186   f(doubleArrayKlassObj());
 187 }
 188 
 189 
 190 void Universe::system_classes_do(void f(klassOop)) {
 191   f(methodKlassObj());
 192   f(constMethodKlassObj());
 193   f(methodDataKlassObj());
 194   f(klassKlassObj());
 195   f(arrayKlassKlassObj());
 196   f(objArrayKlassKlassObj());
 197   f(typeArrayKlassKlassObj());
 198   f(instanceKlassKlassObj());
 199   f(constantPoolKlassObj());
 200   f(systemObjArrayKlassObj());
 201 }
 202 
 203 void Universe::oops_do(OopClosure* f, bool do_all) {
 204 
 205   f->do_oop((oop*) &_int_mirror);
 206   f->do_oop((oop*) &_float_mirror);
 207   f->do_oop((oop*) &_double_mirror);
 208   f->do_oop((oop*) &_byte_mirror);
 209   f->do_oop((oop*) &_bool_mirror);
 210   f->do_oop((oop*) &_char_mirror);
 211   f->do_oop((oop*) &_long_mirror);
 212   f->do_oop((oop*) &_short_mirror);
 213   f->do_oop((oop*) &_void_mirror);
 214 
 215   // It's important to iterate over these guys even if they are null,
 216   // since that's how shared heaps are restored.
 217   for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 218     f->do_oop((oop*) &_mirrors[i]);
 219   }
 220   assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking");
 221 
 222   // %%% Consider moving those "shared oops" over here with the others.
 223   f->do_oop((oop*)&_boolArrayKlassObj);
 224   f->do_oop((oop*)&_byteArrayKlassObj);
 225   f->do_oop((oop*)&_charArrayKlassObj);
 226   f->do_oop((oop*)&_intArrayKlassObj);
 227   f->do_oop((oop*)&_shortArrayKlassObj);
 228   f->do_oop((oop*)&_longArrayKlassObj);
 229   f->do_oop((oop*)&_singleArrayKlassObj);
 230   f->do_oop((oop*)&_doubleArrayKlassObj);
 231   f->do_oop((oop*)&_objectArrayKlassObj);
 232   {
 233     for (int i = 0; i < T_VOID+1; i++) {
 234       if (_typeArrayKlassObjs[i] != NULL) {
 235         assert(i >= T_BOOLEAN, "checking");
 236         f->do_oop((oop*)&_typeArrayKlassObjs[i]);
 237       } else if (do_all) {
 238         f->do_oop((oop*)&_typeArrayKlassObjs[i]);
 239       }
 240     }
 241   }
 242   f->do_oop((oop*)&_methodKlassObj);
 243   f->do_oop((oop*)&_constMethodKlassObj);
 244   f->do_oop((oop*)&_methodDataKlassObj);
 245   f->do_oop((oop*)&_klassKlassObj);
 246   f->do_oop((oop*)&_arrayKlassKlassObj);
 247   f->do_oop((oop*)&_objArrayKlassKlassObj);
 248   f->do_oop((oop*)&_typeArrayKlassKlassObj);
 249   f->do_oop((oop*)&_instanceKlassKlassObj);
 250   f->do_oop((oop*)&_constantPoolKlassObj);
 251   f->do_oop((oop*)&_constantPoolCacheKlassObj);
 252   f->do_oop((oop*)&_compiledICHolderKlassObj);
 253   f->do_oop((oop*)&_systemObjArrayKlassObj);
 254   f->do_oop((oop*)&_the_empty_byte_array);
 255   f->do_oop((oop*)&_the_empty_short_array);
 256   f->do_oop((oop*)&_the_empty_int_array);
 257   f->do_oop((oop*)&_the_empty_system_obj_array);
 258   f->do_oop((oop*)&_the_empty_class_klass_array);
 259   f->do_oop((oop*)&_the_array_interfaces_array);
 260   f->do_oop((oop*)&_the_null_string);
 261   f->do_oop((oop*)&_the_min_jint_string);
 262   _finalizer_register_cache->oops_do(f);
 263   _loader_addClass_cache->oops_do(f);
 264   _reflect_invoke_cache->oops_do(f);
 265   f->do_oop((oop*)&_out_of_memory_error_java_heap);
 266   f->do_oop((oop*)&_out_of_memory_error_perm_gen);
 267   f->do_oop((oop*)&_out_of_memory_error_array_size);
 268   f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
 269   if (_preallocated_out_of_memory_error_array != (oop)NULL) {   // NULL when DumpSharedSpaces
 270     f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
 271   }
 272   f->do_oop((oop*)&_null_ptr_exception_instance);
 273   f->do_oop((oop*)&_arithmetic_exception_instance);
 274   f->do_oop((oop*)&_virtual_machine_error_instance);
 275   f->do_oop((oop*)&_main_thread_group);
 276   f->do_oop((oop*)&_system_thread_group);
 277   f->do_oop((oop*)&_vm_exception);
 278   debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
 279 }
 280 
 281 
 282 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
 283   if (size < alignment || size % alignment != 0) {
 284     ResourceMark rm;
 285     stringStream st;
 286     st.print("Size of %s (%ld bytes) must be aligned to %ld bytes", name, size, alignment);
 287     char* error = st.as_string();
 288     vm_exit_during_initialization(error);
 289   }
 290 }
 291 
 292 
 293 void Universe::genesis(TRAPS) {
 294   ResourceMark rm;
 295   { FlagSetting fs(_bootstrapping, true);
 296 
 297     { MutexLocker mc(Compile_lock);
 298 
 299       // determine base vtable size; without that we cannot create the array klasses
 300       compute_base_vtable_size();
 301 
 302       if (!UseSharedSpaces) {
 303         _klassKlassObj          = klassKlass::create_klass(CHECK);
 304         _arrayKlassKlassObj     = arrayKlassKlass::create_klass(CHECK);
 305 
 306         _objArrayKlassKlassObj  = objArrayKlassKlass::create_klass(CHECK);
 307         _instanceKlassKlassObj  = instanceKlassKlass::create_klass(CHECK);
 308         _typeArrayKlassKlassObj = typeArrayKlassKlass::create_klass(CHECK);
 309 
 310         _boolArrayKlassObj      = typeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK);
 311         _charArrayKlassObj      = typeArrayKlass::create_klass(T_CHAR,    sizeof(jchar),    CHECK);
 312         _singleArrayKlassObj    = typeArrayKlass::create_klass(T_FLOAT,   sizeof(jfloat),   CHECK);
 313         _doubleArrayKlassObj    = typeArrayKlass::create_klass(T_DOUBLE,  sizeof(jdouble),  CHECK);
 314         _byteArrayKlassObj      = typeArrayKlass::create_klass(T_BYTE,    sizeof(jbyte),    CHECK);
 315         _shortArrayKlassObj     = typeArrayKlass::create_klass(T_SHORT,   sizeof(jshort),   CHECK);
 316         _intArrayKlassObj       = typeArrayKlass::create_klass(T_INT,     sizeof(jint),     CHECK);
 317         _longArrayKlassObj      = typeArrayKlass::create_klass(T_LONG,    sizeof(jlong),    CHECK);
 318 
 319         _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj;
 320         _typeArrayKlassObjs[T_CHAR]    = _charArrayKlassObj;
 321         _typeArrayKlassObjs[T_FLOAT]   = _singleArrayKlassObj;
 322         _typeArrayKlassObjs[T_DOUBLE]  = _doubleArrayKlassObj;
 323         _typeArrayKlassObjs[T_BYTE]    = _byteArrayKlassObj;
 324         _typeArrayKlassObjs[T_SHORT]   = _shortArrayKlassObj;
 325         _typeArrayKlassObjs[T_INT]     = _intArrayKlassObj;
 326         _typeArrayKlassObjs[T_LONG]    = _longArrayKlassObj;
 327 
 328         _methodKlassObj             = methodKlass::create_klass(CHECK);
 329         _constMethodKlassObj        = constMethodKlass::create_klass(CHECK);
 330         _methodDataKlassObj         = methodDataKlass::create_klass(CHECK);
 331         _constantPoolKlassObj       = constantPoolKlass::create_klass(CHECK);
 332         _constantPoolCacheKlassObj  = constantPoolCacheKlass::create_klass(CHECK);
 333 
 334         _compiledICHolderKlassObj   = compiledICHolderKlass::create_klass(CHECK);
 335         _systemObjArrayKlassObj     = objArrayKlassKlass::cast(objArrayKlassKlassObj())->allocate_system_objArray_klass(CHECK);
 336 
 337         _the_empty_byte_array       = oopFactory::new_permanent_byteArray(0, CHECK);
 338         _the_empty_short_array      = oopFactory::new_permanent_shortArray(0, CHECK);
 339         _the_empty_int_array        = oopFactory::new_permanent_intArray(0, CHECK);
 340         _the_empty_system_obj_array = oopFactory::new_system_objArray(0, CHECK);
 341 
 342         _the_array_interfaces_array = oopFactory::new_system_objArray(2, CHECK);
 343       }
 344     }
 345 
 346     vmSymbols::initialize(CHECK);
 347 
 348     SystemDictionary::initialize(CHECK);
 349 
 350     klassOop ok = SystemDictionary::Object_klass();
 351 
 352     _the_null_string            = StringTable::intern("null", CHECK);
 353     _the_min_jint_string       = StringTable::intern("-2147483648", CHECK);
 354 
 355     if (UseSharedSpaces) {
 356       // Verify shared interfaces array.
 357       assert(_the_array_interfaces_array->obj_at(0) ==
 358              SystemDictionary::Cloneable_klass(), "u3");
 359       assert(_the_array_interfaces_array->obj_at(1) ==
 360              SystemDictionary::Serializable_klass(), "u3");
 361 
 362       // Verify element klass for system obj array klass
 363       assert(objArrayKlass::cast(_systemObjArrayKlassObj)->element_klass() == ok, "u1");
 364       assert(objArrayKlass::cast(_systemObjArrayKlassObj)->bottom_klass() == ok, "u2");
 365 
 366       // Verify super class for the classes created above
 367       assert(Klass::cast(boolArrayKlassObj()     )->super() == ok, "u3");
 368       assert(Klass::cast(charArrayKlassObj()     )->super() == ok, "u3");
 369       assert(Klass::cast(singleArrayKlassObj()   )->super() == ok, "u3");
 370       assert(Klass::cast(doubleArrayKlassObj()   )->super() == ok, "u3");
 371       assert(Klass::cast(byteArrayKlassObj()     )->super() == ok, "u3");
 372       assert(Klass::cast(shortArrayKlassObj()    )->super() == ok, "u3");
 373       assert(Klass::cast(intArrayKlassObj()      )->super() == ok, "u3");
 374       assert(Klass::cast(longArrayKlassObj()     )->super() == ok, "u3");
 375       assert(Klass::cast(constantPoolKlassObj()  )->super() == ok, "u3");
 376       assert(Klass::cast(systemObjArrayKlassObj())->super() == ok, "u3");
 377     } else {
 378       // Set up shared interfaces array.  (Do this before supers are set up.)
 379       _the_array_interfaces_array->obj_at_put(0, SystemDictionary::Cloneable_klass());
 380       _the_array_interfaces_array->obj_at_put(1, SystemDictionary::Serializable_klass());
 381 
 382       // Set element klass for system obj array klass
 383       objArrayKlass::cast(_systemObjArrayKlassObj)->set_element_klass(ok);
 384       objArrayKlass::cast(_systemObjArrayKlassObj)->set_bottom_klass(ok);
 385 
 386       // Set super class for the classes created above
 387       Klass::cast(boolArrayKlassObj()     )->initialize_supers(ok, CHECK);
 388       Klass::cast(charArrayKlassObj()     )->initialize_supers(ok, CHECK);
 389       Klass::cast(singleArrayKlassObj()   )->initialize_supers(ok, CHECK);
 390       Klass::cast(doubleArrayKlassObj()   )->initialize_supers(ok, CHECK);
 391       Klass::cast(byteArrayKlassObj()     )->initialize_supers(ok, CHECK);
 392       Klass::cast(shortArrayKlassObj()    )->initialize_supers(ok, CHECK);
 393       Klass::cast(intArrayKlassObj()      )->initialize_supers(ok, CHECK);
 394       Klass::cast(longArrayKlassObj()     )->initialize_supers(ok, CHECK);
 395       Klass::cast(constantPoolKlassObj()  )->initialize_supers(ok, CHECK);
 396       Klass::cast(systemObjArrayKlassObj())->initialize_supers(ok, CHECK);
 397       Klass::cast(boolArrayKlassObj()     )->set_super(ok);
 398       Klass::cast(charArrayKlassObj()     )->set_super(ok);
 399       Klass::cast(singleArrayKlassObj()   )->set_super(ok);
 400       Klass::cast(doubleArrayKlassObj()   )->set_super(ok);
 401       Klass::cast(byteArrayKlassObj()     )->set_super(ok);
 402       Klass::cast(shortArrayKlassObj()    )->set_super(ok);
 403       Klass::cast(intArrayKlassObj()      )->set_super(ok);
 404       Klass::cast(longArrayKlassObj()     )->set_super(ok);
 405       Klass::cast(constantPoolKlassObj()  )->set_super(ok);
 406       Klass::cast(systemObjArrayKlassObj())->set_super(ok);
 407     }
 408 
 409     Klass::cast(boolArrayKlassObj()     )->append_to_sibling_list();
 410     Klass::cast(charArrayKlassObj()     )->append_to_sibling_list();
 411     Klass::cast(singleArrayKlassObj()   )->append_to_sibling_list();
 412     Klass::cast(doubleArrayKlassObj()   )->append_to_sibling_list();
 413     Klass::cast(byteArrayKlassObj()     )->append_to_sibling_list();
 414     Klass::cast(shortArrayKlassObj()    )->append_to_sibling_list();
 415     Klass::cast(intArrayKlassObj()      )->append_to_sibling_list();
 416     Klass::cast(longArrayKlassObj()     )->append_to_sibling_list();
 417     Klass::cast(constantPoolKlassObj()  )->append_to_sibling_list();
 418     Klass::cast(systemObjArrayKlassObj())->append_to_sibling_list();
 419   } // end of core bootstrapping
 420 
 421   // Initialize _objectArrayKlass after core bootstraping to make
 422   // sure the super class is set up properly for _objectArrayKlass.
 423   _objectArrayKlassObj = instanceKlass::
 424     cast(SystemDictionary::Object_klass())->array_klass(1, CHECK);
 425   // Add the class to the class hierarchy manually to make sure that
 426   // its vtable is initialized after core bootstrapping is completed.
 427   Klass::cast(_objectArrayKlassObj)->append_to_sibling_list();
 428 
 429   // Compute is_jdk version flags.
 430   // Only 1.3 or later has the java.lang.Shutdown class.
 431   // Only 1.4 or later has the java.lang.CharSequence interface.
 432   // Only 1.5 or later has the java.lang.management.MemoryUsage class.
 433   if (JDK_Version::is_partially_initialized()) {
 434     uint8_t jdk_version;
 435     klassOop k = SystemDictionary::resolve_or_null(
 436         vmSymbols::java_lang_management_MemoryUsage(), THREAD);
 437     CLEAR_PENDING_EXCEPTION; // ignore exceptions
 438     if (k == NULL) {
 439       k = SystemDictionary::resolve_or_null(
 440           vmSymbols::java_lang_CharSequence(), THREAD);
 441       CLEAR_PENDING_EXCEPTION; // ignore exceptions
 442       if (k == NULL) {
 443         k = SystemDictionary::resolve_or_null(
 444             vmSymbols::java_lang_Shutdown(), THREAD);
 445         CLEAR_PENDING_EXCEPTION; // ignore exceptions
 446         if (k == NULL) {
 447           jdk_version = 2;
 448         } else {
 449           jdk_version = 3;
 450         }
 451       } else {
 452         jdk_version = 4;
 453       }
 454     } else {
 455       jdk_version = 5;
 456     }
 457     JDK_Version::fully_initialize(jdk_version);
 458   }
 459 
 460   #ifdef ASSERT
 461   if (FullGCALot) {
 462     // Allocate an array of dummy objects.
 463     // We'd like these to be at the bottom of the old generation,
 464     // so that when we free one and then collect,
 465     // (almost) the whole heap moves
 466     // and we find out if we actually update all the oops correctly.
 467     // But we can't allocate directly in the old generation,
 468     // so we allocate wherever, and hope that the first collection
 469     // moves these objects to the bottom of the old generation.
 470     // We can allocate directly in the permanent generation, so we do.
 471     int size;
 472     if (UseConcMarkSweepGC) {
 473       warning("Using +FullGCALot with concurrent mark sweep gc "
 474               "will not force all objects to relocate");
 475       size = FullGCALotDummies;
 476     } else {
 477       size = FullGCALotDummies * 2;
 478     }
 479     objArrayOop    naked_array = oopFactory::new_system_objArray(size, CHECK);
 480     objArrayHandle dummy_array(THREAD, naked_array);
 481     int i = 0;
 482     while (i < size) {
 483       if (!UseConcMarkSweepGC) {
 484         // Allocate dummy in old generation
 485         oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_instance(CHECK);
 486         dummy_array->obj_at_put(i++, dummy);
 487       }
 488       // Allocate dummy in permanent generation
 489       oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_permanent_instance(CHECK);
 490       dummy_array->obj_at_put(i++, dummy);
 491     }
 492     {
 493       // Only modify the global variable inside the mutex.
 494       // If we had a race to here, the other dummy_array instances
 495       // and their elements just get dropped on the floor, which is fine.
 496       MutexLocker ml(FullGCALot_lock);
 497       if (_fullgc_alot_dummy_array == NULL) {
 498         _fullgc_alot_dummy_array = dummy_array();
 499       }
 500     }
 501     assert(i == _fullgc_alot_dummy_array->length(), "just checking");
 502   }
 503   #endif
 504 }
 505 
 506 
 507 static inline void* dereference(void* addr) {
 508   return *(void**)addr;
 509 }
 510 
 511 static inline void add_vtable(void** list, int* n, void* o, int count) {
 512   guarantee((*n) < count, "vtable list too small");
 513   void* vtable = dereference(o);
 514   assert(dereference(vtable) != NULL, "invalid vtable");
 515   list[(*n)++] = vtable;
 516 }
 517 
 518 void Universe::init_self_patching_vtbl_list(void** list, int count) {
 519   int n = 0;
 520   { klassKlass o;             add_vtable(list, &n, &o, count); }
 521   { arrayKlassKlass o;        add_vtable(list, &n, &o, count); }
 522   { objArrayKlassKlass o;     add_vtable(list, &n, &o, count); }
 523   { instanceKlassKlass o;     add_vtable(list, &n, &o, count); }
 524   { instanceKlass o;          add_vtable(list, &n, &o, count); }
 525   { instanceMirrorKlass o;    add_vtable(list, &n, &o, count); }
 526   { instanceRefKlass o;       add_vtable(list, &n, &o, count); }
 527   { typeArrayKlassKlass o;    add_vtable(list, &n, &o, count); }
 528   { typeArrayKlass o;         add_vtable(list, &n, &o, count); }
 529   { methodKlass o;            add_vtable(list, &n, &o, count); }
 530   { constMethodKlass o;       add_vtable(list, &n, &o, count); }
 531   { constantPoolKlass o;      add_vtable(list, &n, &o, count); }
 532   { constantPoolCacheKlass o; add_vtable(list, &n, &o, count); }
 533   { objArrayKlass o;          add_vtable(list, &n, &o, count); }
 534   { methodDataKlass o;        add_vtable(list, &n, &o, count); }
 535   { compiledICHolderKlass o;  add_vtable(list, &n, &o, count); }
 536 #ifndef PRODUCT
 537   // In non-product builds CHeapObj is derived from AllocatedObj,
 538   // so symbols in CDS archive should have their vtable pointer patched.
 539   { Symbol o;                 add_vtable(list, &n, &o, count); }
 540 #endif
 541 }
 542 
 543 
 544 class FixupMirrorClosure: public ObjectClosure {
 545  public:
 546   virtual void do_object(oop obj) {
 547     if (obj->is_klass()) {
 548       EXCEPTION_MARK;
 549       KlassHandle k(THREAD, klassOop(obj));
 550       // We will never reach the CATCH below since Exceptions::_throw will cause
 551       // the VM to exit if an exception is thrown during initialization
 552       java_lang_Class::fixup_mirror(k, CATCH);
 553       // This call unconditionally creates a new mirror for k,
 554       // and links in k's component_mirror field if k is an array.
 555       // If k is an objArray, k's element type must already have
 556       // a mirror.  In other words, this closure must process
 557       // the component type of an objArray k before it processes k.
 558       // This works because the permgen iterator presents arrays
 559       // and their component types in order of creation.
 560     }
 561   }
 562 };
 563 
 564 void Universe::initialize_basic_type_mirrors(TRAPS) {
 565   if (UseSharedSpaces) {
 566     assert(_int_mirror != NULL, "already loaded");
 567     assert(_void_mirror == _mirrors[T_VOID], "consistently loaded");
 568   } else {
 569 
 570     assert(_int_mirror==NULL, "basic type mirrors already initialized");
 571     _int_mirror     =
 572       java_lang_Class::create_basic_type_mirror("int",    T_INT, CHECK);
 573     _float_mirror   =
 574       java_lang_Class::create_basic_type_mirror("float",  T_FLOAT,   CHECK);
 575     _double_mirror  =
 576       java_lang_Class::create_basic_type_mirror("double", T_DOUBLE,  CHECK);
 577     _byte_mirror    =
 578       java_lang_Class::create_basic_type_mirror("byte",   T_BYTE, CHECK);
 579     _bool_mirror    =
 580       java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK);
 581     _char_mirror    =
 582       java_lang_Class::create_basic_type_mirror("char",   T_CHAR, CHECK);
 583     _long_mirror    =
 584       java_lang_Class::create_basic_type_mirror("long",   T_LONG, CHECK);
 585     _short_mirror   =
 586       java_lang_Class::create_basic_type_mirror("short",  T_SHORT,   CHECK);
 587     _void_mirror    =
 588       java_lang_Class::create_basic_type_mirror("void",   T_VOID, CHECK);
 589 
 590     _mirrors[T_INT]     = _int_mirror;
 591     _mirrors[T_FLOAT]   = _float_mirror;
 592     _mirrors[T_DOUBLE]  = _double_mirror;
 593     _mirrors[T_BYTE]    = _byte_mirror;
 594     _mirrors[T_BOOLEAN] = _bool_mirror;
 595     _mirrors[T_CHAR]    = _char_mirror;
 596     _mirrors[T_LONG]    = _long_mirror;
 597     _mirrors[T_SHORT]   = _short_mirror;
 598     _mirrors[T_VOID]    = _void_mirror;
 599     //_mirrors[T_OBJECT]  = instanceKlass::cast(_object_klass)->java_mirror();
 600     //_mirrors[T_ARRAY]   = instanceKlass::cast(_object_klass)->java_mirror();
 601   }
 602 }
 603 
 604 void Universe::fixup_mirrors(TRAPS) {
 605   // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
 606   // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
 607   // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
 608   // that the number of objects allocated at this point is very small.
 609   assert(SystemDictionary::Class_klass_loaded(), "java.lang.Class should be loaded");
 610 
 611   // Cache the start of the static fields
 612   instanceMirrorKlass::set_offset_of_static_fields(instanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize);
 613 
 614   FixupMirrorClosure blk;
 615   Universe::heap()->permanent_object_iterate(&blk);
 616 }
 617 
 618 
 619 static bool has_run_finalizers_on_exit = false;
 620 
 621 void Universe::run_finalizers_on_exit() {
 622   if (has_run_finalizers_on_exit) return;
 623   has_run_finalizers_on_exit = true;
 624 
 625   // Called on VM exit. This ought to be run in a separate thread.
 626   if (TraceReferenceGC) tty->print_cr("Callback to run finalizers on exit");
 627   {
 628     PRESERVE_EXCEPTION_MARK;
 629     KlassHandle finalizer_klass(THREAD, SystemDictionary::Finalizer_klass());
 630     JavaValue result(T_VOID);
 631     JavaCalls::call_static(
 632       &result,
 633       finalizer_klass,
 634       vmSymbols::run_finalizers_on_exit_name(),
 635       vmSymbols::void_method_signature(),
 636       THREAD
 637     );
 638     // Ignore any pending exceptions
 639     CLEAR_PENDING_EXCEPTION;
 640   }
 641 }
 642 
 643 
 644 // initialize_vtable could cause gc if
 645 // 1) we specified true to initialize_vtable and
 646 // 2) this ran after gc was enabled
 647 // In case those ever change we use handles for oops
 648 void Universe::reinitialize_vtable_of(KlassHandle k_h, TRAPS) {
 649   // init vtable of k and all subclasses
 650   Klass* ko = k_h()->klass_part();
 651   klassVtable* vt = ko->vtable();
 652   if (vt) vt->initialize_vtable(false, CHECK);
 653   if (ko->oop_is_instance()) {
 654     instanceKlass* ik = (instanceKlass*)ko;
 655     for (KlassHandle s_h(THREAD, ik->subklass()); s_h() != NULL; s_h = (THREAD, s_h()->klass_part()->next_sibling())) {
 656       reinitialize_vtable_of(s_h, CHECK);
 657     }
 658   }
 659 }
 660 
 661 
 662 void initialize_itable_for_klass(klassOop k, TRAPS) {
 663   instanceKlass::cast(k)->itable()->initialize_itable(false, CHECK);
 664 }
 665 
 666 
 667 void Universe::reinitialize_itables(TRAPS) {
 668   SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
 669 
 670 }
 671 
 672 
 673 bool Universe::on_page_boundary(void* addr) {
 674   return ((uintptr_t) addr) % os::vm_page_size() == 0;
 675 }
 676 
 677 
 678 bool Universe::should_fill_in_stack_trace(Handle throwable) {
 679   // never attempt to fill in the stack trace of preallocated errors that do not have
 680   // backtrace. These errors are kept alive forever and may be "re-used" when all
 681   // preallocated errors with backtrace have been consumed. Also need to avoid
 682   // a potential loop which could happen if an out of memory occurs when attempting
 683   // to allocate the backtrace.
 684   return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
 685           (throwable() != Universe::_out_of_memory_error_perm_gen)  &&
 686           (throwable() != Universe::_out_of_memory_error_array_size) &&
 687           (throwable() != Universe::_out_of_memory_error_gc_overhead_limit));
 688 }
 689 
 690 
 691 oop Universe::gen_out_of_memory_error(oop default_err) {
 692   // generate an out of memory error:
 693   // - if there is a preallocated error with backtrace available then return it wth
 694   //   a filled in stack trace.
 695   // - if there are no preallocated errors with backtrace available then return
 696   //   an error without backtrace.
 697   int next;
 698   if (_preallocated_out_of_memory_error_avail_count > 0) {
 699     next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count);
 700     assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
 701   } else {
 702     next = -1;
 703   }
 704   if (next < 0) {
 705     // all preallocated errors have been used.
 706     // return default
 707     return default_err;
 708   } else {
 709     // get the error object at the slot and set set it to NULL so that the
 710     // array isn't keeping it alive anymore.
 711     oop exc = preallocated_out_of_memory_errors()->obj_at(next);
 712     assert(exc != NULL, "slot has been used already");
 713     preallocated_out_of_memory_errors()->obj_at_put(next, NULL);
 714 
 715     // use the message from the default error
 716     oop msg = java_lang_Throwable::message(default_err);
 717     assert(msg != NULL, "no message");
 718     java_lang_Throwable::set_message(exc, msg);
 719 
 720     // populate the stack trace and return it.
 721     java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
 722     return exc;
 723   }
 724 }
 725 
 726 static intptr_t non_oop_bits = 0;
 727 
 728 void* Universe::non_oop_word() {
 729   // Neither the high bits nor the low bits of this value is allowed
 730   // to look like (respectively) the high or low bits of a real oop.
 731   //
 732   // High and low are CPU-specific notions, but low always includes
 733   // the low-order bit.  Since oops are always aligned at least mod 4,
 734   // setting the low-order bit will ensure that the low half of the
 735   // word will never look like that of a real oop.
 736   //
 737   // Using the OS-supplied non-memory-address word (usually 0 or -1)
 738   // will take care of the high bits, however many there are.
 739 
 740   if (non_oop_bits == 0) {
 741     non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
 742   }
 743 
 744   return (void*)non_oop_bits;
 745 }
 746 
 747 jint universe_init() {
 748   assert(!Universe::_fully_initialized, "called after initialize_vtables");
 749   guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
 750          "LogHeapWordSize is incorrect.");
 751   guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
 752   guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
 753             "oop size is not not a multiple of HeapWord size");
 754   TraceTime timer("Genesis", TraceStartupTime);
 755   GC_locker::lock();  // do not allow gc during bootstrapping
 756   JavaClasses::compute_hard_coded_offsets();
 757 
 758   // Get map info from shared archive file.
 759   if (DumpSharedSpaces)
 760     UseSharedSpaces = false;
 761 
 762   FileMapInfo* mapinfo = NULL;
 763   if (UseSharedSpaces) {
 764     mapinfo = NEW_C_HEAP_OBJ(FileMapInfo);
 765     memset(mapinfo, 0, sizeof(FileMapInfo));
 766 
 767     // Open the shared archive file, read and validate the header. If
 768     // initialization files, shared spaces [UseSharedSpaces] are
 769     // disabled and the file is closed.
 770 
 771     if (mapinfo->initialize()) {
 772       FileMapInfo::set_current_info(mapinfo);
 773     } else {
 774       assert(!mapinfo->is_open() && !UseSharedSpaces,
 775              "archive file not closed or shared spaces not disabled.");
 776     }
 777   }
 778 
 779   jint status = Universe::initialize_heap();
 780   if (status != JNI_OK) {
 781     return status;
 782   }
 783 
 784   // We have a heap so create the methodOop caches before
 785   // CompactingPermGenGen::initialize_oops() tries to populate them.
 786   Universe::_finalizer_register_cache = new LatestMethodOopCache();
 787   Universe::_loader_addClass_cache    = new LatestMethodOopCache();
 788   Universe::_reflect_invoke_cache     = new ActiveMethodOopsCache();
 789 
 790   if (UseSharedSpaces) {
 791 
 792     // Read the data structures supporting the shared spaces (shared
 793     // system dictionary, symbol table, etc.).  After that, access to
 794     // the file (other than the mapped regions) is no longer needed, and
 795     // the file is closed. Closing the file does not affect the
 796     // currently mapped regions.
 797 
 798     CompactingPermGenGen::initialize_oops();
 799     mapinfo->close();
 800 
 801   } else {
 802     SymbolTable::create_table();
 803     StringTable::create_table();
 804     ClassLoader::create_package_info_table();
 805   }
 806 
 807   return JNI_OK;
 808 }
 809 
 810 // Choose the heap base address and oop encoding mode
 811 // when compressed oops are used:
 812 // Unscaled  - Use 32-bits oops without encoding when
 813 //     NarrowOopHeapBaseMin + heap_size < 4Gb
 814 // ZeroBased - Use zero based compressed oops with encoding when
 815 //     NarrowOopHeapBaseMin + heap_size < 32Gb
 816 // HeapBased - Use compressed oops with heap base + encoding.
 817 
 818 // 4Gb
 819 static const uint64_t NarrowOopHeapMax = (uint64_t(max_juint) + 1);
 820 // 32Gb
 821 // OopEncodingHeapMax == NarrowOopHeapMax << LogMinObjAlignmentInBytes;
 822 
 823 char* Universe::preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode) {
 824   size_t base = 0;
 825 #ifdef _LP64
 826   if (UseCompressedOops) {
 827     assert(mode == UnscaledNarrowOop  ||
 828            mode == ZeroBasedNarrowOop ||
 829            mode == HeapBasedNarrowOop, "mode is invalid");
 830     const size_t total_size = heap_size + HeapBaseMinAddress;
 831     // Return specified base for the first request.
 832     if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) {
 833       base = HeapBaseMinAddress;
 834     } else if (total_size <= OopEncodingHeapMax && (mode != HeapBasedNarrowOop)) {
 835       if (total_size <= NarrowOopHeapMax && (mode == UnscaledNarrowOop) &&
 836           (Universe::narrow_oop_shift() == 0)) {
 837         // Use 32-bits oops without encoding and
 838         // place heap's top on the 4Gb boundary
 839         base = (NarrowOopHeapMax - heap_size);
 840       } else {
 841         // Can't reserve with NarrowOopShift == 0
 842         Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 843         if (mode == UnscaledNarrowOop ||
 844             mode == ZeroBasedNarrowOop && total_size <= NarrowOopHeapMax) {
 845           // Use zero based compressed oops with encoding and
 846           // place heap's top on the 32Gb boundary in case
 847           // total_size > 4Gb or failed to reserve below 4Gb.
 848           base = (OopEncodingHeapMax - heap_size);
 849         }
 850       }
 851     } else {
 852       // Can't reserve below 32Gb.
 853       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 854     }
 855     // Set narrow_oop_base and narrow_oop_use_implicit_null_checks
 856     // used in ReservedHeapSpace() constructors.
 857     // The final values will be set in initialize_heap() below.
 858     if (base != 0 && (base + heap_size) <= OopEncodingHeapMax) {
 859       // Use zero based compressed oops
 860       Universe::set_narrow_oop_base(NULL);
 861       // Don't need guard page for implicit checks in indexed
 862       // addressing mode with zero based Compressed Oops.
 863       Universe::set_narrow_oop_use_implicit_null_checks(true);
 864     } else {
 865       // Set to a non-NULL value so the ReservedSpace ctor computes
 866       // the correct no-access prefix.
 867       // The final value will be set in initialize_heap() below.
 868       Universe::set_narrow_oop_base((address)NarrowOopHeapMax);
 869 #ifdef _WIN64
 870       if (UseLargePages) {
 871         // Cannot allocate guard pages for implicit checks in indexed
 872         // addressing mode when large pages are specified on windows.
 873         Universe::set_narrow_oop_use_implicit_null_checks(false);
 874       }
 875 #endif //  _WIN64
 876     }
 877   }
 878 #endif
 879   return (char*)base; // also return NULL (don't care) for 32-bit VM
 880 }
 881 
 882 jint Universe::initialize_heap() {
 883 
 884   if (UseParallelGC) {
 885 #ifndef SERIALGC
 886     Universe::_collectedHeap = new ParallelScavengeHeap();
 887 #else  // SERIALGC
 888     fatal("UseParallelGC not supported in java kernel vm.");
 889 #endif // SERIALGC
 890 
 891   } else if (UseG1GC) {
 892 #ifndef SERIALGC
 893     G1CollectorPolicy* g1p = new G1CollectorPolicy_BestRegionsFirst();
 894     G1CollectedHeap* g1h = new G1CollectedHeap(g1p);
 895     Universe::_collectedHeap = g1h;
 896 #else  // SERIALGC
 897     fatal("UseG1GC not supported in java kernel vm.");
 898 #endif // SERIALGC
 899 
 900   } else {
 901     GenCollectorPolicy *gc_policy;
 902 
 903     if (UseSerialGC) {
 904       gc_policy = new MarkSweepPolicy();
 905     } else if (UseConcMarkSweepGC) {
 906 #ifndef SERIALGC
 907       if (UseAdaptiveSizePolicy) {
 908         gc_policy = new ASConcurrentMarkSweepPolicy();
 909       } else {
 910         gc_policy = new ConcurrentMarkSweepPolicy();
 911       }
 912 #else   // SERIALGC
 913     fatal("UseConcMarkSweepGC not supported in java kernel vm.");
 914 #endif // SERIALGC
 915     } else { // default old generation
 916       gc_policy = new MarkSweepPolicy();
 917     }
 918 
 919     Universe::_collectedHeap = new GenCollectedHeap(gc_policy);
 920   }
 921 
 922   jint status = Universe::heap()->initialize();
 923   if (status != JNI_OK) {
 924     return status;
 925   }
 926 
 927 #ifdef _LP64
 928   if (UseCompressedOops) {
 929     // Subtract a page because something can get allocated at heap base.
 930     // This also makes implicit null checking work, because the
 931     // memory+1 page below heap_base needs to cause a signal.
 932     // See needs_explicit_null_check.
 933     // Only set the heap base for compressed oops because it indicates
 934     // compressed oops for pstack code.
 935     bool verbose = PrintCompressedOopsMode || (PrintMiscellaneous && Verbose);
 936     if (verbose) {
 937       tty->cr();
 938       tty->print("heap address: " PTR_FORMAT ", size: " SIZE_FORMAT " MB",
 939                  Universe::heap()->base(), Universe::heap()->reserved_region().byte_size()/M);
 940     }
 941     if ((uint64_t)Universe::heap()->reserved_region().end() > OopEncodingHeapMax) {
 942       // Can't reserve heap below 32Gb.
 943       Universe::set_narrow_oop_base(Universe::heap()->base() - os::vm_page_size());
 944       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 945       if (verbose) {
 946         tty->print(", Compressed Oops with base: "PTR_FORMAT, Universe::narrow_oop_base());
 947       }
 948     } else {
 949       Universe::set_narrow_oop_base(0);
 950       if (verbose) {
 951         tty->print(", zero based Compressed Oops");
 952       }
 953 #ifdef _WIN64
 954       if (!Universe::narrow_oop_use_implicit_null_checks()) {
 955         // Don't need guard page for implicit checks in indexed addressing
 956         // mode with zero based Compressed Oops.
 957         Universe::set_narrow_oop_use_implicit_null_checks(true);
 958       }
 959 #endif //  _WIN64
 960       if((uint64_t)Universe::heap()->reserved_region().end() > NarrowOopHeapMax) {
 961         // Can't reserve heap below 4Gb.
 962         Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 963       } else {
 964         Universe::set_narrow_oop_shift(0);
 965         if (verbose) {
 966           tty->print(", 32-bits Oops");
 967         }
 968       }
 969     }
 970     if (verbose) {
 971       tty->cr();
 972       tty->cr();
 973     }
 974   }
 975   assert(Universe::narrow_oop_base() == (Universe::heap()->base() - os::vm_page_size()) ||
 976          Universe::narrow_oop_base() == NULL, "invalid value");
 977   assert(Universe::narrow_oop_shift() == LogMinObjAlignmentInBytes ||
 978          Universe::narrow_oop_shift() == 0, "invalid value");
 979 #endif
 980 
 981   // We will never reach the CATCH below since Exceptions::_throw will cause
 982   // the VM to exit if an exception is thrown during initialization
 983 
 984   if (UseTLAB) {
 985     assert(Universe::heap()->supports_tlab_allocation(),
 986            "Should support thread-local allocation buffers");
 987     ThreadLocalAllocBuffer::startup_initialization();
 988   }
 989   return JNI_OK;
 990 }
 991 
 992 // It's the caller's repsonsibility to ensure glitch-freedom
 993 // (if required).
 994 void Universe::update_heap_info_at_gc() {
 995   _heap_capacity_at_last_gc = heap()->capacity();
 996   _heap_used_at_last_gc     = heap()->used();
 997 }
 998 
 999 
1000 
1001 void universe2_init() {
1002   EXCEPTION_MARK;
1003   Universe::genesis(CATCH);
1004   // Although we'd like to verify here that the state of the heap
1005   // is good, we can't because the main thread has not yet added
1006   // itself to the threads list (so, using current interfaces
1007   // we can't "fill" its TLAB), unless TLABs are disabled.
1008   if (VerifyBeforeGC && !UseTLAB &&
1009       Universe::heap()->total_collections() >= VerifyGCStartAt) {
1010      Universe::heap()->prepare_for_verify();
1011      Universe::verify();   // make sure we're starting with a clean slate
1012   }
1013 }
1014 
1015 
1016 // This function is defined in JVM.cpp
1017 extern void initialize_converter_functions();
1018 
1019 bool universe_post_init() {
1020   assert(!is_init_completed(), "Error: initialization not yet completed!");
1021   Universe::_fully_initialized = true;
1022   EXCEPTION_MARK;
1023   { ResourceMark rm;
1024     Interpreter::initialize();      // needed for interpreter entry points
1025     if (!UseSharedSpaces) {
1026       KlassHandle ok_h(THREAD, SystemDictionary::Object_klass());
1027       Universe::reinitialize_vtable_of(ok_h, CHECK_false);
1028       Universe::reinitialize_itables(CHECK_false);
1029     }
1030   }
1031 
1032   klassOop k;
1033   instanceKlassHandle k_h;
1034   if (!UseSharedSpaces) {
1035     // Setup preallocated empty java.lang.Class array
1036     Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::Class_klass(), 0, CHECK_false);
1037     // Setup preallocated OutOfMemoryError errors
1038     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false);
1039     k_h = instanceKlassHandle(THREAD, k);
1040     Universe::_out_of_memory_error_java_heap = k_h->allocate_permanent_instance(CHECK_false);
1041     Universe::_out_of_memory_error_perm_gen = k_h->allocate_permanent_instance(CHECK_false);
1042     Universe::_out_of_memory_error_array_size = k_h->allocate_permanent_instance(CHECK_false);
1043     Universe::_out_of_memory_error_gc_overhead_limit =
1044       k_h->allocate_permanent_instance(CHECK_false);
1045 
1046     // Setup preallocated NullPointerException
1047     // (this is currently used for a cheap & dirty solution in compiler exception handling)
1048     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false);
1049     Universe::_null_ptr_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1050     // Setup preallocated ArithmeticException
1051     // (this is currently used for a cheap & dirty solution in compiler exception handling)
1052     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false);
1053     Universe::_arithmetic_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1054     // Virtual Machine Error for when we get into a situation we can't resolve
1055     k = SystemDictionary::resolve_or_fail(
1056       vmSymbols::java_lang_VirtualMachineError(), true, CHECK_false);
1057     bool linked = instanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1058     if (!linked) {
1059       tty->print_cr("Unable to link/verify VirtualMachineError class");
1060       return false; // initialization failed
1061     }
1062     Universe::_virtual_machine_error_instance =
1063       instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1064 
1065     Universe::_vm_exception               = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1066 
1067   }
1068   if (!DumpSharedSpaces) {
1069     // These are the only Java fields that are currently set during shared space dumping.
1070     // We prefer to not handle this generally, so we always reinitialize these detail messages.
1071     Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false);
1072     java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
1073 
1074     msg = java_lang_String::create_from_str("PermGen space", CHECK_false);
1075     java_lang_Throwable::set_message(Universe::_out_of_memory_error_perm_gen, msg());
1076 
1077     msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
1078     java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
1079 
1080     msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false);
1081     java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg());
1082 
1083     msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1084     java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
1085 
1086     // Setup the array of errors that have preallocated backtrace
1087     k = Universe::_out_of_memory_error_java_heap->klass();
1088     assert(k->klass_part()->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error");
1089     k_h = instanceKlassHandle(THREAD, k);
1090 
1091     int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
1092     Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(k_h(), len, CHECK_false);
1093     for (int i=0; i<len; i++) {
1094       oop err = k_h->allocate_permanent_instance(CHECK_false);
1095       Handle err_h = Handle(THREAD, err);
1096       java_lang_Throwable::allocate_backtrace(err_h, CHECK_false);
1097       Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h());
1098     }
1099     Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
1100   }
1101 
1102 
1103   // Setup static method for registering finalizers
1104   // The finalizer klass must be linked before looking up the method, in
1105   // case it needs to get rewritten.
1106   instanceKlass::cast(SystemDictionary::Finalizer_klass())->link_class(CHECK_false);
1107   methodOop m = instanceKlass::cast(SystemDictionary::Finalizer_klass())->find_method(
1108                                   vmSymbols::register_method_name(),
1109                                   vmSymbols::register_method_signature());
1110   if (m == NULL || !m->is_static()) {
1111     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1112       "java.lang.ref.Finalizer.register", false);
1113   }
1114   Universe::_finalizer_register_cache->init(
1115     SystemDictionary::Finalizer_klass(), m, CHECK_false);
1116 
1117   // Resolve on first use and initialize class.
1118   // Note: No race-condition here, since a resolve will always return the same result
1119 
1120   // Setup method for security checks
1121   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_reflect_Method(), true, CHECK_false);
1122   k_h = instanceKlassHandle(THREAD, k);
1123   k_h->link_class(CHECK_false);
1124   m = k_h->find_method(vmSymbols::invoke_name(), vmSymbols::object_object_array_object_signature());
1125   if (m == NULL || m->is_static()) {
1126     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1127       "java.lang.reflect.Method.invoke", false);
1128   }
1129   Universe::_reflect_invoke_cache->init(k_h(), m, CHECK_false);
1130 
1131   // Setup method for registering loaded classes in class loader vector
1132   instanceKlass::cast(SystemDictionary::ClassLoader_klass())->link_class(CHECK_false);
1133   m = instanceKlass::cast(SystemDictionary::ClassLoader_klass())->find_method(vmSymbols::addClass_name(), vmSymbols::class_void_signature());
1134   if (m == NULL || m->is_static()) {
1135     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1136       "java.lang.ClassLoader.addClass", false);
1137   }
1138   Universe::_loader_addClass_cache->init(
1139     SystemDictionary::ClassLoader_klass(), m, CHECK_false);
1140 
1141   // The folowing is initializing converter functions for serialization in
1142   // JVM.cpp. If we clean up the StrictMath code above we may want to find
1143   // a better solution for this as well.
1144   initialize_converter_functions();
1145 
1146   // This needs to be done before the first scavenge/gc, since
1147   // it's an input to soft ref clearing policy.
1148   {
1149     MutexLocker x(Heap_lock);
1150     Universe::update_heap_info_at_gc();
1151   }
1152 
1153   // ("weak") refs processing infrastructure initialization
1154   Universe::heap()->post_initialize();
1155 
1156   GC_locker::unlock();  // allow gc after bootstrapping
1157 
1158   MemoryService::set_universe_heap(Universe::_collectedHeap);
1159   return true;
1160 }
1161 
1162 
1163 void Universe::compute_base_vtable_size() {
1164   _base_vtable_size = ClassLoader::compute_Object_vtable();
1165 }
1166 
1167 
1168 // %%% The Universe::flush_foo methods belong in CodeCache.
1169 
1170 // Flushes compiled methods dependent on dependee.
1171 void Universe::flush_dependents_on(instanceKlassHandle dependee) {
1172   assert_lock_strong(Compile_lock);
1173 
1174   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1175 
1176   // CodeCache can only be updated by a thread_in_VM and they will all be
1177   // stopped dring the safepoint so CodeCache will be safe to update without
1178   // holding the CodeCache_lock.
1179 
1180   DepChange changes(dependee);
1181 
1182   // Compute the dependent nmethods
1183   if (CodeCache::mark_for_deoptimization(changes) > 0) {
1184     // At least one nmethod has been marked for deoptimization
1185     VM_Deoptimize op;
1186     VMThread::execute(&op);
1187   }
1188 }
1189 
1190 #ifdef HOTSWAP
1191 // Flushes compiled methods dependent on dependee in the evolutionary sense
1192 void Universe::flush_evol_dependents_on(instanceKlassHandle ev_k_h) {
1193   // --- Compile_lock is not held. However we are at a safepoint.
1194   assert_locked_or_safepoint(Compile_lock);
1195   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1196 
1197   // CodeCache can only be updated by a thread_in_VM and they will all be
1198   // stopped dring the safepoint so CodeCache will be safe to update without
1199   // holding the CodeCache_lock.
1200 
1201   // Compute the dependent nmethods
1202   if (CodeCache::mark_for_evol_deoptimization(ev_k_h) > 0) {
1203     // At least one nmethod has been marked for deoptimization
1204 
1205     // All this already happens inside a VM_Operation, so we'll do all the work here.
1206     // Stuff copied from VM_Deoptimize and modified slightly.
1207 
1208     // We do not want any GCs to happen while we are in the middle of this VM operation
1209     ResourceMark rm;
1210     DeoptimizationMarker dm;
1211 
1212     // Deoptimize all activations depending on marked nmethods
1213     Deoptimization::deoptimize_dependents();
1214 
1215     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1216     CodeCache::make_marked_nmethods_not_entrant();
1217   }
1218 }
1219 #endif // HOTSWAP
1220 
1221 
1222 // Flushes compiled methods dependent on dependee
1223 void Universe::flush_dependents_on_method(methodHandle m_h) {
1224   // --- Compile_lock is not held. However we are at a safepoint.
1225   assert_locked_or_safepoint(Compile_lock);
1226 
1227   // CodeCache can only be updated by a thread_in_VM and they will all be
1228   // stopped dring the safepoint so CodeCache will be safe to update without
1229   // holding the CodeCache_lock.
1230 
1231   // Compute the dependent nmethods
1232   if (CodeCache::mark_for_deoptimization(m_h()) > 0) {
1233     // At least one nmethod has been marked for deoptimization
1234 
1235     // All this already happens inside a VM_Operation, so we'll do all the work here.
1236     // Stuff copied from VM_Deoptimize and modified slightly.
1237 
1238     // We do not want any GCs to happen while we are in the middle of this VM operation
1239     ResourceMark rm;
1240     DeoptimizationMarker dm;
1241 
1242     // Deoptimize all activations depending on marked nmethods
1243     Deoptimization::deoptimize_dependents();
1244 
1245     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1246     CodeCache::make_marked_nmethods_not_entrant();
1247   }
1248 }
1249 
1250 void Universe::print() { print_on(gclog_or_tty); }
1251 
1252 void Universe::print_on(outputStream* st) {
1253   st->print_cr("Heap");
1254   heap()->print_on(st);
1255 }
1256 
1257 void Universe::print_heap_at_SIGBREAK() {
1258   if (PrintHeapAtSIGBREAK) {
1259     MutexLocker hl(Heap_lock);
1260     print_on(tty);
1261     tty->cr();
1262     tty->flush();
1263   }
1264 }
1265 
1266 void Universe::print_heap_before_gc(outputStream* st) {
1267   st->print_cr("{Heap before GC invocations=%u (full %u):",
1268                heap()->total_collections(),
1269                heap()->total_full_collections());
1270   heap()->print_on(st);
1271 }
1272 
1273 void Universe::print_heap_after_gc(outputStream* st) {
1274   st->print_cr("Heap after GC invocations=%u (full %u):",
1275                heap()->total_collections(),
1276                heap()->total_full_collections());
1277   heap()->print_on(st);
1278   st->print_cr("}");
1279 }
1280 
1281 void Universe::verify(bool allow_dirty, bool silent, bool option) {
1282   if (SharedSkipVerify) {
1283     return;
1284   }
1285 
1286   // The use of _verify_in_progress is a temporary work around for
1287   // 6320749.  Don't bother with a creating a class to set and clear
1288   // it since it is only used in this method and the control flow is
1289   // straight forward.
1290   _verify_in_progress = true;
1291 
1292   COMPILER2_PRESENT(
1293     assert(!DerivedPointerTable::is_active(),
1294          "DPT should not be active during verification "
1295          "(of thread stacks below)");
1296   )
1297 
1298   ResourceMark rm;
1299   HandleMark hm;  // Handles created during verification can be zapped
1300   _verify_count++;
1301 
1302   if (!silent) gclog_or_tty->print("[Verifying ");
1303   if (!silent) gclog_or_tty->print("threads ");
1304   Threads::verify();
1305   heap()->verify(allow_dirty, silent, option);
1306 
1307   if (!silent) gclog_or_tty->print("syms ");
1308   SymbolTable::verify();
1309   if (!silent) gclog_or_tty->print("strs ");
1310   StringTable::verify();
1311   {
1312     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1313     if (!silent) gclog_or_tty->print("zone ");
1314     CodeCache::verify();
1315   }
1316   if (!silent) gclog_or_tty->print("dict ");
1317   SystemDictionary::verify();
1318   if (!silent) gclog_or_tty->print("hand ");
1319   JNIHandles::verify();
1320   if (!silent) gclog_or_tty->print("C-heap ");
1321   os::check_heap();
1322   if (!silent) gclog_or_tty->print_cr("]");
1323 
1324   _verify_in_progress = false;
1325 }
1326 
1327 // Oop verification (see MacroAssembler::verify_oop)
1328 
1329 static uintptr_t _verify_oop_data[2]   = {0, (uintptr_t)-1};
1330 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1};
1331 
1332 
1333 static void calculate_verify_data(uintptr_t verify_data[2],
1334                                   HeapWord* low_boundary,
1335                                   HeapWord* high_boundary) {
1336   assert(low_boundary < high_boundary, "bad interval");
1337 
1338   // decide which low-order bits we require to be clear:
1339   size_t alignSize = MinObjAlignmentInBytes;
1340   size_t min_object_size = CollectedHeap::min_fill_size();
1341 
1342   // make an inclusive limit:
1343   uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1344   uintptr_t min = (uintptr_t)low_boundary;
1345   assert(min < max, "bad interval");
1346   uintptr_t diff = max ^ min;
1347 
1348   // throw away enough low-order bits to make the diff vanish
1349   uintptr_t mask = (uintptr_t)(-1);
1350   while ((mask & diff) != 0)
1351     mask <<= 1;
1352   uintptr_t bits = (min & mask);
1353   assert(bits == (max & mask), "correct mask");
1354   // check an intermediate value between min and max, just to make sure:
1355   assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1356 
1357   // require address alignment, too:
1358   mask |= (alignSize - 1);
1359 
1360   if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) {
1361     assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability");
1362   }
1363   verify_data[0] = mask;
1364   verify_data[1] = bits;
1365 }
1366 
1367 
1368 // Oop verification (see MacroAssembler::verify_oop)
1369 #ifndef PRODUCT
1370 
1371 uintptr_t Universe::verify_oop_mask() {
1372   MemRegion m = heap()->reserved_region();
1373   calculate_verify_data(_verify_oop_data,
1374                         m.start(),
1375                         m.end());
1376   return _verify_oop_data[0];
1377 }
1378 
1379 
1380 
1381 uintptr_t Universe::verify_oop_bits() {
1382   verify_oop_mask();
1383   return _verify_oop_data[1];
1384 }
1385 
1386 
1387 uintptr_t Universe::verify_klass_mask() {
1388   /* $$$
1389   // A klass can never live in the new space.  Since the new and old
1390   // spaces can change size, we must settle for bounds-checking against
1391   // the bottom of the world, plus the smallest possible new and old
1392   // space sizes that may arise during execution.
1393   size_t min_new_size = Universe::new_size();   // in bytes
1394   size_t min_old_size = Universe::old_size();   // in bytes
1395   calculate_verify_data(_verify_klass_data,
1396           (HeapWord*)((uintptr_t)_new_gen->low_boundary + min_new_size + min_old_size),
1397           _perm_gen->high_boundary);
1398                         */
1399   // Why doesn't the above just say that klass's always live in the perm
1400   // gen?  I'll see if that seems to work...
1401   MemRegion permanent_reserved;
1402   switch (Universe::heap()->kind()) {
1403   default:
1404     // ???: What if a CollectedHeap doesn't have a permanent generation?
1405     ShouldNotReachHere();
1406     break;
1407   case CollectedHeap::GenCollectedHeap:
1408   case CollectedHeap::G1CollectedHeap: {
1409     SharedHeap* sh = (SharedHeap*) Universe::heap();
1410     permanent_reserved = sh->perm_gen()->reserved();
1411    break;
1412   }
1413 #ifndef SERIALGC
1414   case CollectedHeap::ParallelScavengeHeap: {
1415     ParallelScavengeHeap* psh = (ParallelScavengeHeap*) Universe::heap();
1416     permanent_reserved = psh->perm_gen()->reserved();
1417     break;
1418   }
1419 #endif // SERIALGC
1420   }
1421   calculate_verify_data(_verify_klass_data,
1422                         permanent_reserved.start(),
1423                         permanent_reserved.end());
1424 
1425   return _verify_klass_data[0];
1426 }
1427 
1428 
1429 
1430 uintptr_t Universe::verify_klass_bits() {
1431   verify_klass_mask();
1432   return _verify_klass_data[1];
1433 }
1434 
1435 
1436 uintptr_t Universe::verify_mark_mask() {
1437   return markOopDesc::lock_mask_in_place;
1438 }
1439 
1440 
1441 
1442 uintptr_t Universe::verify_mark_bits() {
1443   intptr_t mask = verify_mark_mask();
1444   intptr_t bits = (intptr_t)markOopDesc::prototype();
1445   assert((bits & ~mask) == 0, "no stray header bits");
1446   return bits;
1447 }
1448 #endif // PRODUCT
1449 
1450 
1451 void Universe::compute_verify_oop_data() {
1452   verify_oop_mask();
1453   verify_oop_bits();
1454   verify_mark_mask();
1455   verify_mark_bits();
1456   verify_klass_mask();
1457   verify_klass_bits();
1458 }
1459 
1460 
1461 void CommonMethodOopCache::init(klassOop k, methodOop m, TRAPS) {
1462   if (!UseSharedSpaces) {
1463     _klass = k;
1464   }
1465 #ifndef PRODUCT
1466   else {
1467     // sharing initilization should have already set up _klass
1468     assert(_klass != NULL, "just checking");
1469   }
1470 #endif
1471 
1472   _method_idnum = m->method_idnum();
1473   assert(_method_idnum >= 0, "sanity check");
1474 }
1475 
1476 
1477 ActiveMethodOopsCache::~ActiveMethodOopsCache() {
1478   if (_prev_methods != NULL) {
1479     for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1480       jweak method_ref = _prev_methods->at(i);
1481       if (method_ref != NULL) {
1482         JNIHandles::destroy_weak_global(method_ref);
1483       }
1484     }
1485     delete _prev_methods;
1486     _prev_methods = NULL;
1487   }
1488 }
1489 
1490 
1491 void ActiveMethodOopsCache::add_previous_version(const methodOop method) {
1492   assert(Thread::current()->is_VM_thread(),
1493     "only VMThread can add previous versions");
1494 
1495   if (_prev_methods == NULL) {
1496     // This is the first previous version so make some space.
1497     // Start with 2 elements under the assumption that the class
1498     // won't be redefined much.
1499     _prev_methods = new (ResourceObj::C_HEAP) GrowableArray<jweak>(2, true);
1500   }
1501 
1502   // RC_TRACE macro has an embedded ResourceMark
1503   RC_TRACE(0x00000100,
1504     ("add: %s(%s): adding prev version ref for cached method @%d",
1505     method->name()->as_C_string(), method->signature()->as_C_string(),
1506     _prev_methods->length()));
1507 
1508   methodHandle method_h(method);
1509   jweak method_ref = JNIHandles::make_weak_global(method_h);
1510   _prev_methods->append(method_ref);
1511 
1512   // Using weak references allows previous versions of the cached
1513   // method to be GC'ed when they are no longer needed. Since the
1514   // caller is the VMThread and we are at a safepoint, this is a good
1515   // time to clear out unused weak references.
1516 
1517   for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1518     jweak method_ref = _prev_methods->at(i);
1519     assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1520     if (method_ref == NULL) {
1521       _prev_methods->remove_at(i);
1522       // Since we are traversing the array backwards, we don't have to
1523       // do anything special with the index.
1524       continue;  // robustness
1525     }
1526 
1527     methodOop m = (methodOop)JNIHandles::resolve(method_ref);
1528     if (m == NULL) {
1529       // this method entry has been GC'ed so remove it
1530       JNIHandles::destroy_weak_global(method_ref);
1531       _prev_methods->remove_at(i);
1532     } else {
1533       // RC_TRACE macro has an embedded ResourceMark
1534       RC_TRACE(0x00000400, ("add: %s(%s): previous cached method @%d is alive",
1535         m->name()->as_C_string(), m->signature()->as_C_string(), i));
1536     }
1537   }
1538 } // end add_previous_version()
1539 
1540 
1541 bool ActiveMethodOopsCache::is_same_method(const methodOop method) const {
1542   instanceKlass* ik = instanceKlass::cast(klass());
1543   methodOop check_method = ik->method_with_idnum(method_idnum());
1544   assert(check_method != NULL, "sanity check");
1545   if (check_method == method) {
1546     // done with the easy case
1547     return true;
1548   }
1549 
1550   if (_prev_methods != NULL) {
1551     // The cached method has been redefined at least once so search
1552     // the previous versions for a match.
1553     for (int i = 0; i < _prev_methods->length(); i++) {
1554       jweak method_ref = _prev_methods->at(i);
1555       assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1556       if (method_ref == NULL) {
1557         continue;  // robustness
1558       }
1559 
1560       check_method = (methodOop)JNIHandles::resolve(method_ref);
1561       if (check_method == method) {
1562         // a previous version matches
1563         return true;
1564       }
1565     }
1566   }
1567 
1568   // either no previous versions or no previous version matched
1569   return false;
1570 }
1571 
1572 
1573 methodOop LatestMethodOopCache::get_methodOop() {
1574   instanceKlass* ik = instanceKlass::cast(klass());
1575   methodOop m = ik->method_with_idnum(method_idnum());
1576   assert(m != NULL, "sanity check");
1577   return m;
1578 }
1579 
1580 
1581 #ifdef ASSERT
1582 // Release dummy object(s) at bottom of heap
1583 bool Universe::release_fullgc_alot_dummy() {
1584   MutexLocker ml(FullGCALot_lock);
1585   if (_fullgc_alot_dummy_array != NULL) {
1586     if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) {
1587       // No more dummies to release, release entire array instead
1588       _fullgc_alot_dummy_array = NULL;
1589       return false;
1590     }
1591     if (!UseConcMarkSweepGC) {
1592       // Release dummy at bottom of old generation
1593       _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1594     }
1595     // Release dummy at bottom of permanent generation
1596     _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1597   }
1598   return true;
1599 }
1600 
1601 #endif // ASSERT