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