1 /*
   2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/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 #ifdef TARGET_OS_FAMILY_bsd
  93 # include "thread_bsd.inline.hpp"
  94 #endif
  95 #ifndef SERIALGC
  96 #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
  97 #include "gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp"
  98 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  99 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
 100 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
 101 #endif
 102 
 103 // Known objects
 104 klassOop Universe::_boolArrayKlassObj                 = NULL;
 105 klassOop Universe::_byteArrayKlassObj                 = NULL;
 106 klassOop Universe::_charArrayKlassObj                 = NULL;
 107 klassOop Universe::_intArrayKlassObj                  = NULL;
 108 klassOop Universe::_shortArrayKlassObj                = NULL;
 109 klassOop Universe::_longArrayKlassObj                 = NULL;
 110 klassOop Universe::_singleArrayKlassObj               = NULL;
 111 klassOop Universe::_doubleArrayKlassObj               = NULL;
 112 klassOop Universe::_typeArrayKlassObjs[T_VOID+1]      = { NULL /*, NULL...*/ };
 113 klassOop Universe::_objectArrayKlassObj               = NULL;
 114 klassOop Universe::_methodKlassObj                    = NULL;
 115 klassOop Universe::_constMethodKlassObj               = NULL;
 116 klassOop Universe::_methodDataKlassObj                = NULL;
 117 klassOop Universe::_klassKlassObj                     = NULL;
 118 klassOop Universe::_arrayKlassKlassObj                = NULL;
 119 klassOop Universe::_objArrayKlassKlassObj             = NULL;
 120 klassOop Universe::_typeArrayKlassKlassObj            = NULL;
 121 klassOop Universe::_instanceKlassKlassObj             = NULL;
 122 klassOop Universe::_constantPoolKlassObj              = NULL;
 123 klassOop Universe::_constantPoolCacheKlassObj         = NULL;
 124 klassOop Universe::_compiledICHolderKlassObj          = NULL;
 125 klassOop Universe::_systemObjArrayKlassObj            = NULL;
 126 oop Universe::_int_mirror                             = NULL;
 127 oop Universe::_float_mirror                           = NULL;
 128 oop Universe::_double_mirror                          = NULL;
 129 oop Universe::_byte_mirror                            = NULL;
 130 oop Universe::_bool_mirror                            = NULL;
 131 oop Universe::_char_mirror                            = NULL;
 132 oop Universe::_long_mirror                            = NULL;
 133 oop Universe::_short_mirror                           = NULL;
 134 oop Universe::_void_mirror                            = NULL;
 135 oop Universe::_mirrors[T_VOID+1]                      = { NULL /*, NULL...*/ };
 136 oop Universe::_main_thread_group                      = NULL;
 137 oop Universe::_system_thread_group                    = NULL;
 138 typeArrayOop Universe::_the_empty_byte_array          = NULL;
 139 typeArrayOop Universe::_the_empty_short_array         = NULL;
 140 typeArrayOop Universe::_the_empty_int_array           = NULL;
 141 objArrayOop Universe::_the_empty_system_obj_array     = NULL;
 142 objArrayOop Universe::_the_empty_class_klass_array    = NULL;
 143 objArrayOop Universe::_the_array_interfaces_array     = NULL;
 144 oop Universe::_the_null_string                        = NULL;
 145 oop Universe::_the_min_jint_string                   = NULL;
 146 LatestMethodOopCache* Universe::_finalizer_register_cache = NULL;
 147 LatestMethodOopCache* Universe::_loader_addClass_cache    = NULL;
 148 ActiveMethodOopsCache* Universe::_reflect_invoke_cache    = NULL;
 149 oop Universe::_out_of_memory_error_java_heap          = NULL;
 150 oop Universe::_out_of_memory_error_perm_gen           = NULL;
 151 oop Universe::_out_of_memory_error_array_size         = NULL;
 152 oop Universe::_out_of_memory_error_gc_overhead_limit  = NULL;
 153 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
 154 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 155 bool Universe::_verify_in_progress                    = false;
 156 oop Universe::_null_ptr_exception_instance            = NULL;
 157 oop Universe::_arithmetic_exception_instance          = NULL;
 158 oop Universe::_virtual_machine_error_instance         = NULL;
 159 oop Universe::_vm_exception                           = NULL;
 160 
 161 // These variables are guarded by FullGCALot_lock.
 162 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;)
 163 debug_only(int Universe::_fullgc_alot_dummy_next      = 0;)
 164 
 165 
 166 // Heap
 167 int             Universe::_verify_count = 0;
 168 
 169 int             Universe::_base_vtable_size = 0;
 170 bool            Universe::_bootstrapping = false;
 171 bool            Universe::_fully_initialized = false;
 172 
 173 size_t          Universe::_heap_capacity_at_last_gc;
 174 size_t          Universe::_heap_used_at_last_gc = 0;
 175 
 176 CollectedHeap*  Universe::_collectedHeap = NULL;
 177 
 178 NarrowOopStruct Universe::_narrow_oop = { NULL, 0, true };
 179 
 180 
 181 void Universe::basic_type_classes_do(void f(klassOop)) {
 182   f(boolArrayKlassObj());
 183   f(byteArrayKlassObj());
 184   f(charArrayKlassObj());
 185   f(intArrayKlassObj());
 186   f(shortArrayKlassObj());
 187   f(longArrayKlassObj());
 188   f(singleArrayKlassObj());
 189   f(doubleArrayKlassObj());
 190 }
 191 
 192 
 193 void Universe::system_classes_do(void f(klassOop)) {
 194   f(methodKlassObj());
 195   f(constMethodKlassObj());
 196   f(methodDataKlassObj());
 197   f(klassKlassObj());
 198   f(arrayKlassKlassObj());
 199   f(objArrayKlassKlassObj());
 200   f(typeArrayKlassKlassObj());
 201   f(instanceKlassKlassObj());
 202   f(constantPoolKlassObj());
 203   f(systemObjArrayKlassObj());
 204 }
 205 
 206 void Universe::oops_do(OopClosure* f, bool do_all) {
 207 
 208   f->do_oop((oop*) &_int_mirror);
 209   f->do_oop((oop*) &_float_mirror);
 210   f->do_oop((oop*) &_double_mirror);
 211   f->do_oop((oop*) &_byte_mirror);
 212   f->do_oop((oop*) &_bool_mirror);
 213   f->do_oop((oop*) &_char_mirror);
 214   f->do_oop((oop*) &_long_mirror);
 215   f->do_oop((oop*) &_short_mirror);
 216   f->do_oop((oop*) &_void_mirror);
 217 
 218   // It's important to iterate over these guys even if they are null,
 219   // since that's how shared heaps are restored.
 220   for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 221     f->do_oop((oop*) &_mirrors[i]);
 222   }
 223   assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking");
 224 
 225   // %%% Consider moving those "shared oops" over here with the others.
 226   f->do_oop((oop*)&_boolArrayKlassObj);
 227   f->do_oop((oop*)&_byteArrayKlassObj);
 228   f->do_oop((oop*)&_charArrayKlassObj);
 229   f->do_oop((oop*)&_intArrayKlassObj);
 230   f->do_oop((oop*)&_shortArrayKlassObj);
 231   f->do_oop((oop*)&_longArrayKlassObj);
 232   f->do_oop((oop*)&_singleArrayKlassObj);
 233   f->do_oop((oop*)&_doubleArrayKlassObj);
 234   f->do_oop((oop*)&_objectArrayKlassObj);
 235   {
 236     for (int i = 0; i < T_VOID+1; i++) {
 237       if (_typeArrayKlassObjs[i] != NULL) {
 238         assert(i >= T_BOOLEAN, "checking");
 239         f->do_oop((oop*)&_typeArrayKlassObjs[i]);
 240       } else if (do_all) {
 241         f->do_oop((oop*)&_typeArrayKlassObjs[i]);
 242       }
 243     }
 244   }
 245   f->do_oop((oop*)&_methodKlassObj);
 246   f->do_oop((oop*)&_constMethodKlassObj);
 247   f->do_oop((oop*)&_methodDataKlassObj);
 248   f->do_oop((oop*)&_klassKlassObj);
 249   f->do_oop((oop*)&_arrayKlassKlassObj);
 250   f->do_oop((oop*)&_objArrayKlassKlassObj);
 251   f->do_oop((oop*)&_typeArrayKlassKlassObj);
 252   f->do_oop((oop*)&_instanceKlassKlassObj);
 253   f->do_oop((oop*)&_constantPoolKlassObj);
 254   f->do_oop((oop*)&_constantPoolCacheKlassObj);
 255   f->do_oop((oop*)&_compiledICHolderKlassObj);
 256   f->do_oop((oop*)&_systemObjArrayKlassObj);
 257   f->do_oop((oop*)&_the_empty_byte_array);
 258   f->do_oop((oop*)&_the_empty_short_array);
 259   f->do_oop((oop*)&_the_empty_int_array);
 260   f->do_oop((oop*)&_the_empty_system_obj_array);
 261   f->do_oop((oop*)&_the_empty_class_klass_array);
 262   f->do_oop((oop*)&_the_array_interfaces_array);
 263   f->do_oop((oop*)&_the_null_string);
 264   f->do_oop((oop*)&_the_min_jint_string);
 265   _finalizer_register_cache->oops_do(f);
 266   _loader_addClass_cache->oops_do(f);
 267   _reflect_invoke_cache->oops_do(f);
 268   f->do_oop((oop*)&_out_of_memory_error_java_heap);
 269   f->do_oop((oop*)&_out_of_memory_error_perm_gen);
 270   f->do_oop((oop*)&_out_of_memory_error_array_size);
 271   f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
 272   if (_preallocated_out_of_memory_error_array != (oop)NULL) {   // NULL when DumpSharedSpaces
 273     f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
 274   }
 275   f->do_oop((oop*)&_null_ptr_exception_instance);
 276   f->do_oop((oop*)&_arithmetic_exception_instance);
 277   f->do_oop((oop*)&_virtual_machine_error_instance);
 278   f->do_oop((oop*)&_main_thread_group);
 279   f->do_oop((oop*)&_system_thread_group);
 280   f->do_oop((oop*)&_vm_exception);
 281   debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
 282 }
 283 
 284 
 285 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
 286   if (size < alignment || size % alignment != 0) {
 287     ResourceMark rm;
 288     stringStream st;
 289     st.print("Size of %s (%ld bytes) must be aligned to %ld bytes", name, size, alignment);
 290     char* error = st.as_string();
 291     vm_exit_during_initialization(error);
 292   }
 293 }
 294 
 295 
 296 void Universe::genesis(TRAPS) {
 297   ResourceMark rm;
 298   { FlagSetting fs(_bootstrapping, true);
 299 
 300     { MutexLocker mc(Compile_lock);
 301 
 302       // determine base vtable size; without that we cannot create the array klasses
 303       compute_base_vtable_size();
 304 
 305       if (!UseSharedSpaces) {
 306         _klassKlassObj          = klassKlass::create_klass(CHECK);
 307         _arrayKlassKlassObj     = arrayKlassKlass::create_klass(CHECK);
 308 
 309         _objArrayKlassKlassObj  = objArrayKlassKlass::create_klass(CHECK);
 310         _instanceKlassKlassObj  = instanceKlassKlass::create_klass(CHECK);
 311         _typeArrayKlassKlassObj = typeArrayKlassKlass::create_klass(CHECK);
 312 
 313         _boolArrayKlassObj      = typeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK);
 314         _charArrayKlassObj      = typeArrayKlass::create_klass(T_CHAR,    sizeof(jchar),    CHECK);
 315         _singleArrayKlassObj    = typeArrayKlass::create_klass(T_FLOAT,   sizeof(jfloat),   CHECK);
 316         _doubleArrayKlassObj    = typeArrayKlass::create_klass(T_DOUBLE,  sizeof(jdouble),  CHECK);
 317         _byteArrayKlassObj      = typeArrayKlass::create_klass(T_BYTE,    sizeof(jbyte),    CHECK);
 318         _shortArrayKlassObj     = typeArrayKlass::create_klass(T_SHORT,   sizeof(jshort),   CHECK);
 319         _intArrayKlassObj       = typeArrayKlass::create_klass(T_INT,     sizeof(jint),     CHECK);
 320         _longArrayKlassObj      = typeArrayKlass::create_klass(T_LONG,    sizeof(jlong),    CHECK);
 321 
 322         _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj;
 323         _typeArrayKlassObjs[T_CHAR]    = _charArrayKlassObj;
 324         _typeArrayKlassObjs[T_FLOAT]   = _singleArrayKlassObj;
 325         _typeArrayKlassObjs[T_DOUBLE]  = _doubleArrayKlassObj;
 326         _typeArrayKlassObjs[T_BYTE]    = _byteArrayKlassObj;
 327         _typeArrayKlassObjs[T_SHORT]   = _shortArrayKlassObj;
 328         _typeArrayKlassObjs[T_INT]     = _intArrayKlassObj;
 329         _typeArrayKlassObjs[T_LONG]    = _longArrayKlassObj;
 330 
 331         _methodKlassObj             = methodKlass::create_klass(CHECK);
 332         _constMethodKlassObj        = constMethodKlass::create_klass(CHECK);
 333         _methodDataKlassObj         = methodDataKlass::create_klass(CHECK);
 334         _constantPoolKlassObj       = constantPoolKlass::create_klass(CHECK);
 335         _constantPoolCacheKlassObj  = constantPoolCacheKlass::create_klass(CHECK);
 336 
 337         _compiledICHolderKlassObj   = compiledICHolderKlass::create_klass(CHECK);
 338         _systemObjArrayKlassObj     = objArrayKlassKlass::cast(objArrayKlassKlassObj())->allocate_system_objArray_klass(CHECK);
 339 
 340         _the_empty_byte_array       = oopFactory::new_permanent_byteArray(0, CHECK);
 341         _the_empty_short_array      = oopFactory::new_permanent_shortArray(0, CHECK);
 342         _the_empty_int_array        = oopFactory::new_permanent_intArray(0, CHECK);
 343         _the_empty_system_obj_array = oopFactory::new_system_objArray(0, CHECK);
 344 
 345         _the_array_interfaces_array = oopFactory::new_system_objArray(2, CHECK);
 346       }
 347     }
 348 
 349     vmSymbols::initialize(CHECK);
 350 
 351     SystemDictionary::initialize(CHECK);
 352 
 353     klassOop ok = SystemDictionary::Object_klass();
 354 
 355     _the_null_string            = StringTable::intern("null", CHECK);
 356     _the_min_jint_string       = StringTable::intern("-2147483648", CHECK);
 357 
 358     if (UseSharedSpaces) {
 359       // Verify shared interfaces array.
 360       assert(_the_array_interfaces_array->obj_at(0) ==
 361              SystemDictionary::Cloneable_klass(), "u3");
 362       assert(_the_array_interfaces_array->obj_at(1) ==
 363              SystemDictionary::Serializable_klass(), "u3");
 364 
 365       // Verify element klass for system obj array klass
 366       assert(objArrayKlass::cast(_systemObjArrayKlassObj)->element_klass() == ok, "u1");
 367       assert(objArrayKlass::cast(_systemObjArrayKlassObj)->bottom_klass() == ok, "u2");
 368 
 369       // Verify super class for the classes created above
 370       assert(Klass::cast(boolArrayKlassObj()     )->super() == ok, "u3");
 371       assert(Klass::cast(charArrayKlassObj()     )->super() == ok, "u3");
 372       assert(Klass::cast(singleArrayKlassObj()   )->super() == ok, "u3");
 373       assert(Klass::cast(doubleArrayKlassObj()   )->super() == ok, "u3");
 374       assert(Klass::cast(byteArrayKlassObj()     )->super() == ok, "u3");
 375       assert(Klass::cast(shortArrayKlassObj()    )->super() == ok, "u3");
 376       assert(Klass::cast(intArrayKlassObj()      )->super() == ok, "u3");
 377       assert(Klass::cast(longArrayKlassObj()     )->super() == ok, "u3");
 378       assert(Klass::cast(constantPoolKlassObj()  )->super() == ok, "u3");
 379       assert(Klass::cast(systemObjArrayKlassObj())->super() == ok, "u3");
 380     } else {
 381       // Set up shared interfaces array.  (Do this before supers are set up.)
 382       _the_array_interfaces_array->obj_at_put(0, SystemDictionary::Cloneable_klass());
 383       _the_array_interfaces_array->obj_at_put(1, SystemDictionary::Serializable_klass());
 384 
 385       // Set element klass for system obj array klass
 386       objArrayKlass::cast(_systemObjArrayKlassObj)->set_element_klass(ok);
 387       objArrayKlass::cast(_systemObjArrayKlassObj)->set_bottom_klass(ok);
 388 
 389       // Set super class for the classes created above
 390       Klass::cast(boolArrayKlassObj()     )->initialize_supers(ok, CHECK);
 391       Klass::cast(charArrayKlassObj()     )->initialize_supers(ok, CHECK);
 392       Klass::cast(singleArrayKlassObj()   )->initialize_supers(ok, CHECK);
 393       Klass::cast(doubleArrayKlassObj()   )->initialize_supers(ok, CHECK);
 394       Klass::cast(byteArrayKlassObj()     )->initialize_supers(ok, CHECK);
 395       Klass::cast(shortArrayKlassObj()    )->initialize_supers(ok, CHECK);
 396       Klass::cast(intArrayKlassObj()      )->initialize_supers(ok, CHECK);
 397       Klass::cast(longArrayKlassObj()     )->initialize_supers(ok, CHECK);
 398       Klass::cast(constantPoolKlassObj()  )->initialize_supers(ok, CHECK);
 399       Klass::cast(systemObjArrayKlassObj())->initialize_supers(ok, CHECK);
 400       Klass::cast(boolArrayKlassObj()     )->set_super(ok);
 401       Klass::cast(charArrayKlassObj()     )->set_super(ok);
 402       Klass::cast(singleArrayKlassObj()   )->set_super(ok);
 403       Klass::cast(doubleArrayKlassObj()   )->set_super(ok);
 404       Klass::cast(byteArrayKlassObj()     )->set_super(ok);
 405       Klass::cast(shortArrayKlassObj()    )->set_super(ok);
 406       Klass::cast(intArrayKlassObj()      )->set_super(ok);
 407       Klass::cast(longArrayKlassObj()     )->set_super(ok);
 408       Klass::cast(constantPoolKlassObj()  )->set_super(ok);
 409       Klass::cast(systemObjArrayKlassObj())->set_super(ok);
 410     }
 411 
 412     Klass::cast(boolArrayKlassObj()     )->append_to_sibling_list();
 413     Klass::cast(charArrayKlassObj()     )->append_to_sibling_list();
 414     Klass::cast(singleArrayKlassObj()   )->append_to_sibling_list();
 415     Klass::cast(doubleArrayKlassObj()   )->append_to_sibling_list();
 416     Klass::cast(byteArrayKlassObj()     )->append_to_sibling_list();
 417     Klass::cast(shortArrayKlassObj()    )->append_to_sibling_list();
 418     Klass::cast(intArrayKlassObj()      )->append_to_sibling_list();
 419     Klass::cast(longArrayKlassObj()     )->append_to_sibling_list();
 420     Klass::cast(constantPoolKlassObj()  )->append_to_sibling_list();
 421     Klass::cast(systemObjArrayKlassObj())->append_to_sibling_list();
 422   } // end of core bootstrapping
 423 
 424   // Initialize _objectArrayKlass after core bootstraping to make
 425   // sure the super class is set up properly for _objectArrayKlass.
 426   _objectArrayKlassObj = instanceKlass::
 427     cast(SystemDictionary::Object_klass())->array_klass(1, CHECK);
 428   // Add the class to the class hierarchy manually to make sure that
 429   // its vtable is initialized after core bootstrapping is completed.
 430   Klass::cast(_objectArrayKlassObj)->append_to_sibling_list();
 431 
 432   // Compute is_jdk version flags.
 433   // Only 1.3 or later has the java.lang.Shutdown class.
 434   // Only 1.4 or later has the java.lang.CharSequence interface.
 435   // Only 1.5 or later has the java.lang.management.MemoryUsage class.
 436   if (JDK_Version::is_partially_initialized()) {
 437     uint8_t jdk_version;
 438     klassOop k = SystemDictionary::resolve_or_null(
 439         vmSymbols::java_lang_management_MemoryUsage(), THREAD);
 440     CLEAR_PENDING_EXCEPTION; // ignore exceptions
 441     if (k == NULL) {
 442       k = SystemDictionary::resolve_or_null(
 443           vmSymbols::java_lang_CharSequence(), THREAD);
 444       CLEAR_PENDING_EXCEPTION; // ignore exceptions
 445       if (k == NULL) {
 446         k = SystemDictionary::resolve_or_null(
 447             vmSymbols::java_lang_Shutdown(), THREAD);
 448         CLEAR_PENDING_EXCEPTION; // ignore exceptions
 449         if (k == NULL) {
 450           jdk_version = 2;
 451         } else {
 452           jdk_version = 3;
 453         }
 454       } else {
 455         jdk_version = 4;
 456       }
 457     } else {
 458       jdk_version = 5;
 459     }
 460     JDK_Version::fully_initialize(jdk_version);
 461   }
 462 
 463   #ifdef ASSERT
 464   if (FullGCALot) {
 465     // Allocate an array of dummy objects.
 466     // We'd like these to be at the bottom of the old generation,
 467     // so that when we free one and then collect,
 468     // (almost) the whole heap moves
 469     // and we find out if we actually update all the oops correctly.
 470     // But we can't allocate directly in the old generation,
 471     // so we allocate wherever, and hope that the first collection
 472     // moves these objects to the bottom of the old generation.
 473     // We can allocate directly in the permanent generation, so we do.
 474     int size;
 475     if (UseConcMarkSweepGC) {
 476       warning("Using +FullGCALot with concurrent mark sweep gc "
 477               "will not force all objects to relocate");
 478       size = FullGCALotDummies;
 479     } else {
 480       size = FullGCALotDummies * 2;
 481     }
 482     objArrayOop    naked_array = oopFactory::new_system_objArray(size, CHECK);
 483     objArrayHandle dummy_array(THREAD, naked_array);
 484     int i = 0;
 485     while (i < size) {
 486       if (!UseConcMarkSweepGC) {
 487         // Allocate dummy in old generation
 488         oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_instance(CHECK);
 489         dummy_array->obj_at_put(i++, dummy);
 490       }
 491       // Allocate dummy in permanent generation
 492       oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_permanent_instance(CHECK);
 493       dummy_array->obj_at_put(i++, dummy);
 494     }
 495     {
 496       // Only modify the global variable inside the mutex.
 497       // If we had a race to here, the other dummy_array instances
 498       // and their elements just get dropped on the floor, which is fine.
 499       MutexLocker ml(FullGCALot_lock);
 500       if (_fullgc_alot_dummy_array == NULL) {
 501         _fullgc_alot_dummy_array = dummy_array();
 502       }
 503     }
 504     assert(i == _fullgc_alot_dummy_array->length(), "just checking");
 505   }
 506   #endif
 507 }
 508 
 509 
 510 static inline void* dereference(void* addr) {
 511   return *(void**)addr;
 512 }
 513 
 514 static inline void add_vtable(void** list, int* n, void* o, int count) {
 515   guarantee((*n) < count, "vtable list too small");
 516   void* vtable = dereference(o);
 517   assert(dereference(vtable) != NULL, "invalid vtable");
 518   list[(*n)++] = vtable;
 519 }
 520 
 521 void Universe::init_self_patching_vtbl_list(void** list, int count) {
 522   int n = 0;
 523   { klassKlass o;             add_vtable(list, &n, &o, count); }
 524   { arrayKlassKlass o;        add_vtable(list, &n, &o, count); }
 525   { objArrayKlassKlass o;     add_vtable(list, &n, &o, count); }
 526   { instanceKlassKlass o;     add_vtable(list, &n, &o, count); }
 527   { instanceKlass o;          add_vtable(list, &n, &o, count); }
 528   { instanceMirrorKlass o;    add_vtable(list, &n, &o, count); }
 529   { instanceRefKlass o;       add_vtable(list, &n, &o, count); }
 530   { typeArrayKlassKlass o;    add_vtable(list, &n, &o, count); }
 531   { typeArrayKlass o;         add_vtable(list, &n, &o, count); }
 532   { methodKlass o;            add_vtable(list, &n, &o, count); }
 533   { constMethodKlass o;       add_vtable(list, &n, &o, count); }
 534   { constantPoolKlass o;      add_vtable(list, &n, &o, count); }
 535   { constantPoolCacheKlass o; add_vtable(list, &n, &o, count); }
 536   { objArrayKlass o;          add_vtable(list, &n, &o, count); }
 537   { methodDataKlass o;        add_vtable(list, &n, &o, count); }
 538   { compiledICHolderKlass o;  add_vtable(list, &n, &o, count); }
 539 #ifndef PRODUCT
 540   // In non-product builds CHeapObj is derived from AllocatedObj,
 541   // so symbols in CDS archive should have their vtable pointer patched.
 542   { Symbol o;                 add_vtable(list, &n, &o, count); }
 543 #endif
 544 }
 545 
 546 
 547 class FixupMirrorClosure: public ObjectClosure {
 548  public:
 549   virtual void do_object(oop obj) {
 550     if (obj->is_klass()) {
 551       EXCEPTION_MARK;
 552       KlassHandle k(THREAD, klassOop(obj));
 553       // We will never reach the CATCH below since Exceptions::_throw will cause
 554       // the VM to exit if an exception is thrown during initialization
 555       java_lang_Class::fixup_mirror(k, CATCH);
 556       // This call unconditionally creates a new mirror for k,
 557       // and links in k's component_mirror field if k is an array.
 558       // If k is an objArray, k's element type must already have
 559       // a mirror.  In other words, this closure must process
 560       // the component type of an objArray k before it processes k.
 561       // This works because the permgen iterator presents arrays
 562       // and their component types in order of creation.
 563     }
 564   }
 565 };
 566 
 567 void Universe::initialize_basic_type_mirrors(TRAPS) {
 568   if (UseSharedSpaces) {
 569     assert(_int_mirror != NULL, "already loaded");
 570     assert(_void_mirror == _mirrors[T_VOID], "consistently loaded");
 571   } else {
 572 
 573     assert(_int_mirror==NULL, "basic type mirrors already initialized");
 574     _int_mirror     =
 575       java_lang_Class::create_basic_type_mirror("int",    T_INT, CHECK);
 576     _float_mirror   =
 577       java_lang_Class::create_basic_type_mirror("float",  T_FLOAT,   CHECK);
 578     _double_mirror  =
 579       java_lang_Class::create_basic_type_mirror("double", T_DOUBLE,  CHECK);
 580     _byte_mirror    =
 581       java_lang_Class::create_basic_type_mirror("byte",   T_BYTE, CHECK);
 582     _bool_mirror    =
 583       java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK);
 584     _char_mirror    =
 585       java_lang_Class::create_basic_type_mirror("char",   T_CHAR, CHECK);
 586     _long_mirror    =
 587       java_lang_Class::create_basic_type_mirror("long",   T_LONG, CHECK);
 588     _short_mirror   =
 589       java_lang_Class::create_basic_type_mirror("short",  T_SHORT,   CHECK);
 590     _void_mirror    =
 591       java_lang_Class::create_basic_type_mirror("void",   T_VOID, CHECK);
 592 
 593     _mirrors[T_INT]     = _int_mirror;
 594     _mirrors[T_FLOAT]   = _float_mirror;
 595     _mirrors[T_DOUBLE]  = _double_mirror;
 596     _mirrors[T_BYTE]    = _byte_mirror;
 597     _mirrors[T_BOOLEAN] = _bool_mirror;
 598     _mirrors[T_CHAR]    = _char_mirror;
 599     _mirrors[T_LONG]    = _long_mirror;
 600     _mirrors[T_SHORT]   = _short_mirror;
 601     _mirrors[T_VOID]    = _void_mirror;
 602     //_mirrors[T_OBJECT]  = instanceKlass::cast(_object_klass)->java_mirror();
 603     //_mirrors[T_ARRAY]   = instanceKlass::cast(_object_klass)->java_mirror();
 604   }
 605 }
 606 
 607 void Universe::fixup_mirrors(TRAPS) {
 608   // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
 609   // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
 610   // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
 611   // that the number of objects allocated at this point is very small.
 612   assert(SystemDictionary::Class_klass_loaded(), "java.lang.Class should be loaded");
 613 
 614   // Cache the start of the static fields
 615   instanceMirrorKlass::init_offset_of_static_fields();
 616 
 617   FixupMirrorClosure blk;
 618   Universe::heap()->permanent_object_iterate(&blk);
 619 }
 620 
 621 
 622 static bool has_run_finalizers_on_exit = false;
 623 
 624 void Universe::run_finalizers_on_exit() {
 625   if (has_run_finalizers_on_exit) return;
 626   has_run_finalizers_on_exit = true;
 627 
 628   // Called on VM exit. This ought to be run in a separate thread.
 629   if (TraceReferenceGC) tty->print_cr("Callback to run finalizers on exit");
 630   {
 631     PRESERVE_EXCEPTION_MARK;
 632     KlassHandle finalizer_klass(THREAD, SystemDictionary::Finalizer_klass());
 633     JavaValue result(T_VOID);
 634     JavaCalls::call_static(
 635       &result,
 636       finalizer_klass,
 637       vmSymbols::run_finalizers_on_exit_name(),
 638       vmSymbols::void_method_signature(),
 639       THREAD
 640     );
 641     // Ignore any pending exceptions
 642     CLEAR_PENDING_EXCEPTION;
 643   }
 644 }
 645 
 646 
 647 // initialize_vtable could cause gc if
 648 // 1) we specified true to initialize_vtable and
 649 // 2) this ran after gc was enabled
 650 // In case those ever change we use handles for oops
 651 void Universe::reinitialize_vtable_of(KlassHandle k_h, TRAPS) {
 652   // init vtable of k and all subclasses
 653   Klass* ko = k_h()->klass_part();
 654   klassVtable* vt = ko->vtable();
 655   if (vt) vt->initialize_vtable(false, CHECK);
 656   if (ko->oop_is_instance()) {
 657     instanceKlass* ik = (instanceKlass*)ko;
 658     for (KlassHandle s_h(THREAD, ik->subklass()); s_h() != NULL; s_h = (THREAD, s_h()->klass_part()->next_sibling())) {
 659       reinitialize_vtable_of(s_h, CHECK);
 660     }
 661   }
 662 }
 663 
 664 
 665 void initialize_itable_for_klass(klassOop k, TRAPS) {
 666   instanceKlass::cast(k)->itable()->initialize_itable(false, CHECK);
 667 }
 668 
 669 
 670 void Universe::reinitialize_itables(TRAPS) {
 671   SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
 672 
 673 }
 674 
 675 
 676 bool Universe::on_page_boundary(void* addr) {
 677   return ((uintptr_t) addr) % os::vm_page_size() == 0;
 678 }
 679 
 680 
 681 bool Universe::should_fill_in_stack_trace(Handle throwable) {
 682   // never attempt to fill in the stack trace of preallocated errors that do not have
 683   // backtrace. These errors are kept alive forever and may be "re-used" when all
 684   // preallocated errors with backtrace have been consumed. Also need to avoid
 685   // a potential loop which could happen if an out of memory occurs when attempting
 686   // to allocate the backtrace.
 687   return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
 688           (throwable() != Universe::_out_of_memory_error_perm_gen)  &&
 689           (throwable() != Universe::_out_of_memory_error_array_size) &&
 690           (throwable() != Universe::_out_of_memory_error_gc_overhead_limit));
 691 }
 692 
 693 
 694 oop Universe::gen_out_of_memory_error(oop default_err) {
 695   // generate an out of memory error:
 696   // - if there is a preallocated error with backtrace available then return it wth
 697   //   a filled in stack trace.
 698   // - if there are no preallocated errors with backtrace available then return
 699   //   an error without backtrace.
 700   int next;
 701   if (_preallocated_out_of_memory_error_avail_count > 0) {
 702     next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count);
 703     assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
 704   } else {
 705     next = -1;
 706   }
 707   if (next < 0) {
 708     // all preallocated errors have been used.
 709     // return default
 710     return default_err;
 711   } else {
 712     // get the error object at the slot and set set it to NULL so that the
 713     // array isn't keeping it alive anymore.
 714     oop exc = preallocated_out_of_memory_errors()->obj_at(next);
 715     assert(exc != NULL, "slot has been used already");
 716     preallocated_out_of_memory_errors()->obj_at_put(next, NULL);
 717 
 718     // use the message from the default error
 719     oop msg = java_lang_Throwable::message(default_err);
 720     assert(msg != NULL, "no message");
 721     java_lang_Throwable::set_message(exc, msg);
 722 
 723     // populate the stack trace and return it.
 724     java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
 725     return exc;
 726   }
 727 }
 728 
 729 static intptr_t non_oop_bits = 0;
 730 
 731 void* Universe::non_oop_word() {
 732   // Neither the high bits nor the low bits of this value is allowed
 733   // to look like (respectively) the high or low bits of a real oop.
 734   //
 735   // High and low are CPU-specific notions, but low always includes
 736   // the low-order bit.  Since oops are always aligned at least mod 4,
 737   // setting the low-order bit will ensure that the low half of the
 738   // word will never look like that of a real oop.
 739   //
 740   // Using the OS-supplied non-memory-address word (usually 0 or -1)
 741   // will take care of the high bits, however many there are.
 742 
 743   if (non_oop_bits == 0) {
 744     non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
 745   }
 746 
 747   return (void*)non_oop_bits;
 748 }
 749 
 750 jint universe_init() {
 751   assert(!Universe::_fully_initialized, "called after initialize_vtables");
 752   guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
 753          "LogHeapWordSize is incorrect.");
 754   guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
 755   guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
 756             "oop size is not not a multiple of HeapWord size");
 757   TraceTime timer("Genesis", TraceStartupTime);
 758   GC_locker::lock();  // do not allow gc during bootstrapping
 759   JavaClasses::compute_hard_coded_offsets();
 760 
 761   // Get map info from shared archive file.
 762   if (DumpSharedSpaces)
 763     UseSharedSpaces = false;
 764 
 765   FileMapInfo* mapinfo = NULL;
 766   if (UseSharedSpaces) {
 767     mapinfo = NEW_C_HEAP_OBJ(FileMapInfo);
 768     memset(mapinfo, 0, sizeof(FileMapInfo));
 769 
 770     // Open the shared archive file, read and validate the header. If
 771     // initialization files, shared spaces [UseSharedSpaces] are
 772     // disabled and the file is closed.
 773 
 774     if (mapinfo->initialize()) {
 775       FileMapInfo::set_current_info(mapinfo);
 776     } else {
 777       assert(!mapinfo->is_open() && !UseSharedSpaces,
 778              "archive file not closed or shared spaces not disabled.");
 779     }
 780   }
 781 
 782   jint status = Universe::initialize_heap();
 783   if (status != JNI_OK) {
 784     return status;
 785   }
 786 
 787   // We have a heap so create the methodOop caches before
 788   // CompactingPermGenGen::initialize_oops() tries to populate them.
 789   Universe::_finalizer_register_cache = new LatestMethodOopCache();
 790   Universe::_loader_addClass_cache    = new LatestMethodOopCache();
 791   Universe::_reflect_invoke_cache     = new ActiveMethodOopsCache();
 792 
 793   if (UseSharedSpaces) {
 794 
 795     // Read the data structures supporting the shared spaces (shared
 796     // system dictionary, symbol table, etc.).  After that, access to
 797     // the file (other than the mapped regions) is no longer needed, and
 798     // the file is closed. Closing the file does not affect the
 799     // currently mapped regions.
 800 
 801     CompactingPermGenGen::initialize_oops();
 802     mapinfo->close();
 803 
 804   } else {
 805     SymbolTable::create_table();
 806     StringTable::create_table();
 807     ClassLoader::create_package_info_table();
 808   }
 809 
 810   return JNI_OK;
 811 }
 812 
 813 // Choose the heap base address and oop encoding mode
 814 // when compressed oops are used:
 815 // Unscaled  - Use 32-bits oops without encoding when
 816 //     NarrowOopHeapBaseMin + heap_size < 4Gb
 817 // ZeroBased - Use zero based compressed oops with encoding when
 818 //     NarrowOopHeapBaseMin + heap_size < 32Gb
 819 // HeapBased - Use compressed oops with heap base + encoding.
 820 
 821 // 4Gb
 822 static const uint64_t NarrowOopHeapMax = (uint64_t(max_juint) + 1);
 823 // 32Gb
 824 // OopEncodingHeapMax == NarrowOopHeapMax << LogMinObjAlignmentInBytes;
 825 
 826 char* Universe::preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode) {
 827   size_t base = 0;
 828 #ifdef _LP64
 829   if (UseCompressedOops) {
 830     assert(mode == UnscaledNarrowOop  ||
 831            mode == ZeroBasedNarrowOop ||
 832            mode == HeapBasedNarrowOop, "mode is invalid");
 833     const size_t total_size = heap_size + HeapBaseMinAddress;
 834     // Return specified base for the first request.
 835     if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) {
 836       base = HeapBaseMinAddress;
 837     } else if (total_size <= OopEncodingHeapMax && (mode != HeapBasedNarrowOop)) {
 838       if (total_size <= NarrowOopHeapMax && (mode == UnscaledNarrowOop) &&
 839           (Universe::narrow_oop_shift() == 0)) {
 840         // Use 32-bits oops without encoding and
 841         // place heap's top on the 4Gb boundary
 842         base = (NarrowOopHeapMax - heap_size);
 843       } else {
 844         // Can't reserve with NarrowOopShift == 0
 845         Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 846         if (mode == UnscaledNarrowOop ||
 847             mode == ZeroBasedNarrowOop && total_size <= NarrowOopHeapMax) {
 848           // Use zero based compressed oops with encoding and
 849           // place heap's top on the 32Gb boundary in case
 850           // total_size > 4Gb or failed to reserve below 4Gb.
 851           base = (OopEncodingHeapMax - heap_size);
 852         }
 853       }
 854     } else {
 855       // Can't reserve below 32Gb.
 856       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 857     }
 858     // Set narrow_oop_base and narrow_oop_use_implicit_null_checks
 859     // used in ReservedHeapSpace() constructors.
 860     // The final values will be set in initialize_heap() below.
 861     if (base != 0 && (base + heap_size) <= OopEncodingHeapMax) {
 862       // Use zero based compressed oops
 863       Universe::set_narrow_oop_base(NULL);
 864       // Don't need guard page for implicit checks in indexed
 865       // addressing mode with zero based Compressed Oops.
 866       Universe::set_narrow_oop_use_implicit_null_checks(true);
 867     } else {
 868       // Set to a non-NULL value so the ReservedSpace ctor computes
 869       // the correct no-access prefix.
 870       // The final value will be set in initialize_heap() below.
 871       Universe::set_narrow_oop_base((address)NarrowOopHeapMax);
 872 #ifdef _WIN64
 873       if (UseLargePages) {
 874         // Cannot allocate guard pages for implicit checks in indexed
 875         // addressing mode when large pages are specified on windows.
 876         Universe::set_narrow_oop_use_implicit_null_checks(false);
 877       }
 878 #endif //  _WIN64
 879     }
 880   }
 881 #endif
 882   return (char*)base; // also return NULL (don't care) for 32-bit VM
 883 }
 884 
 885 jint Universe::initialize_heap() {
 886 
 887   if (UseParallelGC) {
 888 #ifndef SERIALGC
 889     Universe::_collectedHeap = new ParallelScavengeHeap();
 890 #else  // SERIALGC
 891     fatal("UseParallelGC not supported in java kernel vm.");
 892 #endif // SERIALGC
 893 
 894   } else if (UseG1GC) {
 895 #ifndef SERIALGC
 896     G1CollectorPolicy* g1p = new G1CollectorPolicy();
 897     G1CollectedHeap* g1h = new G1CollectedHeap(g1p);
 898     Universe::_collectedHeap = g1h;
 899 #else  // SERIALGC
 900     fatal("UseG1GC not supported in java kernel vm.");
 901 #endif // SERIALGC
 902 
 903   } else {
 904     GenCollectorPolicy *gc_policy;
 905 
 906     if (UseSerialGC) {
 907       gc_policy = new MarkSweepPolicy();
 908     } else if (UseConcMarkSweepGC) {
 909 #ifndef SERIALGC
 910       if (UseAdaptiveSizePolicy) {
 911         gc_policy = new ASConcurrentMarkSweepPolicy();
 912       } else {
 913         gc_policy = new ConcurrentMarkSweepPolicy();
 914       }
 915 #else   // SERIALGC
 916     fatal("UseConcMarkSweepGC not supported in java kernel vm.");
 917 #endif // SERIALGC
 918     } else { // default old generation
 919       gc_policy = new MarkSweepPolicy();
 920     }
 921 
 922     Universe::_collectedHeap = new GenCollectedHeap(gc_policy);
 923   }
 924 
 925   jint status = Universe::heap()->initialize();
 926   if (status != JNI_OK) {
 927     return status;
 928   }
 929 
 930 #ifdef _LP64
 931   if (UseCompressedOops) {
 932     // Subtract a page because something can get allocated at heap base.
 933     // This also makes implicit null checking work, because the
 934     // memory+1 page below heap_base needs to cause a signal.
 935     // See needs_explicit_null_check.
 936     // Only set the heap base for compressed oops because it indicates
 937     // compressed oops for pstack code.
 938     bool verbose = PrintCompressedOopsMode || (PrintMiscellaneous && Verbose);
 939     if (verbose) {
 940       tty->cr();
 941       tty->print("heap address: " PTR_FORMAT ", size: " SIZE_FORMAT " MB",
 942                  Universe::heap()->base(), Universe::heap()->reserved_region().byte_size()/M);
 943     }
 944     if ((uint64_t)Universe::heap()->reserved_region().end() > OopEncodingHeapMax) {
 945       // Can't reserve heap below 32Gb.
 946       Universe::set_narrow_oop_base(Universe::heap()->base() - os::vm_page_size());
 947       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 948       if (verbose) {
 949         tty->print(", Compressed Oops with base: "PTR_FORMAT, Universe::narrow_oop_base());
 950       }
 951     } else {
 952       Universe::set_narrow_oop_base(0);
 953       if (verbose) {
 954         tty->print(", zero based Compressed Oops");
 955       }
 956 #ifdef _WIN64
 957       if (!Universe::narrow_oop_use_implicit_null_checks()) {
 958         // Don't need guard page for implicit checks in indexed addressing
 959         // mode with zero based Compressed Oops.
 960         Universe::set_narrow_oop_use_implicit_null_checks(true);
 961       }
 962 #endif //  _WIN64
 963       if((uint64_t)Universe::heap()->reserved_region().end() > NarrowOopHeapMax) {
 964         // Can't reserve heap below 4Gb.
 965         Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 966       } else {
 967         Universe::set_narrow_oop_shift(0);
 968         if (verbose) {
 969           tty->print(", 32-bits Oops");
 970         }
 971       }
 972     }
 973     if (verbose) {
 974       tty->cr();
 975       tty->cr();
 976     }
 977   }
 978   assert(Universe::narrow_oop_base() == (Universe::heap()->base() - os::vm_page_size()) ||
 979          Universe::narrow_oop_base() == NULL, "invalid value");
 980   assert(Universe::narrow_oop_shift() == LogMinObjAlignmentInBytes ||
 981          Universe::narrow_oop_shift() == 0, "invalid value");
 982 #endif
 983 
 984   // We will never reach the CATCH below since Exceptions::_throw will cause
 985   // the VM to exit if an exception is thrown during initialization
 986 
 987   if (UseTLAB) {
 988     assert(Universe::heap()->supports_tlab_allocation(),
 989            "Should support thread-local allocation buffers");
 990     ThreadLocalAllocBuffer::startup_initialization();
 991   }
 992   return JNI_OK;
 993 }
 994 
 995 // It's the caller's repsonsibility to ensure glitch-freedom
 996 // (if required).
 997 void Universe::update_heap_info_at_gc() {
 998   _heap_capacity_at_last_gc = heap()->capacity();
 999   _heap_used_at_last_gc     = heap()->used();
1000 }
1001 
1002 
1003 
1004 void universe2_init() {
1005   EXCEPTION_MARK;
1006   Universe::genesis(CATCH);
1007   // Although we'd like to verify here that the state of the heap
1008   // is good, we can't because the main thread has not yet added
1009   // itself to the threads list (so, using current interfaces
1010   // we can't "fill" its TLAB), unless TLABs are disabled.
1011   if (VerifyBeforeGC && !UseTLAB &&
1012       Universe::heap()->total_collections() >= VerifyGCStartAt) {
1013      Universe::heap()->prepare_for_verify();
1014      Universe::verify();   // make sure we're starting with a clean slate
1015   }
1016 }
1017 
1018 
1019 // This function is defined in JVM.cpp
1020 extern void initialize_converter_functions();
1021 
1022 bool universe_post_init() {
1023   assert(!is_init_completed(), "Error: initialization not yet completed!");
1024   Universe::_fully_initialized = true;
1025   EXCEPTION_MARK;
1026   { ResourceMark rm;
1027     Interpreter::initialize();      // needed for interpreter entry points
1028     if (!UseSharedSpaces) {
1029       KlassHandle ok_h(THREAD, SystemDictionary::Object_klass());
1030       Universe::reinitialize_vtable_of(ok_h, CHECK_false);
1031       Universe::reinitialize_itables(CHECK_false);
1032     }
1033   }
1034 
1035   klassOop k;
1036   instanceKlassHandle k_h;
1037   if (!UseSharedSpaces) {
1038     // Setup preallocated empty java.lang.Class array
1039     Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::Class_klass(), 0, CHECK_false);
1040     // Setup preallocated OutOfMemoryError errors
1041     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false);
1042     k_h = instanceKlassHandle(THREAD, k);
1043     Universe::_out_of_memory_error_java_heap = k_h->allocate_permanent_instance(CHECK_false);
1044     Universe::_out_of_memory_error_perm_gen = k_h->allocate_permanent_instance(CHECK_false);
1045     Universe::_out_of_memory_error_array_size = k_h->allocate_permanent_instance(CHECK_false);
1046     Universe::_out_of_memory_error_gc_overhead_limit =
1047       k_h->allocate_permanent_instance(CHECK_false);
1048 
1049     // Setup preallocated NullPointerException
1050     // (this is currently used for a cheap & dirty solution in compiler exception handling)
1051     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false);
1052     Universe::_null_ptr_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1053     // Setup preallocated ArithmeticException
1054     // (this is currently used for a cheap & dirty solution in compiler exception handling)
1055     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false);
1056     Universe::_arithmetic_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1057     // Virtual Machine Error for when we get into a situation we can't resolve
1058     k = SystemDictionary::resolve_or_fail(
1059       vmSymbols::java_lang_VirtualMachineError(), true, CHECK_false);
1060     bool linked = instanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1061     if (!linked) {
1062       tty->print_cr("Unable to link/verify VirtualMachineError class");
1063       return false; // initialization failed
1064     }
1065     Universe::_virtual_machine_error_instance =
1066       instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1067 
1068     Universe::_vm_exception               = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1069 
1070   }
1071   if (!DumpSharedSpaces) {
1072     // These are the only Java fields that are currently set during shared space dumping.
1073     // We prefer to not handle this generally, so we always reinitialize these detail messages.
1074     Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false);
1075     java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
1076 
1077     msg = java_lang_String::create_from_str("PermGen space", CHECK_false);
1078     java_lang_Throwable::set_message(Universe::_out_of_memory_error_perm_gen, msg());
1079 
1080     msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
1081     java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
1082 
1083     msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false);
1084     java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg());
1085 
1086     msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1087     java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
1088 
1089     // Setup the array of errors that have preallocated backtrace
1090     k = Universe::_out_of_memory_error_java_heap->klass();
1091     assert(k->klass_part()->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error");
1092     k_h = instanceKlassHandle(THREAD, k);
1093 
1094     int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
1095     Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(k_h(), len, CHECK_false);
1096     for (int i=0; i<len; i++) {
1097       oop err = k_h->allocate_permanent_instance(CHECK_false);
1098       Handle err_h = Handle(THREAD, err);
1099       java_lang_Throwable::allocate_backtrace(err_h, CHECK_false);
1100       Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h());
1101     }
1102     Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
1103   }
1104 
1105 
1106   // Setup static method for registering finalizers
1107   // The finalizer klass must be linked before looking up the method, in
1108   // case it needs to get rewritten.
1109   instanceKlass::cast(SystemDictionary::Finalizer_klass())->link_class(CHECK_false);
1110   methodOop m = instanceKlass::cast(SystemDictionary::Finalizer_klass())->find_method(
1111                                   vmSymbols::register_method_name(),
1112                                   vmSymbols::register_method_signature());
1113   if (m == NULL || !m->is_static()) {
1114     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1115       "java.lang.ref.Finalizer.register", false);
1116   }
1117   Universe::_finalizer_register_cache->init(
1118     SystemDictionary::Finalizer_klass(), m, CHECK_false);
1119 
1120   // Resolve on first use and initialize class.
1121   // Note: No race-condition here, since a resolve will always return the same result
1122 
1123   // Setup method for security checks
1124   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_reflect_Method(), true, CHECK_false);
1125   k_h = instanceKlassHandle(THREAD, k);
1126   k_h->link_class(CHECK_false);
1127   m = k_h->find_method(vmSymbols::invoke_name(), vmSymbols::object_object_array_object_signature());
1128   if (m == NULL || m->is_static()) {
1129     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1130       "java.lang.reflect.Method.invoke", false);
1131   }
1132   Universe::_reflect_invoke_cache->init(k_h(), m, CHECK_false);
1133 
1134   // Setup method for registering loaded classes in class loader vector
1135   instanceKlass::cast(SystemDictionary::ClassLoader_klass())->link_class(CHECK_false);
1136   m = instanceKlass::cast(SystemDictionary::ClassLoader_klass())->find_method(vmSymbols::addClass_name(), vmSymbols::class_void_signature());
1137   if (m == NULL || m->is_static()) {
1138     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1139       "java.lang.ClassLoader.addClass", false);
1140   }
1141   Universe::_loader_addClass_cache->init(
1142     SystemDictionary::ClassLoader_klass(), m, CHECK_false);
1143 
1144   // The folowing is initializing converter functions for serialization in
1145   // JVM.cpp. If we clean up the StrictMath code above we may want to find
1146   // a better solution for this as well.
1147   initialize_converter_functions();
1148 
1149   // This needs to be done before the first scavenge/gc, since
1150   // it's an input to soft ref clearing policy.
1151   {
1152     MutexLocker x(Heap_lock);
1153     Universe::update_heap_info_at_gc();
1154   }
1155 
1156   // ("weak") refs processing infrastructure initialization
1157   Universe::heap()->post_initialize();
1158 
1159   GC_locker::unlock();  // allow gc after bootstrapping
1160 
1161   MemoryService::set_universe_heap(Universe::_collectedHeap);
1162   return true;
1163 }
1164 
1165 
1166 void Universe::compute_base_vtable_size() {
1167   _base_vtable_size = ClassLoader::compute_Object_vtable();
1168 }
1169 
1170 
1171 // %%% The Universe::flush_foo methods belong in CodeCache.
1172 
1173 // Flushes compiled methods dependent on dependee.
1174 void Universe::flush_dependents_on(instanceKlassHandle dependee) {
1175   assert_lock_strong(Compile_lock);
1176 
1177   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1178 
1179   // CodeCache can only be updated by a thread_in_VM and they will all be
1180   // stopped dring the safepoint so CodeCache will be safe to update without
1181   // holding the CodeCache_lock.
1182 
1183   KlassDepChange changes(dependee);
1184 
1185   // Compute the dependent nmethods
1186   if (CodeCache::mark_for_deoptimization(changes) > 0) {
1187     // At least one nmethod has been marked for deoptimization
1188     VM_Deoptimize op;
1189     VMThread::execute(&op);
1190   }
1191 }
1192 
1193 // Flushes compiled methods dependent on a particular CallSite
1194 // instance when its target is different than the given MethodHandle.
1195 void Universe::flush_dependents_on(Handle call_site, Handle method_handle) {
1196   assert_lock_strong(Compile_lock);
1197 
1198   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1199 
1200   // CodeCache can only be updated by a thread_in_VM and they will all be
1201   // stopped dring the safepoint so CodeCache will be safe to update without
1202   // holding the CodeCache_lock.
1203 
1204   CallSiteDepChange changes(call_site(), method_handle());
1205 
1206   // Compute the dependent nmethods that have a reference to a
1207   // CallSite object.  We use instanceKlass::mark_dependent_nmethod
1208   // directly instead of CodeCache::mark_for_deoptimization because we
1209   // want dependents on the call site class only not all classes in
1210   // the ContextStream.
1211   int marked = 0;
1212   {
1213     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1214     instanceKlass* call_site_klass = instanceKlass::cast(call_site->klass());
1215     marked = call_site_klass->mark_dependent_nmethods(changes);
1216   }
1217   if (marked > 0) {
1218     // At least one nmethod has been marked for deoptimization
1219     VM_Deoptimize op;
1220     VMThread::execute(&op);
1221   }
1222 }
1223 
1224 #ifdef HOTSWAP
1225 // Flushes compiled methods dependent on dependee in the evolutionary sense
1226 void Universe::flush_evol_dependents_on(instanceKlassHandle ev_k_h) {
1227   // --- Compile_lock is not held. However we are at a safepoint.
1228   assert_locked_or_safepoint(Compile_lock);
1229   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1230 
1231   // CodeCache can only be updated by a thread_in_VM and they will all be
1232   // stopped dring the safepoint so CodeCache will be safe to update without
1233   // holding the CodeCache_lock.
1234 
1235   // Compute the dependent nmethods
1236   if (CodeCache::mark_for_evol_deoptimization(ev_k_h) > 0) {
1237     // At least one nmethod has been marked for deoptimization
1238 
1239     // All this already happens inside a VM_Operation, so we'll do all the work here.
1240     // Stuff copied from VM_Deoptimize and modified slightly.
1241 
1242     // We do not want any GCs to happen while we are in the middle of this VM operation
1243     ResourceMark rm;
1244     DeoptimizationMarker dm;
1245 
1246     // Deoptimize all activations depending on marked nmethods
1247     Deoptimization::deoptimize_dependents();
1248 
1249     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1250     CodeCache::make_marked_nmethods_not_entrant();
1251   }
1252 }
1253 #endif // HOTSWAP
1254 
1255 
1256 // Flushes compiled methods dependent on dependee
1257 void Universe::flush_dependents_on_method(methodHandle m_h) {
1258   // --- Compile_lock is not held. However we are at a safepoint.
1259   assert_locked_or_safepoint(Compile_lock);
1260 
1261   // CodeCache can only be updated by a thread_in_VM and they will all be
1262   // stopped dring the safepoint so CodeCache will be safe to update without
1263   // holding the CodeCache_lock.
1264 
1265   // Compute the dependent nmethods
1266   if (CodeCache::mark_for_deoptimization(m_h()) > 0) {
1267     // At least one nmethod has been marked for deoptimization
1268 
1269     // All this already happens inside a VM_Operation, so we'll do all the work here.
1270     // Stuff copied from VM_Deoptimize and modified slightly.
1271 
1272     // We do not want any GCs to happen while we are in the middle of this VM operation
1273     ResourceMark rm;
1274     DeoptimizationMarker dm;
1275 
1276     // Deoptimize all activations depending on marked nmethods
1277     Deoptimization::deoptimize_dependents();
1278 
1279     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1280     CodeCache::make_marked_nmethods_not_entrant();
1281   }
1282 }
1283 
1284 void Universe::print() {
1285   print_on(gclog_or_tty);
1286 }
1287 
1288 void Universe::print_on(outputStream* st, bool extended) {
1289   st->print_cr("Heap");
1290   if (!extended) {
1291     heap()->print_on(st);
1292   } else {
1293     heap()->print_extended_on(st);
1294   }
1295 }
1296 
1297 void Universe::print_heap_at_SIGBREAK() {
1298   if (PrintHeapAtSIGBREAK) {
1299     MutexLocker hl(Heap_lock);
1300     print_on(tty);
1301     tty->cr();
1302     tty->flush();
1303   }
1304 }
1305 
1306 void Universe::print_heap_before_gc(outputStream* st, bool ignore_extended) {
1307   st->print_cr("{Heap before GC invocations=%u (full %u):",
1308                heap()->total_collections(),
1309                heap()->total_full_collections());
1310   if (!PrintHeapAtGCExtended || ignore_extended) {
1311     heap()->print_on(st);
1312   } else {
1313     heap()->print_extended_on(st);
1314   }
1315 }
1316 
1317 void Universe::print_heap_after_gc(outputStream* st, bool ignore_extended) {
1318   st->print_cr("Heap after GC invocations=%u (full %u):",
1319                heap()->total_collections(),
1320                heap()->total_full_collections());
1321   if (!PrintHeapAtGCExtended || ignore_extended) {
1322     heap()->print_on(st);
1323   } else {
1324     heap()->print_extended_on(st);
1325   }
1326   st->print_cr("}");
1327 }
1328 
1329 void Universe::verify(bool allow_dirty, bool silent, VerifyOption option) {
1330   if (SharedSkipVerify) {
1331     return;
1332   }
1333 
1334   // The use of _verify_in_progress is a temporary work around for
1335   // 6320749.  Don't bother with a creating a class to set and clear
1336   // it since it is only used in this method and the control flow is
1337   // straight forward.
1338   _verify_in_progress = true;
1339 
1340   COMPILER2_PRESENT(
1341     assert(!DerivedPointerTable::is_active(),
1342          "DPT should not be active during verification "
1343          "(of thread stacks below)");
1344   )
1345 
1346   ResourceMark rm;
1347   HandleMark hm;  // Handles created during verification can be zapped
1348   _verify_count++;
1349 
1350   if (!silent) gclog_or_tty->print("[Verifying ");
1351   if (!silent) gclog_or_tty->print("threads ");
1352   Threads::verify();
1353   heap()->verify(allow_dirty, silent, option);
1354 
1355   if (!silent) gclog_or_tty->print("syms ");
1356   SymbolTable::verify();
1357   if (!silent) gclog_or_tty->print("strs ");
1358   StringTable::verify();
1359   {
1360     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1361     if (!silent) gclog_or_tty->print("zone ");
1362     CodeCache::verify();
1363   }
1364   if (!silent) gclog_or_tty->print("dict ");
1365   SystemDictionary::verify();
1366   if (!silent) gclog_or_tty->print("hand ");
1367   JNIHandles::verify();
1368   if (!silent) gclog_or_tty->print("C-heap ");
1369   os::check_heap();
1370   if (!silent) gclog_or_tty->print("code cache ");
1371   CodeCache::verify_oops();
1372   if (!silent) gclog_or_tty->print_cr("]");
1373 
1374   _verify_in_progress = false;
1375 }
1376 
1377 // Oop verification (see MacroAssembler::verify_oop)
1378 
1379 static uintptr_t _verify_oop_data[2]   = {0, (uintptr_t)-1};
1380 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1};
1381 
1382 
1383 static void calculate_verify_data(uintptr_t verify_data[2],
1384                                   HeapWord* low_boundary,
1385                                   HeapWord* high_boundary) {
1386   assert(low_boundary < high_boundary, "bad interval");
1387 
1388   // decide which low-order bits we require to be clear:
1389   size_t alignSize = MinObjAlignmentInBytes;
1390   size_t min_object_size = CollectedHeap::min_fill_size();
1391 
1392   // make an inclusive limit:
1393   uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1394   uintptr_t min = (uintptr_t)low_boundary;
1395   assert(min < max, "bad interval");
1396   uintptr_t diff = max ^ min;
1397 
1398   // throw away enough low-order bits to make the diff vanish
1399   uintptr_t mask = (uintptr_t)(-1);
1400   while ((mask & diff) != 0)
1401     mask <<= 1;
1402   uintptr_t bits = (min & mask);
1403   assert(bits == (max & mask), "correct mask");
1404   // check an intermediate value between min and max, just to make sure:
1405   assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1406 
1407   // require address alignment, too:
1408   mask |= (alignSize - 1);
1409 
1410   if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) {
1411     assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability");
1412   }
1413   verify_data[0] = mask;
1414   verify_data[1] = bits;
1415 }
1416 
1417 
1418 // Oop verification (see MacroAssembler::verify_oop)
1419 #ifndef PRODUCT
1420 
1421 uintptr_t Universe::verify_oop_mask() {
1422   MemRegion m = heap()->reserved_region();
1423   calculate_verify_data(_verify_oop_data,
1424                         m.start(),
1425                         m.end());
1426   return _verify_oop_data[0];
1427 }
1428 
1429 
1430 
1431 uintptr_t Universe::verify_oop_bits() {
1432   verify_oop_mask();
1433   return _verify_oop_data[1];
1434 }
1435 
1436 
1437 uintptr_t Universe::verify_klass_mask() {
1438   /* $$$
1439   // A klass can never live in the new space.  Since the new and old
1440   // spaces can change size, we must settle for bounds-checking against
1441   // the bottom of the world, plus the smallest possible new and old
1442   // space sizes that may arise during execution.
1443   size_t min_new_size = Universe::new_size();   // in bytes
1444   size_t min_old_size = Universe::old_size();   // in bytes
1445   calculate_verify_data(_verify_klass_data,
1446           (HeapWord*)((uintptr_t)_new_gen->low_boundary + min_new_size + min_old_size),
1447           _perm_gen->high_boundary);
1448                         */
1449   // Why doesn't the above just say that klass's always live in the perm
1450   // gen?  I'll see if that seems to work...
1451   MemRegion permanent_reserved;
1452   switch (Universe::heap()->kind()) {
1453   default:
1454     // ???: What if a CollectedHeap doesn't have a permanent generation?
1455     ShouldNotReachHere();
1456     break;
1457   case CollectedHeap::GenCollectedHeap:
1458   case CollectedHeap::G1CollectedHeap: {
1459     SharedHeap* sh = (SharedHeap*) Universe::heap();
1460     permanent_reserved = sh->perm_gen()->reserved();
1461    break;
1462   }
1463 #ifndef SERIALGC
1464   case CollectedHeap::ParallelScavengeHeap: {
1465     ParallelScavengeHeap* psh = (ParallelScavengeHeap*) Universe::heap();
1466     permanent_reserved = psh->perm_gen()->reserved();
1467     break;
1468   }
1469 #endif // SERIALGC
1470   }
1471   calculate_verify_data(_verify_klass_data,
1472                         permanent_reserved.start(),
1473                         permanent_reserved.end());
1474 
1475   return _verify_klass_data[0];
1476 }
1477 
1478 
1479 
1480 uintptr_t Universe::verify_klass_bits() {
1481   verify_klass_mask();
1482   return _verify_klass_data[1];
1483 }
1484 
1485 
1486 uintptr_t Universe::verify_mark_mask() {
1487   return markOopDesc::lock_mask_in_place;
1488 }
1489 
1490 
1491 
1492 uintptr_t Universe::verify_mark_bits() {
1493   intptr_t mask = verify_mark_mask();
1494   intptr_t bits = (intptr_t)markOopDesc::prototype();
1495   assert((bits & ~mask) == 0, "no stray header bits");
1496   return bits;
1497 }
1498 #endif // PRODUCT
1499 
1500 
1501 void Universe::compute_verify_oop_data() {
1502   verify_oop_mask();
1503   verify_oop_bits();
1504   verify_mark_mask();
1505   verify_mark_bits();
1506   verify_klass_mask();
1507   verify_klass_bits();
1508 }
1509 
1510 
1511 void CommonMethodOopCache::init(klassOop k, methodOop m, TRAPS) {
1512   if (!UseSharedSpaces) {
1513     _klass = k;
1514   }
1515 #ifndef PRODUCT
1516   else {
1517     // sharing initilization should have already set up _klass
1518     assert(_klass != NULL, "just checking");
1519   }
1520 #endif
1521 
1522   _method_idnum = m->method_idnum();
1523   assert(_method_idnum >= 0, "sanity check");
1524 }
1525 
1526 
1527 ActiveMethodOopsCache::~ActiveMethodOopsCache() {
1528   if (_prev_methods != NULL) {
1529     for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1530       jweak method_ref = _prev_methods->at(i);
1531       if (method_ref != NULL) {
1532         JNIHandles::destroy_weak_global(method_ref);
1533       }
1534     }
1535     delete _prev_methods;
1536     _prev_methods = NULL;
1537   }
1538 }
1539 
1540 
1541 void ActiveMethodOopsCache::add_previous_version(const methodOop method) {
1542   assert(Thread::current()->is_VM_thread(),
1543     "only VMThread can add previous versions");
1544 
1545   if (_prev_methods == NULL) {
1546     // This is the first previous version so make some space.
1547     // Start with 2 elements under the assumption that the class
1548     // won't be redefined much.
1549     _prev_methods = new (ResourceObj::C_HEAP) GrowableArray<jweak>(2, true);
1550   }
1551 
1552   // RC_TRACE macro has an embedded ResourceMark
1553   RC_TRACE(0x00000100,
1554     ("add: %s(%s): adding prev version ref for cached method @%d",
1555     method->name()->as_C_string(), method->signature()->as_C_string(),
1556     _prev_methods->length()));
1557 
1558   methodHandle method_h(method);
1559   jweak method_ref = JNIHandles::make_weak_global(method_h);
1560   _prev_methods->append(method_ref);
1561 
1562   // Using weak references allows previous versions of the cached
1563   // method to be GC'ed when they are no longer needed. Since the
1564   // caller is the VMThread and we are at a safepoint, this is a good
1565   // time to clear out unused weak references.
1566 
1567   for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1568     jweak method_ref = _prev_methods->at(i);
1569     assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1570     if (method_ref == NULL) {
1571       _prev_methods->remove_at(i);
1572       // Since we are traversing the array backwards, we don't have to
1573       // do anything special with the index.
1574       continue;  // robustness
1575     }
1576 
1577     methodOop m = (methodOop)JNIHandles::resolve(method_ref);
1578     if (m == NULL) {
1579       // this method entry has been GC'ed so remove it
1580       JNIHandles::destroy_weak_global(method_ref);
1581       _prev_methods->remove_at(i);
1582     } else {
1583       // RC_TRACE macro has an embedded ResourceMark
1584       RC_TRACE(0x00000400, ("add: %s(%s): previous cached method @%d is alive",
1585         m->name()->as_C_string(), m->signature()->as_C_string(), i));
1586     }
1587   }
1588 } // end add_previous_version()
1589 
1590 
1591 bool ActiveMethodOopsCache::is_same_method(const methodOop method) const {
1592   instanceKlass* ik = instanceKlass::cast(klass());
1593   methodOop check_method = ik->method_with_idnum(method_idnum());
1594   assert(check_method != NULL, "sanity check");
1595   if (check_method == method) {
1596     // done with the easy case
1597     return true;
1598   }
1599 
1600   if (_prev_methods != NULL) {
1601     // The cached method has been redefined at least once so search
1602     // the previous versions for a match.
1603     for (int i = 0; i < _prev_methods->length(); i++) {
1604       jweak method_ref = _prev_methods->at(i);
1605       assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1606       if (method_ref == NULL) {
1607         continue;  // robustness
1608       }
1609 
1610       check_method = (methodOop)JNIHandles::resolve(method_ref);
1611       if (check_method == method) {
1612         // a previous version matches
1613         return true;
1614       }
1615     }
1616   }
1617 
1618   // either no previous versions or no previous version matched
1619   return false;
1620 }
1621 
1622 
1623 methodOop LatestMethodOopCache::get_methodOop() {
1624   instanceKlass* ik = instanceKlass::cast(klass());
1625   methodOop m = ik->method_with_idnum(method_idnum());
1626   assert(m != NULL, "sanity check");
1627   return m;
1628 }
1629 
1630 
1631 #ifdef ASSERT
1632 // Release dummy object(s) at bottom of heap
1633 bool Universe::release_fullgc_alot_dummy() {
1634   MutexLocker ml(FullGCALot_lock);
1635   if (_fullgc_alot_dummy_array != NULL) {
1636     if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) {
1637       // No more dummies to release, release entire array instead
1638       _fullgc_alot_dummy_array = NULL;
1639       return false;
1640     }
1641     if (!UseConcMarkSweepGC) {
1642       // Release dummy at bottom of old generation
1643       _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1644     }
1645     // Release dummy at bottom of permanent generation
1646     _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1647   }
1648   return true;
1649 }
1650 
1651 #endif // ASSERT