1 /*
   2  * Copyright (c) 1997, 2012, 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 oop Universe::_primordial_loader_cache                = NULL;
 154 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
 155 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 156 bool Universe::_verify_in_progress                    = false;
 157 oop Universe::_null_ptr_exception_instance            = NULL;
 158 oop Universe::_arithmetic_exception_instance          = NULL;
 159 oop Universe::_virtual_machine_error_instance         = NULL;
 160 oop Universe::_vm_exception                           = NULL;
 161 
 162 // These variables are guarded by FullGCALot_lock.
 163 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;)
 164 debug_only(int Universe::_fullgc_alot_dummy_next      = 0;)
 165 
 166 
 167 // Heap
 168 int             Universe::_verify_count = 0;
 169 
 170 int             Universe::_base_vtable_size = 0;
 171 bool            Universe::_bootstrapping = false;
 172 bool            Universe::_fully_initialized = false;
 173 
 174 size_t          Universe::_heap_capacity_at_last_gc;
 175 size_t          Universe::_heap_used_at_last_gc = 0;
 176 
 177 CollectedHeap*  Universe::_collectedHeap = NULL;
 178 
 179 NarrowOopStruct Universe::_narrow_oop = { NULL, 0, true };
 180 
 181 
 182 void Universe::basic_type_classes_do(void f(klassOop)) {
 183   f(boolArrayKlassObj());
 184   f(byteArrayKlassObj());
 185   f(charArrayKlassObj());
 186   f(intArrayKlassObj());
 187   f(shortArrayKlassObj());
 188   f(longArrayKlassObj());
 189   f(singleArrayKlassObj());
 190   f(doubleArrayKlassObj());
 191 }
 192 
 193 
 194 void Universe::system_classes_do(void f(klassOop)) {
 195   f(methodKlassObj());
 196   f(constMethodKlassObj());
 197   f(methodDataKlassObj());
 198   f(klassKlassObj());
 199   f(arrayKlassKlassObj());
 200   f(objArrayKlassKlassObj());
 201   f(typeArrayKlassKlassObj());
 202   f(instanceKlassKlassObj());
 203   f(constantPoolKlassObj());
 204   f(systemObjArrayKlassObj());
 205 }
 206 
 207 void Universe::oops_do(OopClosure* f, bool do_all) {
 208 
 209   f->do_oop((oop*) &_int_mirror);
 210   f->do_oop((oop*) &_float_mirror);
 211   f->do_oop((oop*) &_double_mirror);
 212   f->do_oop((oop*) &_byte_mirror);
 213   f->do_oop((oop*) &_bool_mirror);
 214   f->do_oop((oop*) &_char_mirror);
 215   f->do_oop((oop*) &_long_mirror);
 216   f->do_oop((oop*) &_short_mirror);
 217   f->do_oop((oop*) &_void_mirror);
 218 
 219   // It's important to iterate over these guys even if they are null,
 220   // since that's how shared heaps are restored.
 221   for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
 222     f->do_oop((oop*) &_mirrors[i]);
 223   }
 224   assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking");
 225 
 226   // %%% Consider moving those "shared oops" over here with the others.
 227   f->do_oop((oop*)&_boolArrayKlassObj);
 228   f->do_oop((oop*)&_byteArrayKlassObj);
 229   f->do_oop((oop*)&_charArrayKlassObj);
 230   f->do_oop((oop*)&_intArrayKlassObj);
 231   f->do_oop((oop*)&_shortArrayKlassObj);
 232   f->do_oop((oop*)&_longArrayKlassObj);
 233   f->do_oop((oop*)&_singleArrayKlassObj);
 234   f->do_oop((oop*)&_doubleArrayKlassObj);
 235   f->do_oop((oop*)&_objectArrayKlassObj);
 236   {
 237     for (int i = 0; i < T_VOID+1; i++) {
 238       if (_typeArrayKlassObjs[i] != NULL) {
 239         assert(i >= T_BOOLEAN, "checking");
 240         f->do_oop((oop*)&_typeArrayKlassObjs[i]);
 241       } else if (do_all) {
 242         f->do_oop((oop*)&_typeArrayKlassObjs[i]);
 243       }
 244     }
 245   }
 246   f->do_oop((oop*)&_methodKlassObj);
 247   f->do_oop((oop*)&_constMethodKlassObj);
 248   f->do_oop((oop*)&_methodDataKlassObj);
 249   f->do_oop((oop*)&_klassKlassObj);
 250   f->do_oop((oop*)&_arrayKlassKlassObj);
 251   f->do_oop((oop*)&_objArrayKlassKlassObj);
 252   f->do_oop((oop*)&_typeArrayKlassKlassObj);
 253   f->do_oop((oop*)&_instanceKlassKlassObj);
 254   f->do_oop((oop*)&_constantPoolKlassObj);
 255   f->do_oop((oop*)&_constantPoolCacheKlassObj);
 256   f->do_oop((oop*)&_compiledICHolderKlassObj);
 257   f->do_oop((oop*)&_systemObjArrayKlassObj);
 258   f->do_oop((oop*)&_the_empty_byte_array);
 259   f->do_oop((oop*)&_the_empty_short_array);
 260   f->do_oop((oop*)&_the_empty_int_array);
 261   f->do_oop((oop*)&_the_empty_system_obj_array);
 262   f->do_oop((oop*)&_the_empty_class_klass_array);
 263   f->do_oop((oop*)&_the_array_interfaces_array);
 264   f->do_oop((oop*)&_the_null_string);
 265   f->do_oop((oop*)&_the_min_jint_string);
 266   _finalizer_register_cache->oops_do(f);
 267   _loader_addClass_cache->oops_do(f);
 268   _reflect_invoke_cache->oops_do(f);
 269   f->do_oop((oop*)&_out_of_memory_error_java_heap);
 270   f->do_oop((oop*)&_out_of_memory_error_perm_gen);
 271   f->do_oop((oop*)&_out_of_memory_error_array_size);
 272   f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
 273   if (_primordial_loader_cache != (oop)NULL && _primordial_loader_cache != (oop)-1) {
 274     f->do_oop((oop*)&_primordial_loader_cache);
 275   }
 276   if (_preallocated_out_of_memory_error_array != (oop)NULL) {   // NULL when DumpSharedSpaces
 277     f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
 278   }
 279   f->do_oop((oop*)&_null_ptr_exception_instance);
 280   f->do_oop((oop*)&_arithmetic_exception_instance);
 281   f->do_oop((oop*)&_virtual_machine_error_instance);
 282   f->do_oop((oop*)&_main_thread_group);
 283   f->do_oop((oop*)&_system_thread_group);
 284   f->do_oop((oop*)&_vm_exception);
 285   debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
 286 }
 287 
 288 
 289 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
 290   if (size < alignment || size % alignment != 0) {
 291     ResourceMark rm;
 292     stringStream st;
 293     st.print("Size of %s (%ld bytes) must be aligned to %ld bytes", name, size, alignment);
 294     char* error = st.as_string();
 295     vm_exit_during_initialization(error);
 296   }
 297 }
 298 
 299 
 300 void Universe::genesis(TRAPS) {
 301   ResourceMark rm;
 302   { FlagSetting fs(_bootstrapping, true);
 303 
 304     { MutexLocker mc(Compile_lock);
 305 
 306       // determine base vtable size; without that we cannot create the array klasses
 307       compute_base_vtable_size();
 308 
 309       if (!UseSharedSpaces) {
 310         _klassKlassObj          = klassKlass::create_klass(CHECK);
 311         _arrayKlassKlassObj     = arrayKlassKlass::create_klass(CHECK);
 312 
 313         _objArrayKlassKlassObj  = objArrayKlassKlass::create_klass(CHECK);
 314         _instanceKlassKlassObj  = instanceKlassKlass::create_klass(CHECK);
 315         _typeArrayKlassKlassObj = typeArrayKlassKlass::create_klass(CHECK);
 316 
 317         _boolArrayKlassObj      = typeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK);
 318         _charArrayKlassObj      = typeArrayKlass::create_klass(T_CHAR,    sizeof(jchar),    CHECK);
 319         _singleArrayKlassObj    = typeArrayKlass::create_klass(T_FLOAT,   sizeof(jfloat),   CHECK);
 320         _doubleArrayKlassObj    = typeArrayKlass::create_klass(T_DOUBLE,  sizeof(jdouble),  CHECK);
 321         _byteArrayKlassObj      = typeArrayKlass::create_klass(T_BYTE,    sizeof(jbyte),    CHECK);
 322         _shortArrayKlassObj     = typeArrayKlass::create_klass(T_SHORT,   sizeof(jshort),   CHECK);
 323         _intArrayKlassObj       = typeArrayKlass::create_klass(T_INT,     sizeof(jint),     CHECK);
 324         _longArrayKlassObj      = typeArrayKlass::create_klass(T_LONG,    sizeof(jlong),    CHECK);
 325 
 326         _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj;
 327         _typeArrayKlassObjs[T_CHAR]    = _charArrayKlassObj;
 328         _typeArrayKlassObjs[T_FLOAT]   = _singleArrayKlassObj;
 329         _typeArrayKlassObjs[T_DOUBLE]  = _doubleArrayKlassObj;
 330         _typeArrayKlassObjs[T_BYTE]    = _byteArrayKlassObj;
 331         _typeArrayKlassObjs[T_SHORT]   = _shortArrayKlassObj;
 332         _typeArrayKlassObjs[T_INT]     = _intArrayKlassObj;
 333         _typeArrayKlassObjs[T_LONG]    = _longArrayKlassObj;
 334 
 335         _methodKlassObj             = methodKlass::create_klass(CHECK);
 336         _constMethodKlassObj        = constMethodKlass::create_klass(CHECK);
 337         _methodDataKlassObj         = methodDataKlass::create_klass(CHECK);
 338         _constantPoolKlassObj       = constantPoolKlass::create_klass(CHECK);
 339         _constantPoolCacheKlassObj  = constantPoolCacheKlass::create_klass(CHECK);
 340 
 341         _compiledICHolderKlassObj   = compiledICHolderKlass::create_klass(CHECK);
 342         _systemObjArrayKlassObj     = objArrayKlassKlass::cast(objArrayKlassKlassObj())->allocate_system_objArray_klass(CHECK);
 343 
 344         _the_empty_byte_array       = oopFactory::new_permanent_byteArray(0, CHECK);
 345         _the_empty_short_array      = oopFactory::new_permanent_shortArray(0, CHECK);
 346         _the_empty_int_array        = oopFactory::new_permanent_intArray(0, CHECK);
 347         _the_empty_system_obj_array = oopFactory::new_system_objArray(0, CHECK);
 348 
 349         _the_array_interfaces_array = oopFactory::new_system_objArray(2, CHECK);
 350       }
 351     }
 352 
 353     vmSymbols::initialize(CHECK);
 354 
 355     SystemDictionary::initialize(CHECK);
 356 
 357     klassOop ok = SystemDictionary::Object_klass();
 358 
 359     _the_null_string            = StringTable::intern("null", CHECK);
 360     _the_min_jint_string       = StringTable::intern("-2147483648", CHECK);
 361 
 362     if (UseSharedSpaces) {
 363       // Verify shared interfaces array.
 364       assert(_the_array_interfaces_array->obj_at(0) ==
 365              SystemDictionary::Cloneable_klass(), "u3");
 366       assert(_the_array_interfaces_array->obj_at(1) ==
 367              SystemDictionary::Serializable_klass(), "u3");
 368 
 369       // Verify element klass for system obj array klass
 370       assert(objArrayKlass::cast(_systemObjArrayKlassObj)->element_klass() == ok, "u1");
 371       assert(objArrayKlass::cast(_systemObjArrayKlassObj)->bottom_klass() == ok, "u2");
 372 
 373       // Verify super class for the classes created above
 374       assert(Klass::cast(boolArrayKlassObj()     )->super() == ok, "u3");
 375       assert(Klass::cast(charArrayKlassObj()     )->super() == ok, "u3");
 376       assert(Klass::cast(singleArrayKlassObj()   )->super() == ok, "u3");
 377       assert(Klass::cast(doubleArrayKlassObj()   )->super() == ok, "u3");
 378       assert(Klass::cast(byteArrayKlassObj()     )->super() == ok, "u3");
 379       assert(Klass::cast(shortArrayKlassObj()    )->super() == ok, "u3");
 380       assert(Klass::cast(intArrayKlassObj()      )->super() == ok, "u3");
 381       assert(Klass::cast(longArrayKlassObj()     )->super() == ok, "u3");
 382       assert(Klass::cast(constantPoolKlassObj()  )->super() == ok, "u3");
 383       assert(Klass::cast(systemObjArrayKlassObj())->super() == ok, "u3");
 384     } else {
 385       // Set up shared interfaces array.  (Do this before supers are set up.)
 386       _the_array_interfaces_array->obj_at_put(0, SystemDictionary::Cloneable_klass());
 387       _the_array_interfaces_array->obj_at_put(1, SystemDictionary::Serializable_klass());
 388 
 389       // Set element klass for system obj array klass
 390       objArrayKlass::cast(_systemObjArrayKlassObj)->set_element_klass(ok);
 391       objArrayKlass::cast(_systemObjArrayKlassObj)->set_bottom_klass(ok);
 392 
 393       // Set super class for the classes created above
 394       Klass::cast(boolArrayKlassObj()     )->initialize_supers(ok, CHECK);
 395       Klass::cast(charArrayKlassObj()     )->initialize_supers(ok, CHECK);
 396       Klass::cast(singleArrayKlassObj()   )->initialize_supers(ok, CHECK);
 397       Klass::cast(doubleArrayKlassObj()   )->initialize_supers(ok, CHECK);
 398       Klass::cast(byteArrayKlassObj()     )->initialize_supers(ok, CHECK);
 399       Klass::cast(shortArrayKlassObj()    )->initialize_supers(ok, CHECK);
 400       Klass::cast(intArrayKlassObj()      )->initialize_supers(ok, CHECK);
 401       Klass::cast(longArrayKlassObj()     )->initialize_supers(ok, CHECK);
 402       Klass::cast(constantPoolKlassObj()  )->initialize_supers(ok, CHECK);
 403       Klass::cast(systemObjArrayKlassObj())->initialize_supers(ok, CHECK);
 404       Klass::cast(boolArrayKlassObj()     )->set_super(ok);
 405       Klass::cast(charArrayKlassObj()     )->set_super(ok);
 406       Klass::cast(singleArrayKlassObj()   )->set_super(ok);
 407       Klass::cast(doubleArrayKlassObj()   )->set_super(ok);
 408       Klass::cast(byteArrayKlassObj()     )->set_super(ok);
 409       Klass::cast(shortArrayKlassObj()    )->set_super(ok);
 410       Klass::cast(intArrayKlassObj()      )->set_super(ok);
 411       Klass::cast(longArrayKlassObj()     )->set_super(ok);
 412       Klass::cast(constantPoolKlassObj()  )->set_super(ok);
 413       Klass::cast(systemObjArrayKlassObj())->set_super(ok);
 414     }
 415 
 416     Klass::cast(boolArrayKlassObj()     )->append_to_sibling_list();
 417     Klass::cast(charArrayKlassObj()     )->append_to_sibling_list();
 418     Klass::cast(singleArrayKlassObj()   )->append_to_sibling_list();
 419     Klass::cast(doubleArrayKlassObj()   )->append_to_sibling_list();
 420     Klass::cast(byteArrayKlassObj()     )->append_to_sibling_list();
 421     Klass::cast(shortArrayKlassObj()    )->append_to_sibling_list();
 422     Klass::cast(intArrayKlassObj()      )->append_to_sibling_list();
 423     Klass::cast(longArrayKlassObj()     )->append_to_sibling_list();
 424     Klass::cast(constantPoolKlassObj()  )->append_to_sibling_list();
 425     Klass::cast(systemObjArrayKlassObj())->append_to_sibling_list();
 426   } // end of core bootstrapping
 427 
 428   // Initialize _objectArrayKlass after core bootstraping to make
 429   // sure the super class is set up properly for _objectArrayKlass.
 430   _objectArrayKlassObj = instanceKlass::
 431     cast(SystemDictionary::Object_klass())->array_klass(1, CHECK);
 432   // Add the class to the class hierarchy manually to make sure that
 433   // its vtable is initialized after core bootstrapping is completed.
 434   Klass::cast(_objectArrayKlassObj)->append_to_sibling_list();
 435 
 436   // Compute is_jdk version flags.
 437   // Only 1.3 or later has the java.lang.Shutdown class.
 438   // Only 1.4 or later has the java.lang.CharSequence interface.
 439   // Only 1.5 or later has the java.lang.management.MemoryUsage class.
 440   if (JDK_Version::is_partially_initialized()) {
 441     uint8_t jdk_version;
 442     klassOop k = SystemDictionary::resolve_or_null(
 443         vmSymbols::java_lang_management_MemoryUsage(), THREAD);
 444     CLEAR_PENDING_EXCEPTION; // ignore exceptions
 445     if (k == NULL) {
 446       k = SystemDictionary::resolve_or_null(
 447           vmSymbols::java_lang_CharSequence(), THREAD);
 448       CLEAR_PENDING_EXCEPTION; // ignore exceptions
 449       if (k == NULL) {
 450         k = SystemDictionary::resolve_or_null(
 451             vmSymbols::java_lang_Shutdown(), THREAD);
 452         CLEAR_PENDING_EXCEPTION; // ignore exceptions
 453         if (k == NULL) {
 454           jdk_version = 2;
 455         } else {
 456           jdk_version = 3;
 457         }
 458       } else {
 459         jdk_version = 4;
 460       }
 461     } else {
 462       jdk_version = 5;
 463     }
 464     JDK_Version::fully_initialize(jdk_version);
 465   }
 466 
 467   #ifdef ASSERT
 468   if (FullGCALot) {
 469     // Allocate an array of dummy objects.
 470     // We'd like these to be at the bottom of the old generation,
 471     // so that when we free one and then collect,
 472     // (almost) the whole heap moves
 473     // and we find out if we actually update all the oops correctly.
 474     // But we can't allocate directly in the old generation,
 475     // so we allocate wherever, and hope that the first collection
 476     // moves these objects to the bottom of the old generation.
 477     // We can allocate directly in the permanent generation, so we do.
 478     int size;
 479     if (UseConcMarkSweepGC) {
 480       warning("Using +FullGCALot with concurrent mark sweep gc "
 481               "will not force all objects to relocate");
 482       size = FullGCALotDummies;
 483     } else {
 484       size = FullGCALotDummies * 2;
 485     }
 486     objArrayOop    naked_array = oopFactory::new_system_objArray(size, CHECK);
 487     objArrayHandle dummy_array(THREAD, naked_array);
 488     int i = 0;
 489     while (i < size) {
 490       if (!UseConcMarkSweepGC) {
 491         // Allocate dummy in old generation
 492         oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_instance(CHECK);
 493         dummy_array->obj_at_put(i++, dummy);
 494       }
 495       // Allocate dummy in permanent generation
 496       oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_permanent_instance(CHECK);
 497       dummy_array->obj_at_put(i++, dummy);
 498     }
 499     {
 500       // Only modify the global variable inside the mutex.
 501       // If we had a race to here, the other dummy_array instances
 502       // and their elements just get dropped on the floor, which is fine.
 503       MutexLocker ml(FullGCALot_lock);
 504       if (_fullgc_alot_dummy_array == NULL) {
 505         _fullgc_alot_dummy_array = dummy_array();
 506       }
 507     }
 508     assert(i == _fullgc_alot_dummy_array->length(), "just checking");
 509   }
 510   #endif
 511 }
 512 
 513 
 514 static inline void* dereference(void* addr) {
 515   return *(void**)addr;
 516 }
 517 
 518 static inline void add_vtable(void** list, int* n, void* o, int count) {
 519   guarantee((*n) < count, "vtable list too small");
 520   void* vtable = dereference(o);
 521   assert(dereference(vtable) != NULL, "invalid vtable");
 522   list[(*n)++] = vtable;
 523 }
 524 
 525 void Universe::init_self_patching_vtbl_list(void** list, int count) {
 526   int n = 0;
 527   { klassKlass o;             add_vtable(list, &n, &o, count); }
 528   { arrayKlassKlass o;        add_vtable(list, &n, &o, count); }
 529   { objArrayKlassKlass o;     add_vtable(list, &n, &o, count); }
 530   { instanceKlassKlass o;     add_vtable(list, &n, &o, count); }
 531   { instanceKlass o;          add_vtable(list, &n, &o, count); }
 532   { instanceMirrorKlass o;    add_vtable(list, &n, &o, count); }
 533   { instanceRefKlass o;       add_vtable(list, &n, &o, count); }
 534   { typeArrayKlassKlass o;    add_vtable(list, &n, &o, count); }
 535   { typeArrayKlass o;         add_vtable(list, &n, &o, count); }
 536   { methodKlass o;            add_vtable(list, &n, &o, count); }
 537   { constMethodKlass o;       add_vtable(list, &n, &o, count); }
 538   { constantPoolKlass o;      add_vtable(list, &n, &o, count); }
 539   { constantPoolCacheKlass o; add_vtable(list, &n, &o, count); }
 540   { objArrayKlass o;          add_vtable(list, &n, &o, count); }
 541   { methodDataKlass o;        add_vtable(list, &n, &o, count); }
 542   { compiledICHolderKlass o;  add_vtable(list, &n, &o, count); }
 543 #ifndef PRODUCT
 544   // In non-product builds CHeapObj is derived from AllocatedObj,
 545   // so symbols in CDS archive should have their vtable pointer patched.
 546   { Symbol o;                 add_vtable(list, &n, &o, count); }
 547 #endif
 548 }
 549 
 550 
 551 class FixupMirrorClosure: public ObjectClosure {
 552  public:
 553   virtual void do_object(oop obj) {
 554     if (obj->is_klass()) {
 555       EXCEPTION_MARK;
 556       KlassHandle k(THREAD, klassOop(obj));
 557       // We will never reach the CATCH below since Exceptions::_throw will cause
 558       // the VM to exit if an exception is thrown during initialization
 559       java_lang_Class::fixup_mirror(k, CATCH);
 560       // This call unconditionally creates a new mirror for k,
 561       // and links in k's component_mirror field if k is an array.
 562       // If k is an objArray, k's element type must already have
 563       // a mirror.  In other words, this closure must process
 564       // the component type of an objArray k before it processes k.
 565       // This works because the permgen iterator presents arrays
 566       // and their component types in order of creation.
 567     }
 568   }
 569 };
 570 
 571 void Universe::initialize_basic_type_mirrors(TRAPS) {
 572   if (UseSharedSpaces) {
 573     assert(_int_mirror != NULL, "already loaded");
 574     assert(_void_mirror == _mirrors[T_VOID], "consistently loaded");
 575   } else {
 576 
 577     assert(_int_mirror==NULL, "basic type mirrors already initialized");
 578     _int_mirror     =
 579       java_lang_Class::create_basic_type_mirror("int",    T_INT, CHECK);
 580     _float_mirror   =
 581       java_lang_Class::create_basic_type_mirror("float",  T_FLOAT,   CHECK);
 582     _double_mirror  =
 583       java_lang_Class::create_basic_type_mirror("double", T_DOUBLE,  CHECK);
 584     _byte_mirror    =
 585       java_lang_Class::create_basic_type_mirror("byte",   T_BYTE, CHECK);
 586     _bool_mirror    =
 587       java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK);
 588     _char_mirror    =
 589       java_lang_Class::create_basic_type_mirror("char",   T_CHAR, CHECK);
 590     _long_mirror    =
 591       java_lang_Class::create_basic_type_mirror("long",   T_LONG, CHECK);
 592     _short_mirror   =
 593       java_lang_Class::create_basic_type_mirror("short",  T_SHORT,   CHECK);
 594     _void_mirror    =
 595       java_lang_Class::create_basic_type_mirror("void",   T_VOID, CHECK);
 596 
 597     _mirrors[T_INT]     = _int_mirror;
 598     _mirrors[T_FLOAT]   = _float_mirror;
 599     _mirrors[T_DOUBLE]  = _double_mirror;
 600     _mirrors[T_BYTE]    = _byte_mirror;
 601     _mirrors[T_BOOLEAN] = _bool_mirror;
 602     _mirrors[T_CHAR]    = _char_mirror;
 603     _mirrors[T_LONG]    = _long_mirror;
 604     _mirrors[T_SHORT]   = _short_mirror;
 605     _mirrors[T_VOID]    = _void_mirror;
 606     //_mirrors[T_OBJECT]  = instanceKlass::cast(_object_klass)->java_mirror();
 607     //_mirrors[T_ARRAY]   = instanceKlass::cast(_object_klass)->java_mirror();
 608   }
 609 }
 610 
 611 void Universe::fixup_mirrors(TRAPS) {
 612   // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
 613   // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
 614   // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
 615   // that the number of objects allocated at this point is very small.
 616   assert(SystemDictionary::Class_klass_loaded(), "java.lang.Class should be loaded");
 617 
 618   // Cache the start of the static fields
 619   instanceMirrorKlass::init_offset_of_static_fields();
 620 
 621   FixupMirrorClosure blk;
 622   Universe::heap()->permanent_object_iterate(&blk);
 623 }
 624 
 625 
 626 static bool has_run_finalizers_on_exit = false;
 627 
 628 void Universe::run_finalizers_on_exit() {
 629   if (has_run_finalizers_on_exit) return;
 630   has_run_finalizers_on_exit = true;
 631 
 632   // Called on VM exit. This ought to be run in a separate thread.
 633   if (TraceReferenceGC) tty->print_cr("Callback to run finalizers on exit");
 634   {
 635     PRESERVE_EXCEPTION_MARK;
 636     KlassHandle finalizer_klass(THREAD, SystemDictionary::Finalizer_klass());
 637     JavaValue result(T_VOID);
 638     JavaCalls::call_static(
 639       &result,
 640       finalizer_klass,
 641       vmSymbols::run_finalizers_on_exit_name(),
 642       vmSymbols::void_method_signature(),
 643       THREAD
 644     );
 645     // Ignore any pending exceptions
 646     CLEAR_PENDING_EXCEPTION;
 647   }
 648 }
 649 
 650 
 651 // initialize_vtable could cause gc if
 652 // 1) we specified true to initialize_vtable and
 653 // 2) this ran after gc was enabled
 654 // In case those ever change we use handles for oops
 655 void Universe::reinitialize_vtable_of(KlassHandle k_h, TRAPS) {
 656   // init vtable of k and all subclasses
 657   Klass* ko = k_h()->klass_part();
 658   klassVtable* vt = ko->vtable();
 659   if (vt) vt->initialize_vtable(false, CHECK);
 660   if (ko->oop_is_instance()) {
 661     instanceKlass* ik = (instanceKlass*)ko;
 662     for (KlassHandle s_h(THREAD, ik->subklass()); s_h() != NULL; s_h = (THREAD, s_h()->klass_part()->next_sibling())) {
 663       reinitialize_vtable_of(s_h, CHECK);
 664     }
 665   }
 666 }
 667 
 668 
 669 void initialize_itable_for_klass(klassOop k, TRAPS) {
 670   instanceKlass::cast(k)->itable()->initialize_itable(false, CHECK);
 671 }
 672 
 673 
 674 void Universe::reinitialize_itables(TRAPS) {
 675   SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
 676 
 677 }
 678 
 679 
 680 bool Universe::on_page_boundary(void* addr) {
 681   return ((uintptr_t) addr) % os::vm_page_size() == 0;
 682 }
 683 
 684 
 685 bool Universe::should_fill_in_stack_trace(Handle throwable) {
 686   // never attempt to fill in the stack trace of preallocated errors that do not have
 687   // backtrace. These errors are kept alive forever and may be "re-used" when all
 688   // preallocated errors with backtrace have been consumed. Also need to avoid
 689   // a potential loop which could happen if an out of memory occurs when attempting
 690   // to allocate the backtrace.
 691   return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
 692           (throwable() != Universe::_out_of_memory_error_perm_gen)  &&
 693           (throwable() != Universe::_out_of_memory_error_array_size) &&
 694           (throwable() != Universe::_out_of_memory_error_gc_overhead_limit));
 695 }
 696 
 697 
 698 oop Universe::gen_out_of_memory_error(oop default_err) {
 699   // generate an out of memory error:
 700   // - if there is a preallocated error with backtrace available then return it wth
 701   //   a filled in stack trace.
 702   // - if there are no preallocated errors with backtrace available then return
 703   //   an error without backtrace.
 704   int next;
 705   if (_preallocated_out_of_memory_error_avail_count > 0) {
 706     next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count);
 707     assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
 708   } else {
 709     next = -1;
 710   }
 711   if (next < 0) {
 712     // all preallocated errors have been used.
 713     // return default
 714     return default_err;
 715   } else {
 716     // get the error object at the slot and set set it to NULL so that the
 717     // array isn't keeping it alive anymore.
 718     oop exc = preallocated_out_of_memory_errors()->obj_at(next);
 719     assert(exc != NULL, "slot has been used already");
 720     preallocated_out_of_memory_errors()->obj_at_put(next, NULL);
 721 
 722     // use the message from the default error
 723     oop msg = java_lang_Throwable::message(default_err);
 724     assert(msg != NULL, "no message");
 725     java_lang_Throwable::set_message(exc, msg);
 726 
 727     // populate the stack trace and return it.
 728     java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
 729     return exc;
 730   }
 731 }
 732 
 733 static intptr_t non_oop_bits = 0;
 734 
 735 void* Universe::non_oop_word() {
 736   // Neither the high bits nor the low bits of this value is allowed
 737   // to look like (respectively) the high or low bits of a real oop.
 738   //
 739   // High and low are CPU-specific notions, but low always includes
 740   // the low-order bit.  Since oops are always aligned at least mod 4,
 741   // setting the low-order bit will ensure that the low half of the
 742   // word will never look like that of a real oop.
 743   //
 744   // Using the OS-supplied non-memory-address word (usually 0 or -1)
 745   // will take care of the high bits, however many there are.
 746 
 747   if (non_oop_bits == 0) {
 748     non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
 749   }
 750 
 751   return (void*)non_oop_bits;
 752 }
 753 
 754 jint universe_init() {
 755   assert(!Universe::_fully_initialized, "called after initialize_vtables");
 756   guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
 757          "LogHeapWordSize is incorrect.");
 758   guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
 759   guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
 760             "oop size is not not a multiple of HeapWord size");
 761   TraceTime timer("Genesis", TraceStartupTime);
 762   GC_locker::lock();  // do not allow gc during bootstrapping
 763   JavaClasses::compute_hard_coded_offsets();
 764 
 765   // Get map info from shared archive file.
 766   if (DumpSharedSpaces)
 767     UseSharedSpaces = false;
 768 
 769   FileMapInfo* mapinfo = NULL;
 770   if (UseSharedSpaces) {
 771     mapinfo = NEW_C_HEAP_OBJ(FileMapInfo);
 772     memset(mapinfo, 0, sizeof(FileMapInfo));
 773 
 774     // Open the shared archive file, read and validate the header. If
 775     // initialization files, shared spaces [UseSharedSpaces] are
 776     // disabled and the file is closed.
 777 
 778     if (mapinfo->initialize()) {
 779       FileMapInfo::set_current_info(mapinfo);
 780     } else {
 781       assert(!mapinfo->is_open() && !UseSharedSpaces,
 782              "archive file not closed or shared spaces not disabled.");
 783     }
 784   }
 785 
 786   jint status = Universe::initialize_heap();
 787   if (status != JNI_OK) {
 788     return status;
 789   }
 790 
 791   // We have a heap so create the methodOop caches before
 792   // CompactingPermGenGen::initialize_oops() tries to populate them.
 793   Universe::_finalizer_register_cache = new LatestMethodOopCache();
 794   Universe::_loader_addClass_cache    = new LatestMethodOopCache();
 795   Universe::_reflect_invoke_cache     = new ActiveMethodOopsCache();
 796 
 797   if (UseSharedSpaces) {
 798 
 799     // Read the data structures supporting the shared spaces (shared
 800     // system dictionary, symbol table, etc.).  After that, access to
 801     // the file (other than the mapped regions) is no longer needed, and
 802     // the file is closed. Closing the file does not affect the
 803     // currently mapped regions.
 804 
 805     CompactingPermGenGen::initialize_oops();
 806     mapinfo->close();
 807 
 808   } else {
 809     SymbolTable::create_table();
 810     StringTable::create_table();
 811     ClassLoader::create_package_info_table();
 812   }
 813 
 814   return JNI_OK;
 815 }
 816 
 817 // Choose the heap base address and oop encoding mode
 818 // when compressed oops are used:
 819 // Unscaled  - Use 32-bits oops without encoding when
 820 //     NarrowOopHeapBaseMin + heap_size < 4Gb
 821 // ZeroBased - Use zero based compressed oops with encoding when
 822 //     NarrowOopHeapBaseMin + heap_size < 32Gb
 823 // HeapBased - Use compressed oops with heap base + encoding.
 824 
 825 // 4Gb
 826 static const uint64_t NarrowOopHeapMax = (uint64_t(max_juint) + 1);
 827 // 32Gb
 828 // OopEncodingHeapMax == NarrowOopHeapMax << LogMinObjAlignmentInBytes;
 829 
 830 char* Universe::preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode) {
 831   size_t base = 0;
 832 #ifdef _LP64
 833   if (UseCompressedOops) {
 834     assert(mode == UnscaledNarrowOop  ||
 835            mode == ZeroBasedNarrowOop ||
 836            mode == HeapBasedNarrowOop, "mode is invalid");
 837     const size_t total_size = heap_size + HeapBaseMinAddress;
 838     // Return specified base for the first request.
 839     if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) {
 840       base = HeapBaseMinAddress;
 841     } else if (total_size <= OopEncodingHeapMax && (mode != HeapBasedNarrowOop)) {
 842       if (total_size <= NarrowOopHeapMax && (mode == UnscaledNarrowOop) &&
 843           (Universe::narrow_oop_shift() == 0)) {
 844         // Use 32-bits oops without encoding and
 845         // place heap's top on the 4Gb boundary
 846         base = (NarrowOopHeapMax - heap_size);
 847       } else {
 848         // Can't reserve with NarrowOopShift == 0
 849         Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 850         if (mode == UnscaledNarrowOop ||
 851             mode == ZeroBasedNarrowOop && total_size <= NarrowOopHeapMax) {
 852           // Use zero based compressed oops with encoding and
 853           // place heap's top on the 32Gb boundary in case
 854           // total_size > 4Gb or failed to reserve below 4Gb.
 855           base = (OopEncodingHeapMax - heap_size);
 856         }
 857       }
 858     } else {
 859       // Can't reserve below 32Gb.
 860       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 861     }
 862     // Set narrow_oop_base and narrow_oop_use_implicit_null_checks
 863     // used in ReservedHeapSpace() constructors.
 864     // The final values will be set in initialize_heap() below.
 865     if (base != 0 && (base + heap_size) <= OopEncodingHeapMax) {
 866       // Use zero based compressed oops
 867       Universe::set_narrow_oop_base(NULL);
 868       // Don't need guard page for implicit checks in indexed
 869       // addressing mode with zero based Compressed Oops.
 870       Universe::set_narrow_oop_use_implicit_null_checks(true);
 871     } else {
 872       // Set to a non-NULL value so the ReservedSpace ctor computes
 873       // the correct no-access prefix.
 874       // The final value will be set in initialize_heap() below.
 875       Universe::set_narrow_oop_base((address)NarrowOopHeapMax);
 876 #ifdef _WIN64
 877       if (UseLargePages) {
 878         // Cannot allocate guard pages for implicit checks in indexed
 879         // addressing mode when large pages are specified on windows.
 880         Universe::set_narrow_oop_use_implicit_null_checks(false);
 881       }
 882 #endif //  _WIN64
 883     }
 884   }
 885 #endif
 886   return (char*)base; // also return NULL (don't care) for 32-bit VM
 887 }
 888 
 889 jint Universe::initialize_heap() {
 890 
 891   if (UseParallelGC) {
 892 #ifndef SERIALGC
 893     Universe::_collectedHeap = new ParallelScavengeHeap();
 894 #else  // SERIALGC
 895     fatal("UseParallelGC not supported in java kernel vm.");
 896 #endif // SERIALGC
 897 
 898   } else if (UseG1GC) {
 899 #ifndef SERIALGC
 900     G1CollectorPolicy* g1p = new G1CollectorPolicy();
 901     G1CollectedHeap* g1h = new G1CollectedHeap(g1p);
 902     Universe::_collectedHeap = g1h;
 903 #else  // SERIALGC
 904     fatal("UseG1GC not supported in java kernel vm.");
 905 #endif // SERIALGC
 906 
 907   } else {
 908     GenCollectorPolicy *gc_policy;
 909 
 910     if (UseSerialGC) {
 911       gc_policy = new MarkSweepPolicy();
 912     } else if (UseConcMarkSweepGC) {
 913 #ifndef SERIALGC
 914       if (UseAdaptiveSizePolicy) {
 915         gc_policy = new ASConcurrentMarkSweepPolicy();
 916       } else {
 917         gc_policy = new ConcurrentMarkSweepPolicy();
 918       }
 919 #else   // SERIALGC
 920     fatal("UseConcMarkSweepGC not supported in java kernel vm.");
 921 #endif // SERIALGC
 922     } else { // default old generation
 923       gc_policy = new MarkSweepPolicy();
 924     }
 925 
 926     Universe::_collectedHeap = new GenCollectedHeap(gc_policy);
 927   }
 928 
 929   jint status = Universe::heap()->initialize();
 930   if (status != JNI_OK) {
 931     return status;
 932   }
 933 
 934 #ifdef _LP64
 935   if (UseCompressedOops) {
 936     // Subtract a page because something can get allocated at heap base.
 937     // This also makes implicit null checking work, because the
 938     // memory+1 page below heap_base needs to cause a signal.
 939     // See needs_explicit_null_check.
 940     // Only set the heap base for compressed oops because it indicates
 941     // compressed oops for pstack code.
 942     bool verbose = PrintCompressedOopsMode || (PrintMiscellaneous && Verbose);
 943     if (verbose) {
 944       tty->cr();
 945       tty->print("heap address: " PTR_FORMAT ", size: " SIZE_FORMAT " MB",
 946                  Universe::heap()->base(), Universe::heap()->reserved_region().byte_size()/M);
 947     }
 948     if ((uint64_t)Universe::heap()->reserved_region().end() > OopEncodingHeapMax) {
 949       // Can't reserve heap below 32Gb.
 950       Universe::set_narrow_oop_base(Universe::heap()->base() - os::vm_page_size());
 951       Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 952       if (verbose) {
 953         tty->print(", Compressed Oops with base: "PTR_FORMAT, Universe::narrow_oop_base());
 954       }
 955     } else {
 956       Universe::set_narrow_oop_base(0);
 957       if (verbose) {
 958         tty->print(", zero based Compressed Oops");
 959       }
 960 #ifdef _WIN64
 961       if (!Universe::narrow_oop_use_implicit_null_checks()) {
 962         // Don't need guard page for implicit checks in indexed addressing
 963         // mode with zero based Compressed Oops.
 964         Universe::set_narrow_oop_use_implicit_null_checks(true);
 965       }
 966 #endif //  _WIN64
 967       if((uint64_t)Universe::heap()->reserved_region().end() > NarrowOopHeapMax) {
 968         // Can't reserve heap below 4Gb.
 969         Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
 970       } else {
 971         Universe::set_narrow_oop_shift(0);
 972         if (verbose) {
 973           tty->print(", 32-bits Oops");
 974         }
 975       }
 976     }
 977     if (verbose) {
 978       tty->cr();
 979       tty->cr();
 980     }
 981   }
 982   assert(Universe::narrow_oop_base() == (Universe::heap()->base() - os::vm_page_size()) ||
 983          Universe::narrow_oop_base() == NULL, "invalid value");
 984   assert(Universe::narrow_oop_shift() == LogMinObjAlignmentInBytes ||
 985          Universe::narrow_oop_shift() == 0, "invalid value");
 986 #endif
 987 
 988   // We will never reach the CATCH below since Exceptions::_throw will cause
 989   // the VM to exit if an exception is thrown during initialization
 990 
 991   if (UseTLAB) {
 992     assert(Universe::heap()->supports_tlab_allocation(),
 993            "Should support thread-local allocation buffers");
 994     ThreadLocalAllocBuffer::startup_initialization();
 995   }
 996   return JNI_OK;
 997 }
 998 
 999 // It's the caller's repsonsibility to ensure glitch-freedom
1000 // (if required).
1001 void Universe::update_heap_info_at_gc() {
1002   _heap_capacity_at_last_gc = heap()->capacity();
1003   _heap_used_at_last_gc     = heap()->used();
1004 }
1005 
1006 
1007 
1008 void universe2_init() {
1009   EXCEPTION_MARK;
1010   Universe::genesis(CATCH);
1011   // Although we'd like to verify here that the state of the heap
1012   // is good, we can't because the main thread has not yet added
1013   // itself to the threads list (so, using current interfaces
1014   // we can't "fill" its TLAB), unless TLABs are disabled.
1015   if (VerifyBeforeGC && !UseTLAB &&
1016       Universe::heap()->total_collections() >= VerifyGCStartAt) {
1017      Universe::heap()->prepare_for_verify();
1018      Universe::verify();   // make sure we're starting with a clean slate
1019   }
1020 }
1021 
1022 
1023 // This function is defined in JVM.cpp
1024 extern void initialize_converter_functions();
1025 
1026 bool universe_post_init() {
1027   assert(!is_init_completed(), "Error: initialization not yet completed!");
1028   Universe::_fully_initialized = true;
1029   EXCEPTION_MARK;
1030   { ResourceMark rm;
1031     Interpreter::initialize();      // needed for interpreter entry points
1032     if (!UseSharedSpaces) {
1033       KlassHandle ok_h(THREAD, SystemDictionary::Object_klass());
1034       Universe::reinitialize_vtable_of(ok_h, CHECK_false);
1035       Universe::reinitialize_itables(CHECK_false);
1036     }
1037   }
1038 
1039   klassOop k;
1040   instanceKlassHandle k_h;
1041   if (!UseSharedSpaces) {
1042     // Setup preallocated empty java.lang.Class array
1043     Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::Class_klass(), 0, CHECK_false);
1044     // Setup preallocated OutOfMemoryError errors
1045     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false);
1046     k_h = instanceKlassHandle(THREAD, k);
1047     Universe::_out_of_memory_error_java_heap = k_h->allocate_permanent_instance(CHECK_false);
1048     Universe::_out_of_memory_error_perm_gen = k_h->allocate_permanent_instance(CHECK_false);
1049     Universe::_out_of_memory_error_array_size = k_h->allocate_permanent_instance(CHECK_false);
1050     Universe::_out_of_memory_error_gc_overhead_limit =
1051       k_h->allocate_permanent_instance(CHECK_false);
1052 
1053     // Setup preallocated NullPointerException
1054     // (this is currently used for a cheap & dirty solution in compiler exception handling)
1055     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false);
1056     Universe::_null_ptr_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1057     // Setup preallocated ArithmeticException
1058     // (this is currently used for a cheap & dirty solution in compiler exception handling)
1059     k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false);
1060     Universe::_arithmetic_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1061     // Virtual Machine Error for when we get into a situation we can't resolve
1062     k = SystemDictionary::resolve_or_fail(
1063       vmSymbols::java_lang_VirtualMachineError(), true, CHECK_false);
1064     bool linked = instanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1065     if (!linked) {
1066       tty->print_cr("Unable to link/verify VirtualMachineError class");
1067       return false; // initialization failed
1068     }
1069     Universe::_virtual_machine_error_instance =
1070       instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1071 
1072     Universe::_vm_exception               = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1073 
1074   }
1075   if (!DumpSharedSpaces) {
1076     // These are the only Java fields that are currently set during shared space dumping.
1077     // We prefer to not handle this generally, so we always reinitialize these detail messages.
1078     Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false);
1079     java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
1080 
1081     msg = java_lang_String::create_from_str("PermGen space", CHECK_false);
1082     java_lang_Throwable::set_message(Universe::_out_of_memory_error_perm_gen, msg());
1083 
1084     msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
1085     java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
1086 
1087     msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false);
1088     java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg());
1089 
1090     msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1091     java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
1092 
1093     // Setup the array of errors that have preallocated backtrace
1094     k = Universe::_out_of_memory_error_java_heap->klass();
1095     assert(k->klass_part()->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error");
1096     k_h = instanceKlassHandle(THREAD, k);
1097 
1098     int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
1099     Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(k_h(), len, CHECK_false);
1100     for (int i=0; i<len; i++) {
1101       oop err = k_h->allocate_permanent_instance(CHECK_false);
1102       Handle err_h = Handle(THREAD, err);
1103       java_lang_Throwable::allocate_backtrace(err_h, CHECK_false);
1104       Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h());
1105     }
1106     Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
1107   }
1108 
1109 
1110   // Setup static method for registering finalizers
1111   // The finalizer klass must be linked before looking up the method, in
1112   // case it needs to get rewritten.
1113   instanceKlass::cast(SystemDictionary::Finalizer_klass())->link_class(CHECK_false);
1114   methodOop m = instanceKlass::cast(SystemDictionary::Finalizer_klass())->find_method(
1115                                   vmSymbols::register_method_name(),
1116                                   vmSymbols::register_method_signature());
1117   if (m == NULL || !m->is_static()) {
1118     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1119       "java.lang.ref.Finalizer.register", false);
1120   }
1121   Universe::_finalizer_register_cache->init(
1122     SystemDictionary::Finalizer_klass(), m, CHECK_false);
1123 
1124   // Resolve on first use and initialize class.
1125   // Note: No race-condition here, since a resolve will always return the same result
1126 
1127   // Setup method for security checks
1128   k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_reflect_Method(), true, CHECK_false);
1129   k_h = instanceKlassHandle(THREAD, k);
1130   k_h->link_class(CHECK_false);
1131   m = k_h->find_method(vmSymbols::invoke_name(), vmSymbols::object_object_array_object_signature());
1132   if (m == NULL || m->is_static()) {
1133     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1134       "java.lang.reflect.Method.invoke", false);
1135   }
1136   Universe::_reflect_invoke_cache->init(k_h(), m, CHECK_false);
1137 
1138   // Setup method for registering loaded classes in class loader vector
1139   instanceKlass::cast(SystemDictionary::ClassLoader_klass())->link_class(CHECK_false);
1140   m = instanceKlass::cast(SystemDictionary::ClassLoader_klass())->find_method(vmSymbols::addClass_name(), vmSymbols::class_void_signature());
1141   if (m == NULL || m->is_static()) {
1142     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1143       "java.lang.ClassLoader.addClass", false);
1144   }
1145   Universe::_loader_addClass_cache->init(
1146     SystemDictionary::ClassLoader_klass(), m, CHECK_false);
1147 
1148   // The folowing is initializing converter functions for serialization in
1149   // JVM.cpp. If we clean up the StrictMath code above we may want to find
1150   // a better solution for this as well.
1151   initialize_converter_functions();
1152 
1153   // This needs to be done before the first scavenge/gc, since
1154   // it's an input to soft ref clearing policy.
1155   {
1156     MutexLocker x(Heap_lock);
1157     Universe::update_heap_info_at_gc();
1158   }
1159 
1160   // ("weak") refs processing infrastructure initialization
1161   Universe::heap()->post_initialize();
1162 
1163   GC_locker::unlock();  // allow gc after bootstrapping
1164 
1165   MemoryService::set_universe_heap(Universe::_collectedHeap);
1166   return true;
1167 }
1168 
1169 
1170 void Universe::compute_base_vtable_size() {
1171   _base_vtable_size = ClassLoader::compute_Object_vtable();
1172 }
1173 
1174 
1175 // %%% The Universe::flush_foo methods belong in CodeCache.
1176 
1177 // Flushes compiled methods dependent on dependee.
1178 void Universe::flush_dependents_on(instanceKlassHandle dependee) {
1179   assert_lock_strong(Compile_lock);
1180 
1181   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1182 
1183   // CodeCache can only be updated by a thread_in_VM and they will all be
1184   // stopped dring the safepoint so CodeCache will be safe to update without
1185   // holding the CodeCache_lock.
1186 
1187   KlassDepChange changes(dependee);
1188 
1189   // Compute the dependent nmethods
1190   if (CodeCache::mark_for_deoptimization(changes) > 0) {
1191     // At least one nmethod has been marked for deoptimization
1192     VM_Deoptimize op;
1193     VMThread::execute(&op);
1194   }
1195 }
1196 
1197 // Flushes compiled methods dependent on a particular CallSite
1198 // instance when its target is different than the given MethodHandle.
1199 void Universe::flush_dependents_on(Handle call_site, Handle method_handle) {
1200   assert_lock_strong(Compile_lock);
1201 
1202   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1203 
1204   // CodeCache can only be updated by a thread_in_VM and they will all be
1205   // stopped dring the safepoint so CodeCache will be safe to update without
1206   // holding the CodeCache_lock.
1207 
1208   CallSiteDepChange changes(call_site(), method_handle());
1209 
1210   // Compute the dependent nmethods that have a reference to a
1211   // CallSite object.  We use instanceKlass::mark_dependent_nmethod
1212   // directly instead of CodeCache::mark_for_deoptimization because we
1213   // want dependents on the call site class only not all classes in
1214   // the ContextStream.
1215   int marked = 0;
1216   {
1217     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1218     instanceKlass* call_site_klass = instanceKlass::cast(call_site->klass());
1219     marked = call_site_klass->mark_dependent_nmethods(changes);
1220   }
1221   if (marked > 0) {
1222     // At least one nmethod has been marked for deoptimization
1223     VM_Deoptimize op;
1224     VMThread::execute(&op);
1225   }
1226 }
1227 
1228 #ifdef HOTSWAP
1229 // Flushes compiled methods dependent on dependee in the evolutionary sense
1230 void Universe::flush_evol_dependents_on(instanceKlassHandle ev_k_h) {
1231   // --- Compile_lock is not held. However we are at a safepoint.
1232   assert_locked_or_safepoint(Compile_lock);
1233   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1234 
1235   // CodeCache can only be updated by a thread_in_VM and they will all be
1236   // stopped dring the safepoint so CodeCache will be safe to update without
1237   // holding the CodeCache_lock.
1238 
1239   // Compute the dependent nmethods
1240   if (CodeCache::mark_for_evol_deoptimization(ev_k_h) > 0) {
1241     // At least one nmethod has been marked for deoptimization
1242 
1243     // All this already happens inside a VM_Operation, so we'll do all the work here.
1244     // Stuff copied from VM_Deoptimize and modified slightly.
1245 
1246     // We do not want any GCs to happen while we are in the middle of this VM operation
1247     ResourceMark rm;
1248     DeoptimizationMarker dm;
1249 
1250     // Deoptimize all activations depending on marked nmethods
1251     Deoptimization::deoptimize_dependents();
1252 
1253     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1254     CodeCache::make_marked_nmethods_not_entrant();
1255   }
1256 }
1257 #endif // HOTSWAP
1258 
1259 
1260 // Flushes compiled methods dependent on dependee
1261 void Universe::flush_dependents_on_method(methodHandle m_h) {
1262   // --- Compile_lock is not held. However we are at a safepoint.
1263   assert_locked_or_safepoint(Compile_lock);
1264 
1265   // CodeCache can only be updated by a thread_in_VM and they will all be
1266   // stopped dring the safepoint so CodeCache will be safe to update without
1267   // holding the CodeCache_lock.
1268 
1269   // Compute the dependent nmethods
1270   if (CodeCache::mark_for_deoptimization(m_h()) > 0) {
1271     // At least one nmethod has been marked for deoptimization
1272 
1273     // All this already happens inside a VM_Operation, so we'll do all the work here.
1274     // Stuff copied from VM_Deoptimize and modified slightly.
1275 
1276     // We do not want any GCs to happen while we are in the middle of this VM operation
1277     ResourceMark rm;
1278     DeoptimizationMarker dm;
1279 
1280     // Deoptimize all activations depending on marked nmethods
1281     Deoptimization::deoptimize_dependents();
1282 
1283     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1284     CodeCache::make_marked_nmethods_not_entrant();
1285   }
1286 }
1287 
1288 void Universe::print() {
1289   print_on(gclog_or_tty);
1290 }
1291 
1292 void Universe::print_on(outputStream* st, bool extended) {
1293   st->print_cr("Heap");
1294   if (!extended) {
1295     heap()->print_on(st);
1296   } else {
1297     heap()->print_extended_on(st);
1298   }
1299 }
1300 
1301 void Universe::print_heap_at_SIGBREAK() {
1302   if (PrintHeapAtSIGBREAK) {
1303     MutexLocker hl(Heap_lock);
1304     print_on(tty);
1305     tty->cr();
1306     tty->flush();
1307   }
1308 }
1309 
1310 void Universe::print_heap_before_gc(outputStream* st, bool ignore_extended) {
1311   st->print_cr("{Heap before GC invocations=%u (full %u):",
1312                heap()->total_collections(),
1313                heap()->total_full_collections());
1314   if (!PrintHeapAtGCExtended || ignore_extended) {
1315     heap()->print_on(st);
1316   } else {
1317     heap()->print_extended_on(st);
1318   }
1319 }
1320 
1321 void Universe::print_heap_after_gc(outputStream* st, bool ignore_extended) {
1322   st->print_cr("Heap after GC invocations=%u (full %u):",
1323                heap()->total_collections(),
1324                heap()->total_full_collections());
1325   if (!PrintHeapAtGCExtended || ignore_extended) {
1326     heap()->print_on(st);
1327   } else {
1328     heap()->print_extended_on(st);
1329   }
1330   st->print_cr("}");
1331 }
1332 
1333 void Universe::verify(bool silent, VerifyOption option) {
1334   if (SharedSkipVerify) {
1335     return;
1336   }
1337 
1338   // The use of _verify_in_progress is a temporary work around for
1339   // 6320749.  Don't bother with a creating a class to set and clear
1340   // it since it is only used in this method and the control flow is
1341   // straight forward.
1342   _verify_in_progress = true;
1343 
1344   COMPILER2_PRESENT(
1345     assert(!DerivedPointerTable::is_active(),
1346          "DPT should not be active during verification "
1347          "(of thread stacks below)");
1348   )
1349 
1350   ResourceMark rm;
1351   HandleMark hm;  // Handles created during verification can be zapped
1352   _verify_count++;
1353 
1354   if (!silent) gclog_or_tty->print("[Verifying ");
1355   if (!silent) gclog_or_tty->print("threads ");
1356   Threads::verify();
1357   heap()->verify(silent, option);
1358 
1359   if (!silent) gclog_or_tty->print("syms ");
1360   SymbolTable::verify();
1361   if (!silent) gclog_or_tty->print("strs ");
1362   StringTable::verify();
1363   {
1364     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1365     if (!silent) gclog_or_tty->print("zone ");
1366     CodeCache::verify();
1367   }
1368   if (!silent) gclog_or_tty->print("dict ");
1369   SystemDictionary::verify();
1370   if (!silent) gclog_or_tty->print("hand ");
1371   JNIHandles::verify();
1372   if (!silent) gclog_or_tty->print("C-heap ");
1373   os::check_heap();
1374   if (!silent) gclog_or_tty->print("code cache ");
1375   CodeCache::verify_oops();
1376   if (!silent) gclog_or_tty->print_cr("]");
1377 
1378   _verify_in_progress = false;
1379 }
1380 
1381 // Oop verification (see MacroAssembler::verify_oop)
1382 
1383 static uintptr_t _verify_oop_data[2]   = {0, (uintptr_t)-1};
1384 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1};
1385 
1386 
1387 static void calculate_verify_data(uintptr_t verify_data[2],
1388                                   HeapWord* low_boundary,
1389                                   HeapWord* high_boundary) {
1390   assert(low_boundary < high_boundary, "bad interval");
1391 
1392   // decide which low-order bits we require to be clear:
1393   size_t alignSize = MinObjAlignmentInBytes;
1394   size_t min_object_size = CollectedHeap::min_fill_size();
1395 
1396   // make an inclusive limit:
1397   uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1398   uintptr_t min = (uintptr_t)low_boundary;
1399   assert(min < max, "bad interval");
1400   uintptr_t diff = max ^ min;
1401 
1402   // throw away enough low-order bits to make the diff vanish
1403   uintptr_t mask = (uintptr_t)(-1);
1404   while ((mask & diff) != 0)
1405     mask <<= 1;
1406   uintptr_t bits = (min & mask);
1407   assert(bits == (max & mask), "correct mask");
1408   // check an intermediate value between min and max, just to make sure:
1409   assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1410 
1411   // require address alignment, too:
1412   mask |= (alignSize - 1);
1413 
1414   if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) {
1415     assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability");
1416   }
1417   verify_data[0] = mask;
1418   verify_data[1] = bits;
1419 }
1420 
1421 
1422 // Oop verification (see MacroAssembler::verify_oop)
1423 #ifndef PRODUCT
1424 
1425 uintptr_t Universe::verify_oop_mask() {
1426   MemRegion m = heap()->reserved_region();
1427   calculate_verify_data(_verify_oop_data,
1428                         m.start(),
1429                         m.end());
1430   return _verify_oop_data[0];
1431 }
1432 
1433 
1434 
1435 uintptr_t Universe::verify_oop_bits() {
1436   verify_oop_mask();
1437   return _verify_oop_data[1];
1438 }
1439 
1440 
1441 uintptr_t Universe::verify_klass_mask() {
1442   /* $$$
1443   // A klass can never live in the new space.  Since the new and old
1444   // spaces can change size, we must settle for bounds-checking against
1445   // the bottom of the world, plus the smallest possible new and old
1446   // space sizes that may arise during execution.
1447   size_t min_new_size = Universe::new_size();   // in bytes
1448   size_t min_old_size = Universe::old_size();   // in bytes
1449   calculate_verify_data(_verify_klass_data,
1450           (HeapWord*)((uintptr_t)_new_gen->low_boundary + min_new_size + min_old_size),
1451           _perm_gen->high_boundary);
1452                         */
1453   // Why doesn't the above just say that klass's always live in the perm
1454   // gen?  I'll see if that seems to work...
1455   MemRegion permanent_reserved;
1456   switch (Universe::heap()->kind()) {
1457   default:
1458     // ???: What if a CollectedHeap doesn't have a permanent generation?
1459     ShouldNotReachHere();
1460     break;
1461   case CollectedHeap::GenCollectedHeap:
1462   case CollectedHeap::G1CollectedHeap: {
1463     SharedHeap* sh = (SharedHeap*) Universe::heap();
1464     permanent_reserved = sh->perm_gen()->reserved();
1465    break;
1466   }
1467 #ifndef SERIALGC
1468   case CollectedHeap::ParallelScavengeHeap: {
1469     ParallelScavengeHeap* psh = (ParallelScavengeHeap*) Universe::heap();
1470     permanent_reserved = psh->perm_gen()->reserved();
1471     break;
1472   }
1473 #endif // SERIALGC
1474   }
1475   calculate_verify_data(_verify_klass_data,
1476                         permanent_reserved.start(),
1477                         permanent_reserved.end());
1478 
1479   return _verify_klass_data[0];
1480 }
1481 
1482 
1483 
1484 uintptr_t Universe::verify_klass_bits() {
1485   verify_klass_mask();
1486   return _verify_klass_data[1];
1487 }
1488 
1489 
1490 uintptr_t Universe::verify_mark_mask() {
1491   return markOopDesc::lock_mask_in_place;
1492 }
1493 
1494 
1495 
1496 uintptr_t Universe::verify_mark_bits() {
1497   intptr_t mask = verify_mark_mask();
1498   intptr_t bits = (intptr_t)markOopDesc::prototype();
1499   assert((bits & ~mask) == 0, "no stray header bits");
1500   return bits;
1501 }
1502 #endif // PRODUCT
1503 
1504 
1505 void Universe::compute_verify_oop_data() {
1506   verify_oop_mask();
1507   verify_oop_bits();
1508   verify_mark_mask();
1509   verify_mark_bits();
1510   verify_klass_mask();
1511   verify_klass_bits();
1512 }
1513 
1514 
1515 void CommonMethodOopCache::init(klassOop k, methodOop m, TRAPS) {
1516   if (!UseSharedSpaces) {
1517     _klass = k;
1518   }
1519 #ifndef PRODUCT
1520   else {
1521     // sharing initilization should have already set up _klass
1522     assert(_klass != NULL, "just checking");
1523   }
1524 #endif
1525 
1526   _method_idnum = m->method_idnum();
1527   assert(_method_idnum >= 0, "sanity check");
1528 }
1529 
1530 
1531 ActiveMethodOopsCache::~ActiveMethodOopsCache() {
1532   if (_prev_methods != NULL) {
1533     for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1534       jweak method_ref = _prev_methods->at(i);
1535       if (method_ref != NULL) {
1536         JNIHandles::destroy_weak_global(method_ref);
1537       }
1538     }
1539     delete _prev_methods;
1540     _prev_methods = NULL;
1541   }
1542 }
1543 
1544 
1545 void ActiveMethodOopsCache::add_previous_version(const methodOop method) {
1546   assert(Thread::current()->is_VM_thread(),
1547     "only VMThread can add previous versions");
1548 
1549   if (_prev_methods == NULL) {
1550     // This is the first previous version so make some space.
1551     // Start with 2 elements under the assumption that the class
1552     // won't be redefined much.
1553     _prev_methods = new (ResourceObj::C_HEAP) GrowableArray<jweak>(2, true);
1554   }
1555 
1556   // RC_TRACE macro has an embedded ResourceMark
1557   RC_TRACE(0x00000100,
1558     ("add: %s(%s): adding prev version ref for cached method @%d",
1559     method->name()->as_C_string(), method->signature()->as_C_string(),
1560     _prev_methods->length()));
1561 
1562   methodHandle method_h(method);
1563   jweak method_ref = JNIHandles::make_weak_global(method_h);
1564   _prev_methods->append(method_ref);
1565 
1566   // Using weak references allows previous versions of the cached
1567   // method to be GC'ed when they are no longer needed. Since the
1568   // caller is the VMThread and we are at a safepoint, this is a good
1569   // time to clear out unused weak references.
1570 
1571   for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1572     jweak method_ref = _prev_methods->at(i);
1573     assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1574     if (method_ref == NULL) {
1575       _prev_methods->remove_at(i);
1576       // Since we are traversing the array backwards, we don't have to
1577       // do anything special with the index.
1578       continue;  // robustness
1579     }
1580 
1581     methodOop m = (methodOop)JNIHandles::resolve(method_ref);
1582     if (m == NULL) {
1583       // this method entry has been GC'ed so remove it
1584       JNIHandles::destroy_weak_global(method_ref);
1585       _prev_methods->remove_at(i);
1586     } else {
1587       // RC_TRACE macro has an embedded ResourceMark
1588       RC_TRACE(0x00000400, ("add: %s(%s): previous cached method @%d is alive",
1589         m->name()->as_C_string(), m->signature()->as_C_string(), i));
1590     }
1591   }
1592 } // end add_previous_version()
1593 
1594 
1595 bool ActiveMethodOopsCache::is_same_method(const methodOop method) const {
1596   instanceKlass* ik = instanceKlass::cast(klass());
1597   methodOop check_method = ik->method_with_idnum(method_idnum());
1598   assert(check_method != NULL, "sanity check");
1599   if (check_method == method) {
1600     // done with the easy case
1601     return true;
1602   }
1603 
1604   if (_prev_methods != NULL) {
1605     // The cached method has been redefined at least once so search
1606     // the previous versions for a match.
1607     for (int i = 0; i < _prev_methods->length(); i++) {
1608       jweak method_ref = _prev_methods->at(i);
1609       assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1610       if (method_ref == NULL) {
1611         continue;  // robustness
1612       }
1613 
1614       check_method = (methodOop)JNIHandles::resolve(method_ref);
1615       if (check_method == method) {
1616         // a previous version matches
1617         return true;
1618       }
1619     }
1620   }
1621 
1622   // either no previous versions or no previous version matched
1623   return false;
1624 }
1625 
1626 
1627 methodOop LatestMethodOopCache::get_methodOop() {
1628   instanceKlass* ik = instanceKlass::cast(klass());
1629   methodOop m = ik->method_with_idnum(method_idnum());
1630   assert(m != NULL, "sanity check");
1631   return m;
1632 }
1633 
1634 
1635 #ifdef ASSERT
1636 // Release dummy object(s) at bottom of heap
1637 bool Universe::release_fullgc_alot_dummy() {
1638   MutexLocker ml(FullGCALot_lock);
1639   if (_fullgc_alot_dummy_array != NULL) {
1640     if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) {
1641       // No more dummies to release, release entire array instead
1642       _fullgc_alot_dummy_array = NULL;
1643       return false;
1644     }
1645     if (!UseConcMarkSweepGC) {
1646       // Release dummy at bottom of old generation
1647       _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1648     }
1649     // Release dummy at bottom of permanent generation
1650     _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1651   }
1652   return true;
1653 }
1654 
1655 #endif // ASSERT