src/share/vm/memory/universe.cpp

Sun, 01 Apr 2012 17:04:26 -0400

author
acorn
date
Sun, 01 Apr 2012 17:04:26 -0400
changeset 3686
749b1464aa81
parent 3571
09d00c18e323
child 3711
b632e80fc9dc
permissions
-rw-r--r--

Merge

     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  */
    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
   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;
   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;)
   166 // Heap
   167 int             Universe::_verify_count = 0;
   169 int             Universe::_base_vtable_size = 0;
   170 bool            Universe::_bootstrapping = false;
   171 bool            Universe::_fully_initialized = false;
   173 size_t          Universe::_heap_capacity_at_last_gc;
   174 size_t          Universe::_heap_used_at_last_gc = 0;
   176 CollectedHeap*  Universe::_collectedHeap = NULL;
   178 NarrowOopStruct Universe::_narrow_oop = { NULL, 0, true };
   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 }
   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 }
   206 void Universe::oops_do(OopClosure* f, bool do_all) {
   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);
   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");
   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 }
   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 }
   296 void Universe::genesis(TRAPS) {
   297   ResourceMark rm;
   298   { FlagSetting fs(_bootstrapping, true);
   300     { MutexLocker mc(Compile_lock);
   302       // determine base vtable size; without that we cannot create the array klasses
   303       compute_base_vtable_size();
   305       if (!UseSharedSpaces) {
   306         _klassKlassObj          = klassKlass::create_klass(CHECK);
   307         _arrayKlassKlassObj     = arrayKlassKlass::create_klass(CHECK);
   309         _objArrayKlassKlassObj  = objArrayKlassKlass::create_klass(CHECK);
   310         _instanceKlassKlassObj  = instanceKlassKlass::create_klass(CHECK);
   311         _typeArrayKlassKlassObj = typeArrayKlassKlass::create_klass(CHECK);
   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);
   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;
   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);
   337         _compiledICHolderKlassObj   = compiledICHolderKlass::create_klass(CHECK);
   338         _systemObjArrayKlassObj     = objArrayKlassKlass::cast(objArrayKlassKlassObj())->allocate_system_objArray_klass(CHECK);
   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);
   345         _the_array_interfaces_array = oopFactory::new_system_objArray(2, CHECK);
   346       }
   347     }
   349     vmSymbols::initialize(CHECK);
   351     SystemDictionary::initialize(CHECK);
   353     klassOop ok = SystemDictionary::Object_klass();
   355     _the_null_string            = StringTable::intern("null", CHECK);
   356     _the_min_jint_string       = StringTable::intern("-2147483648", CHECK);
   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");
   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");
   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());
   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);
   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     }
   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
   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();
   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   }
   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 }
   510 static inline void* dereference(void* addr) {
   511   return *(void**)addr;
   512 }
   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 }
   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 }
   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 };
   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 {
   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);
   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 }
   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");
   614   // Cache the start of the static fields
   615   instanceMirrorKlass::init_offset_of_static_fields();
   617   FixupMirrorClosure blk;
   618   Universe::heap()->permanent_object_iterate(&blk);
   619 }
   622 static bool has_run_finalizers_on_exit = false;
   624 void Universe::run_finalizers_on_exit() {
   625   if (has_run_finalizers_on_exit) return;
   626   has_run_finalizers_on_exit = true;
   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 }
   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 }
   665 void initialize_itable_for_klass(klassOop k, TRAPS) {
   666   instanceKlass::cast(k)->itable()->initialize_itable(false, CHECK);
   667 }
   670 void Universe::reinitialize_itables(TRAPS) {
   671   SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
   673 }
   676 bool Universe::on_page_boundary(void* addr) {
   677   return ((uintptr_t) addr) % os::vm_page_size() == 0;
   678 }
   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 }
   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);
   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);
   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 }
   729 static intptr_t non_oop_bits = 0;
   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.
   743   if (non_oop_bits == 0) {
   744     non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
   745   }
   747   return (void*)non_oop_bits;
   748 }
   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();
   761   // Get map info from shared archive file.
   762   if (DumpSharedSpaces)
   763     UseSharedSpaces = false;
   765   FileMapInfo* mapinfo = NULL;
   766   if (UseSharedSpaces) {
   767     mapinfo = NEW_C_HEAP_OBJ(FileMapInfo);
   768     memset(mapinfo, 0, sizeof(FileMapInfo));
   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.
   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   }
   782   jint status = Universe::initialize_heap();
   783   if (status != JNI_OK) {
   784     return status;
   785   }
   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();
   793   if (UseSharedSpaces) {
   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.
   801     CompactingPermGenGen::initialize_oops();
   802     mapinfo->close();
   804   } else {
   805     SymbolTable::create_table();
   806     StringTable::create_table();
   807     ClassLoader::create_package_info_table();
   808   }
   810   return JNI_OK;
   811 }
   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.
   821 // 4Gb
   822 static const uint64_t NarrowOopHeapMax = (uint64_t(max_juint) + 1);
   823 // 32Gb
   824 // OopEncodingHeapMax == NarrowOopHeapMax << LogMinObjAlignmentInBytes;
   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 }
   885 jint Universe::initialize_heap() {
   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
   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
   903   } else {
   904     GenCollectorPolicy *gc_policy;
   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     }
   922     Universe::_collectedHeap = new GenCollectedHeap(gc_policy);
   923   }
   925   jint status = Universe::heap()->initialize();
   926   if (status != JNI_OK) {
   927     return status;
   928   }
   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
   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
   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 }
   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();
  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
  1019 // This function is defined in JVM.cpp
  1020 extern void initialize_converter_functions();
  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);
  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);
  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
  1065     Universe::_virtual_machine_error_instance =
  1066       instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
  1068     Universe::_vm_exception               = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
  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());
  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());
  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());
  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());
  1086     msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
  1087     java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
  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);
  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());
  1102     Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
  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);
  1117   Universe::_finalizer_register_cache->init(
  1118     SystemDictionary::Finalizer_klass(), m, CHECK_false);
  1120   // Resolve on first use and initialize class.
  1121   // Note: No race-condition here, since a resolve will always return the same result
  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);
  1132   Universe::_reflect_invoke_cache->init(k_h(), m, CHECK_false);
  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);
  1141   Universe::_loader_addClass_cache->init(
  1142     SystemDictionary::ClassLoader_klass(), m, CHECK_false);
  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();
  1149   // This needs to be done before the first scavenge/gc, since
  1150   // it's an input to soft ref clearing policy.
  1152     MutexLocker x(Heap_lock);
  1153     Universe::update_heap_info_at_gc();
  1156   // ("weak") refs processing infrastructure initialization
  1157   Universe::heap()->post_initialize();
  1159   GC_locker::unlock();  // allow gc after bootstrapping
  1161   MemoryService::set_universe_heap(Universe::_collectedHeap);
  1162   return true;
  1166 void Universe::compute_base_vtable_size() {
  1167   _base_vtable_size = ClassLoader::compute_Object_vtable();
  1171 // %%% The Universe::flush_foo methods belong in CodeCache.
  1173 // Flushes compiled methods dependent on dependee.
  1174 void Universe::flush_dependents_on(instanceKlassHandle dependee) {
  1175   assert_lock_strong(Compile_lock);
  1177   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
  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.
  1183   KlassDepChange changes(dependee);
  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);
  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);
  1198   if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
  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.
  1204   CallSiteDepChange changes(call_site(), method_handle());
  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;
  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);
  1217   if (marked > 0) {
  1218     // At least one nmethod has been marked for deoptimization
  1219     VM_Deoptimize op;
  1220     VMThread::execute(&op);
  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;
  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.
  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
  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.
  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;
  1246     // Deoptimize all activations depending on marked nmethods
  1247     Deoptimization::deoptimize_dependents();
  1249     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
  1250     CodeCache::make_marked_nmethods_not_entrant();
  1253 #endif // HOTSWAP
  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);
  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.
  1265   // Compute the dependent nmethods
  1266   if (CodeCache::mark_for_deoptimization(m_h()) > 0) {
  1267     // At least one nmethod has been marked for deoptimization
  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.
  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;
  1276     // Deoptimize all activations depending on marked nmethods
  1277     Deoptimization::deoptimize_dependents();
  1279     // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
  1280     CodeCache::make_marked_nmethods_not_entrant();
  1284 void Universe::print() {
  1285   print_on(gclog_or_tty);
  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);
  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();
  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);
  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);
  1326   st->print_cr("}");
  1329 void Universe::verify(bool allow_dirty, bool silent, VerifyOption option) {
  1330   if (SharedSkipVerify) {
  1331     return;
  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;
  1340   COMPILER2_PRESENT(
  1341     assert(!DerivedPointerTable::is_active(),
  1342          "DPT should not be active during verification "
  1343          "(of thread stacks below)");
  1346   ResourceMark rm;
  1347   HandleMark hm;  // Handles created during verification can be zapped
  1348   _verify_count++;
  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);
  1355   if (!silent) gclog_or_tty->print("syms ");
  1356   SymbolTable::verify();
  1357   if (!silent) gclog_or_tty->print("strs ");
  1358   StringTable::verify();
  1360     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
  1361     if (!silent) gclog_or_tty->print("zone ");
  1362     CodeCache::verify();
  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("]");
  1374   _verify_in_progress = false;
  1377 // Oop verification (see MacroAssembler::verify_oop)
  1379 static uintptr_t _verify_oop_data[2]   = {0, (uintptr_t)-1};
  1380 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1};
  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");
  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();
  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;
  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");
  1407   // require address alignment, too:
  1408   mask |= (alignSize - 1);
  1410   if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) {
  1411     assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability");
  1413   verify_data[0] = mask;
  1414   verify_data[1] = bits;
  1418 // Oop verification (see MacroAssembler::verify_oop)
  1419 #ifndef PRODUCT
  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];
  1431 uintptr_t Universe::verify_oop_bits() {
  1432   verify_oop_mask();
  1433   return _verify_oop_data[1];
  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;
  1463 #ifndef SERIALGC
  1464   case CollectedHeap::ParallelScavengeHeap: {
  1465     ParallelScavengeHeap* psh = (ParallelScavengeHeap*) Universe::heap();
  1466     permanent_reserved = psh->perm_gen()->reserved();
  1467     break;
  1469 #endif // SERIALGC
  1471   calculate_verify_data(_verify_klass_data,
  1472                         permanent_reserved.start(),
  1473                         permanent_reserved.end());
  1475   return _verify_klass_data[0];
  1480 uintptr_t Universe::verify_klass_bits() {
  1481   verify_klass_mask();
  1482   return _verify_klass_data[1];
  1486 uintptr_t Universe::verify_mark_mask() {
  1487   return markOopDesc::lock_mask_in_place;
  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;
  1498 #endif // PRODUCT
  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();
  1511 void CommonMethodOopCache::init(klassOop k, methodOop m, TRAPS) {
  1512   if (!UseSharedSpaces) {
  1513     _klass = k;
  1515 #ifndef PRODUCT
  1516   else {
  1517     // sharing initilization should have already set up _klass
  1518     assert(_klass != NULL, "just checking");
  1520 #endif
  1522   _method_idnum = m->method_idnum();
  1523   assert(_method_idnum >= 0, "sanity check");
  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);
  1535     delete _prev_methods;
  1536     _prev_methods = NULL;
  1541 void ActiveMethodOopsCache::add_previous_version(const methodOop method) {
  1542   assert(Thread::current()->is_VM_thread(),
  1543     "only VMThread can add previous versions");
  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);
  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()));
  1558   methodHandle method_h(method);
  1559   jweak method_ref = JNIHandles::make_weak_global(method_h);
  1560   _prev_methods->append(method_ref);
  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.
  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
  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));
  1588 } // end add_previous_version()
  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;
  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
  1610       check_method = (methodOop)JNIHandles::resolve(method_ref);
  1611       if (check_method == method) {
  1612         // a previous version matches
  1613         return true;
  1618   // either no previous versions or no previous version matched
  1619   return false;
  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;
  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;
  1641     if (!UseConcMarkSweepGC) {
  1642       // Release dummy at bottom of old generation
  1643       _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
  1645     // Release dummy at bottom of permanent generation
  1646     _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
  1648   return true;
  1651 #endif // ASSERT

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