1 /* 2 * Copyright (c) 1997, 2017, 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 #ifndef SHARE_VM_MEMORY_UNIVERSE_HPP 26 #define SHARE_VM_MEMORY_UNIVERSE_HPP 27 28 #include "runtime/handles.hpp" 29 #include "utilities/array.hpp" 30 #include "utilities/growableArray.hpp" 31 32 // Universe is a name space holding known system classes and objects in the VM. 33 // 34 // Loaded classes are accessible through the SystemDictionary. 35 // 36 // The object heap is allocated and accessed through Universe, and various allocation 37 // support is provided. Allocation by the interpreter and compiled code is done inline 38 // and bails out to Scavenge::invoke_and_allocate. 39 40 class CollectedHeap; 41 class DeferredObjAllocEvent; 42 43 44 // A helper class for caching a Method* when the user of the cache 45 // only cares about the latest version of the Method*. This cache safely 46 // interacts with the RedefineClasses API. 47 48 class LatestMethodCache : public CHeapObj<mtClass> { 49 // We save the Klass* and the idnum of Method* in order to get 50 // the current cached Method*. 51 private: 52 Klass* _klass; 53 int _method_idnum; 54 55 public: 56 LatestMethodCache() { _klass = NULL; _method_idnum = -1; } 57 ~LatestMethodCache() { _klass = NULL; _method_idnum = -1; } 58 59 void init(Klass* k, Method* m); 60 Klass* klass() const { return _klass; } 61 int method_idnum() const { return _method_idnum; } 62 63 Method* get_method(); 64 65 // Enhanced Class Redefinition support 66 void classes_do(void f(Klass*)) { 67 f(_klass); 68 } 69 70 // CDS support. Replace the klass in this with the archive version 71 // could use this for Enhanced Class Redefinition also. 72 void serialize(SerializeClosure* f) { 73 f->do_ptr((void**)&_klass); 74 } 75 }; 76 77 78 // For UseCompressedOops. 79 struct NarrowPtrStruct { 80 // Base address for oop-within-java-object materialization. 81 // NULL if using wide oops or zero based narrow oops. 82 address _base; 83 // Number of shift bits for encoding/decoding narrow ptrs. 84 // 0 if using wide ptrs or zero based unscaled narrow ptrs, 85 // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise. 86 int _shift; 87 // Generate code with implicit null checks for narrow ptrs. 88 bool _use_implicit_null_checks; 89 }; 90 91 enum VerifyOption { 92 VerifyOption_Default = 0, 93 94 // G1 95 VerifyOption_G1UsePrevMarking = VerifyOption_Default, 96 VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1, 97 VerifyOption_G1UseMarkWord = VerifyOption_G1UseNextMarking + 1 98 }; 99 100 class Universe: AllStatic { 101 // Ugh. Universe is much too friendly. 102 friend class MarkSweep; 103 friend class oopDesc; 104 friend class ClassLoader; 105 friend class SystemDictionary; 106 friend class ReservedHeapSpace; 107 friend class VMStructs; 108 friend class VM_PopulateDumpSharedSpace; 109 friend class Metaspace; 110 111 friend jint universe_init(); 112 friend void universe2_init(); 113 friend bool universe_post_init(); 114 friend void universe_post_module_init(); 115 116 private: 117 // Known classes in the VM 118 static Klass* _boolArrayKlassObj; 119 static Klass* _byteArrayKlassObj; 120 static Klass* _charArrayKlassObj; 121 static Klass* _intArrayKlassObj; 122 static Klass* _shortArrayKlassObj; 123 static Klass* _longArrayKlassObj; 124 static Klass* _singleArrayKlassObj; 125 static Klass* _doubleArrayKlassObj; 126 static Klass* _typeArrayKlassObjs[T_VOID+1]; 127 128 static Klass* _objectArrayKlassObj; 129 130 // Known objects in the VM 131 132 // Primitive objects 133 static oop _int_mirror; 134 static oop _float_mirror; 135 static oop _double_mirror; 136 static oop _byte_mirror; 137 static oop _bool_mirror; 138 static oop _char_mirror; 139 static oop _long_mirror; 140 static oop _short_mirror; 141 static oop _void_mirror; 142 143 static oop _main_thread_group; // Reference to the main thread group object 144 static oop _system_thread_group; // Reference to the system thread group object 145 146 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class 147 static oop _the_null_string; // A cache of "null" as a Java string 148 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string 149 static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects 150 static LatestMethodCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector 151 static LatestMethodCache* _pd_implies_cache; // method for checking protection domain attributes 152 static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method 153 static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback 154 155 // preallocated error objects (no backtrace) 156 static oop _out_of_memory_error_java_heap; 157 static oop _out_of_memory_error_metaspace; 158 static oop _out_of_memory_error_class_metaspace; 159 static oop _out_of_memory_error_array_size; 160 static oop _out_of_memory_error_gc_overhead_limit; 161 static oop _out_of_memory_error_realloc_objects; 162 163 // preallocated cause message for delayed StackOverflowError 164 static oop _delayed_stack_overflow_error_message; 165 166 static Array<int>* _the_empty_int_array; // Canonicalized int array 167 static Array<u2>* _the_empty_short_array; // Canonicalized short array 168 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array 169 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array 170 171 static Array<Klass*>* _the_array_interfaces_array; 172 173 // array of preallocated error objects with backtrace 174 static objArrayOop _preallocated_out_of_memory_error_array; 175 176 // number of preallocated error objects available for use 177 static volatile jint _preallocated_out_of_memory_error_avail_count; 178 179 static oop _null_ptr_exception_instance; // preallocated exception object 180 static oop _arithmetic_exception_instance; // preallocated exception object 181 static oop _virtual_machine_error_instance; // preallocated exception object 182 // The object used as an exception dummy when exceptions are thrown for 183 // the vm thread. 184 static oop _vm_exception; 185 186 static oop _allocation_context_notification_obj; 187 188 // References waiting to be transferred to the ReferenceHandler 189 static oop _reference_pending_list; 190 191 // The particular choice of collected heap. 192 static CollectedHeap* _collectedHeap; 193 194 static intptr_t _non_oop_bits; 195 196 // For UseCompressedOops. 197 static struct NarrowPtrStruct _narrow_oop; 198 // For UseCompressedClassPointers. 199 static struct NarrowPtrStruct _narrow_klass; 200 static address _narrow_ptrs_base; 201 202 // array of dummy objects used with +FullGCAlot 203 debug_only(static objArrayOop _fullgc_alot_dummy_array;) 204 // index of next entry to clear 205 debug_only(static int _fullgc_alot_dummy_next;) 206 207 // Compiler/dispatch support 208 static int _base_vtable_size; // Java vtbl size of klass Object (in words) 209 210 // Initialization 211 static bool _bootstrapping; // true during genesis 212 static bool _module_initialized; // true after call_initPhase2 called 213 static bool _fully_initialized; // true after universe_init and initialize_vtables called 214 215 // the array of preallocated errors with backtraces 216 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; } 217 218 // generate an out of memory error; if possible using an error with preallocated backtrace; 219 // otherwise return the given default error. 220 static oop gen_out_of_memory_error(oop default_err); 221 222 // Historic gc information 223 static size_t _heap_capacity_at_last_gc; 224 static size_t _heap_used_at_last_gc; 225 226 template <class Heap, class Policy> static CollectedHeap* create_heap_with_policy(); 227 static CollectedHeap* create_heap(); 228 static CollectedHeap* create_heap_ext(); 229 static jint initialize_heap(); 230 static void initialize_basic_type_mirrors(TRAPS); 231 static void fixup_mirrors(TRAPS); 232 233 static void reinitialize_vtable_of(Klass* k, TRAPS); 234 static void reinitialize_itables(TRAPS); 235 static void compute_base_vtable_size(); // compute vtable size of class Object 236 237 static void genesis(TRAPS); // Create the initial world 238 239 // Mirrors for primitive classes (created eagerly) 240 static oop check_mirror(oop m) { 241 assert(m != NULL, "mirror not initialized"); 242 return m; 243 } 244 245 static void set_narrow_oop_base(address base) { 246 assert(UseCompressedOops, "no compressed oops?"); 247 _narrow_oop._base = base; 248 } 249 static void set_narrow_klass_base(address base) { 250 assert(UseCompressedClassPointers, "no compressed klass ptrs?"); 251 _narrow_klass._base = base; 252 } 253 static void set_narrow_oop_use_implicit_null_checks(bool use) { 254 assert(UseCompressedOops, "no compressed ptrs?"); 255 _narrow_oop._use_implicit_null_checks = use; 256 } 257 258 // Debugging 259 static int _verify_count; // number of verifies done 260 261 // True during call to verify(). Should only be set/cleared in verify(). 262 static bool _verify_in_progress; 263 static long verify_flags; 264 265 static uintptr_t _verify_oop_mask; 266 static uintptr_t _verify_oop_bits; 267 268 static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN; 269 static void compute_verify_oop_data(); 270 271 public: 272 // Known classes in the VM 273 static Klass* boolArrayKlassObj() { return _boolArrayKlassObj; } 274 static Klass* byteArrayKlassObj() { return _byteArrayKlassObj; } 275 static Klass* charArrayKlassObj() { return _charArrayKlassObj; } 276 static Klass* intArrayKlassObj() { return _intArrayKlassObj; } 277 static Klass* shortArrayKlassObj() { return _shortArrayKlassObj; } 278 static Klass* longArrayKlassObj() { return _longArrayKlassObj; } 279 static Klass* singleArrayKlassObj() { return _singleArrayKlassObj; } 280 static Klass* doubleArrayKlassObj() { return _doubleArrayKlassObj; } 281 282 static Klass* objectArrayKlassObj() { 283 return _objectArrayKlassObj; 284 } 285 286 static Klass* typeArrayKlassObj(BasicType t) { 287 assert((uint)t < T_VOID+1, "range check for type: %s", type2name(t)); 288 assert(_typeArrayKlassObjs[t] != NULL, "domain check"); 289 return _typeArrayKlassObjs[t]; 290 } 291 292 // Known objects in the VM 293 static oop int_mirror() { return check_mirror(_int_mirror); } 294 static oop float_mirror() { return check_mirror(_float_mirror); } 295 static oop double_mirror() { return check_mirror(_double_mirror); } 296 static oop byte_mirror() { return check_mirror(_byte_mirror); } 297 static oop bool_mirror() { return check_mirror(_bool_mirror); } 298 static oop char_mirror() { return check_mirror(_char_mirror); } 299 static oop long_mirror() { return check_mirror(_long_mirror); } 300 static oop short_mirror() { return check_mirror(_short_mirror); } 301 static oop void_mirror() { return check_mirror(_void_mirror); } 302 303 // table of same 304 static oop _mirrors[T_VOID+1]; 305 306 static oop java_mirror(BasicType t) { 307 assert((uint)t < T_VOID+1, "range check"); 308 return check_mirror(_mirrors[t]); 309 } 310 static oop main_thread_group() { return _main_thread_group; } 311 static void set_main_thread_group(oop group) { _main_thread_group = group;} 312 313 static oop system_thread_group() { return _system_thread_group; } 314 static void set_system_thread_group(oop group) { _system_thread_group = group;} 315 316 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; } 317 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; } 318 static oop the_null_string() { return _the_null_string; } 319 static oop the_min_jint_string() { return _the_min_jint_string; } 320 321 static Method* finalizer_register_method() { return _finalizer_register_cache->get_method(); } 322 static Method* loader_addClass_method() { return _loader_addClass_cache->get_method(); } 323 324 static Method* protection_domain_implies_method() { return _pd_implies_cache->get_method(); } 325 static Method* throw_illegal_access_error() { return _throw_illegal_access_error_cache->get_method(); } 326 327 static Method* do_stack_walk_method() { return _do_stack_walk_cache->get_method(); } 328 329 // Function to initialize these 330 static void initialize_known_methods(TRAPS); 331 332 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; } 333 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; } 334 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; } 335 static oop vm_exception() { return _vm_exception; } 336 337 static inline oop allocation_context_notification_obj(); 338 static inline void set_allocation_context_notification_obj(oop obj); 339 340 // Reference pending list manipulation. Access is protected by 341 // Heap_lock. The getter, setter and predicate require the caller 342 // owns the lock. Swap is used by parallel non-concurrent reference 343 // processing threads, where some higher level controller owns 344 // Heap_lock, so requires the lock is locked, but not necessarily by 345 // the current thread. 346 static oop reference_pending_list(); 347 static void set_reference_pending_list(oop list); 348 static bool has_reference_pending_list(); 349 static oop swap_reference_pending_list(oop list); 350 351 static Array<int>* the_empty_int_array() { return _the_empty_int_array; } 352 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; } 353 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; } 354 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; } 355 356 // OutOfMemoryError support. Returns an error with the required message. The returned error 357 // may or may not have a backtrace. If error has a backtrace then the stack trace is already 358 // filled in. 359 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); } 360 static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); } 361 static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); } 362 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); } 363 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); } 364 static oop out_of_memory_error_realloc_objects() { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects); } 365 static oop delayed_stack_overflow_error_message() { return _delayed_stack_overflow_error_message; } 366 367 // Accessors needed for fast allocation 368 static Klass** boolArrayKlassObj_addr() { return &_boolArrayKlassObj; } 369 static Klass** byteArrayKlassObj_addr() { return &_byteArrayKlassObj; } 370 static Klass** charArrayKlassObj_addr() { return &_charArrayKlassObj; } 371 static Klass** intArrayKlassObj_addr() { return &_intArrayKlassObj; } 372 static Klass** shortArrayKlassObj_addr() { return &_shortArrayKlassObj; } 373 static Klass** longArrayKlassObj_addr() { return &_longArrayKlassObj; } 374 static Klass** singleArrayKlassObj_addr() { return &_singleArrayKlassObj; } 375 static Klass** doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; } 376 static Klass** objectArrayKlassObj_addr() { return &_objectArrayKlassObj; } 377 378 // The particular choice of collected heap. 379 static CollectedHeap* heap() { return _collectedHeap; } 380 381 // For UseCompressedOops 382 // Narrow Oop encoding mode: 383 // 0 - Use 32-bits oops without encoding when 384 // NarrowOopHeapBaseMin + heap_size < 4Gb 385 // 1 - Use zero based compressed oops with encoding when 386 // NarrowOopHeapBaseMin + heap_size < 32Gb 387 // 2 - Use compressed oops with disjoint heap base if 388 // base is 32G-aligned and base > 0. This allows certain 389 // optimizations in encoding/decoding. 390 // Disjoint: Bits used in base are disjoint from bits used 391 // for oops ==> oop = (cOop << 3) | base. One can disjoint 392 // the bits of an oop into base and compressed oop. 393 // 3 - Use compressed oops with heap base + encoding. 394 enum NARROW_OOP_MODE { 395 UnscaledNarrowOop = 0, 396 ZeroBasedNarrowOop = 1, 397 DisjointBaseNarrowOop = 2, 398 HeapBasedNarrowOop = 3, 399 AnyNarrowOopMode = 4 400 }; 401 static NARROW_OOP_MODE narrow_oop_mode(); 402 static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode); 403 static char* preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode); 404 static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode); 405 static address narrow_oop_base() { return _narrow_oop._base; } 406 // Test whether bits of addr and possible offsets into the heap overlap. 407 static bool is_disjoint_heap_base_address(address addr) { 408 return (((uint64_t)(intptr_t)addr) & 409 (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0; 410 } 411 // Check for disjoint base compressed oops. 412 static bool narrow_oop_base_disjoint() { 413 return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base); 414 } 415 // Check for real heapbased compressed oops. 416 // We must subtract the base as the bits overlap. 417 // If we negate above function, we also get unscaled and zerobased. 418 static bool narrow_oop_base_overlaps() { 419 return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base); 420 } 421 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); } 422 static int narrow_oop_shift() { return _narrow_oop._shift; } 423 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; } 424 425 // For UseCompressedClassPointers 426 static address narrow_klass_base() { return _narrow_klass._base; } 427 static bool is_narrow_klass_base(void* addr) { return (narrow_klass_base() == (address)addr); } 428 static int narrow_klass_shift() { return _narrow_klass._shift; } 429 static bool narrow_klass_use_implicit_null_checks() { return _narrow_klass._use_implicit_null_checks; } 430 431 static address* narrow_ptrs_base_addr() { return &_narrow_ptrs_base; } 432 static void set_narrow_ptrs_base(address a) { _narrow_ptrs_base = a; } 433 static address narrow_ptrs_base() { return _narrow_ptrs_base; } 434 435 static void print_compressed_oops_mode(outputStream* st); 436 437 // this is set in vm_version on sparc (and then reset in universe afaict) 438 static void set_narrow_oop_shift(int shift) { 439 _narrow_oop._shift = shift; 440 } 441 442 static void set_narrow_klass_shift(int shift) { 443 assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs"); 444 _narrow_klass._shift = shift; 445 } 446 447 // Reserve Java heap and determine CompressedOops mode 448 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment); 449 450 // Historic gc information 451 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; } 452 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; } 453 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; } 454 static void update_heap_info_at_gc(); 455 456 // Testers 457 static bool is_bootstrapping() { return _bootstrapping; } 458 static bool is_module_initialized() { return _module_initialized; } 459 static bool is_fully_initialized() { return _fully_initialized; } 460 461 static inline bool element_type_should_be_aligned(BasicType type); 462 static inline bool field_type_should_be_aligned(BasicType type); 463 static bool on_page_boundary(void* addr); 464 static bool should_fill_in_stack_trace(Handle throwable); 465 static void check_alignment(uintx size, uintx alignment, const char* name); 466 467 // Finalizer support. 468 static void run_finalizers_on_exit(); 469 470 // Iteration 471 472 // Apply "f" to the addresses of all the direct heap pointers maintained 473 // as static fields of "Universe". 474 static void oops_do(OopClosure* f, bool do_all = false); 475 476 // CDS support 477 static void serialize(SerializeClosure* f, bool do_all = false); 478 479 // Apply "f" to all klasses for basic types (classes not present in 480 // SystemDictionary). 481 static void basic_type_classes_do(void f(Klass*)); 482 483 // Debugging 484 enum VERIFY_FLAGS { 485 Verify_Threads = 1, 486 Verify_Heap = 2, 487 Verify_SymbolTable = 4, 488 Verify_StringTable = 8, 489 Verify_CodeCache = 16, 490 Verify_SystemDictionary = 32, 491 Verify_ClassLoaderDataGraph = 64, 492 Verify_MetaspaceAux = 128, 493 Verify_JNIHandles = 256, 494 Verify_CodeCacheOops = 512, 495 Verify_All = -1 496 }; 497 static void initialize_verify_flags(); 498 static bool should_verify_subset(uint subset); 499 static bool verify_in_progress() { return _verify_in_progress; } 500 static void verify(VerifyOption option, const char* prefix); 501 static void verify(const char* prefix) { 502 verify(VerifyOption_Default, prefix); 503 } 504 static void verify() { 505 verify(""); 506 } 507 508 static int verify_count() { return _verify_count; } 509 static void print_on(outputStream* st); 510 static void print_heap_at_SIGBREAK(); 511 static void print_heap_before_gc(); 512 static void print_heap_after_gc(); 513 514 // Change the number of dummy objects kept reachable by the full gc dummy 515 // array; this should trigger relocation in a sliding compaction collector. 516 debug_only(static bool release_fullgc_alot_dummy();) 517 // The non-oop pattern (see compiledIC.hpp, etc) 518 static void* non_oop_word(); 519 520 // Oop verification (see MacroAssembler::verify_oop) 521 static uintptr_t verify_oop_mask() PRODUCT_RETURN0; 522 static uintptr_t verify_oop_bits() PRODUCT_RETURN0; 523 static uintptr_t verify_mark_bits() PRODUCT_RETURN0; 524 static uintptr_t verify_mark_mask() PRODUCT_RETURN0; 525 526 // Compiler support 527 static int base_vtable_size() { return _base_vtable_size; } 528 }; 529 530 class DeferredObjAllocEvent : public CHeapObj<mtInternal> { 531 private: 532 oop _oop; 533 size_t _bytesize; 534 jint _arena_id; 535 536 public: 537 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) { 538 _oop = o; 539 _bytesize = s; 540 _arena_id = id; 541 } 542 543 ~DeferredObjAllocEvent() { 544 } 545 546 jint arena_id() { return _arena_id; } 547 size_t bytesize() { return _bytesize; } 548 oop get_oop() { return _oop; } 549 }; 550 551 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP