1 /* 2 * Copyright (c) 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 #include "precompiled.hpp" 26 #include "gc/shared/barrierSet.hpp" 27 #include "gc/shared/collectedHeap.inline.hpp" 28 #include "gc/shared/gcLocker.inline.hpp" 29 #include "interpreter/interpreter.hpp" 30 #include "logging/log.hpp" 31 #include "memory/metadataFactory.hpp" 32 #include "oops/access.hpp" 33 #include "oops/compressedOops.inline.hpp" 34 #include "oops/fieldStreams.hpp" 35 #include "oops/instanceKlass.inline.hpp" 36 #include "oops/method.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "oops/objArrayKlass.hpp" 39 #include "oops/valueKlass.hpp" 40 #include "oops/valueArrayKlass.hpp" 41 #include "runtime/fieldDescriptor.inline.hpp" 42 #include "runtime/handles.inline.hpp" 43 #include "runtime/safepointVerifiers.hpp" 44 #include "runtime/sharedRuntime.hpp" 45 #include "runtime/signature.hpp" 46 #include "runtime/thread.inline.hpp" 47 #include "utilities/copy.hpp" 48 49 int ValueKlass::first_field_offset() const { 50 if (UseNewLayout) { 51 return get_first_field_offset(); 52 } 53 #ifdef ASSERT 54 int first_offset = INT_MAX; 55 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 56 if (fs.offset() < first_offset) first_offset= fs.offset(); 57 } 58 #endif 59 int base_offset = instanceOopDesc::base_offset_in_bytes(); 60 // The first field of value types is aligned on a long boundary 61 base_offset = align_up(base_offset, BytesPerLong); 62 assert(base_offset == first_offset, "inconsistent offsets"); 63 return base_offset; 64 } 65 66 int ValueKlass::raw_value_byte_size() const { 67 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop; 68 // If bigger than 64 bits or needs oop alignment, then use jlong aligned 69 // which for values should be jlong aligned, asserts in raw_field_copy otherwise 70 if (heapOopAlignedSize >= longSize || contains_oops()) { 71 return heapOopAlignedSize; 72 } 73 // Small primitives... 74 // If a few small basic type fields, return the actual size, i.e. 75 // 1 byte = 1 76 // 2 byte = 2 77 // 3 byte = 4, because pow2 needed for element stores 78 int first_offset = first_field_offset(); 79 int last_offset = 0; // find the last offset, add basic type size 80 int last_tsz = 0; 81 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 82 if (fs.access_flags().is_static()) { 83 continue; 84 } else if (fs.offset() > last_offset) { 85 BasicType type = fs.field_descriptor().field_type(); 86 if (is_java_primitive(type)) { 87 last_tsz = type2aelembytes(type); 88 } else if (type == T_VALUETYPE) { 89 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is 90 return heapOopAlignedSize; 91 } else { 92 guarantee(0, "Unknown type %d", type); 93 } 94 assert(last_tsz != 0, "Invariant"); 95 last_offset = fs.offset(); 96 } 97 } 98 // Assumes VT with no fields are meaningless and illegal 99 last_offset += last_tsz; 100 assert(last_offset > first_offset && last_tsz, "Invariant"); 101 return 1 << upper_log2(last_offset - first_offset); 102 } 103 104 instanceOop ValueKlass::allocate_instance(TRAPS) { 105 int size = size_helper(); // Query before forming handle. 106 107 instanceOop oop = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL); 108 assert(oop->mark()->is_always_locked(), "Unlocked value type"); 109 return oop; 110 } 111 112 bool ValueKlass::is_atomic() { 113 return (nonstatic_field_size() * heapOopSize) <= longSize; 114 } 115 116 int ValueKlass::nonstatic_oop_count() { 117 int oops = 0; 118 int map_count = nonstatic_oop_map_count(); 119 OopMapBlock* block = start_of_nonstatic_oop_maps(); 120 OopMapBlock* end = block + map_count; 121 while (block != end) { 122 oops += block->count(); 123 block++; 124 } 125 return oops; 126 } 127 128 // Arrays of... 129 130 bool ValueKlass::flatten_array() { 131 if (!ValueArrayFlatten) { 132 return false; 133 } 134 135 int elem_bytes = raw_value_byte_size(); 136 // Too big 137 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) { 138 return false; 139 } 140 // Too many embedded oops 141 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) { 142 return false; 143 } 144 145 return true; 146 } 147 148 149 Klass* ValueKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS) { 150 if (storage_props.is_null_free()) { 151 return value_array_klass(storage_props, or_null, n, THREAD); 152 } else { 153 return InstanceKlass::array_klass_impl(storage_props, or_null, n, THREAD); 154 } 155 } 156 157 Klass* ValueKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS) { 158 return array_klass_impl(storage_props, or_null, 1, THREAD); 159 } 160 161 Klass* ValueKlass::value_array_klass(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS) { 162 Klass* vak = acquire_value_array_klass(); 163 if (vak == NULL) { 164 if (or_null) return NULL; 165 ResourceMark rm; 166 { 167 // Atomic creation of array_klasses 168 MutexLocker ma(MultiArray_lock, THREAD); 169 if (get_value_array_klass() == NULL) { 170 vak = allocate_value_array_klass(CHECK_NULL); 171 OrderAccess::release_store((Klass**)adr_value_array_klass(), vak); 172 } 173 } 174 } 175 if (!vak->is_valueArray_klass()) { 176 storage_props.clear_flattened(); 177 } 178 if (or_null) { 179 return vak->array_klass_or_null(storage_props, rank); 180 } 181 return vak->array_klass(storage_props, rank, THREAD); 182 } 183 184 Klass* ValueKlass::allocate_value_array_klass(TRAPS) { 185 if (flatten_array() && (is_atomic() || (!ValueArrayAtomicAccess))) { 186 return ValueArrayKlass::allocate_klass(ArrayStorageProperties::flattened_and_null_free, this, THREAD); 187 } 188 return ObjArrayKlass::allocate_objArray_klass(ArrayStorageProperties::null_free, 1, this, THREAD); 189 } 190 191 void ValueKlass::array_klasses_do(void f(Klass* k)) { 192 InstanceKlass::array_klasses_do(f); 193 if (get_value_array_klass() != NULL) 194 ArrayKlass::cast(get_value_array_klass())->array_klasses_do(f); 195 } 196 197 void ValueKlass::raw_field_copy(void* src, void* dst, size_t raw_byte_size) { 198 if (!UseNewLayout) { 199 /* 200 * Try not to shear fields even if not an atomic store... 201 * 202 * First 3 cases handle value array store, otherwise works on the same basis 203 * as JVM_Clone, at this size data is aligned. The order of primitive types 204 * is largest to smallest, and it not possible for fields to stradle long 205 * copy boundaries. 206 * 207 * If MT without exclusive access, possible to observe partial value store, 208 * but not partial primitive and reference field values 209 */ 210 switch (raw_byte_size) { 211 case 1: 212 *((jbyte*) dst) = *(jbyte*)src; 213 break; 214 case 2: 215 *((jshort*) dst) = *(jshort*)src; 216 break; 217 case 4: 218 *((jint*) dst) = *(jint*) src; 219 break; 220 default: 221 assert(raw_byte_size % sizeof(jlong) == 0, "Unaligned raw_byte_size"); 222 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, raw_byte_size >> LogBytesPerLong); 223 } 224 } else { 225 int size = this->get_exact_size_in_bytes(); 226 int length; 227 switch (this->get_alignment()) { 228 case BytesPerLong: 229 length = size >> LogBytesPerLong; 230 if (length > 0) { 231 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, length); 232 size -= length << LogBytesPerLong; 233 src = (jlong*)src + length; 234 dst = (jlong*)dst + length; 235 } 236 // Fallthrough 237 case BytesPerInt: 238 length = size >> LogBytesPerInt; 239 if (length > 0) { 240 Copy::conjoint_jints_atomic((jint*)src, (jint*)dst, length); 241 size -= length << LogBytesPerInt; 242 src = (jint*)src + length; 243 dst = (jint*)dst + length; 244 } 245 // Fallthrough 246 case BytesPerShort: 247 length = size >> LogBytesPerShort; 248 if (length > 0) { 249 Copy::conjoint_jshorts_atomic((jshort*)src, (jshort*)dst, length); 250 size -= length << LogBytesPerShort; 251 src = (jshort*)src + length; 252 dst = (jshort*)dst +length; 253 } 254 // Fallthrough 255 case 1: 256 if (size > 0) Copy::conjoint_jbytes_atomic((jbyte*)src, (jbyte*)dst, size); 257 break; 258 default: 259 fatal("Unsupported alignment"); 260 } 261 } 262 } 263 264 /* 265 * Store the value of this klass contained with src into dst. 266 * 267 * This operation is appropriate for use from vastore, vaload and putfield (for values) 268 * 269 * GC barriers currently can lock with no safepoint check and allocate c-heap, 270 * so raw point is "safe" for now. 271 * 272 * Going forward, look to use machine generated (stub gen or bc) version for most used klass layouts 273 * 274 */ 275 void ValueKlass::value_store(void* src, void* dst, size_t raw_byte_size, bool dst_heap, bool dst_uninitialized) { 276 if (contains_oops()) { 277 if (dst_heap) { 278 // src/dst aren't oops, need offset to adjust oop map offset 279 const address dst_oop_addr = ((address) dst) - first_field_offset(); 280 281 ModRefBarrierSet* bs = barrier_set_cast<ModRefBarrierSet>(BarrierSet::barrier_set()); 282 283 // Pre-barriers... 284 OopMapBlock* map = start_of_nonstatic_oop_maps(); 285 OopMapBlock* const end = map + nonstatic_oop_map_count(); 286 while (map != end) { 287 // Shame we can't just use the existing oop iterator...src/dst aren't oop 288 address doop_address = dst_oop_addr + map->offset(); 289 // TEMP HACK: barrier code need to migrate to => access API (need own versions of value type ops) 290 if (UseCompressedOops) { 291 bs->write_ref_array_pre((narrowOop*) doop_address, map->count(), dst_uninitialized); 292 } else { 293 bs->write_ref_array_pre((oop*) doop_address, map->count(), dst_uninitialized); 294 } 295 map++; 296 } 297 298 raw_field_copy(src, dst, raw_byte_size); 299 300 // Post-barriers... 301 map = start_of_nonstatic_oop_maps(); 302 while (map != end) { 303 address doop_address = dst_oop_addr + map->offset(); 304 bs->write_ref_array((HeapWord*) doop_address, map->count()); 305 map++; 306 } 307 } else { // Buffered value case 308 raw_field_copy(src, dst, raw_byte_size); 309 } 310 } else { // Primitive-only case... 311 raw_field_copy(src, dst, raw_byte_size); 312 } 313 } 314 315 // Value type arguments are not passed by reference, instead each 316 // field of the value type is passed as an argument. This helper 317 // function collects the fields of the value types (including embedded 318 // value type's fields) in a list. Included with the field's type is 319 // the offset of each field in the value type: i2c and c2i adapters 320 // need that to load or store fields. Finally, the list of fields is 321 // sorted in order of increasing offsets: the adapters and the 322 // compiled code need to agree upon the order of fields. 323 // 324 // The list of basic types that is returned starts with a T_VALUETYPE 325 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID pairs are used as 326 // delimiters. Every entry between the two is a field of the value 327 // type. If there's an embedded value type in the list, it also starts 328 // with a T_VALUETYPE and ends with a T_VOID. This is so we can 329 // generate a unique fingerprint for the method's adapters and we can 330 // generate the list of basic types from the interpreter point of view 331 // (value types passed as reference: iterate on the list until a 332 // T_VALUETYPE, drop everything until and including the closing 333 // T_VOID) or the compiler point of view (each field of the value 334 // types is an argument: drop all T_VALUETYPE/T_VOID from the list). 335 int ValueKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) const { 336 int count = 0; 337 SigEntry::add_entry(sig, T_VALUETYPE, base_off); 338 for (JavaFieldStream fs(this); !fs.done(); fs.next()) { 339 if (fs.access_flags().is_static()) continue; 340 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0); 341 if (fs.is_flattened()) { 342 // Resolve klass of flattened value type field and recursively collect fields 343 Klass* vk = get_value_field_klass(fs.index()); 344 count += ValueKlass::cast(vk)->collect_fields(sig, offset); 345 } else { 346 BasicType bt = FieldType::basic_type(fs.signature()); 347 if (bt == T_VALUETYPE) { 348 bt = T_OBJECT; 349 } 350 SigEntry::add_entry(sig, bt, offset); 351 count += type2size[bt]; 352 } 353 } 354 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0); 355 SigEntry::add_entry(sig, T_VOID, offset); 356 if (base_off == 0) { 357 sig->sort(SigEntry::compare); 358 } 359 assert(sig->at(0)._bt == T_VALUETYPE && sig->at(sig->length()-1)._bt == T_VOID, "broken structure"); 360 return count; 361 } 362 363 void ValueKlass::initialize_calling_convention(TRAPS) { 364 // Because the pack and unpack handler addresses need to be loadable from generated code, 365 // they are stored at a fixed offset in the klass metadata. Since value type klasses do 366 // not have a vtable, the vtable offset is used to store these addresses. 367 if (is_scalarizable() && (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs)) { 368 ResourceMark rm; 369 GrowableArray<SigEntry> sig_vk; 370 int nb_fields = collect_fields(&sig_vk); 371 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK); 372 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig; 373 for (int i = 0; i < sig_vk.length(); i++) { 374 extended_sig->at_put(i, sig_vk.at(i)); 375 } 376 377 if (ValueTypeReturnedAsFields) { 378 nb_fields++; 379 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields); 380 sig_bt[0] = T_METADATA; 381 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1); 382 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields); 383 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields); 384 385 if (total > 0) { 386 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK); 387 *((Array<VMRegPair>**)adr_return_regs()) = return_regs; 388 for (int i = 0; i < nb_fields; i++) { 389 return_regs->at_put(i, regs[i]); 390 } 391 392 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this); 393 *((address*)adr_pack_handler()) = buffered_blob->pack_fields(); 394 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields(); 395 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob"); 396 } 397 } 398 } 399 } 400 401 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) { 402 if (extended_sig() != NULL) { 403 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig()); 404 } 405 if (return_regs() != NULL) { 406 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs()); 407 } 408 cleanup_blobs(); 409 InstanceKlass::deallocate_contents(loader_data); 410 } 411 412 void ValueKlass::cleanup(ValueKlass* ik) { 413 ik->cleanup_blobs(); 414 } 415 416 void ValueKlass::cleanup_blobs() { 417 if (pack_handler() != NULL) { 418 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler()); 419 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type"); 420 BufferBlob::free((BufferBlob*)buffered_blob); 421 *((address*)adr_pack_handler()) = NULL; 422 *((address*)adr_unpack_handler()) = NULL; 423 } 424 } 425 426 // Can this value type be scalarized? 427 bool ValueKlass::is_scalarizable() const { 428 return ScalarizeValueTypes; 429 } 430 431 // Can this value type be returned as multiple values? 432 bool ValueKlass::can_be_returned_as_fields() const { 433 return return_regs() != NULL; 434 } 435 436 // Create handles for all oop fields returned in registers that are going to be live across a safepoint 437 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const { 438 Thread* thread = Thread::current(); 439 const Array<SigEntry>* sig_vk = extended_sig(); 440 const Array<VMRegPair>* regs = return_regs(); 441 int j = 1; 442 443 for (int i = 0; i < sig_vk->length(); i++) { 444 BasicType bt = sig_vk->at(i)._bt; 445 if (bt == T_OBJECT || bt == T_ARRAY) { 446 VMRegPair pair = regs->at(j); 447 address loc = reg_map.location(pair.first()); 448 oop v = *(oop*)loc; 449 assert(v == NULL || oopDesc::is_oop(v), "not an oop?"); 450 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer"); 451 handles.push(Handle(thread, v)); 452 } 453 if (bt == T_VALUETYPE) { 454 continue; 455 } 456 if (bt == T_VOID && 457 sig_vk->at(i-1)._bt != T_LONG && 458 sig_vk->at(i-1)._bt != T_DOUBLE) { 459 continue; 460 } 461 j++; 462 } 463 assert(j == regs->length(), "missed a field?"); 464 } 465 466 // Update oop fields in registers from handles after a safepoint 467 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const { 468 assert(ValueTypeReturnedAsFields, "inconsistent"); 469 const Array<SigEntry>* sig_vk = extended_sig(); 470 const Array<VMRegPair>* regs = return_regs(); 471 assert(regs != NULL, "inconsistent"); 472 473 int j = 1; 474 for (int i = 0, k = 0; i < sig_vk->length(); i++) { 475 BasicType bt = sig_vk->at(i)._bt; 476 if (bt == T_OBJECT || bt == T_ARRAY) { 477 VMRegPair pair = regs->at(j); 478 address loc = reg_map.location(pair.first()); 479 *(oop*)loc = handles.at(k++)(); 480 } 481 if (bt == T_VALUETYPE) { 482 continue; 483 } 484 if (bt == T_VOID && 485 sig_vk->at(i-1)._bt != T_LONG && 486 sig_vk->at(i-1)._bt != T_DOUBLE) { 487 continue; 488 } 489 j++; 490 } 491 assert(j == regs->length(), "missed a field?"); 492 } 493 494 // Fields are in registers. Create an instance of the value type and 495 // initialize it with the values of the fields. 496 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) { 497 oop new_vt = allocate_instance(CHECK_NULL); 498 const Array<SigEntry>* sig_vk = extended_sig(); 499 const Array<VMRegPair>* regs = return_regs(); 500 501 int j = 1; 502 int k = 0; 503 for (int i = 0; i < sig_vk->length(); i++) { 504 BasicType bt = sig_vk->at(i)._bt; 505 if (bt == T_VALUETYPE) { 506 continue; 507 } 508 if (bt == T_VOID) { 509 if (sig_vk->at(i-1)._bt == T_LONG || 510 sig_vk->at(i-1)._bt == T_DOUBLE) { 511 j++; 512 } 513 continue; 514 } 515 int off = sig_vk->at(i)._offset; 516 assert(off > 0, "offset in object should be positive"); 517 VMRegPair pair = regs->at(j); 518 address loc = reg_map.location(pair.first()); 519 switch(bt) { 520 case T_BOOLEAN: { 521 new_vt->bool_field_put(off, *(jboolean*)loc); 522 break; 523 } 524 case T_CHAR: { 525 new_vt->char_field_put(off, *(jchar*)loc); 526 break; 527 } 528 case T_BYTE: { 529 new_vt->byte_field_put(off, *(jbyte*)loc); 530 break; 531 } 532 case T_SHORT: { 533 new_vt->short_field_put(off, *(jshort*)loc); 534 break; 535 } 536 case T_INT: { 537 new_vt->int_field_put(off, *(jint*)loc); 538 break; 539 } 540 case T_LONG: { 541 #ifdef _LP64 542 new_vt->double_field_put(off, *(jdouble*)loc); 543 #else 544 Unimplemented(); 545 #endif 546 break; 547 } 548 case T_OBJECT: 549 case T_ARRAY: { 550 Handle handle = handles.at(k++); 551 new_vt->obj_field_put(off, handle()); 552 break; 553 } 554 case T_FLOAT: { 555 new_vt->float_field_put(off, *(jfloat*)loc); 556 break; 557 } 558 case T_DOUBLE: { 559 new_vt->double_field_put(off, *(jdouble*)loc); 560 break; 561 } 562 default: 563 ShouldNotReachHere(); 564 } 565 *(intptr_t*)loc = 0xDEAD; 566 j++; 567 } 568 assert(j == regs->length(), "missed a field?"); 569 assert(k == handles.length(), "missed an oop?"); 570 return new_vt; 571 } 572 573 // Check the return register for a ValueKlass oop 574 ValueKlass* ValueKlass::returned_value_klass(const RegisterMap& map) { 575 BasicType bt = T_METADATA; 576 VMRegPair pair; 577 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1); 578 assert(nb == 1, "broken"); 579 580 address loc = map.location(pair.first()); 581 intptr_t ptr = *(intptr_t*)loc; 582 if (is_set_nth_bit(ptr, 0)) { 583 // Oop is tagged, must be a ValueKlass oop 584 clear_nth_bit(ptr, 0); 585 assert(Metaspace::contains((void*)ptr), "should be klass"); 586 ValueKlass* vk = (ValueKlass*)ptr; 587 assert(vk->can_be_returned_as_fields(), "must be able to return as fields"); 588 return vk; 589 } 590 #ifdef ASSERT 591 // Oop is not tagged, must be a valid oop 592 if (VerifyOops) { 593 oopDesc::verify(oop((HeapWord*)ptr)); 594 } 595 #endif 596 return NULL; 597 } 598 599 void ValueKlass::verify_on(outputStream* st) { 600 InstanceKlass::verify_on(st); 601 guarantee(prototype_header()->is_always_locked(), "Prototype header is not always locked"); 602 } 603 604 void ValueKlass::oop_verify_on(oop obj, outputStream* st) { 605 InstanceKlass::oop_verify_on(obj, st); 606 guarantee(obj->mark()->is_always_locked(), "Header is not always locked"); 607 }