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