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/gcLocker.inline.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "logging/log.hpp"
29 #include "memory/metadataFactory.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "oops/fieldStreams.hpp"
32 #include "oops/method.hpp"
33 #include "oops/objArrayKlass.hpp"
34 #include "oops/valueKlass.hpp"
35 #include "oops/valueArrayKlass.hpp"
36 #include "runtime/signature.hpp"
37 #include "utilities/copy.hpp"
38
39 int ValueKlass::first_field_offset() const {
40 #ifdef ASSERT
41 int first_offset = INT_MAX;
42 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
43 if (fs.offset() < first_offset) first_offset= fs.offset();
44 }
45 #endif
46 int base_offset = instanceOopDesc::base_offset_in_bytes();
47 // The first field of value types is aligned on a long boundary
48 base_offset = align_up(base_offset, BytesPerLong);
49 assert(base_offset == first_offset, "inconsistent offsets");
50 return base_offset;
51 }
52
53 int ValueKlass::raw_value_byte_size() const {
54 assert(this != SystemDictionary::___Value_klass(),
55 "This is not the value type klass you are looking for");
56 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop;
57 // If bigger than 64 bits or needs oop alignment, then use jlong aligned
58 // which for values should be jlong aligned, asserts in raw_field_copy otherwise
59 if (heapOopAlignedSize >= longSize || contains_oops()) {
60 return heapOopAlignedSize;
61 }
62 // Small primitives...
63 // If a few small basic type fields, return the actual size, i.e.
64 // 1 byte = 1
65 // 2 byte = 2
66 // 3 byte = 4, because pow2 needed for element stores
67 int first_offset = first_field_offset();
68 int last_offset = 0; // find the last offset, add basic type size
69 int last_tsz = 0;
70 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
71 if (fs.offset() > last_offset) {
72 BasicType type = fs.field_descriptor().field_type();
73 if (is_java_primitive(type)) {
74 last_tsz = type2aelembytes(type);
75 } else if (type == T_VALUETYPE) {
76 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
77 return heapOopAlignedSize;
78 } else {
79 guarantee(0, "Unknown type %d", type);
80 }
81 assert(last_tsz != 0, "Invariant");
82 last_offset = fs.offset();
83 }
84 }
85 // Assumes VT with no fields are meaningless and illegal
86 last_offset += last_tsz;
87 assert(last_offset > first_offset && last_tsz, "Invariant");
88 return 1 << upper_log2(last_offset - first_offset);
89 }
90
91 instanceOop ValueKlass::allocate_instance(TRAPS) {
92 int size = size_helper(); // Query before forming handle.
93
94 return (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
95 }
96
97 instanceOop ValueKlass::allocate_buffered_or_heap_instance(bool* in_heap, TRAPS) {
98 assert(THREAD->is_Java_thread(), "Only Java threads can call this method");
99
100 instanceOop value = NULL;
101 if (is_bufferable()) {
102 value = (instanceOop)VTBuffer::allocate_value(this, CHECK_NULL);
103 *in_heap = false;
104 }
105 if (value == NULL) {
106 log_info(valuetypes)("Value buffering failed, allocating in the Java heap");
107 value = allocate_instance(CHECK_NULL);
108 *in_heap = true;
109 }
110 return value;
111 }
112
113 bool ValueKlass::is_atomic() {
114 return (nonstatic_field_size() * heapOopSize) <= longSize;
115 }
116
117 int ValueKlass::nonstatic_oop_count() {
118 int oops = 0;
119 int map_count = nonstatic_oop_map_count();
120 OopMapBlock* block = start_of_nonstatic_oop_maps();
121 OopMapBlock* end = block + map_count;
122 while (block != end) {
123 oops += block->count();
124 block++;
125 }
126 return oops;
127 }
128
129 // Arrays of...
130
131 bool ValueKlass::flatten_array() {
132 if (!ValueArrayFlatten) {
133 return false;
134 }
135
136 int elem_bytes = raw_value_byte_size();
137 // Too big
138 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
139 return false;
140 }
141 // Too many embedded oops
142 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
143 return false;
144 }
145
146 return true;
147 }
148
149
150 Klass* ValueKlass::array_klass_impl(bool or_null, int n, TRAPS) {
151 if (!flatten_array()) {
152 return InstanceKlass::array_klass_impl(or_null, n, THREAD);
153 }
154
155 // Basically the same as instanceKlass, but using "ValueArrayKlass::allocate_klass"
156 if (array_klasses() == NULL) {
157 if (or_null) return NULL;
158
159 ResourceMark rm;
160 JavaThread *jt = (JavaThread *)THREAD;
161 {
162 // Atomic creation of array_klasses
163 MutexLocker mc(Compile_lock, THREAD); // for vtables
164 MutexLocker ma(MultiArray_lock, THREAD);
165
166 // Check if update has already taken place
167 if (array_klasses() == NULL) {
168 Klass* ak;
169 if (is_atomic() || (!ValueArrayAtomicAccess)) {
170 ak = ValueArrayKlass::allocate_klass(this, CHECK_NULL);
171 } else {
172 ak = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
173 }
174 set_array_klasses(ak);
175 }
176 }
177 }
178 // _this will always be set at this point
179 ArrayKlass* ak = ArrayKlass::cast(array_klasses());
180 if (or_null) {
181 return ak->array_klass_or_null(n);
182 }
183 return ak->array_klass(n, THREAD);
184 }
185
186 Klass* ValueKlass::array_klass_impl(bool or_null, TRAPS) {
187 return array_klass_impl(or_null, 1, THREAD);
188 }
189
190 void ValueKlass::raw_field_copy(void* src, void* dst, size_t raw_byte_size) {
191 /*
192 * Try not to shear fields even if not an atomic store...
193 *
194 * First 3 cases handle value array store, otherwise works on the same basis
195 * as JVM_Clone, at this size data is aligned. The order of primitive types
196 * is largest to smallest, and it not possible for fields to stradle long
197 * copy boundaries.
198 *
199 * If MT without exclusive access, possible to observe partial value store,
200 * but not partial primitive and reference field values
201 */
202 switch (raw_byte_size) {
203 case 1:
204 *((jbyte*) dst) = *(jbyte*)src;
205 break;
206 case 2:
207 *((jshort*) dst) = *(jshort*)src;
208 break;
209 case 4:
210 *((jint*) dst) = *(jint*) src;
211 break;
212 default:
213 assert(raw_byte_size % sizeof(jlong) == 0, "Unaligned raw_byte_size");
214 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, raw_byte_size >> LogBytesPerLong);
215 }
216 }
217
218 /*
219 * Store the value of this klass contained with src into dst.
220 *
221 * This operation is appropriate for use from vastore, vaload and putfield (for values)
222 *
223 * GC barriers currently can lock with no safepoint check and allocate c-heap,
224 * so raw point is "safe" for now.
225 *
226 * Going forward, look to use machine generated (stub gen or bc) version for most used klass layouts
227 *
228 */
229 void ValueKlass::value_store(void* src, void* dst, size_t raw_byte_size, bool dst_heap, bool dst_uninitialized) {
230 if (contains_oops() && dst_heap) {
231 // src/dst aren't oops, need offset to adjust oop map offset
232 const address dst_oop_addr = ((address) dst) - first_field_offset();
233
234 // Pre-barriers...
235 OopMapBlock* map = start_of_nonstatic_oop_maps();
236 OopMapBlock* const end = map + nonstatic_oop_map_count();
237 while (map != end) {
238 // Shame we can't just use the existing oop iterator...src/dst aren't oop
239 address doop_address = dst_oop_addr + map->offset();
240 if (UseCompressedOops) {
241 oopDesc::bs()->write_ref_array_pre((narrowOop*) doop_address, map->count(), dst_uninitialized);
242 } else {
243 oopDesc::bs()->write_ref_array_pre((oop*) doop_address, map->count(), dst_uninitialized);
244 }
245 map++;
246 }
247
248 raw_field_copy(src, dst, raw_byte_size);
249
250 // Post-barriers...
251 map = start_of_nonstatic_oop_maps();
252 while (map != end) {
253 address doop_address = dst_oop_addr + map->offset();
254 oopDesc::bs()->write_ref_array((HeapWord*) doop_address, map->count());
255 map++;
256 }
257 } else { // Primitive-only case...
258 raw_field_copy(src, dst, raw_byte_size);
259 }
260 }
261
262 oop ValueKlass::box(Handle src, InstanceKlass* target_klass, TRAPS) {
263 assert(src()->klass()->is_value(), "src must be a value type");
264 assert(!target_klass->is_value(), "target_klass must not be a value type");
265
266 target_klass->initialize(CHECK_0);
267 instanceOop box = target_klass->allocate_instance(CHECK_0);
268 value_store(data_for_oop(src()), data_for_oop(box), true, false);
269
270 assert(!box->klass()->is_value(), "Sanity check");
271 return box;
272 }
273
274 oop ValueKlass::unbox(Handle src, InstanceKlass* target_klass, TRAPS) {
275 assert(!src()->klass()->is_value(), "src must not be a value type");
276 assert(target_klass->is_value(), "target_klass must be a value type");
277 ValueKlass* vtklass = ValueKlass::cast(target_klass);
278
279 vtklass->initialize(CHECK_0);
280 bool in_heap;
281 instanceOop value = vtklass->allocate_buffered_or_heap_instance(&in_heap, CHECK_0);
282 value_store(data_for_oop(src()), data_for_oop(value), in_heap, false);
283
284 assert(value->klass()->is_value(), "Sanity check");
285 return value;
286 }
287
288 // Value type arguments are not passed by reference, instead each
289 // field of the value type is passed as an argument. This helper
290 // function collects the fields of the value types (including embedded
291 // value type's fields) in a list. Included with the field's type is
292 // the offset of each field in the value type: i2c and c2i adapters
293 // need that to load or store fields. Finally, the list of fields is
294 // sorted in order of increasing offsets: the adapters and the
295 // compiled code need and agreed upon order of fields.
296 //
297 // The list of basic types that is returned starts with a T_VALUETYPE
298 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID are used as
299 // delimiters. Every entry between the two is a field of the value
300 // type. If there's an embedded value type in the list, it also starts
301 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
302 // generate a unique fingerprint for the method's adapters and we can
303 // generate the list of basic types from the interpreter point of view
304 // (value types passed as reference: iterate on the list until a
305 // T_VALUETYPE, drop everything until and including the closing
306 // T_VOID) or the compiler point of view (each field of the value
307 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
308 GrowableArray<SigEntry> ValueKlass::collect_fields(int base_off) const {
309 GrowableArray<SigEntry> sig_extended;
310 sig_extended.push(SigEntry(T_VALUETYPE, base_off));
311 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
312 if (fs.access_flags().is_static()) continue;
313 fieldDescriptor& fd = fs.field_descriptor();
314 BasicType bt = fd.field_type();
315 int offset = base_off + fd.offset() - (base_off > 0 ? first_field_offset() : 0);
316 if (bt == T_VALUETYPE) {
317 if (fd.is_flatten()) {
318 Symbol* signature = fd.signature();
319 JavaThread* THREAD = JavaThread::current();
320 oop loader = class_loader();
321 oop domain = protection_domain();
322 ResetNoHandleMark rnhm;
323 HandleMark hm;
324 NoSafepointVerifier nsv;
325 Klass* klass = SystemDictionary::resolve_or_null(signature,
326 Handle(THREAD, loader), Handle(THREAD, domain),
327 THREAD);
328 assert(klass != NULL && !HAS_PENDING_EXCEPTION, "lookup shouldn't fail");
329 const GrowableArray<SigEntry>& embedded = ValueKlass::cast(klass)->collect_fields(offset);
330 sig_extended.appendAll(&embedded);
331 } else {
332 sig_extended.push(SigEntry(T_OBJECT, offset));
333 }
334 } else {
335 sig_extended.push(SigEntry(bt, offset));
336 if (bt == T_LONG || bt == T_DOUBLE) {
337 sig_extended.push(SigEntry(T_VOID, offset));
338 }
339 }
340 }
341 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
342 sig_extended.push(SigEntry(T_VOID, offset)); // hack: use T_VOID to mark end of value type fields
343 if (base_off == 0) {
344 sig_extended.sort(SigEntry::compare);
345 }
346 assert(sig_extended.at(0)._bt == T_VALUETYPE && sig_extended.at(sig_extended.length()-1)._bt == T_VOID, "broken structure");
347 return sig_extended;
348 }
349
350 void ValueKlass::initialize_calling_convention() {
351 // Because the pack and unpack handler addresses need to be loadable from generated code,
352 // they are stored at a fixed offset in the klass metadata. Since value type klasses do
353 // not have a vtable, the vtable offset is used to store these addresses.
354 guarantee(vtable_length() == 0, "vtables are not supported in value klasses");
355 if (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs) {
356 Thread* THREAD = Thread::current();
357 assert(!HAS_PENDING_EXCEPTION, "should have no exception");
358 ResourceMark rm;
359 const GrowableArray<SigEntry>& sig_vk = collect_fields();
360 int nb_fields = SigEntry::count_fields(sig_vk)+1;
361 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK_AND_CLEAR);
362 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
363 for (int i = 0; i < sig_vk.length(); i++) {
364 extended_sig->at_put(i, sig_vk.at(i));
365 }
366
367 if (ValueTypeReturnedAsFields) {
368 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
369 sig_bt[0] = T_METADATA;
370 SigEntry::fill_sig_bt(sig_vk, sig_bt+1, nb_fields-1, true);
371 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
372 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
373
374 if (total > 0) {
375 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK_AND_CLEAR);
376 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
377 for (int i = 0; i < nb_fields; i++) {
378 return_regs->at_put(i, regs[i]);
379 }
380
381 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this);
382 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
383 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
384 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
385 }
386 }
387 }
388 }
389
390 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) {
391 if (extended_sig() != NULL) {
392 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
393 }
394 if (return_regs() != NULL) {
395 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
396 }
397 cleanup_blobs();
398 InstanceKlass::deallocate_contents(loader_data);
399 }
400
401 void ValueKlass::cleanup(ValueKlass* ik) {
402 ik->cleanup_blobs();
403 }
404
405 void ValueKlass::cleanup_blobs() {
406 if (pack_handler() != NULL) {
407 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
408 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type");
409 BufferBlob::free((BufferBlob*)buffered_blob);
410 *((address*)adr_pack_handler()) = NULL;
411 *((address*)adr_unpack_handler()) = NULL;
412 }
413 }
414
415 // Create handles for all oop fields returned in registers that are
416 // going to be live across a safepoint.
417 bool ValueKlass::save_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
418 if (ValueTypeReturnedAsFields) {
419 if (return_regs() != NULL) {
420 save_oop_fields(reg_map, handles);
421 return true;
422 }
423 }
424 return false;
425 }
426
427 // Same as above but with pre-computed return convention
428 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
429 Thread* thread = Thread::current();
430 const Array<SigEntry>* sig_vk = extended_sig();
431 const Array<VMRegPair>* regs = return_regs();
432 int j = 1;
433
434 for (int i = 0; i < sig_vk->length(); i++) {
435 BasicType bt = sig_vk->at(i)._bt;
436 if (bt == T_OBJECT || bt == T_ARRAY) {
437 int off = sig_vk->at(i)._offset;
438 VMRegPair pair = regs->at(j);
439 address loc = reg_map.location(pair.first());
440 oop v = *(oop*)loc;
441 assert(v == NULL || oopDesc::is_oop(v), "not an oop?");
442 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
443 handles.push(Handle(thread, v));
444 }
445 if (bt == T_VALUETYPE) {
446 continue;
447 }
448 if (bt == T_VOID &&
449 sig_vk->at(i-1)._bt != T_LONG &&
450 sig_vk->at(i-1)._bt != T_DOUBLE) {
451 continue;
452 }
453 j++;
454 }
455 assert(j == regs->length(), "missed a field?");
456 }
457
458 // Update oop fields in registers from handles after a safepoint
459 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
460 assert(ValueTypeReturnedAsFields, "inconsistent");
461 const Array<SigEntry>* sig_vk = extended_sig();
462 const Array<VMRegPair>* regs = return_regs();
463 assert(regs != NULL, "inconsistent");
464
465 int j = 1;
466 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
467 BasicType bt = sig_vk->at(i)._bt;
468 if (bt == T_OBJECT || bt == T_ARRAY) {
469 int off = sig_vk->at(i)._offset;
470 VMRegPair pair = regs->at(j);
471 address loc = reg_map.location(pair.first());
472 *(oop*)loc = handles.at(k++)();
473 }
474 if (bt == T_VALUETYPE) {
475 continue;
476 }
477 if (bt == T_VOID &&
478 sig_vk->at(i-1)._bt != T_LONG &&
479 sig_vk->at(i-1)._bt != T_DOUBLE) {
480 continue;
481 }
482 j++;
483 }
484 assert(j == regs->length(), "missed a field?");
485 }
486
487 // Fields are in registers. Create an instance of the value type and
488 // initialize it with the values of the fields.
489 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, bool buffered, TRAPS) {
490 bool ignored = false;
491 oop new_vt = NULL;
492 if (buffered) {
493 new_vt = allocate_buffered_or_heap_instance(&ignored, CHECK_NULL);
494 } else {
495 new_vt = allocate_instance(CHECK_NULL);
496 }
497
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 VMRegPair pair = regs->at(j);
517 address loc = reg_map.location(pair.first());
518 switch(bt) {
519 case T_BOOLEAN: {
520 jboolean v = *(intptr_t*)loc;
521 *(jboolean*)((address)new_vt + off) = v;
522 break;
523 }
524 case T_CHAR: {
525 jchar v = *(intptr_t*)loc;
526 *(jchar*)((address)new_vt + off) = v;
527 break;
528 }
529 case T_BYTE: {
530 jbyte v = *(intptr_t*)loc;
531 *(jbyte*)((address)new_vt + off) = v;
532 break;
533 }
534 case T_SHORT: {
535 jshort v = *(intptr_t*)loc;
536 *(jshort*)((address)new_vt + off) = v;
537 break;
538 }
539 case T_INT: {
540 jint v = *(intptr_t*)loc;
541 *(jint*)((address)new_vt + off) = v;
542 break;
543 }
544 case T_LONG: {
545 #ifdef _LP64
546 jlong v = *(intptr_t*)loc;
547 *(jlong*)((address)new_vt + off) = v;
548 #else
549 Unimplemented();
550 #endif
551 break;
552 }
553 case T_OBJECT:
554 case T_ARRAY: {
555 Handle handle = handles.at(k++);
556 oop v = handle();
557 if (!UseCompressedOops) {
558 oop* p = (oop*)((address)new_vt + off);
559 oopDesc::store_heap_oop(p, v);
560 } else {
561 narrowOop* p = (narrowOop*)((address)new_vt + off);
562 oopDesc::encode_store_heap_oop(p, v);
563 }
564 break;
565 }
566 case T_FLOAT: {
567 jfloat v = *(jfloat*)loc;
568 *(jfloat*)((address)new_vt + off) = v;
569 break;
570 }
571 case T_DOUBLE: {
572 jdouble v = *(jdouble*)loc;
573 *(jdouble*)((address)new_vt + off) = v;
574 break;
575 }
576 default:
577 ShouldNotReachHere();
578 }
579 *(intptr_t*)loc = 0xDEAD;
580 j++;
581 }
582 assert(j == regs->length(), "missed a field?");
583 assert(k == handles.length(), "missed an oop?");
584 return new_vt;
585 }
586
587 ValueKlass* ValueKlass::returned_value_type(const RegisterMap& map) {
588 BasicType bt = T_METADATA;
589 VMRegPair pair;
590 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
591 assert(nb == 1, "broken");
592
593 address loc = map.location(pair.first());
594 intptr_t ptr = *(intptr_t*)loc;
595 if (is_set_nth_bit(ptr, 0)) {
596 clear_nth_bit(ptr, 0);
597 assert(Metaspace::contains((void*)ptr), "should be klass");
598 return (ValueKlass*)ptr;
599 }
600 return NULL;
601 }