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/gcLocker.inline.hpp"
28 #include "interpreter/interpreter.hpp"
29 #include "logging/log.hpp"
30 #include "memory/metadataFactory.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "oops/fieldStreams.hpp"
34 #include "oops/method.hpp"
35 #include "oops/objArrayKlass.hpp"
36 #include "oops/valueKlass.hpp"
37 #include "oops/valueArrayKlass.hpp"
38 #include "runtime/signature.hpp"
39 #include "utilities/copy.hpp"
40
41 int ValueKlass::first_field_offset() const {
42 #ifdef ASSERT
43 int first_offset = INT_MAX;
44 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
45 if (fs.offset() < first_offset) first_offset= fs.offset();
46 }
47 #endif
48 int base_offset = instanceOopDesc::base_offset_in_bytes();
49 // The first field of value types is aligned on a long boundary
50 base_offset = align_up(base_offset, BytesPerLong);
51 assert(base_offset == first_offset, "inconsistent offsets");
52 return base_offset;
53 }
54
55 int ValueKlass::raw_value_byte_size() const {
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.access_flags().is_static()) {
72 continue;
73 } else if (fs.offset() > last_offset) {
74 BasicType type = fs.field_descriptor().field_type();
75 if (is_java_primitive(type)) {
76 last_tsz = type2aelembytes(type);
77 } else if (type == T_VALUETYPE) {
78 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
79 return heapOopAlignedSize;
80 } else {
81 guarantee(0, "Unknown type %d", type);
82 }
83 assert(last_tsz != 0, "Invariant");
84 last_offset = fs.offset();
85 }
86 }
87 // Assumes VT with no fields are meaningless and illegal
88 last_offset += last_tsz;
89 assert(last_offset > first_offset && last_tsz, "Invariant");
90 return 1 << upper_log2(last_offset - first_offset);
91 }
92
93 instanceOop ValueKlass::allocate_instance(TRAPS) {
94 int size = size_helper(); // Query before forming handle.
95
96 return (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
97 }
98
99 instanceOop ValueKlass::allocate_buffered_or_heap_instance(bool* in_heap, TRAPS) {
100 assert(THREAD->is_Java_thread(), "Only Java threads can call this method");
101
102 instanceOop value = NULL;
103 if (is_bufferable()) {
104 value = (instanceOop)VTBuffer::allocate_value(this, CHECK_NULL);
105 *in_heap = false;
106 }
107 if (value == NULL) {
108 log_info(valuetypes)("Value buffering failed, allocating in the Java heap");
109 value = allocate_instance(CHECK_NULL);
110 *in_heap = true;
111 }
112 return value;
113 }
114
115 bool ValueKlass::is_atomic() {
116 return (nonstatic_field_size() * heapOopSize) <= longSize;
117 }
118
119 int ValueKlass::nonstatic_oop_count() {
120 int oops = 0;
121 int map_count = nonstatic_oop_map_count();
122 OopMapBlock* block = start_of_nonstatic_oop_maps();
123 OopMapBlock* end = block + map_count;
124 while (block != end) {
125 oops += block->count();
126 block++;
127 }
128 return oops;
129 }
130
131 // Arrays of...
132
133 bool ValueKlass::flatten_array() {
134 if (!ValueArrayFlatten) {
135 return false;
136 }
137
138 int elem_bytes = raw_value_byte_size();
139 // Too big
140 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
141 return false;
142 }
143 // Too many embedded oops
144 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
145 return false;
146 }
147
148 return true;
149 }
150
151
152 Klass* ValueKlass::array_klass_impl(bool or_null, int n, TRAPS) {
153 if (!flatten_array()) {
154 return InstanceKlass::array_klass_impl(or_null, n, THREAD);
155 }
156
157 // Basically the same as instanceKlass, but using "ValueArrayKlass::allocate_klass"
158 if (array_klasses() == NULL) {
159 if (or_null) return NULL;
160
161 ResourceMark rm;
162 JavaThread *jt = (JavaThread *)THREAD;
163 {
164 // Atomic creation of array_klasses
165 MutexLocker mc(Compile_lock, THREAD); // for vtables
166 MutexLocker ma(MultiArray_lock, THREAD);
167
168 // Check if update has already taken place
169 if (array_klasses() == NULL) {
170 Klass* ak;
171 if (is_atomic() || (!ValueArrayAtomicAccess)) {
172 ak = ValueArrayKlass::allocate_klass(this, CHECK_NULL);
173 } else {
174 ak = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
175 }
176 set_array_klasses(ak);
177 }
178 }
179 }
180 // _this will always be set at this point
181 ArrayKlass* ak = ArrayKlass::cast(array_klasses());
182 if (or_null) {
183 return ak->array_klass_or_null(n);
184 }
185 return ak->array_klass(n, THREAD);
186 }
187
188 Klass* ValueKlass::array_klass_impl(bool or_null, TRAPS) {
189 return array_klass_impl(or_null, 1, THREAD);
190 }
191
192 void ValueKlass::raw_field_copy(void* src, void* dst, size_t raw_byte_size) {
193 /*
194 * Try not to shear fields even if not an atomic store...
195 *
196 * First 3 cases handle value array store, otherwise works on the same basis
197 * as JVM_Clone, at this size data is aligned. The order of primitive types
198 * is largest to smallest, and it not possible for fields to stradle long
199 * copy boundaries.
200 *
201 * If MT without exclusive access, possible to observe partial value store,
202 * but not partial primitive and reference field values
203 */
204 switch (raw_byte_size) {
205 case 1:
206 *((jbyte*) dst) = *(jbyte*)src;
207 break;
208 case 2:
209 *((jshort*) dst) = *(jshort*)src;
210 break;
211 case 4:
212 *((jint*) dst) = *(jint*) src;
213 break;
214 default:
215 assert(raw_byte_size % sizeof(jlong) == 0, "Unaligned raw_byte_size");
216 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, raw_byte_size >> LogBytesPerLong);
217 }
218 }
219
220 /*
221 * Store the value of this klass contained with src into dst.
222 *
223 * This operation is appropriate for use from vastore, vaload and putfield (for values)
224 *
225 * GC barriers currently can lock with no safepoint check and allocate c-heap,
226 * so raw point is "safe" for now.
227 *
228 * Going forward, look to use machine generated (stub gen or bc) version for most used klass layouts
229 *
230 */
231 void ValueKlass::value_store(void* src, void* dst, size_t raw_byte_size, bool dst_heap, bool dst_uninitialized) {
232 if (contains_oops()) {
233 if (dst_heap) {
234 // src/dst aren't oops, need offset to adjust oop map offset
235 const address dst_oop_addr = ((address) dst) - first_field_offset();
236
237 // Pre-barriers...
238 OopMapBlock* map = start_of_nonstatic_oop_maps();
239 OopMapBlock* const end = map + nonstatic_oop_map_count();
240 while (map != end) {
241 // Shame we can't just use the existing oop iterator...src/dst aren't oop
242 address doop_address = dst_oop_addr + map->offset();
243 // TEMP HACK: barrier code need to migrate to => access API (need own versions of value type ops)
244 if (UseCompressedOops) {
245 BarrierSet::barrier_set()->write_ref_array_pre((narrowOop*) doop_address, map->count(), dst_uninitialized);
246 } else {
247 BarrierSet::barrier_set()->write_ref_array_pre((oop*) doop_address, map->count(), dst_uninitialized);
248 }
249 map++;
250 }
251
252 raw_field_copy(src, dst, raw_byte_size);
253
254 // Post-barriers...
255 map = start_of_nonstatic_oop_maps();
256 while (map != end) {
257 address doop_address = dst_oop_addr + map->offset();
258 BarrierSet::barrier_set()->write_ref_array((HeapWord*) doop_address, map->count());
259 map++;
260 }
261 } else { // Buffered value case
262 raw_field_copy(src, dst, raw_byte_size);
263 }
264 } else { // Primitive-only case...
265 raw_field_copy(src, dst, raw_byte_size);
266 }
267 }
268
269 // Value type arguments are not passed by reference, instead each
270 // field of the value type is passed as an argument. This helper
271 // function collects the fields of the value types (including embedded
272 // value type's fields) in a list. Included with the field's type is
273 // the offset of each field in the value type: i2c and c2i adapters
274 // need that to load or store fields. Finally, the list of fields is
275 // sorted in order of increasing offsets: the adapters and the
276 // compiled code need and agreed upon order of fields.
277 //
278 // The list of basic types that is returned starts with a T_VALUETYPE
279 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID are used as
280 // delimiters. Every entry between the two is a field of the value
281 // type. If there's an embedded value type in the list, it also starts
282 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
283 // generate a unique fingerprint for the method's adapters and we can
284 // generate the list of basic types from the interpreter point of view
285 // (value types passed as reference: iterate on the list until a
286 // T_VALUETYPE, drop everything until and including the closing
287 // T_VOID) or the compiler point of view (each field of the value
288 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
289 GrowableArray<SigEntry> ValueKlass::collect_fields(int base_off) const {
290 GrowableArray<SigEntry> sig_extended;
291 sig_extended.push(SigEntry(T_VALUETYPE, base_off));
292 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
293 if (fs.access_flags().is_static()) continue;
294 fieldDescriptor& fd = fs.field_descriptor();
295 BasicType bt = fd.field_type();
296 int offset = base_off + fd.offset() - (base_off > 0 ? first_field_offset() : 0);
297 if (bt == T_VALUETYPE) {
298 if (fd.is_flattened()) {
299 Symbol* signature = fd.signature();
300 JavaThread* THREAD = JavaThread::current();
301 oop loader = class_loader();
302 oop domain = protection_domain();
303 ResetNoHandleMark rnhm;
304 HandleMark hm;
305 NoSafepointVerifier nsv;
306 Klass* klass = SystemDictionary::resolve_or_null(signature,
307 Handle(THREAD, loader), Handle(THREAD, domain),
308 THREAD);
309 assert(klass != NULL && !HAS_PENDING_EXCEPTION, "lookup shouldn't fail");
310 const GrowableArray<SigEntry>& embedded = ValueKlass::cast(klass)->collect_fields(offset);
311 sig_extended.appendAll(&embedded);
312 } else {
313 sig_extended.push(SigEntry(T_VALUETYPEPTR, offset));
314 }
315 } else {
316 sig_extended.push(SigEntry(bt, offset));
317 if (bt == T_LONG || bt == T_DOUBLE) {
318 sig_extended.push(SigEntry(T_VOID, offset));
319 }
320 }
321 }
322 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
323 sig_extended.push(SigEntry(T_VOID, offset)); // hack: use T_VOID to mark end of value type fields
324 if (base_off == 0) {
325 sig_extended.sort(SigEntry::compare);
326 }
327 assert(sig_extended.at(0)._bt == T_VALUETYPE && sig_extended.at(sig_extended.length()-1)._bt == T_VOID, "broken structure");
328 return sig_extended;
329 }
330
331 void ValueKlass::initialize_calling_convention() {
332 // Because the pack and unpack handler addresses need to be loadable from generated code,
333 // they are stored at a fixed offset in the klass metadata. Since value type klasses do
334 // not have a vtable, the vtable offset is used to store these addresses.
335 //guarantee(vtable_length() == 0, "vtables are not supported in value klasses");
336 if (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs) {
337 Thread* THREAD = Thread::current();
338 assert(!HAS_PENDING_EXCEPTION, "should have no exception");
339 ResourceMark rm;
340 const GrowableArray<SigEntry>& sig_vk = collect_fields();
341 int nb_fields = SigEntry::count_fields(sig_vk)+1;
342 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK_AND_CLEAR);
343 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
344 for (int i = 0; i < sig_vk.length(); i++) {
345 extended_sig->at_put(i, sig_vk.at(i));
346 }
347
348 if (ValueTypeReturnedAsFields) {
349 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
350 sig_bt[0] = T_METADATA;
351 SigEntry::fill_sig_bt(sig_vk, sig_bt+1, nb_fields-1, true);
352 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
353 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
354
355 if (total > 0) {
356 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK_AND_CLEAR);
357 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
358 for (int i = 0; i < nb_fields; i++) {
359 return_regs->at_put(i, regs[i]);
360 }
361
362 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this);
363 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
364 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
365 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
366 }
367 }
368 }
369 }
370
371 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) {
372 if (extended_sig() != NULL) {
373 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
374 }
375 if (return_regs() != NULL) {
376 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
377 }
378 cleanup_blobs();
379 InstanceKlass::deallocate_contents(loader_data);
380 }
381
382 void ValueKlass::cleanup(ValueKlass* ik) {
383 ik->cleanup_blobs();
384 }
385
386 void ValueKlass::cleanup_blobs() {
387 if (pack_handler() != NULL) {
388 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
389 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type");
390 BufferBlob::free((BufferBlob*)buffered_blob);
391 *((address*)adr_pack_handler()) = NULL;
392 *((address*)adr_unpack_handler()) = NULL;
393 }
394 }
395
396 // Can this value type be returned as multiple values?
397 bool ValueKlass::can_be_returned_as_fields() const {
398 return return_regs() != NULL;
399 }
400
401 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
402 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
403 Thread* thread = Thread::current();
404 const Array<SigEntry>* sig_vk = extended_sig();
405 const Array<VMRegPair>* regs = return_regs();
406 int j = 1;
407
408 for (int i = 0; i < sig_vk->length(); i++) {
409 BasicType bt = sig_vk->at(i)._bt;
410 if (bt == T_OBJECT || bt == T_VALUETYPEPTR || bt == T_ARRAY) {
411 int off = sig_vk->at(i)._offset;
412 VMRegPair pair = regs->at(j);
413 address loc = reg_map.location(pair.first());
414 oop v = *(oop*)loc;
415 assert(v == NULL || oopDesc::is_oop(v), "not an oop?");
416 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
417 handles.push(Handle(thread, v));
418 }
419 if (bt == T_VALUETYPE) {
420 continue;
421 }
422 if (bt == T_VOID &&
423 sig_vk->at(i-1)._bt != T_LONG &&
424 sig_vk->at(i-1)._bt != T_DOUBLE) {
425 continue;
426 }
427 j++;
428 }
429 assert(j == regs->length(), "missed a field?");
430 }
431
432 // Update oop fields in registers from handles after a safepoint
433 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
434 assert(ValueTypeReturnedAsFields, "inconsistent");
435 const Array<SigEntry>* sig_vk = extended_sig();
436 const Array<VMRegPair>* regs = return_regs();
437 assert(regs != NULL, "inconsistent");
438
439 int j = 1;
440 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
441 BasicType bt = sig_vk->at(i)._bt;
442 if (bt == T_OBJECT || bt == T_ARRAY) {
443 int off = sig_vk->at(i)._offset;
444 VMRegPair pair = regs->at(j);
445 address loc = reg_map.location(pair.first());
446 *(oop*)loc = handles.at(k++)();
447 }
448 if (bt == T_VALUETYPE) {
449 continue;
450 }
451 if (bt == T_VOID &&
452 sig_vk->at(i-1)._bt != T_LONG &&
453 sig_vk->at(i-1)._bt != T_DOUBLE) {
454 continue;
455 }
456 j++;
457 }
458 assert(j == regs->length(), "missed a field?");
459 }
460
461 // Fields are in registers. Create an instance of the value type and
462 // initialize it with the values of the fields.
463 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, bool buffered, TRAPS) {
464 bool ignored = false;
465 oop new_vt = NULL;
466 if (buffered) {
467 new_vt = allocate_buffered_or_heap_instance(&ignored, CHECK_NULL);
468 } else {
469 new_vt = allocate_instance(CHECK_NULL);
470 }
471
472 const Array<SigEntry>* sig_vk = extended_sig();
473 const Array<VMRegPair>* regs = return_regs();
474
475 int j = 1;
476 int k = 0;
477 for (int i = 0; i < sig_vk->length(); i++) {
478 BasicType bt = sig_vk->at(i)._bt;
479 if (bt == T_VALUETYPE) {
480 continue;
481 }
482 if (bt == T_VOID) {
483 if (sig_vk->at(i-1)._bt == T_LONG ||
484 sig_vk->at(i-1)._bt == T_DOUBLE) {
485 j++;
486 }
487 continue;
488 }
489 int off = sig_vk->at(i)._offset;
490 VMRegPair pair = regs->at(j);
491 address loc = reg_map.location(pair.first());
492 switch(bt) {
493 case T_BOOLEAN: {
494 jboolean v = *(intptr_t*)loc;
495 *(jboolean*)((address)new_vt + off) = v;
496 break;
497 }
498 case T_CHAR: {
499 jchar v = *(intptr_t*)loc;
500 *(jchar*)((address)new_vt + off) = v;
501 break;
502 }
503 case T_BYTE: {
504 jbyte v = *(intptr_t*)loc;
505 *(jbyte*)((address)new_vt + off) = v;
506 break;
507 }
508 case T_SHORT: {
509 jshort v = *(intptr_t*)loc;
510 *(jshort*)((address)new_vt + off) = v;
511 break;
512 }
513 case T_INT: {
514 jint v = *(intptr_t*)loc;
515 *(jint*)((address)new_vt + off) = v;
516 break;
517 }
518 case T_LONG: {
519 #ifdef _LP64
520 jlong v = *(intptr_t*)loc;
521 *(jlong*)((address)new_vt + off) = v;
522 #else
523 Unimplemented();
524 #endif
525 break;
526 }
527 case T_OBJECT:
528 case T_VALUETYPEPTR:
529 case T_ARRAY: {
530 Handle handle = handles.at(k++);
531 oop v = handle();
532 if (!UseCompressedOops) {
533 oop* p = (oop*)((address)new_vt + off);
534 oopDesc::store_heap_oop(p, v);
535 } else {
536 narrowOop* p = (narrowOop*)((address)new_vt + off);
537 oopDesc::encode_store_heap_oop(p, v);
538 }
539 break;
540 }
541 case T_FLOAT: {
542 jfloat v = *(jfloat*)loc;
543 *(jfloat*)((address)new_vt + off) = v;
544 break;
545 }
546 case T_DOUBLE: {
547 jdouble v = *(jdouble*)loc;
548 *(jdouble*)((address)new_vt + off) = v;
549 break;
550 }
551 default:
552 ShouldNotReachHere();
553 }
554 *(intptr_t*)loc = 0xDEAD;
555 j++;
556 }
557 assert(j == regs->length(), "missed a field?");
558 assert(k == handles.length(), "missed an oop?");
559 return new_vt;
560 }
561
562 // Check the return register for a ValueKlass oop
563 ValueKlass* ValueKlass::returned_value_klass(const RegisterMap& map) {
564 BasicType bt = T_METADATA;
565 VMRegPair pair;
566 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
567 assert(nb == 1, "broken");
568
569 address loc = map.location(pair.first());
570 intptr_t ptr = *(intptr_t*)loc;
571 if (is_set_nth_bit(ptr, 0)) {
572 // Oop is tagged, must be a ValueKlass oop
573 clear_nth_bit(ptr, 0);
574 assert(Metaspace::contains((void*)ptr), "should be klass");
575 ValueKlass* vk = (ValueKlass*)ptr;
576 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
577 return vk;
578 }
579 #ifdef ASSERT
580 // Oop is not tagged, must be a valid oop
581 if (VerifyOops) {
582 oop((HeapWord*)ptr)->verify();
583 }
584 #endif
585 return NULL;
586 }
587
588 void ValueKlass::iterate_over_inside_oops(OopClosure* f, oop value) {
589 assert(!Universe::heap()->is_in_reserved(value), "This method is used on buffered values");
590
591 oop* addr_mirror = (oop*)(value)->mark_addr();
592 f->do_oop_no_buffering(addr_mirror);
593
594 if (!contains_oops()) return;
595
596 OopMapBlock* map = start_of_nonstatic_oop_maps();
597 OopMapBlock* const end_map = map + nonstatic_oop_map_count();
598
599 if (!UseCompressedOops) {
600 for (; map < end_map; map++) {
601 oop* p = (oop*) (((char*)(oopDesc*)value) + map->offset());
602 oop* const end = p + map->count();
603 for (; p < end; ++p) {
604 assert(oopDesc::is_oop_or_null(*p), "Sanity check");
605 f->do_oop(p);
606 }
607 }
608 } else {
609 for (; map < end_map; map++) {
610 narrowOop* p = (narrowOop*) (((char*)(oopDesc*)value) + map->offset());
611 narrowOop* const end = p + map->count();
612 for (; p < end; ++p) {
613 oop o = oopDesc::decode_heap_oop(*p);
614 assert(Universe::heap()->is_in_reserved_or_null(o), "Sanity check");
615 assert(oopDesc::is_oop_or_null(o), "Sanity check");
616 f->do_oop(p);
617 }
618 }
619 }
620 }