1 /*
2 * Copyright (c) 2017, 2019, 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/metaspaceClosure.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "oops/access.hpp"
34 #include "oops/compressedOops.inline.hpp"
35 #include "oops/fieldStreams.inline.hpp"
36 #include "oops/instanceKlass.inline.hpp"
37 #include "oops/method.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "oops/objArrayKlass.hpp"
40 #include "oops/valueKlass.inline.hpp"
41 #include "oops/valueArrayKlass.hpp"
42 #include "runtime/fieldDescriptor.inline.hpp"
43 #include "runtime/handles.inline.hpp"
44 #include "runtime/safepointVerifiers.hpp"
45 #include "runtime/sharedRuntime.hpp"
46 #include "runtime/signature.hpp"
47 #include "runtime/thread.inline.hpp"
48 #include "utilities/copy.hpp"
49
50 // Constructor
51 ValueKlass::ValueKlass(const ClassFileParser& parser)
52 : InstanceKlass(parser, InstanceKlass::_misc_kind_value_type, InstanceKlass::ID) {
53 _adr_valueklass_fixed_block = valueklass_static_block();
54 // Addresses used for value type calling convention
55 *((Array<SigEntry>**)adr_extended_sig()) = NULL;
56 *((Array<VMRegPair>**)adr_return_regs()) = NULL;
57 *((address*)adr_pack_handler()) = NULL;
58 *((address*)adr_pack_handler_jobject()) = NULL;
59 *((address*)adr_unpack_handler()) = NULL;
60 assert(pack_handler() == NULL, "pack handler not null");
61 *((int*)adr_default_value_offset()) = 0;
62 *((Klass**)adr_value_array_klass()) = NULL;
63 set_prototype_header(markWord::always_locked_prototype());
64 }
65
66 oop ValueKlass::default_value() {
67 oop val = java_mirror()->obj_field_acquire(default_value_offset());
68 assert(oopDesc::is_oop(val), "Sanity check");
69 assert(val->is_value(), "Sanity check");
70 assert(val->klass() == this, "sanity check");
71 return val;
72 }
73
74 int ValueKlass::first_field_offset_old() {
75 #ifdef ASSERT
76 int first_offset = INT_MAX;
77 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
78 if (fs.offset() < first_offset) first_offset= fs.offset();
79 }
80 #endif
81 int base_offset = instanceOopDesc::base_offset_in_bytes();
82 // The first field of value types is aligned on a long boundary
83 base_offset = align_up(base_offset, BytesPerLong);
84 assert(base_offset == first_offset, "inconsistent offsets");
85 return base_offset;
86 }
87
88 int ValueKlass::raw_value_byte_size() {
89 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop;
90 // If bigger than 64 bits or needs oop alignment, then use jlong aligned
91 // which for values should be jlong aligned, asserts in raw_field_copy otherwise
92 if (heapOopAlignedSize >= longSize || contains_oops()) {
93 return heapOopAlignedSize;
94 }
95 // Small primitives...
96 // If a few small basic type fields, return the actual size, i.e.
97 // 1 byte = 1
98 // 2 byte = 2
99 // 3 byte = 4, because pow2 needed for element stores
100 int first_offset = first_field_offset();
101 int last_offset = 0; // find the last offset, add basic type size
102 int last_tsz = 0;
103 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
104 if (fs.access_flags().is_static()) {
105 continue;
106 } else if (fs.offset() > last_offset) {
107 BasicType type = Signature::basic_type(fs.signature());
108 if (is_java_primitive(type)) {
109 last_tsz = type2aelembytes(type);
110 } else if (type == T_VALUETYPE) {
111 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
112 return heapOopAlignedSize;
113 } else {
114 guarantee(0, "Unknown type %d", type);
115 }
116 assert(last_tsz != 0, "Invariant");
117 last_offset = fs.offset();
118 }
119 }
120 // Assumes VT with no fields are meaningless and illegal
121 last_offset += last_tsz;
122 assert(last_offset > first_offset && last_tsz, "Invariant");
123 return 1 << upper_log2(last_offset - first_offset);
124 }
125
126 instanceOop ValueKlass::allocate_instance(TRAPS) {
127 int size = size_helper(); // Query before forming handle.
128
129 instanceOop oop = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
130 assert(oop->mark().is_always_locked(), "Unlocked value type");
131 return oop;
132 }
133
134 instanceOop ValueKlass::allocate_instance_buffer(TRAPS) {
135 int size = size_helper(); // Query before forming handle.
136
137 instanceOop oop = (instanceOop)Universe::heap()->obj_buffer_allocate(this, size, CHECK_NULL);
138 assert(oop->mark().is_always_locked(), "Unlocked value type");
139 return oop;
140 }
141
142 bool ValueKlass::is_atomic() {
143 return (nonstatic_field_size() * heapOopSize) <= longSize;
144 }
145
146 int ValueKlass::nonstatic_oop_count() {
147 int oops = 0;
148 int map_count = nonstatic_oop_map_count();
149 OopMapBlock* block = start_of_nonstatic_oop_maps();
150 OopMapBlock* end = block + map_count;
151 while (block != end) {
152 oops += block->count();
153 block++;
154 }
155 return oops;
156 }
157
158 oop ValueKlass::read_flattened_field(oop obj, int offset, TRAPS) {
159 oop res = NULL;
160 this->initialize(CHECK_NULL); // will throw an exception if in error state
161 if (is_empty_value()) {
162 res = (instanceOop)default_value();
163 } else {
164 Handle obj_h(THREAD, obj);
165 res = allocate_instance_buffer(CHECK_NULL);
166 value_copy_payload_to_new_oop(((char*)(oopDesc*)obj_h()) + offset, res);
167 }
168 assert(res != NULL, "Must be set in one of two paths above");
169 return res;
170 }
171
172 void ValueKlass::write_flattened_field(oop obj, int offset, oop value, TRAPS) {
173 if (value == NULL) {
174 THROW(vmSymbols::java_lang_NullPointerException());
175 }
176 if (!is_empty_value()) {
177 value_copy_oop_to_payload(value, ((char*)(oopDesc*)obj) + offset);
178 }
179 }
180
181 // Arrays of...
182
183 bool ValueKlass::flatten_array() {
184 if (!ValueArrayFlatten) {
185 return false;
186 }
187
188 int elem_bytes = raw_value_byte_size();
189 // Too big
190 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
191 return false;
192 }
193 // Too many embedded oops
194 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
195 return false;
196 }
197
198 return true;
199 }
200
201 void ValueKlass::remove_unshareable_info() {
202 InstanceKlass::remove_unshareable_info();
203
204 *((Array<SigEntry>**)adr_extended_sig()) = NULL;
205 *((Array<VMRegPair>**)adr_return_regs()) = NULL;
206 *((address*)adr_pack_handler()) = NULL;
207 *((address*)adr_pack_handler_jobject()) = NULL;
208 *((address*)adr_unpack_handler()) = NULL;
209 assert(pack_handler() == NULL, "pack handler not null");
210 *((Klass**)adr_value_array_klass()) = NULL;
211 }
212
213 void ValueKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
214 InstanceKlass::restore_unshareable_info(loader_data, protection_domain, CHECK);
215 oop val = allocate_instance(CHECK);
216 set_default_value(val);
217 }
218
219
220 Klass* ValueKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS) {
221 if (storage_props.is_null_free()) {
222 return value_array_klass(storage_props, or_null, n, THREAD);
223 } else {
224 return InstanceKlass::array_klass_impl(storage_props, or_null, n, THREAD);
225 }
226 }
227
228 Klass* ValueKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS) {
229 return array_klass_impl(storage_props, or_null, 1, THREAD);
230 }
231
232 Klass* ValueKlass::value_array_klass(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS) {
233 Klass* vak = acquire_value_array_klass();
234 if (vak == NULL) {
235 if (or_null) return NULL;
236 ResourceMark rm;
237 {
238 // Atomic creation of array_klasses
239 MutexLocker ma(THREAD, MultiArray_lock);
240 if (get_value_array_klass() == NULL) {
241 vak = allocate_value_array_klass(CHECK_NULL);
242 Atomic::release_store((Klass**)adr_value_array_klass(), vak);
243 }
244 }
245 }
246 if (!vak->is_valueArray_klass()) {
247 storage_props.clear_flattened();
248 }
249 if (or_null) {
250 return vak->array_klass_or_null(storage_props, rank);
251 }
252 return vak->array_klass(storage_props, rank, THREAD);
253 }
254
255 Klass* ValueKlass::allocate_value_array_klass(TRAPS) {
256 if (flatten_array() && (is_atomic() || (!ValueArrayAtomicAccess))) {
257 return ValueArrayKlass::allocate_klass(ArrayStorageProperties::flattened_and_null_free, this, THREAD);
258 }
259 return ObjArrayKlass::allocate_objArray_klass(ArrayStorageProperties::null_free, 1, this, THREAD);
260 }
261
262 void ValueKlass::array_klasses_do(void f(Klass* k)) {
263 InstanceKlass::array_klasses_do(f);
264 if (get_value_array_klass() != NULL)
265 ArrayKlass::cast(get_value_array_klass())->array_klasses_do(f);
266 }
267
268 // Value type arguments are not passed by reference, instead each
269 // field of the value type is passed as an argument. This helper
270 // function collects the fields of the value types (including embedded
271 // value type's fields) in a list. Included with the field's type is
272 // the offset of each field in the value type: i2c and c2i adapters
273 // need that to load or store fields. Finally, the list of fields is
274 // sorted in order of increasing offsets: the adapters and the
275 // compiled code need to agree upon the order of fields.
276 //
277 // The list of basic types that is returned starts with a T_VALUETYPE
278 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID pairs are used as
279 // delimiters. Every entry between the two is a field of the value
280 // type. If there's an embedded value type in the list, it also starts
281 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
282 // generate a unique fingerprint for the method's adapters and we can
283 // generate the list of basic types from the interpreter point of view
284 // (value types passed as reference: iterate on the list until a
285 // T_VALUETYPE, drop everything until and including the closing
286 // T_VOID) or the compiler point of view (each field of the value
287 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
288 int ValueKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) {
289 int count = 0;
290 SigEntry::add_entry(sig, T_VALUETYPE, base_off);
291 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
292 if (fs.access_flags().is_static()) continue;
293 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0);
294 if (fs.is_flattened()) {
295 // Resolve klass of flattened value type field and recursively collect fields
296 Klass* vk = get_value_field_klass(fs.index());
297 count += ValueKlass::cast(vk)->collect_fields(sig, offset);
298 } else {
299 BasicType bt = Signature::basic_type(fs.signature());
300 if (bt == T_VALUETYPE) {
301 bt = T_OBJECT;
302 }
303 SigEntry::add_entry(sig, bt, offset);
304 count += type2size[bt];
305 }
306 }
307 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
308 SigEntry::add_entry(sig, T_VOID, offset);
309 if (base_off == 0) {
310 sig->sort(SigEntry::compare);
311 }
312 assert(sig->at(0)._bt == T_VALUETYPE && sig->at(sig->length()-1)._bt == T_VOID, "broken structure");
313 return count;
314 }
315
316 void ValueKlass::initialize_calling_convention(TRAPS) {
317 // Because the pack and unpack handler addresses need to be loadable from generated code,
318 // they are stored at a fixed offset in the klass metadata. Since value type klasses do
319 // not have a vtable, the vtable offset is used to store these addresses.
320 if (is_scalarizable() && (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs)) {
321 ResourceMark rm;
322 GrowableArray<SigEntry> sig_vk;
323 int nb_fields = collect_fields(&sig_vk);
324 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK);
325 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
326 for (int i = 0; i < sig_vk.length(); i++) {
327 extended_sig->at_put(i, sig_vk.at(i));
328 }
329
330 if (ValueTypeReturnedAsFields) {
331 nb_fields++;
332 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
333 sig_bt[0] = T_METADATA;
334 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1);
335 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
336 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
337
338 if (total > 0) {
339 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK);
340 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
341 for (int i = 0; i < nb_fields; i++) {
342 return_regs->at_put(i, regs[i]);
343 }
344
345 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this);
346 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
347 *((address*)adr_pack_handler_jobject()) = buffered_blob->pack_fields_jobject();
348 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
349 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
350 }
351 }
352 }
353 }
354
355 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) {
356 if (extended_sig() != NULL) {
357 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
358 }
359 if (return_regs() != NULL) {
360 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
361 }
362 cleanup_blobs();
363 InstanceKlass::deallocate_contents(loader_data);
364 }
365
366 void ValueKlass::cleanup(ValueKlass* ik) {
367 ik->cleanup_blobs();
368 }
369
370 void ValueKlass::cleanup_blobs() {
371 if (pack_handler() != NULL) {
372 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
373 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type");
374 BufferBlob::free((BufferBlob*)buffered_blob);
375 *((address*)adr_pack_handler()) = NULL;
376 *((address*)adr_pack_handler_jobject()) = NULL;
377 *((address*)adr_unpack_handler()) = NULL;
378 }
379 }
380
381 // Can this value type be scalarized?
382 bool ValueKlass::is_scalarizable() const {
383 return ScalarizeValueTypes;
384 }
385
386 // Can this value type be returned as multiple values?
387 bool ValueKlass::can_be_returned_as_fields() const {
388 return return_regs() != NULL;
389 }
390
391 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
392 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
393 Thread* thread = Thread::current();
394 const Array<SigEntry>* sig_vk = extended_sig();
395 const Array<VMRegPair>* regs = return_regs();
396 int j = 1;
397
398 for (int i = 0; i < sig_vk->length(); i++) {
399 BasicType bt = sig_vk->at(i)._bt;
400 if (bt == T_OBJECT || bt == T_ARRAY) {
401 VMRegPair pair = regs->at(j);
402 address loc = reg_map.location(pair.first());
403 oop v = *(oop*)loc;
404 assert(v == NULL || oopDesc::is_oop(v), "not an oop?");
405 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
406 handles.push(Handle(thread, v));
407 }
408 if (bt == T_VALUETYPE) {
409 continue;
410 }
411 if (bt == T_VOID &&
412 sig_vk->at(i-1)._bt != T_LONG &&
413 sig_vk->at(i-1)._bt != T_DOUBLE) {
414 continue;
415 }
416 j++;
417 }
418 assert(j == regs->length(), "missed a field?");
419 }
420
421 // Update oop fields in registers from handles after a safepoint
422 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
423 assert(ValueTypeReturnedAsFields, "inconsistent");
424 const Array<SigEntry>* sig_vk = extended_sig();
425 const Array<VMRegPair>* regs = return_regs();
426 assert(regs != NULL, "inconsistent");
427
428 int j = 1;
429 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
430 BasicType bt = sig_vk->at(i)._bt;
431 if (bt == T_OBJECT || bt == T_ARRAY) {
432 VMRegPair pair = regs->at(j);
433 address loc = reg_map.location(pair.first());
434 *(oop*)loc = handles.at(k++)();
435 }
436 if (bt == T_VALUETYPE) {
437 continue;
438 }
439 if (bt == T_VOID &&
440 sig_vk->at(i-1)._bt != T_LONG &&
441 sig_vk->at(i-1)._bt != T_DOUBLE) {
442 continue;
443 }
444 j++;
445 }
446 assert(j == regs->length(), "missed a field?");
447 }
448
449 // Fields are in registers. Create an instance of the value type and
450 // initialize it with the values of the fields.
451 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) {
452 oop new_vt = allocate_instance(CHECK_NULL);
453 const Array<SigEntry>* sig_vk = extended_sig();
454 const Array<VMRegPair>* regs = return_regs();
455
456 int j = 1;
457 int k = 0;
458 for (int i = 0; i < sig_vk->length(); i++) {
459 BasicType bt = sig_vk->at(i)._bt;
460 if (bt == T_VALUETYPE) {
461 continue;
462 }
463 if (bt == T_VOID) {
464 if (sig_vk->at(i-1)._bt == T_LONG ||
465 sig_vk->at(i-1)._bt == T_DOUBLE) {
466 j++;
467 }
468 continue;
469 }
470 int off = sig_vk->at(i)._offset;
471 assert(off > 0, "offset in object should be positive");
472 VMRegPair pair = regs->at(j);
473 address loc = reg_map.location(pair.first());
474 switch(bt) {
475 case T_BOOLEAN: {
476 new_vt->bool_field_put(off, *(jboolean*)loc);
477 break;
478 }
479 case T_CHAR: {
480 new_vt->char_field_put(off, *(jchar*)loc);
481 break;
482 }
483 case T_BYTE: {
484 new_vt->byte_field_put(off, *(jbyte*)loc);
485 break;
486 }
487 case T_SHORT: {
488 new_vt->short_field_put(off, *(jshort*)loc);
489 break;
490 }
491 case T_INT: {
492 new_vt->int_field_put(off, *(jint*)loc);
493 break;
494 }
495 case T_LONG: {
496 #ifdef _LP64
497 new_vt->double_field_put(off, *(jdouble*)loc);
498 #else
499 Unimplemented();
500 #endif
501 break;
502 }
503 case T_OBJECT:
504 case T_ARRAY: {
505 Handle handle = handles.at(k++);
506 new_vt->obj_field_put(off, handle());
507 break;
508 }
509 case T_FLOAT: {
510 new_vt->float_field_put(off, *(jfloat*)loc);
511 break;
512 }
513 case T_DOUBLE: {
514 new_vt->double_field_put(off, *(jdouble*)loc);
515 break;
516 }
517 default:
518 ShouldNotReachHere();
519 }
520 *(intptr_t*)loc = 0xDEAD;
521 j++;
522 }
523 assert(j == regs->length(), "missed a field?");
524 assert(k == handles.length(), "missed an oop?");
525 return new_vt;
526 }
527
528 // Check the return register for a ValueKlass oop
529 ValueKlass* ValueKlass::returned_value_klass(const RegisterMap& map) {
530 BasicType bt = T_METADATA;
531 VMRegPair pair;
532 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
533 assert(nb == 1, "broken");
534
535 address loc = map.location(pair.first());
536 intptr_t ptr = *(intptr_t*)loc;
537 if (is_set_nth_bit(ptr, 0)) {
538 // Oop is tagged, must be a ValueKlass oop
539 clear_nth_bit(ptr, 0);
540 assert(Metaspace::contains((void*)ptr), "should be klass");
541 ValueKlass* vk = (ValueKlass*)ptr;
542 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
543 return vk;
544 }
545 #ifdef ASSERT
546 // Oop is not tagged, must be a valid oop
547 if (VerifyOops) {
548 oopDesc::verify(oop((HeapWord*)ptr));
549 }
550 #endif
551 return NULL;
552 }
553
554 void ValueKlass::verify_on(outputStream* st) {
555 InstanceKlass::verify_on(st);
556 guarantee(prototype_header().is_always_locked(), "Prototype header is not always locked");
557 }
558
559 void ValueKlass::oop_verify_on(oop obj, outputStream* st) {
560 InstanceKlass::oop_verify_on(obj, st);
561 guarantee(obj->mark().is_always_locked(), "Header is not always locked");
562 }
563
564 void ValueKlass::metaspace_pointers_do(MetaspaceClosure* it) {
565 InstanceKlass::metaspace_pointers_do(it);
566
567 ValueKlass* this_ptr = this;
568 it->push_internal_pointer(&this_ptr, (intptr_t*)&_adr_valueklass_fixed_block);
569 }