1 /*
2 * Copyright (c) 2017, 2024, 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 "cds/cdsConfig.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "code/codeCache.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "gc/shared/gcLocker.inline.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "logging/log.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/metadataFactory.hpp"
36 #include "oops/access.hpp"
37 #include "oops/compressedOops.inline.hpp"
38 #include "oops/fieldStreams.inline.hpp"
39 #include "oops/flatArrayKlass.hpp"
40 #include "oops/inlineKlass.inline.hpp"
41 #include "oops/instanceKlass.inline.hpp"
42 #include "oops/method.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "oops/objArrayKlass.hpp"
45 #include "runtime/fieldDescriptor.inline.hpp"
46 #include "runtime/handles.inline.hpp"
47 #include "runtime/safepointVerifiers.hpp"
48 #include "runtime/sharedRuntime.hpp"
49 #include "runtime/signature.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "utilities/copy.hpp"
52
53 // Constructor
54 InlineKlass::InlineKlass(const ClassFileParser& parser)
55 : InstanceKlass(parser, InlineKlass::Kind) {
56 set_prototype_header(markWord::inline_type_prototype());
57 assert(is_inline_klass(), "sanity");
58 assert(prototype_header().is_inline_type(), "sanity");
59 }
60
61 InlineKlass::InlineKlass() {
62 assert(CDSConfig::is_dumping_archive() || UseSharedSpaces, "only for CDS");
63 }
64
65 void InlineKlass::init_fixed_block() {
66 _adr_inlineklass_fixed_block = inlineklass_static_block();
67 // Addresses used for inline type calling convention
68 *((Array<SigEntry>**)adr_extended_sig()) = nullptr;
69 *((Array<VMRegPair>**)adr_return_regs()) = nullptr;
70 *((address*)adr_pack_handler()) = nullptr;
71 *((address*)adr_pack_handler_jobject()) = nullptr;
72 *((address*)adr_unpack_handler()) = nullptr;
73 assert(pack_handler() == nullptr, "pack handler not null");
74 *((int*)adr_default_value_offset()) = 0;
75 *((address*)adr_value_array_klasses()) = nullptr;
76 }
77
78 oop InlineKlass::default_value() {
79 assert(is_initialized() || is_being_initialized() || is_in_error_state(), "default value is set at the beginning of initialization");
80 oop val = java_mirror()->obj_field_acquire(default_value_offset());
81 assert(val != nullptr, "Sanity check");
82 assert(oopDesc::is_oop(val), "Sanity check");
83 assert(val->is_inline_type(), "Sanity check");
84 assert(val->klass() == this, "sanity check");
85 return val;
86 }
87
88 int InlineKlass::first_field_offset_old() {
89 #ifdef ASSERT
90 int first_offset = INT_MAX;
91 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
92 if (fs.offset() < first_offset) first_offset= fs.offset();
93 }
94 #endif
95 int base_offset = instanceOopDesc::base_offset_in_bytes();
96 // The first field of line types is aligned on a long boundary
97 base_offset = align_up(base_offset, BytesPerLong);
98 assert(base_offset == first_offset, "inconsistent offsets");
99 return base_offset;
100 }
101
102 instanceOop InlineKlass::allocate_instance(TRAPS) {
103 int size = size_helper(); // Query before forming handle.
104
105 instanceOop oop = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
106 assert(oop->mark().is_inline_type(), "Expected inline type");
107 return oop;
108 }
109
110 instanceOop InlineKlass::allocate_instance_buffer(TRAPS) {
111 int size = size_helper(); // Query before forming handle.
112
113 instanceOop oop = (instanceOop)Universe::heap()->obj_buffer_allocate(this, size, CHECK_NULL);
114 assert(oop->mark().is_inline_type(), "Expected inline type");
115 return oop;
116 }
117
118 int InlineKlass::nonstatic_oop_count() {
119 int oops = 0;
120 int map_count = nonstatic_oop_map_count();
121 OopMapBlock* block = start_of_nonstatic_oop_maps();
122 OopMapBlock* end = block + map_count;
123 while (block != end) {
124 oops += block->count();
125 block++;
126 }
127 return oops;
128 }
129
130 oop InlineKlass::read_flat_field(oop obj, int offset, TRAPS) {
131 oop res = nullptr;
132 assert(is_initialized() || is_being_initialized()|| is_in_error_state(),
133 "Must be initialized, initializing or in a corner case of an escaped instance of a class that failed its initialization");
134 if (is_empty_inline_type()) {
135 res = (instanceOop)default_value();
136 } else {
137 Handle obj_h(THREAD, obj);
138 res = allocate_instance_buffer(CHECK_NULL);
139 inline_copy_payload_to_new_oop(((char*)(oopDesc*)obj_h()) + offset, res);
140 }
141 assert(res != nullptr, "Must be set in one of two paths above");
142 return res;
143 }
144
145 void InlineKlass::write_flat_field(oop obj, int offset, oop value, TRAPS) {
146 if (value == nullptr) {
147 THROW(vmSymbols::java_lang_NullPointerException());
148 }
149 write_non_null_flat_field(obj, offset, value);
150 }
151
152 void InlineKlass::write_non_null_flat_field(oop obj, int offset, oop value) {
153 assert(value != nullptr, "");
154 if (!is_empty_inline_type()) {
155 inline_copy_oop_to_payload(value, ((char*)(oopDesc*)obj) + offset);
156 }
157 }
158
159 // Arrays of...
160
161 bool InlineKlass::flat_array() {
162 if (!UseFlatArray) {
163 return false;
164 }
165 // Too big
166 int elem_bytes = get_payload_size_in_bytes();
167 if ((FlatArrayElementMaxSize >= 0) && (elem_bytes > FlatArrayElementMaxSize)) {
168 return false;
169 }
170 // Too many embedded oops
171 if ((FlatArrayElementMaxOops >= 0) && (nonstatic_oop_count() > FlatArrayElementMaxOops)) {
172 return false;
173 }
174 // Declared atomic but not naturally atomic.
175 if (must_be_atomic() && !is_naturally_atomic()) {
176 return false;
177 }
178 // VM enforcing InlineArrayAtomicAccess only...
179 if (InlineArrayAtomicAccess && (!is_naturally_atomic())) {
180 return false;
181 }
182 return true;
183 }
184
185 Klass* InlineKlass::value_array_klass(int n, TRAPS) {
186 if (Atomic::load_acquire(adr_value_array_klasses()) == nullptr) {
187 ResourceMark rm(THREAD);
188 JavaThread *jt = JavaThread::cast(THREAD);
189 {
190 // Atomic creation of array_klasses
191 MutexLocker ma(THREAD, MultiArray_lock);
192
193 // Check if update has already taken place
194 if (value_array_klasses() == nullptr) {
195 ArrayKlass* k;
196 if (flat_array()) {
197 k = FlatArrayKlass::allocate_klass(this, CHECK_NULL);
198 } else {
199 k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, true, CHECK_NULL);
200
201 }
202 // use 'release' to pair with lock-free load
203 Atomic::release_store(adr_value_array_klasses(), k);
204 }
205 }
206 }
207 ArrayKlass* ak = value_array_klasses();
208 return ak->array_klass(n, THREAD);
209 }
210
211 Klass* InlineKlass::value_array_klass_or_null(int n) {
212 // Need load-acquire for lock-free read
213 ArrayKlass* ak = Atomic::load_acquire(adr_value_array_klasses());
214 if (ak == nullptr) {
215 return nullptr;
216 } else {
217 return ak->array_klass_or_null(n);
218 }
219 }
220
221 Klass* InlineKlass::value_array_klass(TRAPS) {
222 return value_array_klass(1, THREAD);
223 }
224
225 Klass* InlineKlass::value_array_klass_or_null() {
226 return value_array_klass_or_null(1);
227 }
228
229 // Inline type arguments are not passed by reference, instead each
230 // field of the inline type is passed as an argument. This helper
231 // function collects the flat field (recursively)
232 // in a list. Included with the field's type is
233 // the offset of each field in the inline type: i2c and c2i adapters
234 // need that to load or store fields. Finally, the list of fields is
235 // sorted in order of increasing offsets: the adapters and the
236 // compiled code need to agree upon the order of fields.
237 //
238 // The list of basic types that is returned starts with a T_METADATA
239 // and ends with an extra T_VOID. T_METADATA/T_VOID pairs are used as
240 // delimiters. Every entry between the two is a field of the inline
241 // type. If there's an embedded inline type in the list, it also starts
242 // with a T_METADATA and ends with a T_VOID. This is so we can
243 // generate a unique fingerprint for the method's adapters and we can
244 // generate the list of basic types from the interpreter point of view
245 // (inline types passed as reference: iterate on the list until a
246 // T_METADATA, drop everything until and including the closing
247 // T_VOID) or the compiler point of view (each field of the inline
248 // types is an argument: drop all T_METADATA/T_VOID from the list).
249 int InlineKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) {
250 int count = 0;
251 SigEntry::add_entry(sig, T_METADATA, name(), base_off);
252 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
253 if (fs.access_flags().is_static()) continue;
254 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0);
255 // TODO 8284443 Use different heuristic to decide what should be scalarized in the calling convention
256 if (fs.is_flat()) {
257 // Resolve klass of flat field and recursively collect fields
258 Klass* vk = get_inline_type_field_klass(fs.index());
259 count += InlineKlass::cast(vk)->collect_fields(sig, offset);
260 } else {
261 BasicType bt = Signature::basic_type(fs.signature());
262 SigEntry::add_entry(sig, bt, fs.signature(), offset);
263 count += type2size[bt];
264 }
265 }
266 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
267 SigEntry::add_entry(sig, T_VOID, name(), offset);
268 if (base_off == 0) {
269 sig->sort(SigEntry::compare);
270 }
271 assert(sig->at(0)._bt == T_METADATA && sig->at(sig->length()-1)._bt == T_VOID, "broken structure");
272 return count;
273 }
274
275 void InlineKlass::initialize_calling_convention(TRAPS) {
276 // Because the pack and unpack handler addresses need to be loadable from generated code,
277 // they are stored at a fixed offset in the klass metadata. Since inline type klasses do
278 // not have a vtable, the vtable offset is used to store these addresses.
279 if (InlineTypeReturnedAsFields || InlineTypePassFieldsAsArgs) {
280 ResourceMark rm;
281 GrowableArray<SigEntry> sig_vk;
282 int nb_fields = collect_fields(&sig_vk);
283 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK);
284 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
285 for (int i = 0; i < sig_vk.length(); i++) {
286 extended_sig->at_put(i, sig_vk.at(i));
287 }
288 if (can_be_returned_as_fields(/* init= */ true)) {
289 nb_fields++;
290 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
291 sig_bt[0] = T_METADATA;
292 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1);
293 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
294 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
295
296 if (total > 0) {
297 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK);
298 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
299 for (int i = 0; i < nb_fields; i++) {
300 return_regs->at_put(i, regs[i]);
301 }
302
303 BufferedInlineTypeBlob* buffered_blob = SharedRuntime::generate_buffered_inline_type_adapter(this);
304 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
305 *((address*)adr_pack_handler_jobject()) = buffered_blob->pack_fields_jobject();
306 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
307 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
308 assert(can_be_returned_as_fields(), "sanity");
309 }
310 }
311 if (!can_be_returned_as_fields() && !can_be_passed_as_fields()) {
312 MetadataFactory::free_array<SigEntry>(class_loader_data(), extended_sig);
313 assert(return_regs() == nullptr, "sanity");
314 }
315 }
316 }
317
318 void InlineKlass::deallocate_contents(ClassLoaderData* loader_data) {
319 if (extended_sig() != nullptr) {
320 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
321 *((Array<SigEntry>**)adr_extended_sig()) = nullptr;
322 }
323 if (return_regs() != nullptr) {
324 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
325 *((Array<VMRegPair>**)adr_return_regs()) = nullptr;
326 }
327 cleanup_blobs();
328 InstanceKlass::deallocate_contents(loader_data);
329 }
330
331 void InlineKlass::cleanup(InlineKlass* ik) {
332 ik->cleanup_blobs();
333 }
334
335 void InlineKlass::cleanup_blobs() {
336 if (pack_handler() != nullptr) {
337 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
338 assert(buffered_blob->is_buffered_inline_type_blob(), "bad blob type");
339 BufferBlob::free((BufferBlob*)buffered_blob);
340 *((address*)adr_pack_handler()) = nullptr;
341 *((address*)adr_pack_handler_jobject()) = nullptr;
342 *((address*)adr_unpack_handler()) = nullptr;
343 }
344 }
345
346 // Can this inline type be passed as multiple values?
347 bool InlineKlass::can_be_passed_as_fields() const {
348 return InlineTypePassFieldsAsArgs;
349 }
350
351 // Can this inline type be returned as multiple values?
352 bool InlineKlass::can_be_returned_as_fields(bool init) const {
353 return InlineTypeReturnedAsFields && (init || return_regs() != nullptr);
354 }
355
356 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
357 void InlineKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
358 Thread* thread = Thread::current();
359 const Array<SigEntry>* sig_vk = extended_sig();
360 const Array<VMRegPair>* regs = return_regs();
361 int j = 1;
362
363 for (int i = 0; i < sig_vk->length(); i++) {
364 BasicType bt = sig_vk->at(i)._bt;
365 if (bt == T_OBJECT || bt == T_ARRAY) {
366 VMRegPair pair = regs->at(j);
367 address loc = reg_map.location(pair.first(), nullptr);
368 oop v = *(oop*)loc;
369 assert(v == nullptr || oopDesc::is_oop(v), "not an oop?");
370 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
371 handles.push(Handle(thread, v));
372 }
373 if (bt == T_METADATA) {
374 continue;
375 }
376 if (bt == T_VOID &&
377 sig_vk->at(i-1)._bt != T_LONG &&
378 sig_vk->at(i-1)._bt != T_DOUBLE) {
379 continue;
380 }
381 j++;
382 }
383 assert(j == regs->length(), "missed a field?");
384 }
385
386 // Update oop fields in registers from handles after a safepoint
387 void InlineKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
388 assert(InlineTypeReturnedAsFields, "Inline types should never be returned as fields");
389 const Array<SigEntry>* sig_vk = extended_sig();
390 const Array<VMRegPair>* regs = return_regs();
391 assert(regs != nullptr, "inconsistent");
392
393 int j = 1;
394 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
395 BasicType bt = sig_vk->at(i)._bt;
396 if (bt == T_OBJECT || bt == T_ARRAY) {
397 VMRegPair pair = regs->at(j);
398 address loc = reg_map.location(pair.first(), nullptr);
399 *(oop*)loc = handles.at(k++)();
400 }
401 if (bt == T_METADATA) {
402 continue;
403 }
404 if (bt == T_VOID &&
405 sig_vk->at(i-1)._bt != T_LONG &&
406 sig_vk->at(i-1)._bt != T_DOUBLE) {
407 continue;
408 }
409 j++;
410 }
411 assert(j == regs->length(), "missed a field?");
412 }
413
414 // Fields are in registers. Create an instance of the inline type and
415 // initialize it with the values of the fields.
416 oop InlineKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) {
417 oop new_vt = allocate_instance(CHECK_NULL);
418 const Array<SigEntry>* sig_vk = extended_sig();
419 const Array<VMRegPair>* regs = return_regs();
420
421 int j = 1;
422 int k = 0;
423 for (int i = 0; i < sig_vk->length(); i++) {
424 BasicType bt = sig_vk->at(i)._bt;
425 if (bt == T_METADATA) {
426 continue;
427 }
428 if (bt == T_VOID) {
429 if (sig_vk->at(i-1)._bt == T_LONG ||
430 sig_vk->at(i-1)._bt == T_DOUBLE) {
431 j++;
432 }
433 continue;
434 }
435 int off = sig_vk->at(i)._offset;
436 assert(off > 0, "offset in object should be positive");
437 VMRegPair pair = regs->at(j);
438 address loc = reg_map.location(pair.first(), nullptr);
439 switch(bt) {
440 case T_BOOLEAN: {
441 new_vt->bool_field_put(off, *(jboolean*)loc);
442 break;
443 }
444 case T_CHAR: {
445 new_vt->char_field_put(off, *(jchar*)loc);
446 break;
447 }
448 case T_BYTE: {
449 new_vt->byte_field_put(off, *(jbyte*)loc);
450 break;
451 }
452 case T_SHORT: {
453 new_vt->short_field_put(off, *(jshort*)loc);
454 break;
455 }
456 case T_INT: {
457 new_vt->int_field_put(off, *(jint*)loc);
458 break;
459 }
460 case T_LONG: {
461 #ifdef _LP64
462 new_vt->double_field_put(off, *(jdouble*)loc);
463 #else
464 Unimplemented();
465 #endif
466 break;
467 }
468 case T_OBJECT:
469 case T_ARRAY: {
470 Handle handle = handles.at(k++);
471 new_vt->obj_field_put(off, handle());
472 break;
473 }
474 case T_FLOAT: {
475 new_vt->float_field_put(off, *(jfloat*)loc);
476 break;
477 }
478 case T_DOUBLE: {
479 new_vt->double_field_put(off, *(jdouble*)loc);
480 break;
481 }
482 default:
483 ShouldNotReachHere();
484 }
485 *(intptr_t*)loc = 0xDEAD;
486 j++;
487 }
488 assert(j == regs->length(), "missed a field?");
489 assert(k == handles.length(), "missed an oop?");
490 return new_vt;
491 }
492
493 // Check the return register for an InlineKlass oop
494 InlineKlass* InlineKlass::returned_inline_klass(const RegisterMap& map) {
495 BasicType bt = T_METADATA;
496 VMRegPair pair;
497 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
498 assert(nb == 1, "broken");
499
500 address loc = map.location(pair.first(), nullptr);
501 intptr_t ptr = *(intptr_t*)loc;
502 if (is_set_nth_bit(ptr, 0)) {
503 // Return value is tagged, must be an InlineKlass pointer
504 clear_nth_bit(ptr, 0);
505 assert(Metaspace::contains((void*)ptr), "should be klass");
506 InlineKlass* vk = (InlineKlass*)ptr;
507 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
508 return vk;
509 }
510 // Return value is not tagged, must be a valid oop
511 assert(oopDesc::is_oop_or_null(cast_to_oop(ptr), true),
512 "Bad oop return: " PTR_FORMAT, ptr);
513 return nullptr;
514 }
515
516 // CDS support
517
518 void InlineKlass::metaspace_pointers_do(MetaspaceClosure* it) {
519 InstanceKlass::metaspace_pointers_do(it);
520
521 InlineKlass* this_ptr = this;
522 it->push((Klass**)adr_value_array_klasses());
523 }
524
525 void InlineKlass::remove_unshareable_info() {
526 InstanceKlass::remove_unshareable_info();
527
528 *((Array<SigEntry>**)adr_extended_sig()) = nullptr;
529 *((Array<VMRegPair>**)adr_return_regs()) = nullptr;
530 *((address*)adr_pack_handler()) = nullptr;
531 *((address*)adr_pack_handler_jobject()) = nullptr;
532 *((address*)adr_unpack_handler()) = nullptr;
533 assert(pack_handler() == nullptr, "pack handler not null");
534 if (value_array_klasses() != nullptr) {
535 value_array_klasses()->remove_unshareable_info();
536 }
537 }
538
539 void InlineKlass::remove_java_mirror() {
540 InstanceKlass::remove_java_mirror();
541 if (value_array_klasses() != nullptr) {
542 value_array_klasses()->remove_java_mirror();
543 }
544 }
545
546 void InlineKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS) {
547 // We are no longer bookkeeping pointer to fixed block during serialization, hence reinitializing
548 // fixed block address since its size was already accounted by InstanceKlass::size() and it will
549 // anyways be part of shared archive.
550 _adr_inlineklass_fixed_block = inlineklass_static_block();
551 InstanceKlass::restore_unshareable_info(loader_data, protection_domain, pkg_entry, CHECK);
552 if (value_array_klasses() != nullptr) {
553 value_array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
554 }
555 }
556
557 // oop verify
558
559 void InlineKlass::verify_on(outputStream* st) {
560 InstanceKlass::verify_on(st);
561 guarantee(prototype_header().is_inline_type(), "Prototype header is not inline type");
562 }
563
564 void InlineKlass::oop_verify_on(oop obj, outputStream* st) {
565 InstanceKlass::oop_verify_on(obj, st);
566 guarantee(obj->mark().is_inline_type(), "Header is not inline type");
567 }