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 if (!is_empty_inline_type()) {
150 inline_copy_oop_to_payload(value, ((char*)(oopDesc*)obj) + offset);
151 }
152 }
153
154 // Arrays of...
155
156 bool InlineKlass::flat_array() {
157 if (!UseFlatArray) {
158 return false;
159 }
160 // Too big
161 int elem_bytes = get_exact_size_in_bytes();
162 if ((FlatArrayElementMaxSize >= 0) && (elem_bytes > FlatArrayElementMaxSize)) {
163 return false;
164 }
165 // Too many embedded oops
166 if ((FlatArrayElementMaxOops >= 0) && (nonstatic_oop_count() > FlatArrayElementMaxOops)) {
167 return false;
168 }
169 // Declared atomic but not naturally atomic.
170 if (must_be_atomic() && !is_naturally_atomic()) {
171 return false;
172 }
173 // VM enforcing InlineArrayAtomicAccess only...
174 if (InlineArrayAtomicAccess && (!is_naturally_atomic())) {
175 return false;
176 }
177 return true;
178 }
179
180 Klass* InlineKlass::value_array_klass(int n, TRAPS) {
181 if (Atomic::load_acquire(adr_value_array_klasses()) == nullptr) {
182 ResourceMark rm(THREAD);
183 JavaThread *jt = JavaThread::cast(THREAD);
184 {
185 // Atomic creation of array_klasses
186 MutexLocker ma(THREAD, MultiArray_lock);
187
188 // Check if update has already taken place
189 if (value_array_klasses() == nullptr) {
190 ArrayKlass* k;
191 if (flat_array()) {
192 k = FlatArrayKlass::allocate_klass(this, CHECK_NULL);
193 } else {
194 k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, true, CHECK_NULL);
195
196 }
197 // use 'release' to pair with lock-free load
198 Atomic::release_store(adr_value_array_klasses(), k);
199 }
200 }
201 }
202 ArrayKlass* ak = value_array_klasses();
203 return ak->array_klass(n, THREAD);
204 }
205
206 Klass* InlineKlass::value_array_klass_or_null(int n) {
207 // Need load-acquire for lock-free read
208 ArrayKlass* ak = Atomic::load_acquire(adr_value_array_klasses());
209 if (ak == nullptr) {
210 return nullptr;
211 } else {
212 return ak->array_klass_or_null(n);
213 }
214 }
215
216 Klass* InlineKlass::value_array_klass(TRAPS) {
217 return value_array_klass(1, THREAD);
218 }
219
220 Klass* InlineKlass::value_array_klass_or_null() {
221 return value_array_klass_or_null(1);
222 }
223
224 // Inline type arguments are not passed by reference, instead each
225 // field of the inline type is passed as an argument. This helper
226 // function collects the flat field (recursively)
227 // in a list. Included with the field's type is
228 // the offset of each field in the inline type: i2c and c2i adapters
229 // need that to load or store fields. Finally, the list of fields is
230 // sorted in order of increasing offsets: the adapters and the
231 // compiled code need to agree upon the order of fields.
232 //
233 // The list of basic types that is returned starts with a T_METADATA
234 // and ends with an extra T_VOID. T_METADATA/T_VOID pairs are used as
235 // delimiters. Every entry between the two is a field of the inline
236 // type. If there's an embedded inline type in the list, it also starts
237 // with a T_METADATA and ends with a T_VOID. This is so we can
238 // generate a unique fingerprint for the method's adapters and we can
239 // generate the list of basic types from the interpreter point of view
240 // (inline types passed as reference: iterate on the list until a
241 // T_METADATA, drop everything until and including the closing
242 // T_VOID) or the compiler point of view (each field of the inline
243 // types is an argument: drop all T_METADATA/T_VOID from the list).
244 int InlineKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) {
245 int count = 0;
246 SigEntry::add_entry(sig, T_METADATA, name(), base_off);
247 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
248 if (fs.access_flags().is_static()) continue;
249 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0);
250 // TODO 8284443 Use different heuristic to decide what should be scalarized in the calling convention
251 if (fs.is_flat()) {
252 // Resolve klass of flat field and recursively collect fields
253 Klass* vk = get_inline_type_field_klass(fs.index());
254 count += InlineKlass::cast(vk)->collect_fields(sig, offset);
255 } else {
256 BasicType bt = Signature::basic_type(fs.signature());
257 SigEntry::add_entry(sig, bt, fs.signature(), offset);
258 count += type2size[bt];
259 }
260 }
261 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
262 SigEntry::add_entry(sig, T_VOID, name(), offset);
263 if (base_off == 0) {
264 sig->sort(SigEntry::compare);
265 }
266 assert(sig->at(0)._bt == T_METADATA && sig->at(sig->length()-1)._bt == T_VOID, "broken structure");
267 return count;
268 }
269
270 void InlineKlass::initialize_calling_convention(TRAPS) {
271 // Because the pack and unpack handler addresses need to be loadable from generated code,
272 // they are stored at a fixed offset in the klass metadata. Since inline type klasses do
273 // not have a vtable, the vtable offset is used to store these addresses.
274 if (InlineTypeReturnedAsFields || InlineTypePassFieldsAsArgs) {
275 ResourceMark rm;
276 GrowableArray<SigEntry> sig_vk;
277 int nb_fields = collect_fields(&sig_vk);
278 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK);
279 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
280 for (int i = 0; i < sig_vk.length(); i++) {
281 extended_sig->at_put(i, sig_vk.at(i));
282 }
283 if (can_be_returned_as_fields(/* init= */ true)) {
284 nb_fields++;
285 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
286 sig_bt[0] = T_METADATA;
287 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1);
288 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
289 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
290
291 if (total > 0) {
292 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK);
293 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
294 for (int i = 0; i < nb_fields; i++) {
295 return_regs->at_put(i, regs[i]);
296 }
297
298 BufferedInlineTypeBlob* buffered_blob = SharedRuntime::generate_buffered_inline_type_adapter(this);
299 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
300 *((address*)adr_pack_handler_jobject()) = buffered_blob->pack_fields_jobject();
301 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
302 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
303 assert(can_be_returned_as_fields(), "sanity");
304 }
305 }
306 if (!can_be_returned_as_fields() && !can_be_passed_as_fields()) {
307 MetadataFactory::free_array<SigEntry>(class_loader_data(), extended_sig);
308 assert(return_regs() == nullptr, "sanity");
309 }
310 }
311 }
312
313 void InlineKlass::deallocate_contents(ClassLoaderData* loader_data) {
314 if (extended_sig() != nullptr) {
315 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
316 }
317 if (return_regs() != nullptr) {
318 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
319 }
320 cleanup_blobs();
321 InstanceKlass::deallocate_contents(loader_data);
322 }
323
324 void InlineKlass::cleanup(InlineKlass* ik) {
325 ik->cleanup_blobs();
326 }
327
328 void InlineKlass::cleanup_blobs() {
329 if (pack_handler() != nullptr) {
330 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
331 assert(buffered_blob->is_buffered_inline_type_blob(), "bad blob type");
332 BufferBlob::free((BufferBlob*)buffered_blob);
333 *((address*)adr_pack_handler()) = nullptr;
334 *((address*)adr_pack_handler_jobject()) = nullptr;
335 *((address*)adr_unpack_handler()) = nullptr;
336 }
337 }
338
339 // Can this inline type be passed as multiple values?
340 bool InlineKlass::can_be_passed_as_fields() const {
341 return InlineTypePassFieldsAsArgs;
342 }
343
344 // Can this inline type be returned as multiple values?
345 bool InlineKlass::can_be_returned_as_fields(bool init) const {
346 return InlineTypeReturnedAsFields && (init || return_regs() != nullptr);
347 }
348
349 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
350 void InlineKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
351 Thread* thread = Thread::current();
352 const Array<SigEntry>* sig_vk = extended_sig();
353 const Array<VMRegPair>* regs = return_regs();
354 int j = 1;
355
356 for (int i = 0; i < sig_vk->length(); i++) {
357 BasicType bt = sig_vk->at(i)._bt;
358 if (bt == T_OBJECT || bt == T_ARRAY) {
359 VMRegPair pair = regs->at(j);
360 address loc = reg_map.location(pair.first(), nullptr);
361 oop v = *(oop*)loc;
362 assert(v == nullptr || oopDesc::is_oop(v), "not an oop?");
363 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
364 handles.push(Handle(thread, v));
365 }
366 if (bt == T_METADATA) {
367 continue;
368 }
369 if (bt == T_VOID &&
370 sig_vk->at(i-1)._bt != T_LONG &&
371 sig_vk->at(i-1)._bt != T_DOUBLE) {
372 continue;
373 }
374 j++;
375 }
376 assert(j == regs->length(), "missed a field?");
377 }
378
379 // Update oop fields in registers from handles after a safepoint
380 void InlineKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
381 assert(InlineTypeReturnedAsFields, "Inline types should never be returned as fields");
382 const Array<SigEntry>* sig_vk = extended_sig();
383 const Array<VMRegPair>* regs = return_regs();
384 assert(regs != nullptr, "inconsistent");
385
386 int j = 1;
387 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
388 BasicType bt = sig_vk->at(i)._bt;
389 if (bt == T_OBJECT || bt == T_ARRAY) {
390 VMRegPair pair = regs->at(j);
391 address loc = reg_map.location(pair.first(), nullptr);
392 *(oop*)loc = handles.at(k++)();
393 }
394 if (bt == T_METADATA) {
395 continue;
396 }
397 if (bt == T_VOID &&
398 sig_vk->at(i-1)._bt != T_LONG &&
399 sig_vk->at(i-1)._bt != T_DOUBLE) {
400 continue;
401 }
402 j++;
403 }
404 assert(j == regs->length(), "missed a field?");
405 }
406
407 // Fields are in registers. Create an instance of the inline type and
408 // initialize it with the values of the fields.
409 oop InlineKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) {
410 oop new_vt = allocate_instance(CHECK_NULL);
411 const Array<SigEntry>* sig_vk = extended_sig();
412 const Array<VMRegPair>* regs = return_regs();
413
414 int j = 1;
415 int k = 0;
416 for (int i = 0; i < sig_vk->length(); i++) {
417 BasicType bt = sig_vk->at(i)._bt;
418 if (bt == T_METADATA) {
419 continue;
420 }
421 if (bt == T_VOID) {
422 if (sig_vk->at(i-1)._bt == T_LONG ||
423 sig_vk->at(i-1)._bt == T_DOUBLE) {
424 j++;
425 }
426 continue;
427 }
428 int off = sig_vk->at(i)._offset;
429 assert(off > 0, "offset in object should be positive");
430 VMRegPair pair = regs->at(j);
431 address loc = reg_map.location(pair.first(), nullptr);
432 switch(bt) {
433 case T_BOOLEAN: {
434 new_vt->bool_field_put(off, *(jboolean*)loc);
435 break;
436 }
437 case T_CHAR: {
438 new_vt->char_field_put(off, *(jchar*)loc);
439 break;
440 }
441 case T_BYTE: {
442 new_vt->byte_field_put(off, *(jbyte*)loc);
443 break;
444 }
445 case T_SHORT: {
446 new_vt->short_field_put(off, *(jshort*)loc);
447 break;
448 }
449 case T_INT: {
450 new_vt->int_field_put(off, *(jint*)loc);
451 break;
452 }
453 case T_LONG: {
454 #ifdef _LP64
455 new_vt->double_field_put(off, *(jdouble*)loc);
456 #else
457 Unimplemented();
458 #endif
459 break;
460 }
461 case T_OBJECT:
462 case T_ARRAY: {
463 Handle handle = handles.at(k++);
464 new_vt->obj_field_put(off, handle());
465 break;
466 }
467 case T_FLOAT: {
468 new_vt->float_field_put(off, *(jfloat*)loc);
469 break;
470 }
471 case T_DOUBLE: {
472 new_vt->double_field_put(off, *(jdouble*)loc);
473 break;
474 }
475 default:
476 ShouldNotReachHere();
477 }
478 *(intptr_t*)loc = 0xDEAD;
479 j++;
480 }
481 assert(j == regs->length(), "missed a field?");
482 assert(k == handles.length(), "missed an oop?");
483 return new_vt;
484 }
485
486 // Check the return register for an InlineKlass oop
487 InlineKlass* InlineKlass::returned_inline_klass(const RegisterMap& map) {
488 BasicType bt = T_METADATA;
489 VMRegPair pair;
490 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
491 assert(nb == 1, "broken");
492
493 address loc = map.location(pair.first(), nullptr);
494 intptr_t ptr = *(intptr_t*)loc;
495 if (is_set_nth_bit(ptr, 0)) {
496 // Return value is tagged, must be an InlineKlass pointer
497 clear_nth_bit(ptr, 0);
498 assert(Metaspace::contains((void*)ptr), "should be klass");
499 InlineKlass* vk = (InlineKlass*)ptr;
500 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
501 return vk;
502 }
503 // Return value is not tagged, must be a valid oop
504 assert(oopDesc::is_oop_or_null(cast_to_oop(ptr), true),
505 "Bad oop return: " PTR_FORMAT, ptr);
506 return nullptr;
507 }
508
509 // CDS support
510
511 void InlineKlass::metaspace_pointers_do(MetaspaceClosure* it) {
512 InstanceKlass::metaspace_pointers_do(it);
513
514 InlineKlass* this_ptr = this;
515 it->push((Klass**)adr_value_array_klasses());
516 }
517
518 void InlineKlass::remove_unshareable_info() {
519 InstanceKlass::remove_unshareable_info();
520
521 *((Array<SigEntry>**)adr_extended_sig()) = nullptr;
522 *((Array<VMRegPair>**)adr_return_regs()) = nullptr;
523 *((address*)adr_pack_handler()) = nullptr;
524 *((address*)adr_pack_handler_jobject()) = nullptr;
525 *((address*)adr_unpack_handler()) = nullptr;
526 assert(pack_handler() == nullptr, "pack handler not null");
527 if (value_array_klasses() != nullptr) {
528 value_array_klasses()->remove_unshareable_info();
529 }
530 }
531
532 void InlineKlass::remove_java_mirror() {
533 InstanceKlass::remove_java_mirror();
534 if (value_array_klasses() != nullptr) {
535 value_array_klasses()->remove_java_mirror();
536 }
537 }
538
539 void InlineKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS) {
540 // We are no longer bookkeeping pointer to fixed block during serialization, hence reinitializing
541 // fixed block address since its size was already accounted by InstanceKlass::size() and it will
542 // anyways be part of shared archive.
543 _adr_inlineklass_fixed_block = inlineklass_static_block();
544 InstanceKlass::restore_unshareable_info(loader_data, protection_domain, pkg_entry, CHECK);
545 if (value_array_klasses() != nullptr) {
546 value_array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
547 }
548 }
549
550 // oop verify
551
552 void InlineKlass::verify_on(outputStream* st) {
553 InstanceKlass::verify_on(st);
554 guarantee(prototype_header().is_inline_type(), "Prototype header is not inline type");
555 }
556
557 void InlineKlass::oop_verify_on(oop obj, outputStream* st) {
558 InstanceKlass::oop_verify_on(obj, st);
559 guarantee(obj->mark().is_inline_type(), "Header is not inline type");
560 }