1 /*
2 * Copyright (c) 2017, 2020, 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 "classfile/vmSymbols.hpp"
27 #include "code/codeCache.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/collectedHeap.inline.hpp"
30 #include "gc/shared/gcLocker.inline.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "logging/log.hpp"
33 #include "memory/metaspaceClosure.hpp"
34 #include "memory/metadataFactory.hpp"
35 #include "oops/access.hpp"
36 #include "oops/compressedOops.inline.hpp"
37 #include "oops/fieldStreams.inline.hpp"
38 #include "oops/flatArrayKlass.hpp"
39 #include "oops/inlineKlass.inline.hpp"
40 #include "oops/instanceKlass.inline.hpp"
41 #include "oops/method.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/objArrayKlass.hpp"
44 #include "runtime/fieldDescriptor.inline.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/safepointVerifiers.hpp"
47 #include "runtime/sharedRuntime.hpp"
48 #include "runtime/signature.hpp"
49 #include "runtime/thread.inline.hpp"
50 #include "utilities/copy.hpp"
51
52 // Constructor
53 InlineKlass::InlineKlass(const ClassFileParser& parser)
54 : InstanceKlass(parser, InlineKlass::Kind) {
55 set_prototype_header(markWord::inline_type_prototype());
56 assert(is_inline_klass(), "sanity");
57 assert(prototype_header().is_inline_type(), "sanity");
58 }
59
60 void InlineKlass::init_fixed_block() {
61 _adr_inlineklass_fixed_block = inlineklass_static_block();
62 // Addresses used for inline type calling convention
63 *((Array<SigEntry>**)adr_extended_sig()) = nullptr;
64 *((Array<VMRegPair>**)adr_return_regs()) = nullptr;
65 *((address*)adr_pack_handler()) = nullptr;
66 *((address*)adr_pack_handler_jobject()) = nullptr;
67 *((address*)adr_unpack_handler()) = nullptr;
68 assert(pack_handler() == nullptr, "pack handler not null");
69 *((int*)adr_default_value_offset()) = 0;
70 *((address*)adr_value_array_klasses()) = nullptr;
71 }
72
73 oop InlineKlass::default_value() {
74 assert(is_initialized() || is_being_initialized() || is_in_error_state(), "default value is set at the beginning of initialization");
75 oop val = java_mirror()->obj_field_acquire(default_value_offset());
76 assert(val != nullptr, "Sanity check");
77 assert(oopDesc::is_oop(val), "Sanity check");
78 assert(val->is_inline_type(), "Sanity check");
79 assert(val->klass() == this, "sanity check");
80 return val;
81 }
82
83 int InlineKlass::first_field_offset_old() {
84 #ifdef ASSERT
85 int first_offset = INT_MAX;
86 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
87 if (fs.offset() < first_offset) first_offset= fs.offset();
88 }
89 #endif
90 int base_offset = instanceOopDesc::base_offset_in_bytes();
91 // The first field of line types is aligned on a long boundary
92 base_offset = align_up(base_offset, BytesPerLong);
93 assert(base_offset == first_offset, "inconsistent offsets");
94 return base_offset;
95 }
96
97 instanceOop InlineKlass::allocate_instance(TRAPS) {
98 int size = size_helper(); // Query before forming handle.
99
100 instanceOop oop = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
101 assert(oop->mark().is_inline_type(), "Expected inline type");
102 return oop;
103 }
104
105 instanceOop InlineKlass::allocate_instance_buffer(TRAPS) {
106 int size = size_helper(); // Query before forming handle.
107
108 instanceOop oop = (instanceOop)Universe::heap()->obj_buffer_allocate(this, size, CHECK_NULL);
109 assert(oop->mark().is_inline_type(), "Expected inline type");
110 return oop;
111 }
112
113 int InlineKlass::nonstatic_oop_count() {
114 int oops = 0;
115 int map_count = nonstatic_oop_map_count();
116 OopMapBlock* block = start_of_nonstatic_oop_maps();
117 OopMapBlock* end = block + map_count;
118 while (block != end) {
119 oops += block->count();
120 block++;
121 }
122 return oops;
123 }
124
125 oop InlineKlass::read_flat_field(oop obj, int offset, TRAPS) {
126 oop res = nullptr;
127 assert(is_initialized() || is_being_initialized()|| is_in_error_state(),
128 "Must be initialized, initializing or in a corner case of an escaped instance of a class that failed its initialization");
129 if (is_empty_inline_type()) {
130 res = (instanceOop)default_value();
131 } else {
132 Handle obj_h(THREAD, obj);
133 res = allocate_instance_buffer(CHECK_NULL);
134 inline_copy_payload_to_new_oop(((char*)(oopDesc*)obj_h()) + offset, res);
135 }
136 assert(res != nullptr, "Must be set in one of two paths above");
137 return res;
138 }
139
140 void InlineKlass::write_flat_field(oop obj, int offset, oop value, TRAPS) {
141 if (value == nullptr) {
142 THROW(vmSymbols::java_lang_NullPointerException());
143 }
144 if (!is_empty_inline_type()) {
145 inline_copy_oop_to_payload(value, ((char*)(oopDesc*)obj) + offset);
146 }
147 }
148
149 // Arrays of...
150
151 bool InlineKlass::flat_array() {
152 if (!UseFlatArray) {
153 return false;
154 }
155 // Too big
156 int elem_bytes = get_exact_size_in_bytes();
157 if ((FlatArrayElementMaxSize >= 0) && (elem_bytes > FlatArrayElementMaxSize)) {
158 return false;
159 }
160 // Too many embedded oops
161 if ((FlatArrayElementMaxOops >= 0) && (nonstatic_oop_count() > FlatArrayElementMaxOops)) {
162 return false;
163 }
164 // Declared atomic but not naturally atomic.
165 if (is_declared_atomic() && !is_naturally_atomic()) {
166 return false;
167 }
168 // VM enforcing InlineArrayAtomicAccess only...
169 if (InlineArrayAtomicAccess && (!is_naturally_atomic())) {
170 return false;
171 }
172 return true;
173 }
174
175 Klass* InlineKlass::value_array_klass(int n, TRAPS) {
176 if (Atomic::load_acquire(adr_value_array_klasses()) == nullptr) {
177 ResourceMark rm(THREAD);
178 JavaThread *jt = JavaThread::cast(THREAD);
179 {
180 // Atomic creation of array_klasses
181 MutexLocker ma(THREAD, MultiArray_lock);
182
183 // Check if update has already taken place
184 if (value_array_klasses() == nullptr) {
185 ArrayKlass* k;
186 if (flat_array()) {
187 k = FlatArrayKlass::allocate_klass(this, CHECK_NULL);
188 } else {
189 k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, true, true, CHECK_NULL);
190
191 }
192 // use 'release' to pair with lock-free load
193 Atomic::release_store(adr_value_array_klasses(), k);
194 }
195 }
196 }
197 ArrayKlass* ak = value_array_klasses();
198 return ak->array_klass(n, THREAD);
199 }
200
201 Klass* InlineKlass::value_array_klass_or_null(int n) {
202 // Need load-acquire for lock-free read
203 ArrayKlass* ak = Atomic::load_acquire(adr_value_array_klasses());
204 if (ak == nullptr) {
205 return nullptr;
206 } else {
207 return ak->array_klass_or_null(n);
208 }
209 }
210
211 Klass* InlineKlass::value_array_klass(TRAPS) {
212 return value_array_klass(1, THREAD);
213 }
214
215 Klass* InlineKlass::value_array_klass_or_null() {
216 return value_array_klass_or_null(1);
217 }
218
219 // Inline type arguments are not passed by reference, instead each
220 // field of the inline type is passed as an argument. This helper
221 // function collects the flat field (recursively)
222 // in a list. Included with the field's type is
223 // the offset of each field in the inline type: i2c and c2i adapters
224 // need that to load or store fields. Finally, the list of fields is
225 // sorted in order of increasing offsets: the adapters and the
226 // compiled code need to agree upon the order of fields.
227 //
228 // The list of basic types that is returned starts with a T_METADATA
229 // and ends with an extra T_VOID. T_METADATA/T_VOID pairs are used as
230 // delimiters. Every entry between the two is a field of the inline
231 // type. If there's an embedded inline type in the list, it also starts
232 // with a T_METADATA and ends with a T_VOID. This is so we can
233 // generate a unique fingerprint for the method's adapters and we can
234 // generate the list of basic types from the interpreter point of view
235 // (inline types passed as reference: iterate on the list until a
236 // T_METADATA, drop everything until and including the closing
237 // T_VOID) or the compiler point of view (each field of the inline
238 // types is an argument: drop all T_METADATA/T_VOID from the list).
239 int InlineKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) {
240 int count = 0;
241 SigEntry::add_entry(sig, T_METADATA, name(), base_off);
242 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
243 if (fs.access_flags().is_static()) continue;
244 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0);
245 if (fs.is_flat()) {
246 // Resolve klass of flat field and recursively collect fields
247 Klass* vk = get_inline_type_field_klass(fs.index());
248 count += InlineKlass::cast(vk)->collect_fields(sig, offset);
249 } else {
250 BasicType bt = Signature::basic_type(fs.signature());
251 if (bt == T_PRIMITIVE_OBJECT) {
252 bt = T_OBJECT;
253 }
254 SigEntry::add_entry(sig, bt, fs.signature(), offset);
255 count += type2size[bt];
256 }
257 }
258 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
259 SigEntry::add_entry(sig, T_VOID, name(), offset);
260 if (base_off == 0) {
261 sig->sort(SigEntry::compare);
262 }
263 assert(sig->at(0)._bt == T_METADATA && sig->at(sig->length()-1)._bt == T_VOID, "broken structure");
264 return count;
265 }
266
267 void InlineKlass::initialize_calling_convention(TRAPS) {
268 // Because the pack and unpack handler addresses need to be loadable from generated code,
269 // they are stored at a fixed offset in the klass metadata. Since inline type klasses do
270 // not have a vtable, the vtable offset is used to store these addresses.
271 if (InlineTypeReturnedAsFields || InlineTypePassFieldsAsArgs) {
272 ResourceMark rm;
273 GrowableArray<SigEntry> sig_vk;
274 int nb_fields = collect_fields(&sig_vk);
275 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK);
276 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
277 for (int i = 0; i < sig_vk.length(); i++) {
278 extended_sig->at_put(i, sig_vk.at(i));
279 }
280 if (can_be_returned_as_fields(/* init= */ true)) {
281 nb_fields++;
282 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
283 sig_bt[0] = T_METADATA;
284 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1);
285 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
286 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
287
288 if (total > 0) {
289 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK);
290 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
291 for (int i = 0; i < nb_fields; i++) {
292 return_regs->at_put(i, regs[i]);
293 }
294
295 BufferedInlineTypeBlob* buffered_blob = SharedRuntime::generate_buffered_inline_type_adapter(this);
296 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
297 *((address*)adr_pack_handler_jobject()) = buffered_blob->pack_fields_jobject();
298 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
299 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
300 assert(can_be_returned_as_fields(), "sanity");
301 }
302 }
303 if (!can_be_returned_as_fields() && !can_be_passed_as_fields()) {
304 MetadataFactory::free_array<SigEntry>(class_loader_data(), extended_sig);
305 assert(return_regs() == nullptr, "sanity");
306 }
307 }
308 }
309
310 void InlineKlass::deallocate_contents(ClassLoaderData* loader_data) {
311 if (extended_sig() != nullptr) {
312 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
313 }
314 if (return_regs() != nullptr) {
315 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
316 }
317 cleanup_blobs();
318 InstanceKlass::deallocate_contents(loader_data);
319 }
320
321 void InlineKlass::cleanup(InlineKlass* ik) {
322 ik->cleanup_blobs();
323 }
324
325 void InlineKlass::cleanup_blobs() {
326 if (pack_handler() != nullptr) {
327 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
328 assert(buffered_blob->is_buffered_inline_type_blob(), "bad blob type");
329 BufferBlob::free((BufferBlob*)buffered_blob);
330 *((address*)adr_pack_handler()) = nullptr;
331 *((address*)adr_pack_handler_jobject()) = nullptr;
332 *((address*)adr_unpack_handler()) = nullptr;
333 }
334 }
335
336 // Can this inline type be passed as multiple values?
337 bool InlineKlass::can_be_passed_as_fields() const {
338 return InlineTypePassFieldsAsArgs;
339 }
340
341 // Can this inline type be returned as multiple values?
342 bool InlineKlass::can_be_returned_as_fields(bool init) const {
343 return InlineTypeReturnedAsFields && (init || return_regs() != nullptr);
344 }
345
346 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
347 void InlineKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
348 Thread* thread = Thread::current();
349 const Array<SigEntry>* sig_vk = extended_sig();
350 const Array<VMRegPair>* regs = return_regs();
351 int j = 1;
352
353 for (int i = 0; i < sig_vk->length(); i++) {
354 BasicType bt = sig_vk->at(i)._bt;
355 if (bt == T_OBJECT || bt == T_ARRAY) {
356 VMRegPair pair = regs->at(j);
357 address loc = reg_map.location(pair.first(), nullptr);
358 oop v = *(oop*)loc;
359 assert(v == nullptr || oopDesc::is_oop(v), "not an oop?");
360 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
361 handles.push(Handle(thread, v));
362 }
363 if (bt == T_METADATA) {
364 continue;
365 }
366 if (bt == T_VOID &&
367 sig_vk->at(i-1)._bt != T_LONG &&
368 sig_vk->at(i-1)._bt != T_DOUBLE) {
369 continue;
370 }
371 j++;
372 }
373 assert(j == regs->length(), "missed a field?");
374 }
375
376 // Update oop fields in registers from handles after a safepoint
377 void InlineKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
378 assert(InlineTypeReturnedAsFields, "Inline types should never be returned as fields");
379 const Array<SigEntry>* sig_vk = extended_sig();
380 const Array<VMRegPair>* regs = return_regs();
381 assert(regs != nullptr, "inconsistent");
382
383 int j = 1;
384 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
385 BasicType bt = sig_vk->at(i)._bt;
386 if (bt == T_OBJECT || bt == T_ARRAY) {
387 VMRegPair pair = regs->at(j);
388 address loc = reg_map.location(pair.first(), nullptr);
389 *(oop*)loc = handles.at(k++)();
390 }
391 if (bt == T_METADATA) {
392 continue;
393 }
394 if (bt == T_VOID &&
395 sig_vk->at(i-1)._bt != T_LONG &&
396 sig_vk->at(i-1)._bt != T_DOUBLE) {
397 continue;
398 }
399 j++;
400 }
401 assert(j == regs->length(), "missed a field?");
402 }
403
404 // Fields are in registers. Create an instance of the inline type and
405 // initialize it with the values of the fields.
406 oop InlineKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) {
407 oop new_vt = allocate_instance(CHECK_NULL);
408 const Array<SigEntry>* sig_vk = extended_sig();
409 const Array<VMRegPair>* regs = return_regs();
410
411 int j = 1;
412 int k = 0;
413 for (int i = 0; i < sig_vk->length(); i++) {
414 BasicType bt = sig_vk->at(i)._bt;
415 if (bt == T_METADATA) {
416 continue;
417 }
418 if (bt == T_VOID) {
419 if (sig_vk->at(i-1)._bt == T_LONG ||
420 sig_vk->at(i-1)._bt == T_DOUBLE) {
421 j++;
422 }
423 continue;
424 }
425 int off = sig_vk->at(i)._offset;
426 assert(off > 0, "offset in object should be positive");
427 VMRegPair pair = regs->at(j);
428 address loc = reg_map.location(pair.first(), nullptr);
429 switch(bt) {
430 case T_BOOLEAN: {
431 new_vt->bool_field_put(off, *(jboolean*)loc);
432 break;
433 }
434 case T_CHAR: {
435 new_vt->char_field_put(off, *(jchar*)loc);
436 break;
437 }
438 case T_BYTE: {
439 new_vt->byte_field_put(off, *(jbyte*)loc);
440 break;
441 }
442 case T_SHORT: {
443 new_vt->short_field_put(off, *(jshort*)loc);
444 break;
445 }
446 case T_INT: {
447 new_vt->int_field_put(off, *(jint*)loc);
448 break;
449 }
450 case T_LONG: {
451 #ifdef _LP64
452 new_vt->double_field_put(off, *(jdouble*)loc);
453 #else
454 Unimplemented();
455 #endif
456 break;
457 }
458 case T_OBJECT:
459 case T_ARRAY: {
460 Handle handle = handles.at(k++);
461 new_vt->obj_field_put(off, handle());
462 break;
463 }
464 case T_FLOAT: {
465 new_vt->float_field_put(off, *(jfloat*)loc);
466 break;
467 }
468 case T_DOUBLE: {
469 new_vt->double_field_put(off, *(jdouble*)loc);
470 break;
471 }
472 default:
473 ShouldNotReachHere();
474 }
475 *(intptr_t*)loc = 0xDEAD;
476 j++;
477 }
478 assert(j == regs->length(), "missed a field?");
479 assert(k == handles.length(), "missed an oop?");
480 return new_vt;
481 }
482
483 // Check the return register for an InlineKlass oop
484 InlineKlass* InlineKlass::returned_inline_klass(const RegisterMap& map) {
485 BasicType bt = T_METADATA;
486 VMRegPair pair;
487 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
488 assert(nb == 1, "broken");
489
490 address loc = map.location(pair.first(), nullptr);
491 intptr_t ptr = *(intptr_t*)loc;
492 if (is_set_nth_bit(ptr, 0)) {
493 // Return value is tagged, must be an InlineKlass pointer
494 clear_nth_bit(ptr, 0);
495 assert(Metaspace::contains((void*)ptr), "should be klass");
496 InlineKlass* vk = (InlineKlass*)ptr;
497 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
498 return vk;
499 }
500 // Return value is not tagged, must be a valid oop
501 assert(oopDesc::is_oop_or_null(cast_to_oop(ptr), true),
502 "Bad oop return: " PTR_FORMAT, ptr);
503 return nullptr;
504 }
505
506 // CDS support
507
508 void InlineKlass::metaspace_pointers_do(MetaspaceClosure* it) {
509 InstanceKlass::metaspace_pointers_do(it);
510
511 InlineKlass* this_ptr = this;
512 it->push((Klass**)adr_value_array_klasses());
513 }
514
515 void InlineKlass::remove_unshareable_info() {
516 InstanceKlass::remove_unshareable_info();
517
518 *((Array<SigEntry>**)adr_extended_sig()) = nullptr;
519 *((Array<VMRegPair>**)adr_return_regs()) = nullptr;
520 *((address*)adr_pack_handler()) = nullptr;
521 *((address*)adr_pack_handler_jobject()) = nullptr;
522 *((address*)adr_unpack_handler()) = nullptr;
523 assert(pack_handler() == nullptr, "pack handler not null");
524 if (value_array_klasses() != nullptr) {
525 value_array_klasses()->remove_unshareable_info();
526 }
527 }
528
529 void InlineKlass::remove_java_mirror() {
530 InstanceKlass::remove_java_mirror();
531 if (value_array_klasses() != nullptr) {
532 value_array_klasses()->remove_java_mirror();
533 }
534 }
535
536 void InlineKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS) {
537 // We are no longer bookkeeping pointer to fixed block during serialization, hence reinitializing
538 // fixed block address since its size was already accounted by InstanceKlass::size() and it will
539 // anyways be part of shared archive.
540 _adr_inlineklass_fixed_block = inlineklass_static_block();
541 InstanceKlass::restore_unshareable_info(loader_data, protection_domain, pkg_entry, CHECK);
542 if (value_array_klasses() != nullptr) {
543 value_array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
544 }
545 }
546
547 // oop verify
548
549 void InlineKlass::verify_on(outputStream* st) {
550 InstanceKlass::verify_on(st);
551 guarantee(prototype_header().is_inline_type(), "Prototype header is not inline type");
552 }
553
554 void InlineKlass::oop_verify_on(oop obj, outputStream* st) {
555 InstanceKlass::oop_verify_on(obj, st);
556 guarantee(obj->mark().is_inline_type(), "Header is not inline type");
557 }