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/collectedHeap.inline.hpp"
28 #include "gc/shared/gcLocker.inline.hpp"
29 #include "interpreter/interpreter.hpp"
30 #include "logging/log.hpp"
31 #include "memory/metadataFactory.hpp"
32 #include "oops/access.hpp"
33 #include "oops/compressedOops.inline.hpp"
34 #include "oops/fieldStreams.hpp"
35 #include "oops/instanceKlass.inline.hpp"
36 #include "oops/method.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "oops/objArrayKlass.hpp"
39 #include "oops/valueKlass.inline.hpp"
40 #include "oops/valueArrayKlass.hpp"
41 #include "runtime/fieldDescriptor.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/safepointVerifiers.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/thread.inline.hpp"
47 #include "utilities/copy.hpp"
48
49 // Constructor
50 ValueKlass::ValueKlass(const ClassFileParser& parser)
51 : InstanceKlass(parser, InstanceKlass::_misc_kind_value_type, InstanceKlass::ID) {
52 _adr_valueklass_fixed_block = valueklass_static_block();
53 // Addresses used for value type calling convention
54 *((Array<SigEntry>**)adr_extended_sig()) = NULL;
55 *((Array<VMRegPair>**)adr_return_regs()) = NULL;
56 *((address*)adr_pack_handler()) = NULL;
57 *((address*)adr_pack_handler_jobject()) = NULL;
58 *((address*)adr_unpack_handler()) = NULL;
59 assert(pack_handler() == NULL, "pack handler not null");
60 *((int*)adr_default_value_offset()) = 0;
61 *((Klass**)adr_value_array_klass()) = NULL;
62 set_prototype_header(markWord::always_locked_prototype());
63 }
64
65 oop ValueKlass::default_value() {
66 oop val = java_mirror()->obj_field_acquire(default_value_offset());
67 assert(oopDesc::is_oop(val), "Sanity check");
68 assert(val->is_value(), "Sanity check");
69 assert(val->klass() == this, "sanity check");
70 return val;
71 }
72
73 int ValueKlass::first_field_offset_old() {
74 #ifdef ASSERT
75 int first_offset = INT_MAX;
76 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
77 if (fs.offset() < first_offset) first_offset= fs.offset();
78 }
79 #endif
80 int base_offset = instanceOopDesc::base_offset_in_bytes();
81 // The first field of value types is aligned on a long boundary
82 base_offset = align_up(base_offset, BytesPerLong);
83 assert(base_offset == first_offset, "inconsistent offsets");
84 return base_offset;
85 }
86
87 int ValueKlass::raw_value_byte_size() {
88 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop;
89 // If bigger than 64 bits or needs oop alignment, then use jlong aligned
90 // which for values should be jlong aligned, asserts in raw_field_copy otherwise
91 if (heapOopAlignedSize >= longSize || contains_oops()) {
92 return heapOopAlignedSize;
93 }
94 // Small primitives...
95 // If a few small basic type fields, return the actual size, i.e.
96 // 1 byte = 1
97 // 2 byte = 2
98 // 3 byte = 4, because pow2 needed for element stores
99 int first_offset = first_field_offset();
100 int last_offset = 0; // find the last offset, add basic type size
101 int last_tsz = 0;
102 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
103 if (fs.access_flags().is_static()) {
104 continue;
105 } else if (fs.offset() > last_offset) {
106 BasicType type = char2type(fs.signature()->char_at(0));
107 if (is_java_primitive(type)) {
108 last_tsz = type2aelembytes(type);
109 } else if (type == T_VALUETYPE) {
110 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
111 return heapOopAlignedSize;
112 } else {
113 guarantee(0, "Unknown type %d", type);
114 }
115 assert(last_tsz != 0, "Invariant");
116 last_offset = fs.offset();
117 }
118 }
119 // Assumes VT with no fields are meaningless and illegal
120 last_offset += last_tsz;
121 assert(last_offset > first_offset && last_tsz, "Invariant");
122 return 1 << upper_log2(last_offset - first_offset);
123 }
124
125 instanceOop ValueKlass::allocate_instance(TRAPS) {
126 int size = size_helper(); // Query before forming handle.
127
128 instanceOop oop = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
129 assert(oop->mark().is_always_locked(), "Unlocked value type");
130 return oop;
131 }
132
133 instanceOop ValueKlass::allocate_instance_buffer(TRAPS) {
134 int size = size_helper(); // Query before forming handle.
135
136 instanceOop oop = (instanceOop)Universe::heap()->obj_buffer_allocate(this, size, CHECK_NULL);
137 assert(oop->mark().is_always_locked(), "Unlocked value type");
138 return oop;
139 }
140
141 bool ValueKlass::is_atomic() {
142 return (nonstatic_field_size() * heapOopSize) <= longSize;
143 }
144
145 int ValueKlass::nonstatic_oop_count() {
146 int oops = 0;
147 int map_count = nonstatic_oop_map_count();
148 OopMapBlock* block = start_of_nonstatic_oop_maps();
149 OopMapBlock* end = block + map_count;
150 while (block != end) {
151 oops += block->count();
152 block++;
153 }
154 return oops;
155 }
156
157 oop ValueKlass::read_flattened_field(oop obj, int offset, TRAPS) {
158 oop res = NULL;
159 this->initialize(CHECK_NULL); // will throw an exception if in error state
160 if (is_empty_value()) {
161 res = (instanceOop)default_value();
162 } else {
163 Handle obj_h(THREAD, obj);
164 res = allocate_instance_buffer(CHECK_NULL);
165 value_copy_payload_to_new_oop(((char*)(oopDesc*)obj_h()) + offset, res);
166 }
167 assert(res != NULL, "Must be set in one of two paths above");
168 return res;
169 }
170
171 void ValueKlass::write_flattened_field(oop obj, int offset, oop value, TRAPS) {
172 if (value == NULL) {
173 THROW(vmSymbols::java_lang_NullPointerException());
174 }
175 if (!is_empty_value()) {
176 value_copy_oop_to_payload(value, ((char*)(oopDesc*)obj) + offset);
177 }
178 }
179
180 // Arrays of...
181
182 bool ValueKlass::flatten_array() {
183 if (!ValueArrayFlatten) {
184 return false;
185 }
186
187 int elem_bytes = raw_value_byte_size();
188 // Too big
189 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
190 return false;
191 }
192 // Too many embedded oops
193 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
194 return false;
195 }
196
197 return true;
198 }
199
200
201 Klass* ValueKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, int n, TRAPS) {
202 if (storage_props.is_null_free()) {
203 return value_array_klass(storage_props, or_null, n, THREAD);
204 } else {
205 return InstanceKlass::array_klass_impl(storage_props, or_null, n, THREAD);
206 }
207 }
208
209 Klass* ValueKlass::array_klass_impl(ArrayStorageProperties storage_props, bool or_null, TRAPS) {
210 return array_klass_impl(storage_props, or_null, 1, THREAD);
211 }
212
213 Klass* ValueKlass::value_array_klass(ArrayStorageProperties storage_props, bool or_null, int rank, TRAPS) {
214 Klass* vak = acquire_value_array_klass();
215 if (vak == NULL) {
216 if (or_null) return NULL;
217 ResourceMark rm;
218 {
219 // Atomic creation of array_klasses
220 MutexLocker ma(MultiArray_lock, THREAD);
221 if (get_value_array_klass() == NULL) {
222 vak = allocate_value_array_klass(CHECK_NULL);
223 OrderAccess::release_store((Klass**)adr_value_array_klass(), vak);
224 }
225 }
226 }
227 if (!vak->is_valueArray_klass()) {
228 storage_props.clear_flattened();
229 }
230 if (or_null) {
231 return vak->array_klass_or_null(storage_props, rank);
232 }
233 return vak->array_klass(storage_props, rank, THREAD);
234 }
235
236 Klass* ValueKlass::allocate_value_array_klass(TRAPS) {
237 if (flatten_array() && (is_atomic() || (!ValueArrayAtomicAccess))) {
238 return ValueArrayKlass::allocate_klass(ArrayStorageProperties::flattened_and_null_free, this, THREAD);
239 }
240 return ObjArrayKlass::allocate_objArray_klass(ArrayStorageProperties::null_free, 1, this, THREAD);
241 }
242
243 void ValueKlass::array_klasses_do(void f(Klass* k)) {
244 InstanceKlass::array_klasses_do(f);
245 if (get_value_array_klass() != NULL)
246 ArrayKlass::cast(get_value_array_klass())->array_klasses_do(f);
247 }
248
249 // Value type arguments are not passed by reference, instead each
250 // field of the value type is passed as an argument. This helper
251 // function collects the fields of the value types (including embedded
252 // value type's fields) in a list. Included with the field's type is
253 // the offset of each field in the value type: i2c and c2i adapters
254 // need that to load or store fields. Finally, the list of fields is
255 // sorted in order of increasing offsets: the adapters and the
256 // compiled code need to agree upon the order of fields.
257 //
258 // The list of basic types that is returned starts with a T_VALUETYPE
259 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID pairs are used as
260 // delimiters. Every entry between the two is a field of the value
261 // type. If there's an embedded value type in the list, it also starts
262 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
263 // generate a unique fingerprint for the method's adapters and we can
264 // generate the list of basic types from the interpreter point of view
265 // (value types passed as reference: iterate on the list until a
266 // T_VALUETYPE, drop everything until and including the closing
267 // T_VOID) or the compiler point of view (each field of the value
268 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
269 int ValueKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) {
270 int count = 0;
271 SigEntry::add_entry(sig, T_VALUETYPE, base_off);
272 for (AllFieldStream fs(this); !fs.done(); fs.next()) {
273 if (fs.access_flags().is_static()) continue;
274 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0);
275 if (fs.is_flattened()) {
276 // Resolve klass of flattened value type field and recursively collect fields
277 Klass* vk = get_value_field_klass(fs.index());
278 count += ValueKlass::cast(vk)->collect_fields(sig, offset);
279 } else {
280 BasicType bt = FieldType::basic_type(fs.signature());
281 if (bt == T_VALUETYPE) {
282 bt = T_OBJECT;
283 }
284 SigEntry::add_entry(sig, bt, offset);
285 count += type2size[bt];
286 }
287 }
288 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
289 SigEntry::add_entry(sig, T_VOID, offset);
290 if (base_off == 0) {
291 sig->sort(SigEntry::compare);
292 }
293 assert(sig->at(0)._bt == T_VALUETYPE && sig->at(sig->length()-1)._bt == T_VOID, "broken structure");
294 return count;
295 }
296
297 void ValueKlass::initialize_calling_convention(TRAPS) {
298 // Because the pack and unpack handler addresses need to be loadable from generated code,
299 // they are stored at a fixed offset in the klass metadata. Since value type klasses do
300 // not have a vtable, the vtable offset is used to store these addresses.
301 if (is_scalarizable() && (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs)) {
302 ResourceMark rm;
303 GrowableArray<SigEntry> sig_vk;
304 int nb_fields = collect_fields(&sig_vk);
305 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK);
306 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
307 for (int i = 0; i < sig_vk.length(); i++) {
308 extended_sig->at_put(i, sig_vk.at(i));
309 }
310
311 if (ValueTypeReturnedAsFields) {
312 nb_fields++;
313 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
314 sig_bt[0] = T_METADATA;
315 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1);
316 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
317 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
318
319 if (total > 0) {
320 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK);
321 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
322 for (int i = 0; i < nb_fields; i++) {
323 return_regs->at_put(i, regs[i]);
324 }
325
326 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this);
327 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
328 *((address*)adr_pack_handler_jobject()) = buffered_blob->pack_fields_jobject();
329 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
330 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
331 }
332 }
333 }
334 }
335
336 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) {
337 if (extended_sig() != NULL) {
338 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
339 }
340 if (return_regs() != NULL) {
341 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
342 }
343 cleanup_blobs();
344 InstanceKlass::deallocate_contents(loader_data);
345 }
346
347 void ValueKlass::cleanup(ValueKlass* ik) {
348 ik->cleanup_blobs();
349 }
350
351 void ValueKlass::cleanup_blobs() {
352 if (pack_handler() != NULL) {
353 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
354 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type");
355 BufferBlob::free((BufferBlob*)buffered_blob);
356 *((address*)adr_pack_handler()) = NULL;
357 *((address*)adr_pack_handler_jobject()) = NULL;
358 *((address*)adr_unpack_handler()) = NULL;
359 }
360 }
361
362 // Can this value type be scalarized?
363 bool ValueKlass::is_scalarizable() const {
364 return ScalarizeValueTypes;
365 }
366
367 // Can this value type be returned as multiple values?
368 bool ValueKlass::can_be_returned_as_fields() const {
369 return return_regs() != NULL;
370 }
371
372 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
373 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
374 Thread* thread = Thread::current();
375 const Array<SigEntry>* sig_vk = extended_sig();
376 const Array<VMRegPair>* regs = return_regs();
377 int j = 1;
378
379 for (int i = 0; i < sig_vk->length(); i++) {
380 BasicType bt = sig_vk->at(i)._bt;
381 if (bt == T_OBJECT || bt == T_ARRAY) {
382 VMRegPair pair = regs->at(j);
383 address loc = reg_map.location(pair.first());
384 oop v = *(oop*)loc;
385 assert(v == NULL || oopDesc::is_oop(v), "not an oop?");
386 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
387 handles.push(Handle(thread, v));
388 }
389 if (bt == T_VALUETYPE) {
390 continue;
391 }
392 if (bt == T_VOID &&
393 sig_vk->at(i-1)._bt != T_LONG &&
394 sig_vk->at(i-1)._bt != T_DOUBLE) {
395 continue;
396 }
397 j++;
398 }
399 assert(j == regs->length(), "missed a field?");
400 }
401
402 // Update oop fields in registers from handles after a safepoint
403 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
404 assert(ValueTypeReturnedAsFields, "inconsistent");
405 const Array<SigEntry>* sig_vk = extended_sig();
406 const Array<VMRegPair>* regs = return_regs();
407 assert(regs != NULL, "inconsistent");
408
409 int j = 1;
410 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
411 BasicType bt = sig_vk->at(i)._bt;
412 if (bt == T_OBJECT || bt == T_ARRAY) {
413 VMRegPair pair = regs->at(j);
414 address loc = reg_map.location(pair.first());
415 *(oop*)loc = handles.at(k++)();
416 }
417 if (bt == T_VALUETYPE) {
418 continue;
419 }
420 if (bt == T_VOID &&
421 sig_vk->at(i-1)._bt != T_LONG &&
422 sig_vk->at(i-1)._bt != T_DOUBLE) {
423 continue;
424 }
425 j++;
426 }
427 assert(j == regs->length(), "missed a field?");
428 }
429
430 // Fields are in registers. Create an instance of the value type and
431 // initialize it with the values of the fields.
432 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) {
433 oop new_vt = allocate_instance(CHECK_NULL);
434 const Array<SigEntry>* sig_vk = extended_sig();
435 const Array<VMRegPair>* regs = return_regs();
436
437 int j = 1;
438 int k = 0;
439 for (int i = 0; i < sig_vk->length(); i++) {
440 BasicType bt = sig_vk->at(i)._bt;
441 if (bt == T_VALUETYPE) {
442 continue;
443 }
444 if (bt == T_VOID) {
445 if (sig_vk->at(i-1)._bt == T_LONG ||
446 sig_vk->at(i-1)._bt == T_DOUBLE) {
447 j++;
448 }
449 continue;
450 }
451 int off = sig_vk->at(i)._offset;
452 assert(off > 0, "offset in object should be positive");
453 VMRegPair pair = regs->at(j);
454 address loc = reg_map.location(pair.first());
455 switch(bt) {
456 case T_BOOLEAN: {
457 new_vt->bool_field_put(off, *(jboolean*)loc);
458 break;
459 }
460 case T_CHAR: {
461 new_vt->char_field_put(off, *(jchar*)loc);
462 break;
463 }
464 case T_BYTE: {
465 new_vt->byte_field_put(off, *(jbyte*)loc);
466 break;
467 }
468 case T_SHORT: {
469 new_vt->short_field_put(off, *(jshort*)loc);
470 break;
471 }
472 case T_INT: {
473 new_vt->int_field_put(off, *(jint*)loc);
474 break;
475 }
476 case T_LONG: {
477 #ifdef _LP64
478 new_vt->double_field_put(off, *(jdouble*)loc);
479 #else
480 Unimplemented();
481 #endif
482 break;
483 }
484 case T_OBJECT:
485 case T_ARRAY: {
486 Handle handle = handles.at(k++);
487 new_vt->obj_field_put(off, handle());
488 break;
489 }
490 case T_FLOAT: {
491 new_vt->float_field_put(off, *(jfloat*)loc);
492 break;
493 }
494 case T_DOUBLE: {
495 new_vt->double_field_put(off, *(jdouble*)loc);
496 break;
497 }
498 default:
499 ShouldNotReachHere();
500 }
501 *(intptr_t*)loc = 0xDEAD;
502 j++;
503 }
504 assert(j == regs->length(), "missed a field?");
505 assert(k == handles.length(), "missed an oop?");
506 return new_vt;
507 }
508
509 // Check the return register for a ValueKlass oop
510 ValueKlass* ValueKlass::returned_value_klass(const RegisterMap& map) {
511 BasicType bt = T_METADATA;
512 VMRegPair pair;
513 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
514 assert(nb == 1, "broken");
515
516 address loc = map.location(pair.first());
517 intptr_t ptr = *(intptr_t*)loc;
518 if (is_set_nth_bit(ptr, 0)) {
519 // Oop is tagged, must be a ValueKlass oop
520 clear_nth_bit(ptr, 0);
521 assert(Metaspace::contains((void*)ptr), "should be klass");
522 ValueKlass* vk = (ValueKlass*)ptr;
523 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
524 return vk;
525 }
526 #ifdef ASSERT
527 // Oop is not tagged, must be a valid oop
528 if (VerifyOops) {
529 oopDesc::verify(oop((HeapWord*)ptr));
530 }
531 #endif
532 return NULL;
533 }
534
535 void ValueKlass::verify_on(outputStream* st) {
536 InstanceKlass::verify_on(st);
537 guarantee(prototype_header().is_always_locked(), "Prototype header is not always locked");
538 }
539
540 void ValueKlass::oop_verify_on(oop obj, outputStream* st) {
541 InstanceKlass::oop_verify_on(obj, st);
542 guarantee(obj->mark().is_always_locked(), "Header is not always locked");
543 }