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.hpp"
36 #include "oops/method.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "oops/objArrayKlass.hpp"
39 #include "oops/valueKlass.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 int ValueKlass::first_field_offset() const {
50 #ifdef ASSERT
51 int first_offset = INT_MAX;
52 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
53 if (fs.offset() < first_offset) first_offset= fs.offset();
54 }
55 #endif
56 int base_offset = instanceOopDesc::base_offset_in_bytes();
57 // The first field of value types is aligned on a long boundary
58 base_offset = align_up(base_offset, BytesPerLong);
59 assert(base_offset == first_offset, "inconsistent offsets");
60 return base_offset;
61 }
62
63 int ValueKlass::raw_value_byte_size() const {
64 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop;
65 // If bigger than 64 bits or needs oop alignment, then use jlong aligned
66 // which for values should be jlong aligned, asserts in raw_field_copy otherwise
67 if (heapOopAlignedSize >= longSize || contains_oops()) {
68 return heapOopAlignedSize;
69 }
70 // Small primitives...
71 // If a few small basic type fields, return the actual size, i.e.
72 // 1 byte = 1
73 // 2 byte = 2
74 // 3 byte = 4, because pow2 needed for element stores
75 int first_offset = first_field_offset();
76 int last_offset = 0; // find the last offset, add basic type size
77 int last_tsz = 0;
78 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
79 if (fs.access_flags().is_static()) {
80 continue;
81 } else if (fs.offset() > last_offset) {
82 BasicType type = fs.field_descriptor().field_type();
83 if (is_java_primitive(type)) {
84 last_tsz = type2aelembytes(type);
85 } else if (type == T_VALUETYPE) {
86 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
87 return heapOopAlignedSize;
88 } else {
89 guarantee(0, "Unknown type %d", type);
90 }
91 assert(last_tsz != 0, "Invariant");
92 last_offset = fs.offset();
93 }
94 }
95 // Assumes VT with no fields are meaningless and illegal
96 last_offset += last_tsz;
97 assert(last_offset > first_offset && last_tsz, "Invariant");
98 return 1 << upper_log2(last_offset - first_offset);
99 }
100
101 instanceOop ValueKlass::allocate_instance(TRAPS) {
102 int size = size_helper(); // Query before forming handle.
103
104 instanceOop oop = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
105 assert(oop->mark()->is_always_locked(), "Unlocked value type");
106 return oop;
107 }
108
109 bool ValueKlass::is_atomic() {
110 return (nonstatic_field_size() * heapOopSize) <= longSize;
111 }
112
113 int ValueKlass::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 // Arrays of...
126
127 bool ValueKlass::flatten_array() {
128 if (!ValueArrayFlatten) {
129 return false;
130 }
131
132 int elem_bytes = raw_value_byte_size();
133 // Too big
134 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
135 return false;
136 }
137 // Too many embedded oops
138 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
139 return false;
140 }
141
142 return true;
143 }
144
145
146 Klass* ValueKlass::array_klass_impl(bool or_null, int n, TRAPS) {
147 if (!flatten_array()) {
148 return InstanceKlass::array_klass_impl(or_null, n, THREAD);
149 }
150
151 // Basically the same as instanceKlass, but using "ValueArrayKlass::allocate_klass"
152 if (array_klasses() == NULL) {
153 if (or_null) return NULL;
154
155 ResourceMark rm;
156 JavaThread *jt = (JavaThread *)THREAD;
157 {
158 // Atomic creation of array_klasses
159 MutexLocker ma(MultiArray_lock, THREAD);
160
161 // Check if update has already taken place
162 if (array_klasses() == NULL) {
163 Klass* ak;
164 if (is_atomic() || (!ValueArrayAtomicAccess)) {
165 ak = ValueArrayKlass::allocate_klass(this, CHECK_NULL);
166 } else {
167 ak = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
168 }
169 set_array_klasses(ak);
170 }
171 }
172 }
173 // _this will always be set at this point
174 ArrayKlass* ak = ArrayKlass::cast(array_klasses());
175 if (or_null) {
176 return ak->array_klass_or_null(n);
177 }
178 return ak->array_klass(n, THREAD);
179 }
180
181 Klass* ValueKlass::array_klass_impl(bool or_null, TRAPS) {
182 return array_klass_impl(or_null, 1, THREAD);
183 }
184
185 void ValueKlass::raw_field_copy(void* src, void* dst, size_t raw_byte_size) {
186 /*
187 * Try not to shear fields even if not an atomic store...
188 *
189 * First 3 cases handle value array store, otherwise works on the same basis
190 * as JVM_Clone, at this size data is aligned. The order of primitive types
191 * is largest to smallest, and it not possible for fields to stradle long
192 * copy boundaries.
193 *
194 * If MT without exclusive access, possible to observe partial value store,
195 * but not partial primitive and reference field values
196 */
197 switch (raw_byte_size) {
198 case 1:
199 *((jbyte*) dst) = *(jbyte*)src;
200 break;
201 case 2:
202 *((jshort*) dst) = *(jshort*)src;
203 break;
204 case 4:
205 *((jint*) dst) = *(jint*) src;
206 break;
207 default:
208 assert(raw_byte_size % sizeof(jlong) == 0, "Unaligned raw_byte_size");
209 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, raw_byte_size >> LogBytesPerLong);
210 }
211 }
212
213 /*
214 * Store the value of this klass contained with src into dst.
215 *
216 * This operation is appropriate for use from vastore, vaload and putfield (for values)
217 *
218 * GC barriers currently can lock with no safepoint check and allocate c-heap,
219 * so raw point is "safe" for now.
220 *
221 * Going forward, look to use machine generated (stub gen or bc) version for most used klass layouts
222 *
223 */
224 void ValueKlass::value_store(void* src, void* dst, size_t raw_byte_size, bool dst_heap, bool dst_uninitialized) {
225 if (contains_oops()) {
226 if (dst_heap) {
227 // src/dst aren't oops, need offset to adjust oop map offset
228 const address dst_oop_addr = ((address) dst) - first_field_offset();
229
230 ModRefBarrierSet* bs = barrier_set_cast<ModRefBarrierSet>(BarrierSet::barrier_set());
231
232 // Pre-barriers...
233 OopMapBlock* map = start_of_nonstatic_oop_maps();
234 OopMapBlock* const end = map + nonstatic_oop_map_count();
235 while (map != end) {
236 // Shame we can't just use the existing oop iterator...src/dst aren't oop
237 address doop_address = dst_oop_addr + map->offset();
238 // TEMP HACK: barrier code need to migrate to => access API (need own versions of value type ops)
239 if (UseCompressedOops) {
240 bs->write_ref_array_pre((narrowOop*) doop_address, map->count(), dst_uninitialized);
241 } else {
242 bs->write_ref_array_pre((oop*) doop_address, map->count(), dst_uninitialized);
243 }
244 map++;
245 }
246
247 raw_field_copy(src, dst, raw_byte_size);
248
249 // Post-barriers...
250 map = start_of_nonstatic_oop_maps();
251 while (map != end) {
252 address doop_address = dst_oop_addr + map->offset();
253 bs->write_ref_array((HeapWord*) doop_address, map->count());
254 map++;
255 }
256 } else { // Buffered value case
257 raw_field_copy(src, dst, raw_byte_size);
258 }
259 } else { // Primitive-only case...
260 raw_field_copy(src, dst, raw_byte_size);
261 }
262 }
263
264 // Value type arguments are not passed by reference, instead each
265 // field of the value type is passed as an argument. This helper
266 // function collects the fields of the value types (including embedded
267 // value type's fields) in a list. Included with the field's type is
268 // the offset of each field in the value type: i2c and c2i adapters
269 // need that to load or store fields. Finally, the list of fields is
270 // sorted in order of increasing offsets: the adapters and the
271 // compiled code need to agree upon the order of fields.
272 //
273 // The list of basic types that is returned starts with a T_VALUETYPE
274 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID pairs are used as
275 // delimiters. Every entry between the two is a field of the value
276 // type. If there's an embedded value type in the list, it also starts
277 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
278 // generate a unique fingerprint for the method's adapters and we can
279 // generate the list of basic types from the interpreter point of view
280 // (value types passed as reference: iterate on the list until a
281 // T_VALUETYPE, drop everything until and including the closing
282 // T_VOID) or the compiler point of view (each field of the value
283 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
284 int ValueKlass::collect_fields(GrowableArray<SigEntry>* sig, int base_off) const {
285 int count = 0;
286 SigEntry::add_entry(sig, T_VALUETYPE, base_off);
287 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
288 if (fs.access_flags().is_static()) continue;
289 int offset = base_off + fs.offset() - (base_off > 0 ? first_field_offset() : 0);
290 if (fs.is_flattened()) {
291 // Resolve klass of flattened value type field and recursively collect fields
292 Klass* vk = get_value_field_klass(fs.index());
293 count += ValueKlass::cast(vk)->collect_fields(sig, offset);
294 } else {
295 BasicType bt = FieldType::basic_type(fs.signature());
296 if (bt == T_VALUETYPE) {
297 bt = T_OBJECT;
298 }
299 SigEntry::add_entry(sig, bt, offset);
300 count += type2size[bt];
301 }
302 }
303 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
304 SigEntry::add_entry(sig, T_VOID, offset);
305 if (base_off == 0) {
306 sig->sort(SigEntry::compare);
307 }
308 assert(sig->at(0)._bt == T_VALUETYPE && sig->at(sig->length()-1)._bt == T_VOID, "broken structure");
309 return count;
310 }
311
312 void ValueKlass::initialize_calling_convention(TRAPS) {
313 // Because the pack and unpack handler addresses need to be loadable from generated code,
314 // they are stored at a fixed offset in the klass metadata. Since value type klasses do
315 // not have a vtable, the vtable offset is used to store these addresses.
316 if (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs) {
317 ResourceMark rm;
318 GrowableArray<SigEntry> sig_vk;
319 int nb_fields = collect_fields(&sig_vk);
320 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK);
321 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
322 for (int i = 0; i < sig_vk.length(); i++) {
323 extended_sig->at_put(i, sig_vk.at(i));
324 }
325
326 if (ValueTypeReturnedAsFields) {
327 nb_fields++;
328 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
329 sig_bt[0] = T_METADATA;
330 SigEntry::fill_sig_bt(&sig_vk, sig_bt+1);
331 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
332 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
333
334 if (total > 0) {
335 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK);
336 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
337 for (int i = 0; i < nb_fields; i++) {
338 return_regs->at_put(i, regs[i]);
339 }
340
341 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this);
342 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
343 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
344 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
345 }
346 }
347 }
348 }
349
350 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) {
351 if (extended_sig() != NULL) {
352 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
353 }
354 if (return_regs() != NULL) {
355 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
356 }
357 cleanup_blobs();
358 InstanceKlass::deallocate_contents(loader_data);
359 }
360
361 void ValueKlass::cleanup(ValueKlass* ik) {
362 ik->cleanup_blobs();
363 }
364
365 void ValueKlass::cleanup_blobs() {
366 if (pack_handler() != NULL) {
367 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
368 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type");
369 BufferBlob::free((BufferBlob*)buffered_blob);
370 *((address*)adr_pack_handler()) = NULL;
371 *((address*)adr_unpack_handler()) = NULL;
372 }
373 }
374
375 // Can this value type be returned as multiple values?
376 bool ValueKlass::can_be_returned_as_fields() const {
377 return return_regs() != NULL;
378 }
379
380 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
381 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
382 Thread* thread = Thread::current();
383 const Array<SigEntry>* sig_vk = extended_sig();
384 const Array<VMRegPair>* regs = return_regs();
385 int j = 1;
386
387 for (int i = 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());
392 oop v = *(oop*)loc;
393 assert(v == NULL || oopDesc::is_oop(v), "not an oop?");
394 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
395 handles.push(Handle(thread, v));
396 }
397 if (bt == T_VALUETYPE) {
398 continue;
399 }
400 if (bt == T_VOID &&
401 sig_vk->at(i-1)._bt != T_LONG &&
402 sig_vk->at(i-1)._bt != T_DOUBLE) {
403 continue;
404 }
405 j++;
406 }
407 assert(j == regs->length(), "missed a field?");
408 }
409
410 // Update oop fields in registers from handles after a safepoint
411 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
412 assert(ValueTypeReturnedAsFields, "inconsistent");
413 const Array<SigEntry>* sig_vk = extended_sig();
414 const Array<VMRegPair>* regs = return_regs();
415 assert(regs != NULL, "inconsistent");
416
417 int j = 1;
418 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
419 BasicType bt = sig_vk->at(i)._bt;
420 if (bt == T_OBJECT || bt == T_ARRAY) {
421 VMRegPair pair = regs->at(j);
422 address loc = reg_map.location(pair.first());
423 *(oop*)loc = handles.at(k++)();
424 }
425 if (bt == T_VALUETYPE) {
426 continue;
427 }
428 if (bt == T_VOID &&
429 sig_vk->at(i-1)._bt != T_LONG &&
430 sig_vk->at(i-1)._bt != T_DOUBLE) {
431 continue;
432 }
433 j++;
434 }
435 assert(j == regs->length(), "missed a field?");
436 }
437
438 // Fields are in registers. Create an instance of the value type and
439 // initialize it with the values of the fields.
440 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, TRAPS) {
441 oop new_vt = allocate_instance(CHECK_NULL);
442 const Array<SigEntry>* sig_vk = extended_sig();
443 const Array<VMRegPair>* regs = return_regs();
444
445 int j = 1;
446 int k = 0;
447 for (int i = 0; i < sig_vk->length(); i++) {
448 BasicType bt = sig_vk->at(i)._bt;
449 if (bt == T_VALUETYPE) {
450 continue;
451 }
452 if (bt == T_VOID) {
453 if (sig_vk->at(i-1)._bt == T_LONG ||
454 sig_vk->at(i-1)._bt == T_DOUBLE) {
455 j++;
456 }
457 continue;
458 }
459 int off = sig_vk->at(i)._offset;
460 assert(off > 0, "offset in object should be positive");
461 VMRegPair pair = regs->at(j);
462 address loc = reg_map.location(pair.first());
463 switch(bt) {
464 case T_BOOLEAN: {
465 new_vt->bool_field_put(off, *(jboolean*)loc);
466 break;
467 }
468 case T_CHAR: {
469 new_vt->char_field_put(off, *(jchar*)loc);
470 break;
471 }
472 case T_BYTE: {
473 new_vt->byte_field_put(off, *(jbyte*)loc);
474 break;
475 }
476 case T_SHORT: {
477 new_vt->short_field_put(off, *(jshort*)loc);
478 break;
479 }
480 case T_INT: {
481 new_vt->int_field_put(off, *(jint*)loc);
482 break;
483 }
484 case T_LONG: {
485 #ifdef _LP64
486 new_vt->double_field_put(off, *(jdouble*)loc);
487 #else
488 Unimplemented();
489 #endif
490 break;
491 }
492 case T_OBJECT:
493 case T_ARRAY: {
494 Handle handle = handles.at(k++);
495 new_vt->obj_field_put(off, handle());
496 break;
497 }
498 case T_FLOAT: {
499 new_vt->float_field_put(off, *(jfloat*)loc);
500 break;
501 }
502 case T_DOUBLE: {
503 new_vt->double_field_put(off, *(jdouble*)loc);
504 break;
505 }
506 default:
507 ShouldNotReachHere();
508 }
509 *(intptr_t*)loc = 0xDEAD;
510 j++;
511 }
512 assert(j == regs->length(), "missed a field?");
513 assert(k == handles.length(), "missed an oop?");
514 return new_vt;
515 }
516
517 // Check the return register for a ValueKlass oop
518 ValueKlass* ValueKlass::returned_value_klass(const RegisterMap& map) {
519 BasicType bt = T_METADATA;
520 VMRegPair pair;
521 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
522 assert(nb == 1, "broken");
523
524 address loc = map.location(pair.first());
525 intptr_t ptr = *(intptr_t*)loc;
526 if (is_set_nth_bit(ptr, 0)) {
527 // Oop is tagged, must be a ValueKlass oop
528 clear_nth_bit(ptr, 0);
529 assert(Metaspace::contains((void*)ptr), "should be klass");
530 ValueKlass* vk = (ValueKlass*)ptr;
531 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
532 return vk;
533 }
534 #ifdef ASSERT
535 // Oop is not tagged, must be a valid oop
536 if (VerifyOops) {
537 oopDesc::verify(oop((HeapWord*)ptr));
538 }
539 #endif
540 return NULL;
541 }
542
543 void ValueKlass::iterate_over_inside_oops(OopClosure* f, oop value) {
544 assert(!Universe::heap()->is_in_reserved(value), "This method is used on buffered values");
545
546 oop* addr_mirror = (oop*)(value)->mark_addr_raw();
547 f->do_oop_no_buffering(addr_mirror);
548
549 if (!contains_oops()) return;
550
551 OopMapBlock* map = start_of_nonstatic_oop_maps();
552 OopMapBlock* const end_map = map + nonstatic_oop_map_count();
553
554 if (!UseCompressedOops) {
555 for (; map < end_map; map++) {
556 oop* p = (oop*) (((char*)(oopDesc*)value) + map->offset());
557 oop* const end = p + map->count();
558 for (; p < end; ++p) {
559 assert(oopDesc::is_oop_or_null(*p), "Sanity check");
560 f->do_oop(p);
561 }
562 }
563 } else {
564 for (; map < end_map; map++) {
565 narrowOop* p = (narrowOop*) (((char*)(oopDesc*)value) + map->offset());
566 narrowOop* const end = p + map->count();
567 for (; p < end; ++p) {
568 oop o = CompressedOops::decode(*p);
569 assert(Universe::heap()->is_in_reserved_or_null(o), "Sanity check");
570 assert(oopDesc::is_oop_or_null(o), "Sanity check");
571 f->do_oop(p);
572 }
573 }
574 }
575 }
576
577 void ValueKlass::verify_on(outputStream* st) {
578 InstanceKlass::verify_on(st);
579 guarantee(prototype_header()->is_always_locked(), "Prototype header is not always locked");
580 }
581
582 void ValueKlass::oop_verify_on(oop obj, outputStream* st) {
583 InstanceKlass::oop_verify_on(obj, st);
584 guarantee(obj->mark()->is_always_locked(), "Header is not always locked");
585 }