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