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 }