1/* 2 * Copyright (c) 1997, 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#ifndef SHARE_VM_OOPS_OOP_INLINE_HPP 26#define SHARE_VM_OOPS_OOP_INLINE_HPP 27 28#include "gc/shared/ageTable.hpp" 29#include "gc/shared/barrierSet.inline.hpp" 30#include "gc/shared/cardTableModRefBS.hpp" 31#include "gc/shared/collectedHeap.inline.hpp" 32#include "gc/shared/genCollectedHeap.hpp" 33#include "gc/shared/generation.hpp" 34#include "oops/arrayKlass.hpp" 35#include "oops/arrayOop.hpp" 36#include "oops/klass.inline.hpp" 37#include "oops/markOop.inline.hpp" 38#include "oops/oop.hpp" 39#include "runtime/atomic.hpp" 40#include "runtime/orderAccess.inline.hpp" 41#include "runtime/os.hpp" 42#include "utilities/align.hpp" 43#include "utilities/macros.hpp" 44 45inline void update_barrier_set(void* p, oop v, bool release = false) { 46 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!"); 47 oopDesc::bs()->write_ref_field(p, v, release); 48} 49 50template <class T> inline void update_barrier_set_pre(T* p, oop v) { 51 oopDesc::bs()->write_ref_field_pre(p, v); 52} 53 54template <class T> void oop_store(T* p, oop v) { 55 if (always_do_update_barrier) { 56 oop_store((volatile T*)p, v); 57 } else { 58 update_barrier_set_pre(p, v); 59 oopDesc::encode_store_heap_oop(p, v); 60 // always_do_update_barrier == false => 61 // Either we are at a safepoint (in GC) or CMS is not used. In both 62 // cases it's unnecessary to mark the card as dirty with release sematics. 63 update_barrier_set((void*)p, v, false /* release */); // cast away type 64 } 65} 66 67template <class T> void oop_store(volatile T* p, oop v) { 68 update_barrier_set_pre((T*)p, v); // cast away volatile 69 // Used by release_obj_field_put, so use release_store_ptr. 70 oopDesc::release_encode_store_heap_oop(p, v); 71 // When using CMS we must mark the card corresponding to p as dirty 72 // with release sematics to prevent that CMS sees the dirty card but 73 // not the new value v at p due to reordering of the two 74 // stores. Note that CMS has a concurrent precleaning phase, where 75 // it reads the card table while the Java threads are running. 76 update_barrier_set((void*)p, v, true /* release */); // cast away type 77} 78 79// Should replace *addr = oop assignments where addr type depends on UseCompressedOops 80// (without having to remember the function name this calls). 81inline void oop_store_raw(HeapWord* addr, oop value) { 82 if (UseCompressedOops) { 83 oopDesc::encode_store_heap_oop((narrowOop*)addr, value); 84 } else { 85 oopDesc::encode_store_heap_oop((oop*)addr, value); 86 } 87} 88 89// Implementation of all inlined member functions defined in oop.hpp 90// We need a separate file to avoid circular references 91 92void oopDesc::release_set_mark(markOop m) { 93 OrderAccess::release_store_ptr(&_mark, m); 94} 95 96markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) { 97 return Atomic::cmpxchg(new_mark, &_mark, old_mark); 98} 99 100void oopDesc::init_mark() { 101 set_mark(markOopDesc::prototype_for_object(this)); 102} 103 104Klass* oopDesc::klass() const { 105 if (UseCompressedClassPointers) { 106 return Klass::decode_klass_not_null(_metadata._compressed_klass); 107 } else { 108 return _metadata._klass; 109 } 110} 111 112Klass* oopDesc::klass_or_null() const volatile { 113 if (UseCompressedClassPointers) { 114 return Klass::decode_klass(_metadata._compressed_klass); 115 } else { 116 return _metadata._klass; 117 } 118} 119 120Klass* oopDesc::klass_or_null_acquire() const volatile { 121 if (UseCompressedClassPointers) { 122 // Workaround for non-const load_acquire parameter. 123 const volatile narrowKlass* addr = &_metadata._compressed_klass; 124 volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr); 125 return Klass::decode_klass(OrderAccess::load_acquire(xaddr)); 126 } else { 127 return (Klass*)OrderAccess::load_ptr_acquire(&_metadata._klass); 128 } 129} 130 131Klass** oopDesc::klass_addr() { 132 // Only used internally and with CMS and will not work with 133 // UseCompressedOops 134 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers"); 135 return (Klass**) &_metadata._klass; 136} 137 138narrowKlass* oopDesc::compressed_klass_addr() { 139 assert(UseCompressedClassPointers, "only called by compressed klass pointers"); 140 return &_metadata._compressed_klass; 141} 142 143#define CHECK_SET_KLASS(k) \ 144 do { \ 145 assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass"); \ 146 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \ 147 } while (0) 148 149void oopDesc::set_klass(Klass* k) { 150 CHECK_SET_KLASS(k); 151 if (UseCompressedClassPointers) { 152 *compressed_klass_addr() = Klass::encode_klass_not_null(k); 153 } else { 154 *klass_addr() = k; 155 } 156} 157 158void oopDesc::release_set_klass(Klass* k) { 159 CHECK_SET_KLASS(k); 160 if (UseCompressedClassPointers) { 161 OrderAccess::release_store(compressed_klass_addr(), 162 Klass::encode_klass_not_null(k)); 163 } else { 164 OrderAccess::release_store_ptr(klass_addr(), k); 165 } 166} 167 168#undef CHECK_SET_KLASS 169 170int oopDesc::klass_gap() const { 171 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()); 172} 173 174void oopDesc::set_klass_gap(int v) { 175 if (UseCompressedClassPointers) { 176 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v; 177 } 178} 179 180void oopDesc::set_klass_to_list_ptr(oop k) { 181 // This is only to be used during GC, for from-space objects, so no 182 // barrier is needed. 183 if (UseCompressedClassPointers) { 184 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling) 185 } else { 186 _metadata._klass = (Klass*)(address)k; 187 } 188} 189 190oop oopDesc::list_ptr_from_klass() { 191 // This is only to be used during GC, for from-space objects. 192 if (UseCompressedClassPointers) { 193 return decode_heap_oop((narrowOop)_metadata._compressed_klass); 194 } else { 195 // Special case for GC 196 return (oop)(address)_metadata._klass; 197 } 198} 199 200bool oopDesc::is_a(Klass* k) const { 201 return klass()->is_subtype_of(k); 202} 203 204int oopDesc::size() { 205 return size_given_klass(klass()); 206} 207 208int oopDesc::size_given_klass(Klass* klass) { 209 int lh = klass->layout_helper(); 210 int s; 211 212 // lh is now a value computed at class initialization that may hint 213 // at the size. For instances, this is positive and equal to the 214 // size. For arrays, this is negative and provides log2 of the 215 // array element size. For other oops, it is zero and thus requires 216 // a virtual call. 217 // 218 // We go to all this trouble because the size computation is at the 219 // heart of phase 2 of mark-compaction, and called for every object, 220 // alive or dead. So the speed here is equal in importance to the 221 // speed of allocation. 222 223 if (lh > Klass::_lh_neutral_value) { 224 if (!Klass::layout_helper_needs_slow_path(lh)) { 225 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize 226 } else { 227 s = klass->oop_size(this); 228 } 229 } else if (lh <= Klass::_lh_neutral_value) { 230 // The most common case is instances; fall through if so. 231 if (lh < Klass::_lh_neutral_value) { 232 // Second most common case is arrays. We have to fetch the 233 // length of the array, shift (multiply) it appropriately, 234 // up to wordSize, add the header, and align to object size. 235 size_t size_in_bytes; 236 size_t array_length = (size_t) ((arrayOop)this)->length(); 237 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh); 238 size_in_bytes += Klass::layout_helper_header_size(lh); 239 240 // This code could be simplified, but by keeping array_header_in_bytes 241 // in units of bytes and doing it this way we can round up just once, 242 // skipping the intermediate round to HeapWordSize. 243 s = (int)(align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize); 244 245 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field 246 // of an "old copy" of an object array in the young gen so it indicates 247 // the grey portion of an already copied array. This will cause the first 248 // disjunct below to fail if the two comparands are computed across such 249 // a concurrent change. 250 // ParNew also runs with promotion labs (which look like int 251 // filler arrays) which are subject to changing their declared size 252 // when finally retiring a PLAB; this also can cause the first disjunct 253 // to fail for another worker thread that is concurrently walking the block 254 // offset table. Both these invariant failures are benign for their 255 // current uses; we relax the assertion checking to cover these two cases below: 256 // is_objArray() && is_forwarded() // covers first scenario above 257 // || is_typeArray() // covers second scenario above 258 // If and when UseParallelGC uses the same obj array oop stealing/chunking 259 // technique, we will need to suitably modify the assertion. 260 assert((s == klass->oop_size(this)) || 261 (Universe::heap()->is_gc_active() && 262 ((is_typeArray() && UseConcMarkSweepGC) || 263 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))), 264 "wrong array object size"); 265 } else { 266 // Must be zero, so bite the bullet and take the virtual call. 267 s = klass->oop_size(this); 268 } 269 } 270 271 assert(s > 0, "Oop size must be greater than zero, not %d", s); 272 assert(is_object_aligned(s), "Oop size is not properly aligned: %d", s); 273 return s; 274} 275 276bool oopDesc::is_instance() const { return klass()->is_instance_klass(); } 277bool oopDesc::is_array() const { return klass()->is_array_klass(); } 278bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); } 279bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); } 280 281void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; } 282 283jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); } 284jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); } 285jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*) field_base(offset); } 286jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); } 287jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); } 288jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); } 289jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); } 290jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); } 291Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); } 292 293template <class T> T* oopDesc::obj_field_addr(int offset) const { return (T*) field_base(offset); } 294address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); } 295 296 297// Functions for getting and setting oops within instance objects. 298// If the oops are compressed, the type passed to these overloaded functions 299// is narrowOop. All functions are overloaded so they can be called by 300// template functions without conditionals (the compiler instantiates via 301// the right type and inlines the appopriate code). 302 303// Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit 304// offset from the heap base. Saving the check for null can save instructions 305// in inner GC loops so these are separated. 306 307inline bool check_obj_alignment(oop obj) { 308 return (cast_from_oop<intptr_t>(obj) & MinObjAlignmentInBytesMask) == 0; 309} 310 311oop oopDesc::decode_heap_oop_not_null(narrowOop v) { 312 assert(!is_null(v), "narrow oop value can never be zero"); 313 address base = Universe::narrow_oop_base(); 314 int shift = Universe::narrow_oop_shift(); 315 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift)); 316 assert(check_obj_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result)); 317 return result; 318} 319 320oop oopDesc::decode_heap_oop(narrowOop v) { 321 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v); 322} 323 324narrowOop oopDesc::encode_heap_oop_not_null(oop v) { 325 assert(!is_null(v), "oop value can never be zero"); 326 assert(check_obj_alignment(v), "Address not aligned"); 327 assert(Universe::heap()->is_in_reserved(v), "Address not in heap"); 328 address base = Universe::narrow_oop_base(); 329 int shift = Universe::narrow_oop_shift(); 330 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1)); 331 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding"); 332 uint64_t result = pd >> shift; 333 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow"); 334 assert(decode_heap_oop(result) == v, "reversibility"); 335 return (narrowOop)result; 336} 337 338narrowOop oopDesc::encode_heap_oop(oop v) { 339 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v); 340} 341 342// Load and decode an oop out of the Java heap into a wide oop. 343oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) { 344 return decode_heap_oop_not_null(*p); 345} 346 347// Load and decode an oop out of the heap accepting null 348oop oopDesc::load_decode_heap_oop(narrowOop* p) { 349 return decode_heap_oop(*p); 350} 351 352// Encode and store a heap oop. 353void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) { 354 *p = encode_heap_oop_not_null(v); 355} 356 357// Encode and store a heap oop allowing for null. 358void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) { 359 *p = encode_heap_oop(v); 360} 361 362// Store heap oop as is for volatile fields. 363void oopDesc::release_store_heap_oop(volatile oop* p, oop v) { 364 OrderAccess::release_store_ptr(p, v); 365} 366void oopDesc::release_store_heap_oop(volatile narrowOop* p, narrowOop v) { 367 OrderAccess::release_store(p, v); 368} 369 370void oopDesc::release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v) { 371 // heap oop is not pointer sized. 372 OrderAccess::release_store(p, encode_heap_oop_not_null(v)); 373} 374void oopDesc::release_encode_store_heap_oop_not_null(volatile oop* p, oop v) { 375 OrderAccess::release_store_ptr(p, v); 376} 377 378void oopDesc::release_encode_store_heap_oop(volatile oop* p, oop v) { 379 OrderAccess::release_store_ptr(p, v); 380} 381void oopDesc::release_encode_store_heap_oop(volatile narrowOop* p, oop v) { 382 OrderAccess::release_store(p, encode_heap_oop(v)); 383} 384 385// These functions are only used to exchange oop fields in instances, 386// not headers. 387oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) { 388 if (UseCompressedOops) { 389 // encode exchange value from oop to T 390 narrowOop val = encode_heap_oop(exchange_value); 391 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest); 392 // decode old from T to oop 393 return decode_heap_oop(old); 394 } else { 395 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest); 396 } 397} 398 399oop oopDesc::atomic_compare_exchange_oop(oop exchange_value, 400 volatile HeapWord *dest, 401 oop compare_value, 402 bool prebarrier) { 403 if (UseCompressedOops) { 404 if (prebarrier) { 405 update_barrier_set_pre((narrowOop*)dest, exchange_value); 406 } 407 // encode exchange and compare value from oop to T 408 narrowOop val = encode_heap_oop(exchange_value); 409 narrowOop cmp = encode_heap_oop(compare_value); 410 411 narrowOop old = Atomic::cmpxchg(val, (narrowOop*)dest, cmp); 412 // decode old from T to oop 413 return decode_heap_oop(old); 414 } else { 415 if (prebarrier) { 416 update_barrier_set_pre((oop*)dest, exchange_value); 417 } 418 return Atomic::cmpxchg(exchange_value, (oop*)dest, compare_value); 419 } 420} 421 422// In order to put or get a field out of an instance, must first check 423// if the field has been compressed and uncompress it. 424oop oopDesc::obj_field(int offset) const { 425 return UseCompressedOops ? 426 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) : 427 load_decode_heap_oop(obj_field_addr<oop>(offset)); 428} 429 430void oopDesc::obj_field_put(int offset, oop value) { 431 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) : 432 oop_store(obj_field_addr<oop>(offset), value); 433} 434 435void oopDesc::obj_field_put_raw(int offset, oop value) { 436 UseCompressedOops ? 437 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) : 438 encode_store_heap_oop(obj_field_addr<oop>(offset), value); 439} 440void oopDesc::obj_field_put_volatile(int offset, oop value) { 441 OrderAccess::release(); 442 obj_field_put(offset, value); 443 OrderAccess::fence(); 444} 445 446Metadata* oopDesc::metadata_field(int offset) const { return *metadata_field_addr(offset); } 447void oopDesc::metadata_field_put(int offset, Metadata* value) { *metadata_field_addr(offset) = value; } 448 449Metadata* oopDesc::metadata_field_acquire(int offset) const { 450 return (Metadata*)OrderAccess::load_ptr_acquire(metadata_field_addr(offset)); 451} 452 453void oopDesc::release_metadata_field_put(int offset, Metadata* value) { 454 OrderAccess::release_store_ptr(metadata_field_addr(offset), value); 455} 456 457jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); } 458void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; } 459 460jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); } 461void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; } 462 463jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); } 464void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (((jint) contents) & 1); } 465 466jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); } 467void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; } 468 469jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); } 470void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;} 471 472jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); } 473void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; } 474 475jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); } 476void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; } 477 478jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); } 479void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; } 480 481address oopDesc::address_field(int offset) const { return *address_field_addr(offset); } 482void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; } 483 484oop oopDesc::obj_field_acquire(int offset) const { 485 return UseCompressedOops ? 486 decode_heap_oop((narrowOop) 487 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset))) 488 : decode_heap_oop((oop) 489 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset))); 490} 491void oopDesc::release_obj_field_put(int offset, oop value) { 492 UseCompressedOops ? 493 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) : 494 oop_store((volatile oop*) obj_field_addr<oop>(offset), value); 495} 496 497jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); } 498void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); } 499 500jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); } 501void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); } 502 503jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); } 504void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), (contents & 1)); } 505 506jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); } 507void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); } 508 509jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); } 510void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); } 511 512jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); } 513void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); } 514 515jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); } 516void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); } 517 518jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); } 519void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); } 520 521address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); } 522void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); } 523 524bool oopDesc::is_locked() const { 525 return mark()->is_locked(); 526} 527 528bool oopDesc::is_unlocked() const { 529 return mark()->is_unlocked(); 530} 531 532bool oopDesc::has_bias_pattern() const { 533 return mark()->has_bias_pattern(); 534} 535 536// Used only for markSweep, scavenging 537bool oopDesc::is_gc_marked() const { 538 return mark()->is_marked(); 539} 540 541bool oopDesc::is_scavengable() const { 542 return Universe::heap()->is_scavengable(this); 543} 544 545// Used by scavengers 546bool oopDesc::is_forwarded() const { 547 // The extra heap check is needed since the obj might be locked, in which case the 548 // mark would point to a stack location and have the sentinel bit cleared 549 return mark()->is_marked(); 550} 551 552// Used by scavengers 553void oopDesc::forward_to(oop p) { 554 assert(check_obj_alignment(p), 555 "forwarding to something not aligned"); 556 assert(Universe::heap()->is_in_reserved(p), 557 "forwarding to something not in heap"); 558 assert(!is_archive_object(oop(this)) && 559 !is_archive_object(p), 560 "forwarding archive object"); 561 markOop m = markOopDesc::encode_pointer_as_mark(p); 562 assert(m->decode_pointer() == p, "encoding must be reversable"); 563 set_mark(m); 564} 565 566// Used by parallel scavengers 567bool oopDesc::cas_forward_to(oop p, markOop compare) { 568 assert(check_obj_alignment(p), 569 "forwarding to something not aligned"); 570 assert(Universe::heap()->is_in_reserved(p), 571 "forwarding to something not in heap"); 572 markOop m = markOopDesc::encode_pointer_as_mark(p); 573 assert(m->decode_pointer() == p, "encoding must be reversable"); 574 return cas_set_mark(m, compare) == compare; 575} 576 577#if INCLUDE_ALL_GCS 578oop oopDesc::forward_to_atomic(oop p) { 579 markOop oldMark = mark(); 580 markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p); 581 markOop curMark; 582 583 assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable"); 584 assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this."); 585 586 while (!oldMark->is_marked()) { 587 curMark = Atomic::cmpxchg(forwardPtrMark, &_mark, oldMark); 588 assert(is_forwarded(), "object should have been forwarded"); 589 if (curMark == oldMark) { 590 return NULL; 591 } 592 // If the CAS was unsuccessful then curMark->is_marked() 593 // should return true as another thread has CAS'd in another 594 // forwarding pointer. 595 oldMark = curMark; 596 } 597 return forwardee(); 598} 599#endif 600 601// Note that the forwardee is not the same thing as the displaced_mark. 602// The forwardee is used when copying during scavenge and mark-sweep. 603// It does need to clear the low two locking- and GC-related bits. 604oop oopDesc::forwardee() const { 605 return (oop) mark()->decode_pointer(); 606} 607 608// The following method needs to be MT safe. 609uint oopDesc::age() const { 610 assert(!is_forwarded(), "Attempt to read age from forwarded mark"); 611 if (has_displaced_mark()) { 612 return displaced_mark()->age(); 613 } else { 614 return mark()->age(); 615 } 616} 617 618void oopDesc::incr_age() { 619 assert(!is_forwarded(), "Attempt to increment age of forwarded mark"); 620 if (has_displaced_mark()) { 621 set_displaced_mark(displaced_mark()->incr_age()); 622 } else { 623 set_mark(mark()->incr_age()); 624 } 625} 626 627#if INCLUDE_ALL_GCS 628void oopDesc::pc_follow_contents(ParCompactionManager* cm) { 629 klass()->oop_pc_follow_contents(this, cm); 630} 631 632void oopDesc::pc_update_contents(ParCompactionManager* cm) { 633 Klass* k = klass(); 634 if (!k->is_typeArray_klass()) { 635 // It might contain oops beyond the header, so take the virtual call. 636 k->oop_pc_update_pointers(this, cm); 637 } 638 // Else skip it. The TypeArrayKlass in the header never needs scavenging. 639} 640 641void oopDesc::ps_push_contents(PSPromotionManager* pm) { 642 Klass* k = klass(); 643 if (!k->is_typeArray_klass()) { 644 // It might contain oops beyond the header, so take the virtual call. 645 k->oop_ps_push_contents(this, pm); 646 } 647 // Else skip it. The TypeArrayKlass in the header never needs scavenging. 648} 649#endif // INCLUDE_ALL_GCS 650 651#define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 652 \ 653void oopDesc::oop_iterate(OopClosureType* blk) { \ 654 klass()->oop_oop_iterate##nv_suffix(this, blk); \ 655} \ 656 \ 657void oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \ 658 klass()->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \ 659} 660 661#define OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \ 662 \ 663int oopDesc::oop_iterate_size(OopClosureType* blk) { \ 664 Klass* k = klass(); \ 665 int size = size_given_klass(k); \ 666 k->oop_oop_iterate##nv_suffix(this, blk); \ 667 return size; \ 668} \ 669 \ 670int oopDesc::oop_iterate_size(OopClosureType* blk, MemRegion mr) { \ 671 Klass* k = klass(); \ 672 int size = size_given_klass(k); \ 673 k->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \ 674 return size; \ 675} 676 677int oopDesc::oop_iterate_no_header(OopClosure* blk) { 678 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all 679 // the do_oop calls, but turns off all other features in ExtendedOopClosure. 680 NoHeaderExtendedOopClosure cl(blk); 681 return oop_iterate_size(&cl); 682} 683 684int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) { 685 NoHeaderExtendedOopClosure cl(blk); 686 return oop_iterate_size(&cl, mr); 687} 688 689#if INCLUDE_ALL_GCS 690#define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 691 \ 692inline void oopDesc::oop_iterate_backwards(OopClosureType* blk) { \ 693 klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \ 694} 695#else 696#define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) 697#endif // INCLUDE_ALL_GCS 698 699#define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix) \ 700 OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 701 OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \ 702 OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) 703 704ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE) 705ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE) 706 707intptr_t oopDesc::identity_hash() { 708 // Fast case; if the object is unlocked and the hash value is set, no locking is needed 709 // Note: The mark must be read into local variable to avoid concurrent updates. 710 markOop mrk = mark(); 711 if (mrk->is_unlocked() && !mrk->has_no_hash()) { 712 return mrk->hash(); 713 } else if (mrk->is_marked()) { 714 return mrk->hash(); 715 } else { 716 return slow_identity_hash(); 717 } 718} 719 720bool oopDesc::has_displaced_mark() const { 721 return mark()->has_displaced_mark_helper(); 722} 723 724markOop oopDesc::displaced_mark() const { 725 return mark()->displaced_mark_helper(); 726} 727 728void oopDesc::set_displaced_mark(markOop m) { 729 mark()->set_displaced_mark_helper(m); 730} 731 732#endif // SHARE_VM_OOPS_OOP_INLINE_HPP 733