1 /* 2 * Copyright (c) 1997, 2016, 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_implementation/shared/ageTable.hpp" 29 #include "gc_implementation/shared/markSweep.inline.hpp" 30 #include "gc_interface/collectedHeap.inline.hpp" 31 #include "memory/barrierSet.inline.hpp" 32 #include "memory/cardTableModRefBS.hpp" 33 #include "memory/genCollectedHeap.hpp" 34 #include "memory/generation.hpp" 35 #include "memory/specialized_oop_closures.hpp" 36 #include "oops/arrayKlass.hpp" 37 #include "oops/arrayOop.hpp" 38 #include "oops/klass.inline.hpp" 39 #include "oops/markOop.inline.hpp" 40 #include "oops/oop.hpp" 41 #include "runtime/atomic.inline.hpp" 42 #include "runtime/orderAccess.inline.hpp" 43 #include "runtime/os.hpp" 44 #include "utilities/macros.hpp" 45 #ifdef TARGET_ARCH_x86 46 # include "bytes_x86.hpp" 47 #endif 48 #ifdef TARGET_ARCH_aarch64 49 # include "bytes_aarch64.hpp" 50 #endif 51 #ifdef TARGET_ARCH_sparc 52 # include "bytes_sparc.hpp" 53 #endif 54 #ifdef TARGET_ARCH_zero 55 # include "bytes_zero.hpp" 56 #endif 57 #ifdef TARGET_ARCH_arm 58 # include "bytes_arm.hpp" 59 #endif 60 #ifdef TARGET_ARCH_ppc 61 # include "bytes_ppc.hpp" 62 #endif 63 64 #if INCLUDE_ALL_GCS 65 #include "gc_implementation/shenandoah/shenandoahBarrierSet.hpp" 66 #endif 67 68 // Implementation of all inlined member functions defined in oop.hpp 69 // We need a separate file to avoid circular references 70 71 inline void oopDesc::release_set_mark(markOop m) { 72 OrderAccess::release_store_ptr(&_mark, m); 73 } 74 75 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) { 76 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark); 77 } 78 79 inline Klass* oopDesc::klass() const { 80 if (UseCompressedClassPointers) { 81 return Klass::decode_klass_not_null(_metadata._compressed_klass); 82 } else { 83 return _metadata._klass; 84 } 85 } 86 87 inline Klass* oopDesc::klass_or_null() const volatile { 88 // can be NULL in CMS 89 if (UseCompressedClassPointers) { 90 return Klass::decode_klass(_metadata._compressed_klass); 91 } else { 92 return _metadata._klass; 93 } 94 } 95 96 inline int oopDesc::klass_gap_offset_in_bytes() { 97 assert(UseCompressedClassPointers, "only applicable to compressed klass pointers"); 98 return oopDesc::klass_offset_in_bytes() + sizeof(narrowKlass); 99 } 100 101 inline Klass** oopDesc::klass_addr() { 102 // Only used internally and with CMS and will not work with 103 // UseCompressedOops 104 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers"); 105 return (Klass**) &_metadata._klass; 106 } 107 108 inline narrowKlass* oopDesc::compressed_klass_addr() { 109 assert(UseCompressedClassPointers, "only called by compressed klass pointers"); 110 return &_metadata._compressed_klass; 111 } 112 113 inline void oopDesc::set_klass(Klass* k) { 114 // since klasses are promoted no store check is needed 115 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*"); 116 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*"); 117 if (UseCompressedClassPointers) { 118 *compressed_klass_addr() = Klass::encode_klass_not_null(k); 119 } else { 120 *klass_addr() = k; 121 } 122 } 123 124 inline int oopDesc::klass_gap() const { 125 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()); 126 } 127 128 inline void oopDesc::set_klass_gap(int v) { 129 if (UseCompressedClassPointers) { 130 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v; 131 } 132 } 133 134 inline void oopDesc::set_klass_to_list_ptr(oop k) { 135 // This is only to be used during GC, for from-space objects, so no 136 // barrier is needed. 137 if (UseCompressedClassPointers) { 138 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling) 139 } else { 140 _metadata._klass = (Klass*)(address)k; 141 } 142 } 143 144 inline oop oopDesc::list_ptr_from_klass() { 145 // This is only to be used during GC, for from-space objects. 146 if (UseCompressedClassPointers) { 147 return decode_heap_oop((narrowOop)_metadata._compressed_klass); 148 } else { 149 // Special case for GC 150 return (oop)(address)_metadata._klass; 151 } 152 } 153 154 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); } 155 156 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); } 157 158 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); } 159 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); } 160 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); } 161 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); } 162 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); } 163 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); } 164 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); } 165 166 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; } 167 168 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); } 169 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); } 170 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); } 171 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); } 172 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); } 173 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); } 174 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); } 175 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); } 176 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); } 177 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); } 178 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); } 179 180 181 // Functions for getting and setting oops within instance objects. 182 // If the oops are compressed, the type passed to these overloaded functions 183 // is narrowOop. All functions are overloaded so they can be called by 184 // template functions without conditionals (the compiler instantiates via 185 // the right type and inlines the appopriate code). 186 187 inline bool oopDesc::is_null(oop obj) { return obj == NULL; } 188 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; } 189 190 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit 191 // offset from the heap base. Saving the check for null can save instructions 192 // in inner GC loops so these are separated. 193 194 inline bool check_obj_alignment(oop obj) { 195 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0; 196 } 197 198 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) { 199 assert(!is_null(v), "oop value can never be zero"); 200 assert(check_obj_alignment(v), "Address not aligned"); 201 assert(Universe::heap()->is_in_reserved(v), "Address not in heap"); 202 address base = Universe::narrow_oop_base(); 203 int shift = Universe::narrow_oop_shift(); 204 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1)); 205 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding"); 206 uint64_t result = pd >> shift; 207 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow"); 208 assert(decode_heap_oop(result) == v, "reversibility"); 209 return (narrowOop)result; 210 } 211 212 inline narrowOop oopDesc::encode_heap_oop(oop v) { 213 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v); 214 } 215 216 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) { 217 assert(!is_null(v), "narrow oop value can never be zero"); 218 address base = Universe::narrow_oop_base(); 219 int shift = Universe::narrow_oop_shift(); 220 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift)); 221 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result))); 222 return result; 223 } 224 225 inline oop oopDesc::decode_heap_oop(narrowOop v) { 226 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v); 227 } 228 229 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; } 230 inline oop oopDesc::decode_heap_oop(oop v) { return v; } 231 232 // Load an oop out of the Java heap as is without decoding. 233 // Called by GC to check for null before decoding. 234 inline oop oopDesc::load_heap_oop(oop* p) { return *p; } 235 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; } 236 237 // Load and decode an oop out of the Java heap into a wide oop. 238 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; } 239 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) { 240 return decode_heap_oop_not_null(*p); 241 } 242 243 // Load and decode an oop out of the heap accepting null 244 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; } 245 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) { 246 return decode_heap_oop(*p); 247 } 248 249 // Store already encoded heap oop into the heap. 250 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; } 251 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; } 252 253 // Encode and store a heap oop. 254 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) { 255 *p = encode_heap_oop_not_null(v); 256 } 257 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; } 258 259 // Encode and store a heap oop allowing for null. 260 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) { 261 *p = encode_heap_oop(v); 262 } 263 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; } 264 265 // Store heap oop as is for volatile fields. 266 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) { 267 OrderAccess::release_store_ptr(p, v); 268 } 269 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p, 270 narrowOop v) { 271 OrderAccess::release_store(p, v); 272 } 273 274 inline void oopDesc::release_encode_store_heap_oop_not_null( 275 volatile narrowOop* p, oop v) { 276 // heap oop is not pointer sized. 277 OrderAccess::release_store(p, encode_heap_oop_not_null(v)); 278 } 279 280 inline void oopDesc::release_encode_store_heap_oop_not_null( 281 volatile oop* p, oop v) { 282 OrderAccess::release_store_ptr(p, v); 283 } 284 285 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p, 286 oop v) { 287 OrderAccess::release_store_ptr(p, v); 288 } 289 inline void oopDesc::release_encode_store_heap_oop( 290 volatile narrowOop* p, oop v) { 291 OrderAccess::release_store(p, encode_heap_oop(v)); 292 } 293 294 295 // These functions are only used to exchange oop fields in instances, 296 // not headers. 297 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) { 298 oop result; 299 if (UseCompressedOops) { 300 // encode exchange value from oop to T 301 narrowOop val = encode_heap_oop(exchange_value); 302 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest); 303 // decode old from T to oop 304 result = decode_heap_oop(old); 305 } else { 306 result = (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest); 307 } 308 #if INCLUDE_ALL_GCS 309 if (UseShenandoahGC) { 310 result = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(result); 311 } 312 #endif 313 return result; 314 } 315 316 // In order to put or get a field out of an instance, must first check 317 // if the field has been compressed and uncompress it. 318 inline oop oopDesc::obj_field(int offset) const { 319 oop obj = UseCompressedOops ? 320 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) : 321 load_decode_heap_oop(obj_field_addr<oop>(offset)); 322 #if INCLUDE_ALL_GCS 323 if (UseShenandoahGC) { 324 obj = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(obj); 325 } 326 #endif 327 return obj; 328 } 329 inline volatile oop oopDesc::obj_field_volatile(int offset) const { 330 volatile oop value = obj_field(offset); 331 OrderAccess::acquire(); 332 return value; 333 } 334 inline void oopDesc::obj_field_put(int offset, oop value) { 335 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) : 336 oop_store(obj_field_addr<oop>(offset), value); 337 } 338 339 inline Metadata* oopDesc::metadata_field(int offset) const { 340 return *metadata_field_addr(offset); 341 } 342 343 inline void oopDesc::metadata_field_put(int offset, Metadata* value) { 344 *metadata_field_addr(offset) = value; 345 } 346 347 inline void oopDesc::obj_field_put_raw(int offset, oop value) { 348 UseCompressedOops ? 349 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) : 350 encode_store_heap_oop(obj_field_addr<oop>(offset), value); 351 } 352 inline void oopDesc::obj_field_put_volatile(int offset, oop value) { 353 OrderAccess::release(); 354 obj_field_put(offset, value); 355 OrderAccess::fence(); 356 } 357 358 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); } 359 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; } 360 361 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); } 362 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (( (jint) contents) & 1); } 363 364 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); } 365 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; } 366 367 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); } 368 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; } 369 370 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); } 371 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;} 372 373 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); } 374 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; } 375 376 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); } 377 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; } 378 379 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); } 380 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; } 381 382 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); } 383 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; } 384 385 inline oop oopDesc::obj_field_acquire(int offset) const { 386 oop obj = UseCompressedOops ? 387 decode_heap_oop((narrowOop) 388 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset))) 389 : decode_heap_oop((oop) 390 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset))); 391 #if INCLUDE_ALL_GCS 392 if (UseShenandoahGC) { 393 obj = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(obj); 394 } 395 #endif 396 return obj; 397 } 398 inline void oopDesc::release_obj_field_put(int offset, oop value) { 399 UseCompressedOops ? 400 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) : 401 oop_store((volatile oop*) obj_field_addr<oop>(offset), value); 402 } 403 404 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); } 405 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); } 406 407 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); } 408 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), (contents & 1)); } 409 410 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); } 411 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); } 412 413 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); } 414 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); } 415 416 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); } 417 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); } 418 419 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); } 420 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); } 421 422 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); } 423 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); } 424 425 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); } 426 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); } 427 428 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); } 429 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); } 430 431 inline int oopDesc::size_given_klass(Klass* klass) { 432 int lh = klass->layout_helper(); 433 int s; 434 435 // lh is now a value computed at class initialization that may hint 436 // at the size. For instances, this is positive and equal to the 437 // size. For arrays, this is negative and provides log2 of the 438 // array element size. For other oops, it is zero and thus requires 439 // a virtual call. 440 // 441 // We go to all this trouble because the size computation is at the 442 // heart of phase 2 of mark-compaction, and called for every object, 443 // alive or dead. So the speed here is equal in importance to the 444 // speed of allocation. 445 446 if (lh > Klass::_lh_neutral_value) { 447 if (!Klass::layout_helper_needs_slow_path(lh)) { 448 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize 449 } else { 450 s = klass->oop_size(this); 451 } 452 } else if (lh <= Klass::_lh_neutral_value) { 453 // The most common case is instances; fall through if so. 454 if (lh < Klass::_lh_neutral_value) { 455 // Second most common case is arrays. We have to fetch the 456 // length of the array, shift (multiply) it appropriately, 457 // up to wordSize, add the header, and align to object size. 458 size_t size_in_bytes; 459 #ifdef _M_IA64 460 // The Windows Itanium Aug 2002 SDK hoists this load above 461 // the check for s < 0. An oop at the end of the heap will 462 // cause an access violation if this load is performed on a non 463 // array oop. Making the reference volatile prohibits this. 464 // (%%% please explain by what magic the length is actually fetched!) 465 volatile int *array_length; 466 array_length = (volatile int *)( (intptr_t)this + 467 arrayOopDesc::length_offset_in_bytes() ); 468 assert(array_length > 0, "Integer arithmetic problem somewhere"); 469 // Put into size_t to avoid overflow. 470 size_in_bytes = (size_t) array_length; 471 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh); 472 #else 473 size_t array_length = (size_t) ((arrayOop)this)->length(); 474 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh); 475 #endif 476 size_in_bytes += Klass::layout_helper_header_size(lh); 477 478 // This code could be simplified, but by keeping array_header_in_bytes 479 // in units of bytes and doing it this way we can round up just once, 480 // skipping the intermediate round to HeapWordSize. Cast the result 481 // of round_to to size_t to guarantee unsigned division == right shift. 482 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) / 483 HeapWordSize); 484 485 // UseParNewGC, UseParallelGC and UseG1GC can change the length field 486 // of an "old copy" of an object array in the young gen so it indicates 487 // the grey portion of an already copied array. This will cause the first 488 // disjunct below to fail if the two comparands are computed across such 489 // a concurrent change. 490 // UseParNewGC also runs with promotion labs (which look like int 491 // filler arrays) which are subject to changing their declared size 492 // when finally retiring a PLAB; this also can cause the first disjunct 493 // to fail for another worker thread that is concurrently walking the block 494 // offset table. Both these invariant failures are benign for their 495 // current uses; we relax the assertion checking to cover these two cases below: 496 // is_objArray() && is_forwarded() // covers first scenario above 497 // || is_typeArray() // covers second scenario above 498 // If and when UseParallelGC uses the same obj array oop stealing/chunking 499 // technique, we will need to suitably modify the assertion. 500 assert((s == klass->oop_size(this)) || 501 (Universe::heap()->is_gc_active() && 502 ((is_typeArray() && UseParNewGC) || 503 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))), 504 "wrong array object size"); 505 } else { 506 // Must be zero, so bite the bullet and take the virtual call. 507 s = klass->oop_size(this); 508 } 509 } 510 511 assert(s % MinObjAlignment == 0, "alignment check"); 512 assert(s > 0, "Bad size calculated"); 513 return s; 514 } 515 516 517 inline int oopDesc::size() { 518 return size_given_klass(klass()); 519 } 520 521 inline void update_barrier_set(void* p, oop v, bool release = false) { 522 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!"); 523 oopDesc::bs()->write_ref_field(p, v, release); 524 } 525 526 template <class T> inline void update_barrier_set_pre(T* p, oop v) { 527 oopDesc::bs()->write_ref_field_pre(p, v); 528 } 529 530 template <class T> inline void oop_store(T* p, oop v) { 531 if (always_do_update_barrier) { 532 oop_store((volatile T*)p, v); 533 } else { 534 update_barrier_set_pre(p, v); 535 oopDesc::encode_store_heap_oop(p, v); 536 // always_do_update_barrier == false => 537 // Either we are at a safepoint (in GC) or CMS is not used. In both 538 // cases it's unnecessary to mark the card as dirty with release sematics. 539 update_barrier_set((void*)p, v, false /* release */); // cast away type 540 } 541 } 542 543 template <class T> inline void oop_store(volatile T* p, oop v) { 544 update_barrier_set_pre((T*)p, v); // cast away volatile 545 // Used by release_obj_field_put, so use release_store_ptr. 546 oopDesc::release_encode_store_heap_oop(p, v); 547 // When using CMS we must mark the card corresponding to p as dirty 548 // with release sematics to prevent that CMS sees the dirty card but 549 // not the new value v at p due to reordering of the two 550 // stores. Note that CMS has a concurrent precleaning phase, where 551 // it reads the card table while the Java threads are running. 552 update_barrier_set((void*)p, v, true /* release */); // cast away type 553 } 554 555 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops 556 // (without having to remember the function name this calls). 557 inline void oop_store_raw(HeapWord* addr, oop value) { 558 if (UseCompressedOops) { 559 oopDesc::encode_store_heap_oop((narrowOop*)addr, value); 560 } else { 561 oopDesc::encode_store_heap_oop((oop*)addr, value); 562 } 563 } 564 565 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value, 566 volatile HeapWord *dest, 567 oop compare_value, 568 bool prebarrier) { 569 #if INCLUDE_ALL_GCS 570 if (UseShenandoahGC && ShenandoahCASBarrier) { 571 return ShenandoahBarrierSet::barrier_set()->oop_atomic_cmpxchg_in_heap(exchange_value, dest, compare_value); 572 } 573 #endif 574 if (UseCompressedOops) { 575 if (prebarrier) { 576 update_barrier_set_pre((narrowOop*)dest, exchange_value); 577 } 578 // encode exchange and compare value from oop to T 579 narrowOop val = encode_heap_oop(exchange_value); 580 narrowOop cmp = encode_heap_oop(compare_value); 581 582 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp); 583 // decode old from T to oop 584 return decode_heap_oop(old); 585 } else { 586 if (prebarrier) { 587 update_barrier_set_pre((oop*)dest, exchange_value); 588 } 589 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value); 590 } 591 } 592 593 // Used only for markSweep, scavenging 594 inline bool oopDesc::is_gc_marked() const { 595 return mark()->is_marked(); 596 } 597 598 inline bool oopDesc::is_locked() const { 599 return mark()->is_locked(); 600 } 601 602 inline bool oopDesc::is_unlocked() const { 603 return mark()->is_unlocked(); 604 } 605 606 inline bool oopDesc::has_bias_pattern() const { 607 return mark()->has_bias_pattern(); 608 } 609 610 611 // used only for asserts 612 inline bool oopDesc::is_oop(bool ignore_mark_word) const { 613 oop obj = (oop) this; 614 if (!check_obj_alignment(obj)) return false; 615 if (!Universe::heap()->is_in_reserved(obj)) return false; 616 // obj is aligned and accessible in heap 617 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false; 618 619 // Header verification: the mark is typically non-NULL. If we're 620 // at a safepoint, it must not be null. 621 // Outside of a safepoint, the header could be changing (for example, 622 // another thread could be inflating a lock on this object). 623 if (ignore_mark_word) { 624 return true; 625 } 626 if (mark() != NULL) { 627 return true; 628 } 629 return !SafepointSynchronize::is_at_safepoint(); 630 } 631 632 633 // used only for asserts 634 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const { 635 return this == NULL ? true : is_oop(ignore_mark_word); 636 } 637 638 #ifndef PRODUCT 639 // used only for asserts 640 inline bool oopDesc::is_unlocked_oop() const { 641 if (!Universe::heap()->is_in_reserved(this)) return false; 642 return mark()->is_unlocked(); 643 } 644 #endif // PRODUCT 645 646 inline void oopDesc::follow_contents(void) { 647 assert (is_gc_marked(), "should be marked"); 648 klass()->oop_follow_contents(this); 649 } 650 651 // Used by scavengers 652 653 inline bool oopDesc::is_forwarded() const { 654 // The extra heap check is needed since the obj might be locked, in which case the 655 // mark would point to a stack location and have the sentinel bit cleared 656 return mark()->is_marked(); 657 } 658 659 // Used by scavengers 660 inline void oopDesc::forward_to(oop p) { 661 assert(check_obj_alignment(p), 662 "forwarding to something not aligned"); 663 assert(Universe::heap()->is_in_reserved(p), 664 "forwarding to something not in heap"); 665 markOop m = markOopDesc::encode_pointer_as_mark(p); 666 assert(m->decode_pointer() == p, "encoding must be reversable"); 667 set_mark(m); 668 } 669 670 // Used by parallel scavengers 671 inline bool oopDesc::cas_forward_to(oop p, markOop compare) { 672 assert(check_obj_alignment(p), 673 "forwarding to something not aligned"); 674 assert(Universe::heap()->is_in_reserved(p), 675 "forwarding to something not in heap"); 676 markOop m = markOopDesc::encode_pointer_as_mark(p); 677 assert(m->decode_pointer() == p, "encoding must be reversable"); 678 return cas_set_mark(m, compare) == compare; 679 } 680 681 // Note that the forwardee is not the same thing as the displaced_mark. 682 // The forwardee is used when copying during scavenge and mark-sweep. 683 // It does need to clear the low two locking- and GC-related bits. 684 inline oop oopDesc::forwardee() const { 685 return (oop) mark()->decode_pointer(); 686 } 687 688 inline bool oopDesc::has_displaced_mark() const { 689 return mark()->has_displaced_mark_helper(); 690 } 691 692 inline markOop oopDesc::displaced_mark() const { 693 return mark()->displaced_mark_helper(); 694 } 695 696 inline void oopDesc::set_displaced_mark(markOop m) { 697 mark()->set_displaced_mark_helper(m); 698 } 699 700 // The following method needs to be MT safe. 701 inline uint oopDesc::age() const { 702 assert(!is_forwarded(), "Attempt to read age from forwarded mark"); 703 if (has_displaced_mark()) { 704 return displaced_mark()->age(); 705 } else { 706 return mark()->age(); 707 } 708 } 709 710 inline void oopDesc::incr_age() { 711 assert(!is_forwarded(), "Attempt to increment age of forwarded mark"); 712 if (has_displaced_mark()) { 713 set_displaced_mark(displaced_mark()->incr_age()); 714 } else { 715 set_mark(mark()->incr_age()); 716 } 717 } 718 719 720 inline intptr_t oopDesc::identity_hash() { 721 // Fast case; if the object is unlocked and the hash value is set, no locking is needed 722 // Note: The mark must be read into local variable to avoid concurrent updates. 723 markOop mrk = mark(); 724 if (mrk->is_unlocked() && !mrk->has_no_hash()) { 725 return mrk->hash(); 726 } else if (mrk->is_marked()) { 727 return mrk->hash(); 728 } else { 729 return slow_identity_hash(); 730 } 731 } 732 733 inline int oopDesc::adjust_pointers() { 734 debug_only(int check_size = size()); 735 int s = klass()->oop_adjust_pointers(this); 736 assert(s == check_size, "should be the same"); 737 return s; 738 } 739 740 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 741 \ 742 inline int oopDesc::oop_iterate(OopClosureType* blk) { \ 743 SpecializationStats::record_call(); \ 744 return klass()->oop_oop_iterate##nv_suffix(this, blk); \ 745 } \ 746 \ 747 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \ 748 SpecializationStats::record_call(); \ 749 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \ 750 } 751 752 753 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) { 754 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all 755 // the do_oop calls, but turns off all other features in ExtendedOopClosure. 756 NoHeaderExtendedOopClosure cl(blk); 757 return oop_iterate(&cl); 758 } 759 760 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) { 761 NoHeaderExtendedOopClosure cl(blk); 762 return oop_iterate(&cl, mr); 763 } 764 765 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN) 766 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN) 767 768 #if INCLUDE_ALL_GCS 769 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 770 \ 771 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \ 772 SpecializationStats::record_call(); \ 773 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \ 774 } 775 776 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN) 777 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN) 778 #endif // INCLUDE_ALL_GCS 779 780 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP