1 /* 2 * Copyright (c) 1997, 2015, 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 46 // Implementation of all inlined member functions defined in oop.hpp 47 // We need a separate file to avoid circular references 48 49 inline void oopDesc::release_set_mark(markOop m) { 50 OrderAccess::release_store_ptr(&_mark, m); 51 } 52 53 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) { 54 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark); 55 } 56 57 inline Klass* oopDesc::klass() const { 58 if (UseCompressedClassPointers) { 59 return Klass::decode_klass_not_null(_metadata._compressed_klass); 60 } else { 61 return _metadata._klass; 62 } 63 } 64 65 inline Klass* oopDesc::klass_or_null() const volatile { 66 // can be NULL in CMS 67 if (UseCompressedClassPointers) { 68 return Klass::decode_klass(_metadata._compressed_klass); 69 } else { 70 return _metadata._klass; 71 } 72 } 73 74 inline Klass** oopDesc::klass_addr() { 75 // Only used internally and with CMS and will not work with 76 // UseCompressedOops 77 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers"); 78 return (Klass**) &_metadata._klass; 79 } 80 81 inline narrowKlass* oopDesc::compressed_klass_addr() { 82 assert(UseCompressedClassPointers, "only called by compressed klass pointers"); 83 return &_metadata._compressed_klass; 84 } 85 86 inline void oopDesc::set_klass(Klass* k) { 87 // since klasses are promoted no store check is needed 88 assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*"); 89 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*"); 90 if (UseCompressedClassPointers) { 91 *compressed_klass_addr() = Klass::encode_klass_not_null(k); 92 } else { 93 *klass_addr() = k; 94 } 95 } 96 97 inline int oopDesc::klass_gap() const { 98 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()); 99 } 100 101 inline void oopDesc::set_klass_gap(int v) { 102 if (UseCompressedClassPointers) { 103 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v; 104 } 105 } 106 107 inline void oopDesc::set_klass_to_list_ptr(oop k) { 108 // This is only to be used during GC, for from-space objects, so no 109 // barrier is needed. 110 if (UseCompressedClassPointers) { 111 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling) 112 } else { 113 _metadata._klass = (Klass*)(address)k; 114 } 115 } 116 117 inline oop oopDesc::list_ptr_from_klass() { 118 // This is only to be used during GC, for from-space objects. 119 if (UseCompressedClassPointers) { 120 return decode_heap_oop((narrowOop)_metadata._compressed_klass); 121 } else { 122 // Special case for GC 123 return (oop)(address)_metadata._klass; 124 } 125 } 126 127 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); } 128 129 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); } 130 131 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); } 132 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); } 133 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); } 134 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); } 135 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); } 136 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); } 137 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); } 138 139 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; } 140 141 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); } 142 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); } 143 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); } 144 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); } 145 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); } 146 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); } 147 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); } 148 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); } 149 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); } 150 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); } 151 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); } 152 153 154 // Functions for getting and setting oops within instance objects. 155 // If the oops are compressed, the type passed to these overloaded functions 156 // is narrowOop. All functions are overloaded so they can be called by 157 // template functions without conditionals (the compiler instantiates via 158 // the right type and inlines the appopriate code). 159 160 inline bool oopDesc::is_null(oop obj) { return obj == NULL; } 161 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; } 162 163 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit 164 // offset from the heap base. Saving the check for null can save instructions 165 // in inner GC loops so these are separated. 166 167 inline bool check_obj_alignment(oop obj) { 168 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0; 169 } 170 171 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) { 172 assert(!is_null(v), "oop value can never be zero"); 173 assert(check_obj_alignment(v), "Address not aligned"); 174 assert(Universe::heap()->is_in_reserved(v), "Address not in heap"); 175 address base = Universe::narrow_oop_base(); 176 int shift = Universe::narrow_oop_shift(); 177 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1)); 178 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding"); 179 uint64_t result = pd >> shift; 180 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow"); 181 assert(decode_heap_oop(result) == v, "reversibility"); 182 return (narrowOop)result; 183 } 184 185 inline narrowOop oopDesc::encode_heap_oop(oop v) { 186 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v); 187 } 188 189 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) { 190 assert(!is_null(v), "narrow oop value can never be zero"); 191 address base = Universe::narrow_oop_base(); 192 int shift = Universe::narrow_oop_shift(); 193 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift)); 194 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result))); 195 return result; 196 } 197 198 inline oop oopDesc::decode_heap_oop(narrowOop v) { 199 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v); 200 } 201 202 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; } 203 inline oop oopDesc::decode_heap_oop(oop v) { return v; } 204 205 // Load an oop out of the Java heap as is without decoding. 206 // Called by GC to check for null before decoding. 207 inline oop oopDesc::load_heap_oop(oop* p) { return *p; } 208 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; } 209 210 // Load and decode an oop out of the Java heap into a wide oop. 211 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; } 212 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) { 213 return decode_heap_oop_not_null(*p); 214 } 215 216 // Load and decode an oop out of the heap accepting null 217 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; } 218 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) { 219 return decode_heap_oop(*p); 220 } 221 222 // Store already encoded heap oop into the heap. 223 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; } 224 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; } 225 226 // Encode and store a heap oop. 227 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) { 228 *p = encode_heap_oop_not_null(v); 229 } 230 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; } 231 232 // Encode and store a heap oop allowing for null. 233 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) { 234 *p = encode_heap_oop(v); 235 } 236 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; } 237 238 // Store heap oop as is for volatile fields. 239 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) { 240 OrderAccess::release_store_ptr(p, v); 241 } 242 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p, 243 narrowOop v) { 244 OrderAccess::release_store(p, v); 245 } 246 247 inline void oopDesc::release_encode_store_heap_oop_not_null( 248 volatile narrowOop* p, oop v) { 249 // heap oop is not pointer sized. 250 OrderAccess::release_store(p, encode_heap_oop_not_null(v)); 251 } 252 253 inline void oopDesc::release_encode_store_heap_oop_not_null( 254 volatile oop* p, oop v) { 255 OrderAccess::release_store_ptr(p, v); 256 } 257 258 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p, 259 oop v) { 260 OrderAccess::release_store_ptr(p, v); 261 } 262 inline void oopDesc::release_encode_store_heap_oop( 263 volatile narrowOop* p, oop v) { 264 OrderAccess::release_store(p, encode_heap_oop(v)); 265 } 266 267 268 // These functions are only used to exchange oop fields in instances, 269 // not headers. 270 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) { 271 if (UseCompressedOops) { 272 // encode exchange value from oop to T 273 narrowOop val = encode_heap_oop(exchange_value); 274 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest); 275 // decode old from T to oop 276 return decode_heap_oop(old); 277 } else { 278 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest); 279 } 280 } 281 282 // In order to put or get a field out of an instance, must first check 283 // if the field has been compressed and uncompress it. 284 inline oop oopDesc::obj_field(int offset) const { 285 return UseCompressedOops ? 286 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) : 287 load_decode_heap_oop(obj_field_addr<oop>(offset)); 288 } 289 inline volatile oop oopDesc::obj_field_volatile(int offset) const { 290 volatile oop value = obj_field(offset); 291 OrderAccess::acquire(); 292 return value; 293 } 294 inline void oopDesc::obj_field_put(int offset, oop value) { 295 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) : 296 oop_store(obj_field_addr<oop>(offset), value); 297 } 298 299 inline Metadata* oopDesc::metadata_field(int offset) const { 300 return *metadata_field_addr(offset); 301 } 302 303 inline void oopDesc::metadata_field_put(int offset, Metadata* value) { 304 *metadata_field_addr(offset) = value; 305 } 306 307 inline void oopDesc::obj_field_put_raw(int offset, oop value) { 308 UseCompressedOops ? 309 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) : 310 encode_store_heap_oop(obj_field_addr<oop>(offset), value); 311 } 312 inline void oopDesc::obj_field_put_volatile(int offset, oop value) { 313 OrderAccess::release(); 314 obj_field_put(offset, value); 315 OrderAccess::fence(); 316 } 317 318 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); } 319 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; } 320 321 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); } 322 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (jint) contents; } 323 324 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); } 325 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; } 326 327 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); } 328 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; } 329 330 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); } 331 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;} 332 333 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); } 334 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; } 335 336 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); } 337 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; } 338 339 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); } 340 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; } 341 342 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); } 343 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; } 344 345 inline oop oopDesc::obj_field_acquire(int offset) const { 346 return UseCompressedOops ? 347 decode_heap_oop((narrowOop) 348 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset))) 349 : decode_heap_oop((oop) 350 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset))); 351 } 352 inline void oopDesc::release_obj_field_put(int offset, oop value) { 353 UseCompressedOops ? 354 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) : 355 oop_store((volatile oop*) obj_field_addr<oop>(offset), value); 356 } 357 358 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); } 359 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); } 360 361 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); } 362 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), contents); } 363 364 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); } 365 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); } 366 367 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); } 368 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); } 369 370 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); } 371 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); } 372 373 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); } 374 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); } 375 376 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); } 377 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); } 378 379 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); } 380 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); } 381 382 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); } 383 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); } 384 385 inline int oopDesc::size_given_klass(Klass* klass) { 386 int lh = klass->layout_helper(); 387 int s; 388 389 // lh is now a value computed at class initialization that may hint 390 // at the size. For instances, this is positive and equal to the 391 // size. For arrays, this is negative and provides log2 of the 392 // array element size. For other oops, it is zero and thus requires 393 // a virtual call. 394 // 395 // We go to all this trouble because the size computation is at the 396 // heart of phase 2 of mark-compaction, and called for every object, 397 // alive or dead. So the speed here is equal in importance to the 398 // speed of allocation. 399 400 if (lh > Klass::_lh_neutral_value) { 401 if (!Klass::layout_helper_needs_slow_path(lh)) { 402 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize 403 } else { 404 s = klass->oop_size(this); 405 } 406 } else if (lh <= Klass::_lh_neutral_value) { 407 // The most common case is instances; fall through if so. 408 if (lh < Klass::_lh_neutral_value) { 409 // Second most common case is arrays. We have to fetch the 410 // length of the array, shift (multiply) it appropriately, 411 // up to wordSize, add the header, and align to object size. 412 size_t size_in_bytes; 413 #ifdef _M_IA64 414 // The Windows Itanium Aug 2002 SDK hoists this load above 415 // the check for s < 0. An oop at the end of the heap will 416 // cause an access violation if this load is performed on a non 417 // array oop. Making the reference volatile prohibits this. 418 // (%%% please explain by what magic the length is actually fetched!) 419 volatile int *array_length; 420 array_length = (volatile int *)( (intptr_t)this + 421 arrayOopDesc::length_offset_in_bytes() ); 422 assert(array_length > 0, "Integer arithmetic problem somewhere"); 423 // Put into size_t to avoid overflow. 424 size_in_bytes = (size_t) array_length; 425 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh); 426 #else 427 size_t array_length = (size_t) ((arrayOop)this)->length(); 428 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh); 429 #endif 430 size_in_bytes += Klass::layout_helper_header_size(lh); 431 432 // This code could be simplified, but by keeping array_header_in_bytes 433 // in units of bytes and doing it this way we can round up just once, 434 // skipping the intermediate round to HeapWordSize. Cast the result 435 // of round_to to size_t to guarantee unsigned division == right shift. 436 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) / 437 HeapWordSize); 438 439 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field 440 // of an "old copy" of an object array in the young gen so it indicates 441 // the grey portion of an already copied array. This will cause the first 442 // disjunct below to fail if the two comparands are computed across such 443 // a concurrent change. 444 // ParNew also runs with promotion labs (which look like int 445 // filler arrays) which are subject to changing their declared size 446 // when finally retiring a PLAB; this also can cause the first disjunct 447 // to fail for another worker thread that is concurrently walking the block 448 // offset table. Both these invariant failures are benign for their 449 // current uses; we relax the assertion checking to cover these two cases below: 450 // is_objArray() && is_forwarded() // covers first scenario above 451 // || is_typeArray() // covers second scenario above 452 // If and when UseParallelGC uses the same obj array oop stealing/chunking 453 // technique, we will need to suitably modify the assertion. 454 assert((s == klass->oop_size(this)) || 455 (Universe::heap()->is_gc_active() && 456 ((is_typeArray() && UseConcMarkSweepGC) || 457 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))), 458 "wrong array object size"); 459 } else { 460 // Must be zero, so bite the bullet and take the virtual call. 461 s = klass->oop_size(this); 462 } 463 } 464 465 assert(s % MinObjAlignment == 0, "alignment check"); 466 assert(s > 0, "Bad size calculated"); 467 return s; 468 } 469 470 471 inline int oopDesc::size() { 472 return size_given_klass(klass()); 473 } 474 475 inline void update_barrier_set(void* p, oop v, bool release = false) { 476 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!"); 477 oopDesc::bs()->write_ref_field(p, v, release); 478 } 479 480 template <class T> inline void update_barrier_set_pre(T* p, oop v) { 481 oopDesc::bs()->write_ref_field_pre(p, v); 482 } 483 484 template <class T> inline void oop_store(T* p, oop v) { 485 if (always_do_update_barrier) { 486 oop_store((volatile T*)p, v); 487 } else { 488 update_barrier_set_pre(p, v); 489 oopDesc::encode_store_heap_oop(p, v); 490 // always_do_update_barrier == false => 491 // Either we are at a safepoint (in GC) or CMS is not used. In both 492 // cases it's unnecessary to mark the card as dirty with release sematics. 493 update_barrier_set((void*)p, v, false /* release */); // cast away type 494 } 495 } 496 497 template <class T> inline void oop_store(volatile T* p, oop v) { 498 update_barrier_set_pre((T*)p, v); // cast away volatile 499 // Used by release_obj_field_put, so use release_store_ptr. 500 oopDesc::release_encode_store_heap_oop(p, v); 501 // When using CMS we must mark the card corresponding to p as dirty 502 // with release sematics to prevent that CMS sees the dirty card but 503 // not the new value v at p due to reordering of the two 504 // stores. Note that CMS has a concurrent precleaning phase, where 505 // it reads the card table while the Java threads are running. 506 update_barrier_set((void*)p, v, true /* release */); // cast away type 507 } 508 509 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops 510 // (without having to remember the function name this calls). 511 inline void oop_store_raw(HeapWord* addr, oop value) { 512 if (UseCompressedOops) { 513 oopDesc::encode_store_heap_oop((narrowOop*)addr, value); 514 } else { 515 oopDesc::encode_store_heap_oop((oop*)addr, value); 516 } 517 } 518 519 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value, 520 volatile HeapWord *dest, 521 oop compare_value, 522 bool prebarrier) { 523 if (UseCompressedOops) { 524 if (prebarrier) { 525 update_barrier_set_pre((narrowOop*)dest, exchange_value); 526 } 527 // encode exchange and compare value from oop to T 528 narrowOop val = encode_heap_oop(exchange_value); 529 narrowOop cmp = encode_heap_oop(compare_value); 530 531 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp); 532 // decode old from T to oop 533 return decode_heap_oop(old); 534 } else { 535 if (prebarrier) { 536 update_barrier_set_pre((oop*)dest, exchange_value); 537 } 538 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value); 539 } 540 } 541 542 // Used only for markSweep, scavenging 543 inline bool oopDesc::is_gc_marked() const { 544 return mark()->is_marked(); 545 } 546 547 inline bool oopDesc::is_locked() const { 548 return mark()->is_locked(); 549 } 550 551 inline bool oopDesc::is_unlocked() const { 552 return mark()->is_unlocked(); 553 } 554 555 inline bool oopDesc::has_bias_pattern() const { 556 return mark()->has_bias_pattern(); 557 } 558 559 560 // used only for asserts 561 inline bool oopDesc::is_oop(bool ignore_mark_word) const { 562 oop obj = (oop) this; 563 if (!check_obj_alignment(obj)) return false; 564 if (!Universe::heap()->is_in_reserved(obj)) return false; 565 // obj is aligned and accessible in heap 566 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false; 567 568 // Header verification: the mark is typically non-NULL. If we're 569 // at a safepoint, it must not be null. 570 // Outside of a safepoint, the header could be changing (for example, 571 // another thread could be inflating a lock on this object). 572 if (ignore_mark_word) { 573 return true; 574 } 575 if (mark() != NULL) { 576 return true; 577 } 578 return !SafepointSynchronize::is_at_safepoint(); 579 } 580 581 582 // used only for asserts 583 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const { 584 return this == NULL ? true : is_oop(ignore_mark_word); 585 } 586 587 #ifndef PRODUCT 588 // used only for asserts 589 inline bool oopDesc::is_unlocked_oop() const { 590 if (!Universe::heap()->is_in_reserved(this)) return false; 591 return mark()->is_unlocked(); 592 } 593 #endif // PRODUCT 594 595 inline void oopDesc::follow_contents(void) { 596 assert (is_gc_marked(), "should be marked"); 597 klass()->oop_follow_contents(this); 598 } 599 600 inline bool oopDesc::is_scavengable() const { 601 return Universe::heap()->is_scavengable(this); 602 } 603 604 // Used by scavengers 605 inline bool oopDesc::is_forwarded() const { 606 // The extra heap check is needed since the obj might be locked, in which case the 607 // mark would point to a stack location and have the sentinel bit cleared 608 return mark()->is_marked(); 609 } 610 611 // Used by scavengers 612 inline void oopDesc::forward_to(oop p) { 613 assert(check_obj_alignment(p), 614 "forwarding to something not aligned"); 615 assert(Universe::heap()->is_in_reserved(p), 616 "forwarding to something not in heap"); 617 markOop m = markOopDesc::encode_pointer_as_mark(p); 618 assert(m->decode_pointer() == p, "encoding must be reversable"); 619 set_mark(m); 620 } 621 622 // Used by parallel scavengers 623 inline bool oopDesc::cas_forward_to(oop p, markOop compare) { 624 assert(check_obj_alignment(p), 625 "forwarding to something not aligned"); 626 assert(Universe::heap()->is_in_reserved(p), 627 "forwarding to something not in heap"); 628 markOop m = markOopDesc::encode_pointer_as_mark(p); 629 assert(m->decode_pointer() == p, "encoding must be reversable"); 630 return cas_set_mark(m, compare) == compare; 631 } 632 633 // Note that the forwardee is not the same thing as the displaced_mark. 634 // The forwardee is used when copying during scavenge and mark-sweep. 635 // It does need to clear the low two locking- and GC-related bits. 636 inline oop oopDesc::forwardee() const { 637 return (oop) mark()->decode_pointer(); 638 } 639 640 inline bool oopDesc::has_displaced_mark() const { 641 return mark()->has_displaced_mark_helper(); 642 } 643 644 inline markOop oopDesc::displaced_mark() const { 645 return mark()->displaced_mark_helper(); 646 } 647 648 inline void oopDesc::set_displaced_mark(markOop m) { 649 mark()->set_displaced_mark_helper(m); 650 } 651 652 // The following method needs to be MT safe. 653 inline uint oopDesc::age() const { 654 assert(!is_forwarded(), "Attempt to read age from forwarded mark"); 655 if (has_displaced_mark()) { 656 return displaced_mark()->age(); 657 } else { 658 return mark()->age(); 659 } 660 } 661 662 inline void oopDesc::incr_age() { 663 assert(!is_forwarded(), "Attempt to increment age of forwarded mark"); 664 if (has_displaced_mark()) { 665 set_displaced_mark(displaced_mark()->incr_age()); 666 } else { 667 set_mark(mark()->incr_age()); 668 } 669 } 670 671 672 inline intptr_t oopDesc::identity_hash() { 673 // Fast case; if the object is unlocked and the hash value is set, no locking is needed 674 // Note: The mark must be read into local variable to avoid concurrent updates. 675 markOop mrk = mark(); 676 if (mrk->is_unlocked() && !mrk->has_no_hash()) { 677 return mrk->hash(); 678 } else if (mrk->is_marked()) { 679 return mrk->hash(); 680 } else { 681 return slow_identity_hash(); 682 } 683 } 684 685 inline int oopDesc::adjust_pointers() { 686 debug_only(int check_size = size()); 687 int s = klass()->oop_adjust_pointers(this); 688 assert(s == check_size, "should be the same"); 689 return s; 690 } 691 692 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 693 \ 694 inline int oopDesc::oop_iterate(OopClosureType* blk) { \ 695 return klass()->oop_oop_iterate##nv_suffix(this, blk); \ 696 } \ 697 \ 698 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \ 699 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \ 700 } 701 702 703 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) { 704 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all 705 // the do_oop calls, but turns off all other features in ExtendedOopClosure. 706 NoHeaderExtendedOopClosure cl(blk); 707 return oop_iterate(&cl); 708 } 709 710 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) { 711 NoHeaderExtendedOopClosure cl(blk); 712 return oop_iterate(&cl, mr); 713 } 714 715 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN) 716 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN) 717 718 #if INCLUDE_ALL_GCS 719 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 720 \ 721 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \ 722 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \ 723 } 724 725 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN) 726 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN) 727 #endif // INCLUDE_ALL_GCS 728 729 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP