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