1 /* 2 * Copyright (c) 1997, 2023, 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_OOPS_OOP_INLINE_HPP 26 #define SHARE_OOPS_OOP_INLINE_HPP 27 28 #include "oops/oop.hpp" 29 30 #include "memory/universe.hpp" 31 #include "memory/iterator.inline.hpp" 32 #include "oops/access.inline.hpp" 33 #include "oops/arrayKlass.hpp" 34 #include "oops/arrayOop.hpp" 35 #include "oops/compressedOops.inline.hpp" 36 #include "oops/instanceKlass.hpp" 37 #include "oops/markWord.hpp" 38 #include "oops/oopsHierarchy.hpp" 39 #include "runtime/atomic.hpp" 40 #include "runtime/globals.hpp" 41 #include "utilities/align.hpp" 42 #include "utilities/debug.hpp" 43 #include "utilities/macros.hpp" 44 #include "utilities/globalDefinitions.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 markWord oopDesc::mark() const { 50 return Atomic::load(&_mark); 51 } 52 53 markWord oopDesc::mark_acquire() const { 54 return Atomic::load_acquire(&_mark); 55 } 56 57 markWord* oopDesc::mark_addr() const { 58 return (markWord*) &_mark; 59 } 60 61 void oopDesc::set_mark(markWord m) { 62 Atomic::store(&_mark, m); 63 } 64 65 void oopDesc::set_mark(HeapWord* mem, markWord m) { 66 *(markWord*)(((char*)mem) + mark_offset_in_bytes()) = m; 67 } 68 69 void oopDesc::release_set_mark(markWord m) { 70 Atomic::release_store(&_mark, m); 71 } 72 73 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark) { 74 return Atomic::cmpxchg(&_mark, old_mark, new_mark); 75 } 76 77 markWord oopDesc::cas_set_mark(markWord new_mark, markWord old_mark, atomic_memory_order order) { 78 return Atomic::cmpxchg(&_mark, old_mark, new_mark, order); 79 } 80 81 void oopDesc::init_mark() { 82 set_mark(markWord::prototype()); 83 } 84 85 Klass* oopDesc::klass() const { 86 if (UseCompressedClassPointers) { 87 return CompressedKlassPointers::decode_not_null(_metadata._compressed_klass); 88 } else { 89 return _metadata._klass; 90 } 91 } 92 93 Klass* oopDesc::klass_or_null() const { 94 if (UseCompressedClassPointers) { 95 return CompressedKlassPointers::decode(_metadata._compressed_klass); 96 } else { 97 return _metadata._klass; 98 } 99 } 100 101 Klass* oopDesc::klass_or_null_acquire() const { 102 if (UseCompressedClassPointers) { 103 narrowKlass nklass = Atomic::load_acquire(&_metadata._compressed_klass); 104 return CompressedKlassPointers::decode(nklass); 105 } else { 106 return Atomic::load_acquire(&_metadata._klass); 107 } 108 } 109 110 void oopDesc::set_klass(Klass* k) { 111 assert(Universe::is_bootstrapping() || (k != NULL && k->is_klass()), "incorrect Klass"); 112 if (UseCompressedClassPointers) { 113 _metadata._compressed_klass = CompressedKlassPointers::encode_not_null(k); 114 } else { 115 _metadata._klass = k; 116 } 117 } 118 119 void oopDesc::release_set_klass(HeapWord* mem, Klass* k) { 120 assert(Universe::is_bootstrapping() || (k != NULL && k->is_klass()), "incorrect Klass"); 121 char* raw_mem = ((char*)mem + klass_offset_in_bytes()); 122 if (UseCompressedClassPointers) { 123 Atomic::release_store((narrowKlass*)raw_mem, 124 CompressedKlassPointers::encode_not_null(k)); 125 } else { 126 Atomic::release_store((Klass**)raw_mem, k); 127 } 128 } 129 130 void oopDesc::set_klass_gap(HeapWord* mem, int v) { 131 if (UseCompressedClassPointers) { 132 *(int*)(((char*)mem) + klass_gap_offset_in_bytes()) = v; 133 } 134 } 135 136 bool oopDesc::is_a(Klass* k) const { 137 return klass()->is_subtype_of(k); 138 } 139 140 size_t oopDesc::size() { 141 return size_given_klass(klass()); 142 } 143 144 size_t oopDesc::size_given_klass(Klass* klass) { 145 int lh = klass->layout_helper(); 146 size_t s; 147 148 // lh is now a value computed at class initialization that may hint 149 // at the size. For instances, this is positive and equal to the 150 // size. For arrays, this is negative and provides log2 of the 151 // array element size. For other oops, it is zero and thus requires 152 // a virtual call. 153 // 154 // We go to all this trouble because the size computation is at the 155 // heart of phase 2 of mark-compaction, and called for every object, 156 // alive or dead. So the speed here is equal in importance to the 157 // speed of allocation. 158 159 if (lh > Klass::_lh_neutral_value) { 160 if (!Klass::layout_helper_needs_slow_path(lh)) { 161 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize 162 } else { 163 s = klass->oop_size(this); 164 } 165 } else if (lh <= Klass::_lh_neutral_value) { 166 // The most common case is instances; fall through if so. 167 if (lh < Klass::_lh_neutral_value) { 168 // Second most common case is arrays. We have to fetch the 169 // length of the array, shift (multiply) it appropriately, 170 // up to wordSize, add the header, and align to object size. 171 size_t size_in_bytes; 172 size_t array_length = (size_t) ((arrayOop)this)->length(); 173 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh); 174 size_in_bytes += Klass::layout_helper_header_size(lh); 175 176 // This code could be simplified, but by keeping array_header_in_bytes 177 // in units of bytes and doing it this way we can round up just once, 178 // skipping the intermediate round to HeapWordSize. 179 s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize; 180 181 assert(s == klass->oop_size(this) || size_might_change(), "wrong array object size"); 182 } else { 183 // Must be zero, so bite the bullet and take the virtual call. 184 s = klass->oop_size(this); 185 } 186 } 187 188 assert(s > 0, "Oop size must be greater than zero, not " SIZE_FORMAT, s); 189 assert(is_object_aligned(s), "Oop size is not properly aligned: " SIZE_FORMAT, s); 190 return s; 191 } 192 193 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); } 194 bool oopDesc::is_instanceRef() const { return klass()->is_reference_instance_klass(); } 195 bool oopDesc::is_stackChunk() const { return klass()->is_stack_chunk_instance_klass(); } 196 bool oopDesc::is_array() const { return klass()->is_array_klass(); } 197 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); } 198 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); } 199 200 template<typename T> 201 T* oopDesc::field_addr(int offset) const { return reinterpret_cast<T*>(cast_from_oop<intptr_t>(as_oop()) + offset); } 202 203 template <typename T> 204 size_t oopDesc::field_offset(T* p) const { return pointer_delta((void*)p, (void*)this, 1); } 205 206 template <DecoratorSet decorators> 207 inline oop oopDesc::obj_field_access(int offset) const { return HeapAccess<decorators>::oop_load_at(as_oop(), offset); } 208 inline oop oopDesc::obj_field(int offset) const { return HeapAccess<>::oop_load_at(as_oop(), offset); } 209 210 inline void oopDesc::obj_field_put(int offset, oop value) { HeapAccess<>::oop_store_at(as_oop(), offset, value); } 211 template <DecoratorSet decorators> 212 inline void oopDesc::obj_field_put_access(int offset, oop value) { HeapAccess<decorators>::oop_store_at(as_oop(), offset, value); } 213 214 inline jbyte oopDesc::byte_field(int offset) const { return *field_addr<jbyte>(offset); } 215 inline void oopDesc::byte_field_put(int offset, jbyte value) { *field_addr<jbyte>(offset) = value; } 216 217 inline jchar oopDesc::char_field(int offset) const { return *field_addr<jchar>(offset); } 218 inline void oopDesc::char_field_put(int offset, jchar value) { *field_addr<jchar>(offset) = value; } 219 220 inline jboolean oopDesc::bool_field(int offset) const { return *field_addr<jboolean>(offset); } 221 inline void oopDesc::bool_field_put(int offset, jboolean value) { *field_addr<jboolean>(offset) = jboolean(value & 1); } 222 inline jboolean oopDesc::bool_field_volatile(int offset) const { return RawAccess<MO_SEQ_CST>::load(field_addr<jboolean>(offset)); } 223 inline void oopDesc::bool_field_put_volatile(int offset, jboolean value) { RawAccess<MO_SEQ_CST>::store(field_addr<jboolean>(offset), jboolean(value & 1)); } 224 inline jshort oopDesc::short_field(int offset) const { return *field_addr<jshort>(offset); } 225 inline void oopDesc::short_field_put(int offset, jshort value) { *field_addr<jshort>(offset) = value; } 226 227 inline jint oopDesc::int_field(int offset) const { return *field_addr<jint>(offset); } 228 inline void oopDesc::int_field_put(int offset, jint value) { *field_addr<jint>(offset) = value; } 229 230 inline jlong oopDesc::long_field(int offset) const { return *field_addr<jlong>(offset); } 231 inline void oopDesc::long_field_put(int offset, jlong value) { *field_addr<jlong>(offset) = value; } 232 233 inline jfloat oopDesc::float_field(int offset) const { return *field_addr<jfloat>(offset); } 234 inline void oopDesc::float_field_put(int offset, jfloat value) { *field_addr<jfloat>(offset) = value; } 235 236 inline jdouble oopDesc::double_field(int offset) const { return *field_addr<jdouble>(offset); } 237 inline void oopDesc::double_field_put(int offset, jdouble value) { *field_addr<jdouble>(offset) = value; } 238 239 bool oopDesc::is_locked() const { 240 return mark().is_locked(); 241 } 242 243 bool oopDesc::is_unlocked() const { 244 return mark().is_unlocked(); 245 } 246 247 // Used only for markSweep, scavenging 248 bool oopDesc::is_gc_marked() const { 249 return mark().is_marked(); 250 } 251 252 // Used by scavengers 253 bool oopDesc::is_forwarded() const { 254 // The extra heap check is needed since the obj might be locked, in which case the 255 // mark would point to a stack location and have the sentinel bit cleared 256 return mark().is_marked(); 257 } 258 259 // Used by scavengers 260 void oopDesc::forward_to(oop p) { 261 verify_forwardee(p); 262 markWord m = markWord::encode_pointer_as_mark(p); 263 assert(m.decode_pointer() == p, "encoding must be reversible"); 264 set_mark(m); 265 } 266 267 oop oopDesc::forward_to_atomic(oop p, markWord compare, atomic_memory_order order) { 268 verify_forwardee(p); 269 markWord m = markWord::encode_pointer_as_mark(p); 270 assert(m.decode_pointer() == p, "encoding must be reversible"); 271 markWord old_mark = cas_set_mark(m, compare, order); 272 if (old_mark == compare) { 273 return NULL; 274 } else { 275 return cast_to_oop(old_mark.decode_pointer()); 276 } 277 } 278 279 // Note that the forwardee is not the same thing as the displaced_mark. 280 // The forwardee is used when copying during scavenge and mark-sweep. 281 // It does need to clear the low two locking- and GC-related bits. 282 oop oopDesc::forwardee() const { 283 assert(is_forwarded(), "only decode when actually forwarded"); 284 return cast_to_oop(mark().decode_pointer()); 285 } 286 287 // The following method needs to be MT safe. 288 uint oopDesc::age() const { 289 assert(!mark().is_marked(), "Attempt to read age from forwarded mark"); 290 if (has_displaced_mark()) { 291 return displaced_mark().age(); 292 } else { 293 return mark().age(); 294 } 295 } 296 297 void oopDesc::incr_age() { 298 assert(!mark().is_marked(), "Attempt to increment age of forwarded mark"); 299 if (has_displaced_mark()) { 300 set_displaced_mark(displaced_mark().incr_age()); 301 } else { 302 set_mark(mark().incr_age()); 303 } 304 } 305 306 template <typename OopClosureType> 307 void oopDesc::oop_iterate(OopClosureType* cl) { 308 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass()); 309 } 310 311 template <typename OopClosureType> 312 void oopDesc::oop_iterate(OopClosureType* cl, MemRegion mr) { 313 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, klass(), mr); 314 } 315 316 template <typename OopClosureType> 317 size_t oopDesc::oop_iterate_size(OopClosureType* cl) { 318 Klass* k = klass(); 319 size_t size = size_given_klass(k); 320 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k); 321 return size; 322 } 323 324 template <typename OopClosureType> 325 size_t oopDesc::oop_iterate_size(OopClosureType* cl, MemRegion mr) { 326 Klass* k = klass(); 327 size_t size = size_given_klass(k); 328 OopIteratorClosureDispatch::oop_oop_iterate(cl, this, k, mr); 329 return size; 330 } 331 332 template <typename OopClosureType> 333 void oopDesc::oop_iterate_backwards(OopClosureType* cl) { 334 oop_iterate_backwards(cl, klass()); 335 } 336 337 template <typename OopClosureType> 338 void oopDesc::oop_iterate_backwards(OopClosureType* cl, Klass* k) { 339 assert(k == klass(), "wrong klass"); 340 OopIteratorClosureDispatch::oop_oop_iterate_backwards(cl, this, k); 341 } 342 343 bool oopDesc::is_instanceof_or_null(oop obj, Klass* klass) { 344 return obj == NULL || obj->klass()->is_subtype_of(klass); 345 } 346 347 intptr_t oopDesc::identity_hash() { 348 // Fast case; if the object is unlocked and the hash value is set, no locking is needed 349 // Note: The mark must be read into local variable to avoid concurrent updates. 350 markWord mrk = mark(); 351 if (mrk.is_unlocked() && !mrk.has_no_hash()) { 352 return mrk.hash(); 353 } else if (mrk.is_marked()) { 354 return mrk.hash(); 355 } else { 356 return slow_identity_hash(); 357 } 358 } 359 360 // This checks fast simple case of whether the oop has_no_hash, 361 // to optimize JVMTI table lookup. 362 bool oopDesc::fast_no_hash_check() { 363 markWord mrk = mark_acquire(); 364 assert(!mrk.is_marked(), "should never be marked"); 365 return mrk.is_unlocked() && mrk.has_no_hash(); 366 } 367 368 bool oopDesc::has_displaced_mark() const { 369 return mark().has_displaced_mark_helper(); 370 } 371 372 markWord oopDesc::displaced_mark() const { 373 return mark().displaced_mark_helper(); 374 } 375 376 void oopDesc::set_displaced_mark(markWord m) { 377 mark().set_displaced_mark_helper(m); 378 } 379 380 bool oopDesc::mark_must_be_preserved() const { 381 return mark_must_be_preserved(mark()); 382 } 383 384 bool oopDesc::mark_must_be_preserved(markWord m) const { 385 return m.must_be_preserved(this); 386 } 387 388 #endif // SHARE_OOPS_OOP_INLINE_HPP