| 1 | /* | 
|---|
| 2 | * Copyright (c) 2017, 2019, 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_ACCESSBACKEND_INLINE_HPP | 
|---|
| 26 | #define SHARE_OOPS_ACCESSBACKEND_INLINE_HPP | 
|---|
| 27 |  | 
|---|
| 28 | #include "oops/access.hpp" | 
|---|
| 29 | #include "oops/accessBackend.hpp" | 
|---|
| 30 | #include "oops/compressedOops.inline.hpp" | 
|---|
| 31 | #include "oops/oopsHierarchy.hpp" | 
|---|
| 32 |  | 
|---|
| 33 | template <DecoratorSet decorators> | 
|---|
| 34 | template <DecoratorSet idecorators, typename T> | 
|---|
| 35 | inline typename EnableIf< | 
|---|
| 36 | AccessInternal::MustConvertCompressedOop<idecorators, T>::value, T>::type | 
|---|
| 37 | RawAccessBarrier<decorators>::decode_internal(typename HeapOopType<idecorators>::type value) { | 
|---|
| 38 | if (HasDecorator<decorators, IS_NOT_NULL>::value) { | 
|---|
| 39 | return CompressedOops::decode_not_null(value); | 
|---|
| 40 | } else { | 
|---|
| 41 | return CompressedOops::decode(value); | 
|---|
| 42 | } | 
|---|
| 43 | } | 
|---|
| 44 |  | 
|---|
| 45 | template <DecoratorSet decorators> | 
|---|
| 46 | template <DecoratorSet idecorators, typename T> | 
|---|
| 47 | inline typename EnableIf< | 
|---|
| 48 | AccessInternal::MustConvertCompressedOop<idecorators, T>::value, | 
|---|
| 49 | typename HeapOopType<idecorators>::type>::type | 
|---|
| 50 | RawAccessBarrier<decorators>::encode_internal(T value) { | 
|---|
| 51 | if (HasDecorator<decorators, IS_NOT_NULL>::value) { | 
|---|
| 52 | return CompressedOops::encode_not_null(value); | 
|---|
| 53 | } else { | 
|---|
| 54 | return CompressedOops::encode(value); | 
|---|
| 55 | } | 
|---|
| 56 | } | 
|---|
| 57 |  | 
|---|
| 58 | template <DecoratorSet decorators> | 
|---|
| 59 | template <typename T> | 
|---|
| 60 | inline void RawAccessBarrier<decorators>::oop_store(void* addr, T value) { | 
|---|
| 61 | typedef typename AccessInternal::EncodedType<decorators, T>::type Encoded; | 
|---|
| 62 | Encoded encoded = encode(value); | 
|---|
| 63 | store(reinterpret_cast<Encoded*>(addr), encoded); | 
|---|
| 64 | } | 
|---|
| 65 |  | 
|---|
| 66 | template <DecoratorSet decorators> | 
|---|
| 67 | template <typename T> | 
|---|
| 68 | inline void RawAccessBarrier<decorators>::oop_store_at(oop base, ptrdiff_t offset, T value) { | 
|---|
| 69 | oop_store(field_addr(base, offset), value); | 
|---|
| 70 | } | 
|---|
| 71 |  | 
|---|
| 72 | template <DecoratorSet decorators> | 
|---|
| 73 | template <typename T> | 
|---|
| 74 | inline T RawAccessBarrier<decorators>::oop_load(void* addr) { | 
|---|
| 75 | typedef typename AccessInternal::EncodedType<decorators, T>::type Encoded; | 
|---|
| 76 | Encoded encoded = load<Encoded>(reinterpret_cast<Encoded*>(addr)); | 
|---|
| 77 | return decode<T>(encoded); | 
|---|
| 78 | } | 
|---|
| 79 |  | 
|---|
| 80 | template <DecoratorSet decorators> | 
|---|
| 81 | template <typename T> | 
|---|
| 82 | inline T RawAccessBarrier<decorators>::oop_load_at(oop base, ptrdiff_t offset) { | 
|---|
| 83 | return oop_load<T>(field_addr(base, offset)); | 
|---|
| 84 | } | 
|---|
| 85 |  | 
|---|
| 86 | template <DecoratorSet decorators> | 
|---|
| 87 | template <typename T> | 
|---|
| 88 | inline T RawAccessBarrier<decorators>::oop_atomic_cmpxchg(T new_value, void* addr, T compare_value) { | 
|---|
| 89 | typedef typename AccessInternal::EncodedType<decorators, T>::type Encoded; | 
|---|
| 90 | Encoded encoded_new = encode(new_value); | 
|---|
| 91 | Encoded encoded_compare = encode(compare_value); | 
|---|
| 92 | Encoded encoded_result = atomic_cmpxchg(encoded_new, | 
|---|
| 93 | reinterpret_cast<Encoded*>(addr), | 
|---|
| 94 | encoded_compare); | 
|---|
| 95 | return decode<T>(encoded_result); | 
|---|
| 96 | } | 
|---|
| 97 |  | 
|---|
| 98 | template <DecoratorSet decorators> | 
|---|
| 99 | template <typename T> | 
|---|
| 100 | inline T RawAccessBarrier<decorators>::oop_atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value) { | 
|---|
| 101 | return oop_atomic_cmpxchg(new_value, field_addr(base, offset), compare_value); | 
|---|
| 102 | } | 
|---|
| 103 |  | 
|---|
| 104 | template <DecoratorSet decorators> | 
|---|
| 105 | template <typename T> | 
|---|
| 106 | inline T RawAccessBarrier<decorators>::oop_atomic_xchg(T new_value, void* addr) { | 
|---|
| 107 | typedef typename AccessInternal::EncodedType<decorators, T>::type Encoded; | 
|---|
| 108 | Encoded encoded_new = encode(new_value); | 
|---|
| 109 | Encoded encoded_result = atomic_xchg(encoded_new, reinterpret_cast<Encoded*>(addr)); | 
|---|
| 110 | return decode<T>(encoded_result); | 
|---|
| 111 | } | 
|---|
| 112 |  | 
|---|
| 113 | template <DecoratorSet decorators> | 
|---|
| 114 | template <typename T> | 
|---|
| 115 | inline T RawAccessBarrier<decorators>::oop_atomic_xchg_at(T new_value, oop base, ptrdiff_t offset) { | 
|---|
| 116 | return oop_atomic_xchg(new_value, field_addr(base, offset)); | 
|---|
| 117 | } | 
|---|
| 118 |  | 
|---|
| 119 | template <DecoratorSet decorators> | 
|---|
| 120 | template <typename T> | 
|---|
| 121 | inline bool RawAccessBarrier<decorators>::oop_arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 122 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 123 | size_t length) { | 
|---|
| 124 | return arraycopy(src_obj, src_offset_in_bytes, src_raw, | 
|---|
| 125 | dst_obj, dst_offset_in_bytes, dst_raw, | 
|---|
| 126 | length); | 
|---|
| 127 | } | 
|---|
| 128 |  | 
|---|
| 129 | template <DecoratorSet decorators> | 
|---|
| 130 | template <DecoratorSet ds, typename T> | 
|---|
| 131 | inline typename EnableIf< | 
|---|
| 132 | HasDecorator<ds, MO_SEQ_CST>::value, T>::type | 
|---|
| 133 | RawAccessBarrier<decorators>::load_internal(void* addr) { | 
|---|
| 134 | if (support_IRIW_for_not_multiple_copy_atomic_cpu) { | 
|---|
| 135 | OrderAccess::fence(); | 
|---|
| 136 | } | 
|---|
| 137 | return OrderAccess::load_acquire(reinterpret_cast<const volatile T*>(addr)); | 
|---|
| 138 | } | 
|---|
| 139 |  | 
|---|
| 140 | template <DecoratorSet decorators> | 
|---|
| 141 | template <DecoratorSet ds, typename T> | 
|---|
| 142 | inline typename EnableIf< | 
|---|
| 143 | HasDecorator<ds, MO_ACQUIRE>::value, T>::type | 
|---|
| 144 | RawAccessBarrier<decorators>::load_internal(void* addr) { | 
|---|
| 145 | return OrderAccess::load_acquire(reinterpret_cast<const volatile T*>(addr)); | 
|---|
| 146 | } | 
|---|
| 147 |  | 
|---|
| 148 | template <DecoratorSet decorators> | 
|---|
| 149 | template <DecoratorSet ds, typename T> | 
|---|
| 150 | inline typename EnableIf< | 
|---|
| 151 | HasDecorator<ds, MO_RELAXED>::value, T>::type | 
|---|
| 152 | RawAccessBarrier<decorators>::load_internal(void* addr) { | 
|---|
| 153 | return Atomic::load(reinterpret_cast<const volatile T*>(addr)); | 
|---|
| 154 | } | 
|---|
| 155 |  | 
|---|
| 156 | template <DecoratorSet decorators> | 
|---|
| 157 | template <DecoratorSet ds, typename T> | 
|---|
| 158 | inline typename EnableIf< | 
|---|
| 159 | HasDecorator<ds, MO_SEQ_CST>::value>::type | 
|---|
| 160 | RawAccessBarrier<decorators>::store_internal(void* addr, T value) { | 
|---|
| 161 | OrderAccess::release_store_fence(reinterpret_cast<volatile T*>(addr), value); | 
|---|
| 162 | } | 
|---|
| 163 |  | 
|---|
| 164 | template <DecoratorSet decorators> | 
|---|
| 165 | template <DecoratorSet ds, typename T> | 
|---|
| 166 | inline typename EnableIf< | 
|---|
| 167 | HasDecorator<ds, MO_RELEASE>::value>::type | 
|---|
| 168 | RawAccessBarrier<decorators>::store_internal(void* addr, T value) { | 
|---|
| 169 | OrderAccess::release_store(reinterpret_cast<volatile T*>(addr), value); | 
|---|
| 170 | } | 
|---|
| 171 |  | 
|---|
| 172 | template <DecoratorSet decorators> | 
|---|
| 173 | template <DecoratorSet ds, typename T> | 
|---|
| 174 | inline typename EnableIf< | 
|---|
| 175 | HasDecorator<ds, MO_RELAXED>::value>::type | 
|---|
| 176 | RawAccessBarrier<decorators>::store_internal(void* addr, T value) { | 
|---|
| 177 | Atomic::store(value, reinterpret_cast<volatile T*>(addr)); | 
|---|
| 178 | } | 
|---|
| 179 |  | 
|---|
| 180 | template <DecoratorSet decorators> | 
|---|
| 181 | template <DecoratorSet ds, typename T> | 
|---|
| 182 | inline typename EnableIf< | 
|---|
| 183 | HasDecorator<ds, MO_RELAXED>::value, T>::type | 
|---|
| 184 | RawAccessBarrier<decorators>::atomic_cmpxchg_internal(T new_value, void* addr, T compare_value) { | 
|---|
| 185 | return Atomic::cmpxchg(new_value, | 
|---|
| 186 | reinterpret_cast<volatile T*>(addr), | 
|---|
| 187 | compare_value, | 
|---|
| 188 | memory_order_relaxed); | 
|---|
| 189 | } | 
|---|
| 190 |  | 
|---|
| 191 | template <DecoratorSet decorators> | 
|---|
| 192 | template <DecoratorSet ds, typename T> | 
|---|
| 193 | inline typename EnableIf< | 
|---|
| 194 | HasDecorator<ds, MO_SEQ_CST>::value, T>::type | 
|---|
| 195 | RawAccessBarrier<decorators>::atomic_cmpxchg_internal(T new_value, void* addr, T compare_value) { | 
|---|
| 196 | return Atomic::cmpxchg(new_value, | 
|---|
| 197 | reinterpret_cast<volatile T*>(addr), | 
|---|
| 198 | compare_value, | 
|---|
| 199 | memory_order_conservative); | 
|---|
| 200 | } | 
|---|
| 201 |  | 
|---|
| 202 | template <DecoratorSet decorators> | 
|---|
| 203 | template <DecoratorSet ds, typename T> | 
|---|
| 204 | inline typename EnableIf< | 
|---|
| 205 | HasDecorator<ds, MO_SEQ_CST>::value, T>::type | 
|---|
| 206 | RawAccessBarrier<decorators>::atomic_xchg_internal(T new_value, void* addr) { | 
|---|
| 207 | return Atomic::xchg(new_value, | 
|---|
| 208 | reinterpret_cast<volatile T*>(addr)); | 
|---|
| 209 | } | 
|---|
| 210 |  | 
|---|
| 211 | // For platforms that do not have native support for wide atomics, | 
|---|
| 212 | // we can emulate the atomicity using a lock. So here we check | 
|---|
| 213 | // whether that is necessary or not. | 
|---|
| 214 |  | 
|---|
| 215 | template <DecoratorSet ds> | 
|---|
| 216 | template <DecoratorSet decorators, typename T> | 
|---|
| 217 | inline typename EnableIf< | 
|---|
| 218 | AccessInternal::PossiblyLockedAccess<T>::value, T>::type | 
|---|
| 219 | RawAccessBarrier<ds>::atomic_xchg_maybe_locked(T new_value, void* addr) { | 
|---|
| 220 | if (!AccessInternal::wide_atomic_needs_locking()) { | 
|---|
| 221 | return atomic_xchg_internal<ds>(new_value, addr); | 
|---|
| 222 | } else { | 
|---|
| 223 | AccessInternal::AccessLocker access_lock; | 
|---|
| 224 | volatile T* p = reinterpret_cast<volatile T*>(addr); | 
|---|
| 225 | T old_val = RawAccess<>::load(p); | 
|---|
| 226 | RawAccess<>::store(p, new_value); | 
|---|
| 227 | return old_val; | 
|---|
| 228 | } | 
|---|
| 229 | } | 
|---|
| 230 |  | 
|---|
| 231 | template <DecoratorSet ds> | 
|---|
| 232 | template <DecoratorSet decorators, typename T> | 
|---|
| 233 | inline typename EnableIf< | 
|---|
| 234 | AccessInternal::PossiblyLockedAccess<T>::value, T>::type | 
|---|
| 235 | RawAccessBarrier<ds>::atomic_cmpxchg_maybe_locked(T new_value, void* addr, T compare_value) { | 
|---|
| 236 | if (!AccessInternal::wide_atomic_needs_locking()) { | 
|---|
| 237 | return atomic_cmpxchg_internal<ds>(new_value, addr, compare_value); | 
|---|
| 238 | } else { | 
|---|
| 239 | AccessInternal::AccessLocker access_lock; | 
|---|
| 240 | volatile T* p = reinterpret_cast<volatile T*>(addr); | 
|---|
| 241 | T old_val = RawAccess<>::load(p); | 
|---|
| 242 | if (old_val == compare_value) { | 
|---|
| 243 | RawAccess<>::store(p, new_value); | 
|---|
| 244 | } | 
|---|
| 245 | return old_val; | 
|---|
| 246 | } | 
|---|
| 247 | } | 
|---|
| 248 |  | 
|---|
| 249 | class RawAccessBarrierArrayCopy: public AllStatic { | 
|---|
| 250 | template<typename T> struct IsHeapWordSized: public IntegralConstant<bool, sizeof(T) == HeapWordSize> { }; | 
|---|
| 251 | public: | 
|---|
| 252 | template <DecoratorSet decorators, typename T> | 
|---|
| 253 | static inline typename EnableIf< | 
|---|
| 254 | HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value>::type | 
|---|
| 255 | arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 256 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 257 | size_t length) { | 
|---|
| 258 | src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw); | 
|---|
| 259 | dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw); | 
|---|
| 260 |  | 
|---|
| 261 | // We do not check for ARRAYCOPY_ATOMIC for oops, because they are unconditionally always atomic. | 
|---|
| 262 | if (HasDecorator<decorators, ARRAYCOPY_ARRAYOF>::value) { | 
|---|
| 263 | AccessInternal::arraycopy_arrayof_conjoint_oops(src_raw, dst_raw, length); | 
|---|
| 264 | } else { | 
|---|
| 265 | typedef typename HeapOopType<decorators>::type OopType; | 
|---|
| 266 | AccessInternal::arraycopy_conjoint_oops(reinterpret_cast<OopType*>(src_raw), | 
|---|
| 267 | reinterpret_cast<OopType*>(dst_raw), length); | 
|---|
| 268 | } | 
|---|
| 269 | } | 
|---|
| 270 |  | 
|---|
| 271 | template <DecoratorSet decorators, typename T> | 
|---|
| 272 | static inline typename EnableIf< | 
|---|
| 273 | !HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value && | 
|---|
| 274 | HasDecorator<decorators, ARRAYCOPY_ARRAYOF>::value>::type | 
|---|
| 275 | arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 276 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 277 | size_t length) { | 
|---|
| 278 | src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw); | 
|---|
| 279 | dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw); | 
|---|
| 280 |  | 
|---|
| 281 | AccessInternal::arraycopy_arrayof_conjoint(src_raw, dst_raw, length); | 
|---|
| 282 | } | 
|---|
| 283 |  | 
|---|
| 284 | template <DecoratorSet decorators, typename T> | 
|---|
| 285 | static inline typename EnableIf< | 
|---|
| 286 | !HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value && | 
|---|
| 287 | HasDecorator<decorators, ARRAYCOPY_DISJOINT>::value && IsHeapWordSized<T>::value>::type | 
|---|
| 288 | arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 289 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 290 | size_t length) { | 
|---|
| 291 | src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw); | 
|---|
| 292 | dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw); | 
|---|
| 293 |  | 
|---|
| 294 | // There is only a disjoint optimization for word granularity copying | 
|---|
| 295 | if (HasDecorator<decorators, ARRAYCOPY_ATOMIC>::value) { | 
|---|
| 296 | AccessInternal::arraycopy_disjoint_words_atomic(src_raw, dst_raw, length); | 
|---|
| 297 | } else { | 
|---|
| 298 | AccessInternal::arraycopy_disjoint_words(src_raw, dst_raw, length); | 
|---|
| 299 | } | 
|---|
| 300 | } | 
|---|
| 301 |  | 
|---|
| 302 | template <DecoratorSet decorators, typename T> | 
|---|
| 303 | static inline typename EnableIf< | 
|---|
| 304 | !HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value && | 
|---|
| 305 | !(HasDecorator<decorators, ARRAYCOPY_DISJOINT>::value && IsHeapWordSized<T>::value) && | 
|---|
| 306 | !HasDecorator<decorators, ARRAYCOPY_ARRAYOF>::value && | 
|---|
| 307 | !HasDecorator<decorators, ARRAYCOPY_ATOMIC>::value>::type | 
|---|
| 308 | arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 309 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 310 | size_t length) { | 
|---|
| 311 | src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw); | 
|---|
| 312 | dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw); | 
|---|
| 313 |  | 
|---|
| 314 | AccessInternal::arraycopy_conjoint(src_raw, dst_raw, length); | 
|---|
| 315 | } | 
|---|
| 316 |  | 
|---|
| 317 | template <DecoratorSet decorators, typename T> | 
|---|
| 318 | static inline typename EnableIf< | 
|---|
| 319 | !HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value && | 
|---|
| 320 | !(HasDecorator<decorators, ARRAYCOPY_DISJOINT>::value && IsHeapWordSized<T>::value) && | 
|---|
| 321 | !HasDecorator<decorators, ARRAYCOPY_ARRAYOF>::value && | 
|---|
| 322 | HasDecorator<decorators, ARRAYCOPY_ATOMIC>::value>::type | 
|---|
| 323 | arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 324 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 325 | size_t length) { | 
|---|
| 326 | src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw); | 
|---|
| 327 | dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw); | 
|---|
| 328 |  | 
|---|
| 329 | AccessInternal::arraycopy_conjoint_atomic(src_raw, dst_raw, length); | 
|---|
| 330 | } | 
|---|
| 331 | }; | 
|---|
| 332 |  | 
|---|
| 333 | template<> struct RawAccessBarrierArrayCopy::IsHeapWordSized<void>: public IntegralConstant<bool, false> { }; | 
|---|
| 334 |  | 
|---|
| 335 | template <DecoratorSet decorators> | 
|---|
| 336 | template <typename T> | 
|---|
| 337 | inline bool RawAccessBarrier<decorators>::arraycopy(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw, | 
|---|
| 338 | arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw, | 
|---|
| 339 | size_t length) { | 
|---|
| 340 | RawAccessBarrierArrayCopy::arraycopy<decorators>(src_obj, src_offset_in_bytes, src_raw, | 
|---|
| 341 | dst_obj, dst_offset_in_bytes, dst_raw, | 
|---|
| 342 | length); | 
|---|
| 343 | return true; | 
|---|
| 344 | } | 
|---|
| 345 |  | 
|---|
| 346 | template <DecoratorSet decorators> | 
|---|
| 347 | inline void RawAccessBarrier<decorators>::clone(oop src, oop dst, size_t size) { | 
|---|
| 348 | // 4839641 (4840070): We must do an oop-atomic copy, because if another thread | 
|---|
| 349 | // is modifying a reference field in the clonee, a non-oop-atomic copy might | 
|---|
| 350 | // be suspended in the middle of copying the pointer and end up with parts | 
|---|
| 351 | // of two different pointers in the field.  Subsequent dereferences will crash. | 
|---|
| 352 | // 4846409: an oop-copy of objects with long or double fields or arrays of same | 
|---|
| 353 | // won't copy the longs/doubles atomically in 32-bit vm's, so we copy jlongs instead | 
|---|
| 354 | // of oops.  We know objects are aligned on a minimum of an jlong boundary. | 
|---|
| 355 | // The same is true of StubRoutines::object_copy and the various oop_copy | 
|---|
| 356 | // variants, and of the code generated by the inline_native_clone intrinsic. | 
|---|
| 357 |  | 
|---|
| 358 | assert(MinObjAlignmentInBytes >= BytesPerLong, "objects misaligned"); | 
|---|
| 359 | AccessInternal::arraycopy_conjoint_atomic(reinterpret_cast<jlong*>((oopDesc*)src), | 
|---|
| 360 | reinterpret_cast<jlong*>((oopDesc*)dst), | 
|---|
| 361 | align_object_size(size) / HeapWordsPerLong); | 
|---|
| 362 | // Clear the header | 
|---|
| 363 | dst->init_mark_raw(); | 
|---|
| 364 | } | 
|---|
| 365 |  | 
|---|
| 366 | #endif // SHARE_OOPS_ACCESSBACKEND_INLINE_HPP | 
|---|
| 367 |  | 
|---|