1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24
25 #ifndef SHARE_VM_RUNTIME_ACCESS_HPP
26 #define SHARE_VM_RUNTIME_ACCESS_HPP
27
28 #include "memory/allocation.hpp"
29 #include "metaprogramming/decay.hpp"
30 #include "metaprogramming/integralConstant.hpp"
31 #include "oops/oopsHierarchy.hpp"
32 #include "utilities/debug.hpp"
33 #include "utilities/globalDefinitions.hpp"
34
35 // = GENERAL =
36 // Access is an API for performing accesses with declarative semantics. Each access can have a number of "decorators".
37 // A decorator is an attribute or property that affects the way a memory access is performed in some way.
38 // There are different groups of decorators. Some have to do with memory ordering, others to do with,
39 // e.g. strength of references, strength of GC barriers, or whether compression should be applied or not.
40 // Some decorators are set at buildtime, such as whether primitives require GC barriers or not, others
41 // at callsites such as whether an access is in the heap or not, and others are resolved at runtime
42 // such as GC-specific barriers and encoding/decoding compressed oops.
43 // By pipelining handling of these decorators, the design of the Access API allows separation of concern
44 // over the different orthogonal concerns of decorators, while providing a powerful way of
45 // expressing these orthogonal semantic properties in a unified way.
46
47 // == OPERATIONS ==
48 // * load: Load a value from an address.
49 // * load_at: Load a value from an internal pointer relative to a base object.
50 // * store: Store a value at an address.
51 // * store_at: Store a value in an internal pointer relative to a base object.
52 // * atomic_cmpxchg: Atomically compare-and-swap a new value at an address if previous value matched the compared value.
53 // * atomic_cmpxchg_at: Atomically compare-and-swap a new value at an internal pointer address if previous value matched the compared value.
54 // * atomic_xchg: Atomically swap a new value at an address if previous value matched the compared value.
55 // * atomic_xchg_at: Atomically swap a new value at an internal pointer address if previous value matched the compared value.
56 // * arraycopy: Copy data from one heap array to another heap array.
57 // * clone: Clone the contents of an object to a newly allocated object.
58 // * resolve: Resolve a stable to-space invariant oop that is guaranteed not to relocate its payload until a subsequent thread transition.
59
60 typedef uint64_t DecoratorSet;
61
62 // == Internal Decorators - do not use ==
63 // * INTERNAL_EMPTY: This is the name for the empty decorator set (in absence of other decorators).
64 // * INTERNAL_CONVERT_COMPRESSED_OOPS: This is an oop access that will require converting an oop
65 // to a narrowOop or vice versa, if UseCompressedOops is known to be set.
66 // * INTERNAL_VALUE_IS_OOP: Remember that the involved access is on oop rather than primitive.
67 const DecoratorSet INTERNAL_EMPTY = UCONST64(0);
68 const DecoratorSet INTERNAL_CONVERT_COMPRESSED_OOP = UCONST64(1) << 1;
69 const DecoratorSet INTERNAL_VALUE_IS_OOP = UCONST64(1) << 2;
70
71 // == Internal build-time Decorators ==
72 // * INTERNAL_BT_BARRIER_ON_PRIMITIVES: This is set in the barrierSetConfig.hpp file.
73 // * INTERNAL_BT_TO_SPACE_INVARIANT: This is set in the barrierSetConfig.hpp file iff
74 // no GC is bundled in the build that is to-space invariant.
75 const DecoratorSet INTERNAL_BT_BARRIER_ON_PRIMITIVES = UCONST64(1) << 3;
76 const DecoratorSet INTERNAL_BT_TO_SPACE_INVARIANT = UCONST64(1) << 4;
77
78 // == Internal run-time Decorators ==
79 // * INTERNAL_RT_USE_COMPRESSED_OOPS: This decorator will be set in runtime resolved
80 // access backends iff UseCompressedOops is true.
81 const DecoratorSet INTERNAL_RT_USE_COMPRESSED_OOPS = UCONST64(1) << 5;
82
83 const DecoratorSet INTERNAL_DECORATOR_MASK = INTERNAL_CONVERT_COMPRESSED_OOP | INTERNAL_VALUE_IS_OOP |
84 INTERNAL_BT_BARRIER_ON_PRIMITIVES | INTERNAL_RT_USE_COMPRESSED_OOPS;
85
86 // == Memory Ordering Decorators ==
87 // The memory ordering decorators can be described in the following way:
88 // === Decorator Rules ===
89 // The different types of memory ordering guarantees have a strict order of strength.
90 // Explicitly specifying the stronger ordering implies that the guarantees of the weaker
91 // property holds too. The names come from the C++11 atomic operations, and typically
92 // have a JMM equivalent property.
93 // The equivalence may be viewed like this:
94 // MO_UNORDERED is equivalent to JMM plain.
95 // MO_VOLATILE has no equivalence in JMM, because it's a C++ thing.
96 // MO_RELAXED is equivalent to JMM opaque.
97 // MO_ACQUIRE is equivalent to JMM acquire.
98 // MO_RELEASE is equivalent to JMM release.
99 // MO_SEQ_CST is equivalent to JMM volatile.
100 //
101 // === Stores ===
102 // * MO_UNORDERED (Default): No guarantees.
103 // - The compiler and hardware are free to reorder aggressively. And they will.
104 // * MO_VOLATILE: Volatile stores (in the C++ sense).
105 // - The stores are not reordered by the compiler (but possibly the HW) w.r.t. other
106 // volatile accesses in program order (but possibly non-volatile accesses).
107 // * MO_RELAXED: Relaxed atomic stores.
108 // - The stores are atomic.
109 // - Guarantees from volatile stores hold.
110 // * MO_RELEASE: Releasing stores.
111 // - The releasing store will make its preceding memory accesses observable to memory accesses
112 // subsequent to an acquiring load observing this releasing store.
113 // - Guarantees from relaxed stores hold.
114 // * MO_SEQ_CST: Sequentially consistent stores.
115 // - The stores are observed in the same order by MO_SEQ_CST loads on other processors
116 // - Preceding loads and stores in program order are not reordered with subsequent loads and stores in program order.
117 // - Guarantees from releasing stores hold.
118 // === Loads ===
119 // * MO_UNORDERED (Default): No guarantees
120 // - The compiler and hardware are free to reorder aggressively. And they will.
121 // * MO_VOLATILE: Volatile loads (in the C++ sense).
122 // - The loads are not reordered by the compiler (but possibly the HW) w.r.t. other
123 // volatile accesses in program order (but possibly non-volatile accesses).
124 // * MO_RELAXED: Relaxed atomic loads.
125 // - The stores are atomic.
126 // - Guarantees from volatile loads hold.
127 // * MO_ACQUIRE: Acquiring loads.
128 // - An acquiring load will make subsequent memory accesses observe the memory accesses
129 // preceding the releasing store that the acquiring load observed.
130 // - Guarantees from relaxed loads hold.
131 // * MO_SEQ_CST: Sequentially consistent loads.
132 // - These loads observe MO_SEQ_CST stores in the same order on other processors
133 // - Preceding loads and stores in program order are not reordered with subsequent loads and stores in program order.
134 // - Guarantees from acquiring loads hold.
135 // === Atomic Cmpxchg ===
136 // * MO_RELAXED: Atomic but relaxed cmpxchg.
137 // - Guarantees from MO_RELAXED loads and MO_RELAXED stores hold unconditionally.
138 // * MO_SEQ_CST: Sequentially consistent cmpxchg.
139 // - Guarantees from MO_SEQ_CST loads and MO_SEQ_CST stores hold unconditionally.
140 // === Atomic Xchg ===
141 // * MO_RELAXED: Atomic but relaxed atomic xchg.
142 // - Guarantees from MO_RELAXED loads and MO_RELAXED stores hold.
143 // * MO_SEQ_CST: Sequentially consistent xchg.
144 // - Guarantees from MO_SEQ_CST loads and MO_SEQ_CST stores hold.
145 const DecoratorSet MO_UNORDERED = UCONST64(1) << 6;
146 const DecoratorSet MO_VOLATILE = UCONST64(1) << 7;
147 const DecoratorSet MO_RELAXED = UCONST64(1) << 8;
148 const DecoratorSet MO_ACQUIRE = UCONST64(1) << 9;
149 const DecoratorSet MO_RELEASE = UCONST64(1) << 10;
150 const DecoratorSet MO_SEQ_CST = UCONST64(1) << 11;
151 const DecoratorSet MO_DECORATOR_MASK = MO_UNORDERED | MO_VOLATILE | MO_RELAXED |
152 MO_ACQUIRE | MO_RELEASE | MO_SEQ_CST;
153
154 // === Barrier Strength Decorators ===
155 // * AS_RAW: The access will translate into a raw memory access, hence ignoring all semantic concerns
156 // except memory ordering and compressed oops. This will bypass runtime function pointer dispatching
157 // in the pipeline and hardwire to raw accesses without going trough the GC access barriers.
158 // - Accesses on oop* translate to raw memory accesses without runtime checks
159 // - Accesses on narrowOop* translate to encoded/decoded memory accesses without runtime checks
160 // - Accesses on HeapWord* translate to a runtime check choosing one of the above
161 // - Accesses on other types translate to raw memory accesses without runtime checks
162 // * AS_DEST_NOT_INITIALIZED: This property can be important to e.g. SATB barriers by
163 // marking that the previous value is uninitialized nonsense rather than a real value.
164 // * AS_NO_KEEPALIVE: The barrier is used only on oop references and will not keep any involved objects
165 // alive, regardless of the type of reference being accessed. It will however perform the memory access
166 // in a consistent way w.r.t. e.g. concurrent compaction, so that the right field is being accessed,
167 // or maintain, e.g. intergenerational or interregional pointers if applicable. This should be used with
168 // extreme caution in isolated scopes.
169 // * AS_NORMAL: The accesses will be resolved to an accessor on the BarrierSet class, giving the
170 // responsibility of performing the access and what barriers to be performed to the GC. This is the default.
171 // Note that primitive accesses will only be resolved on the barrier set if the appropriate build-time
172 // decorator for enabling primitive barriers is enabled for the build.
173 const DecoratorSet AS_RAW = UCONST64(1) << 12;
174 const DecoratorSet AS_DEST_NOT_INITIALIZED = UCONST64(1) << 13;
175 const DecoratorSet AS_NO_KEEPALIVE = UCONST64(1) << 14;
176 const DecoratorSet AS_NORMAL = UCONST64(1) << 15;
177 const DecoratorSet AS_DECORATOR_MASK = AS_RAW | AS_DEST_NOT_INITIALIZED |
178 AS_NO_KEEPALIVE | AS_NORMAL;
179
180 // === Reference Strength Decorators ===
181 // These decorators only apply to accesses on oop-like types (oop/narrowOop).
182 // * ON_STRONG_OOP_REF: Memory access is performed on a strongly reachable reference.
183 // * ON_WEAK_OOP_REF: The memory access is performed on a weakly reachable reference.
184 // * ON_PHANTOM_OOP_REF: The memory access is performed on a phantomly reachable reference.
185 // This is the same ring of strength as jweak and weak oops in the VM.
186 // * ON_UNKNOWN_OOP_REF: The memory access is performed on a reference of unknown strength.
187 // This could for example come from the unsafe API.
188 // * Default (no explicit reference strength specified): ON_STRONG_OOP_REF
189 const DecoratorSet ON_STRONG_OOP_REF = UCONST64(1) << 16;
190 const DecoratorSet ON_WEAK_OOP_REF = UCONST64(1) << 17;
191 const DecoratorSet ON_PHANTOM_OOP_REF = UCONST64(1) << 18;
192 const DecoratorSet ON_UNKNOWN_OOP_REF = UCONST64(1) << 19;
193 const DecoratorSet ON_DECORATOR_MASK = ON_STRONG_OOP_REF | ON_WEAK_OOP_REF |
194 ON_PHANTOM_OOP_REF | ON_UNKNOWN_OOP_REF;
195
196 // === Access Location ===
197 // Accesses can take place in, e.g. the heap, old or young generation and different native roots.
198 // The location is important to the GC as it may imply different actions. The following decorators are used:
199 // * IN_HEAP: The access is performed in the heap. Many barriers such as card marking will
200 // be omitted if this decorator is not set.
201 // * IN_HEAP_ARRAY: The access is performed on a heap allocated array. This is sometimes a special case
202 // for some GCs, and implies that it is an IN_HEAP.
203 // * IN_ROOT: The access is performed in an off-heap data structure pointing into the Java heap.
204 // * IN_CONCURRENT_ROOT: The access is performed in an off-heap data structure pointing into the Java heap,
205 // but is notably not scanned during safepoints. This is sometimes a special case for some GCs and
206 // implies that it is also an IN_ROOT.
207 const DecoratorSet IN_HEAP = UCONST64(1) << 20;
208 const DecoratorSet IN_HEAP_ARRAY = UCONST64(1) << 21;
209 const DecoratorSet IN_ROOT = UCONST64(1) << 22;
210 const DecoratorSet IN_CONCURRENT_ROOT = UCONST64(1) << 23;
211 const DecoratorSet IN_ARCHIVE_ROOT = UCONST64(1) << 24;
212 const DecoratorSet IN_DECORATOR_MASK = IN_HEAP | IN_HEAP_ARRAY |
213 IN_ROOT | IN_CONCURRENT_ROOT |
214 IN_ARCHIVE_ROOT;
215
216 // == Value Decorators ==
217 // * OOP_NOT_NULL: This property can make certain barriers faster such as compressing oops.
218 const DecoratorSet OOP_NOT_NULL = UCONST64(1) << 25;
219 const DecoratorSet OOP_DECORATOR_MASK = OOP_NOT_NULL;
220
221 // == Arraycopy Decorators ==
222 // * ARRAYCOPY_CHECKCAST: This property means that the class of the objects in source
223 // are not guaranteed to be subclasses of the class of the destination array. This requires
224 // a check-cast barrier during the copying operation. If this is not set, it is assumed
225 // that the array is covariant: (the source array type is-a destination array type)
226 // * ARRAYCOPY_DISJOINT: This property means that it is known that the two array ranges
227 // are disjoint.
228 // * ARRAYCOPY_ARRAYOF: The copy is in the arrayof form.
229 // * ARRAYCOPY_ATOMIC: The accesses have to be atomic over the size of its elements.
230 // * ARRAYCOPY_ALIGNED: The accesses have to be aligned on a HeapWord.
231 const DecoratorSet ARRAYCOPY_CHECKCAST = UCONST64(1) << 26;
232 const DecoratorSet ARRAYCOPY_DISJOINT = UCONST64(1) << 27;
233 const DecoratorSet ARRAYCOPY_ARRAYOF = UCONST64(1) << 28;
234 const DecoratorSet ARRAYCOPY_ATOMIC = UCONST64(1) << 29;
235 const DecoratorSet ARRAYCOPY_ALIGNED = UCONST64(1) << 30;
236 const DecoratorSet ARRAYCOPY_DECORATOR_MASK = ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT |
237 ARRAYCOPY_DISJOINT | ARRAYCOPY_ARRAYOF |
238 ARRAYCOPY_ATOMIC | ARRAYCOPY_ALIGNED;
239
240 // The HasDecorator trait can help at compile-time determining whether a decorator set
241 // has an intersection with a certain other decorator set
242 template <DecoratorSet decorators, DecoratorSet decorator>
243 struct HasDecorator: public IntegralConstant<bool, (decorators & decorator) != 0> {};
244
245 namespace AccessInternal {
246 template <typename T>
247 struct OopOrNarrowOopInternal: AllStatic {
248 typedef oop type;
249 };
250
251 template <>
252 struct OopOrNarrowOopInternal<narrowOop>: AllStatic {
253 typedef narrowOop type;
254 };
255
256 // This metafunction returns a canonicalized oop/narrowOop type for a passed
257 // in oop-like types passed in from oop_* overloads where the user has sworn
258 // that the passed in values should be oop-like (e.g. oop, oopDesc*, arrayOop,
259 // narrowOoop, instanceOopDesc*, and random other things).
260 // In the oop_* overloads, it must hold that if the passed in type T is not
261 // narrowOop, then it by contract has to be one of many oop-like types implicitly
262 // convertible to oop, and hence returns oop as the canonical oop type.
263 // If it turns out it was not, then the implicit conversion to oop will fail
264 // to compile, as desired.
265 template <typename T>
266 struct OopOrNarrowOop: AllStatic {
267 typedef typename OopOrNarrowOopInternal<typename Decay<T>::type>::type type;
268 };
269
270 inline void* field_addr(oop base, ptrdiff_t byte_offset) {
271 return reinterpret_cast<void*>(reinterpret_cast<intptr_t>((void*)base) + byte_offset);
272 }
273
274 template <DecoratorSet decorators, typename T>
275 void store_at(oop base, ptrdiff_t offset, T value);
276
277 template <DecoratorSet decorators, typename T>
278 T load_at(oop base, ptrdiff_t offset);
279
280 template <DecoratorSet decorators, typename T>
281 T atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value);
282
283 template <DecoratorSet decorators, typename T>
284 T atomic_xchg_at(T new_value, oop base, ptrdiff_t offset);
285
286 template <DecoratorSet decorators, typename P, typename T>
287 void store(P* addr, T value);
288
289 template <DecoratorSet decorators, typename P, typename T>
290 T load(P* addr);
291
292 template <DecoratorSet decorators, typename P, typename T>
293 T atomic_cmpxchg(T new_value, P* addr, T compare_value);
294
295 template <DecoratorSet decorators, typename P, typename T>
296 T atomic_xchg(T new_value, P* addr);
297
298 template <DecoratorSet decorators, typename T>
299 bool arraycopy(arrayOop src_obj, arrayOop dst_obj, T *src, T *dst, size_t length);
300
301 template <DecoratorSet decorators>
302 void clone(oop src, oop dst, size_t size);
303
304 template <DecoratorSet decorators>
305 oop resolve(oop src);
306
307 // Infer the type that should be returned from a load.
308 template <typename P, DecoratorSet decorators>
309 class LoadProxy: public StackObj {
310 private:
311 P *const _addr;
312 public:
313 LoadProxy(P* addr) : _addr(addr) {}
314
315 template <typename T>
316 inline operator T() {
317 return load<decorators, P, T>(_addr);
318 }
319
320 inline operator P() {
321 return load<decorators, P, P>(_addr);
322 }
323 };
324
325 // Infer the type that should be returned from a load_at.
326 template <DecoratorSet decorators>
327 class LoadAtProxy: public StackObj {
328 private:
329 const oop _base;
330 const ptrdiff_t _offset;
331 public:
332 LoadAtProxy(oop base, ptrdiff_t offset) : _base(base), _offset(offset) {}
333
334 template <typename T>
335 inline operator T() const {
336 return load_at<decorators, T>(_base, _offset);
337 }
338 };
339 }
340
341 template <DecoratorSet decorators = INTERNAL_EMPTY>
342 class Access: public AllStatic {
343 // This function asserts that if an access gets passed in a decorator outside
344 // of the expected_decorators, then something is wrong. It additionally checks
345 // the consistency of the decorators so that supposedly disjoint decorators are indeed
346 // disjoint. For example, an access can not be both in heap and on root at the
347 // same time.
348 template <DecoratorSet expected_decorators>
349 static void verify_decorators();
350
351 template <DecoratorSet expected_mo_decorators>
352 static void verify_primitive_decorators() {
353 const DecoratorSet primitive_decorators = (AS_DECORATOR_MASK ^ AS_NO_KEEPALIVE ^ AS_DEST_NOT_INITIALIZED) |
354 IN_HEAP | IN_HEAP_ARRAY;
355 verify_decorators<expected_mo_decorators | primitive_decorators>();
356 }
357
358 template <DecoratorSet expected_mo_decorators>
359 static void verify_oop_decorators() {
360 const DecoratorSet oop_decorators = AS_DECORATOR_MASK | IN_DECORATOR_MASK |
361 (ON_DECORATOR_MASK ^ ON_UNKNOWN_OOP_REF) | // no unknown oop refs outside of the heap
362 OOP_DECORATOR_MASK;
363 verify_decorators<expected_mo_decorators | oop_decorators>();
364 }
365
366 template <DecoratorSet expected_mo_decorators>
367 static void verify_heap_oop_decorators() {
368 const DecoratorSet heap_oop_decorators = AS_DECORATOR_MASK | ON_DECORATOR_MASK |
369 OOP_DECORATOR_MASK | (IN_DECORATOR_MASK ^
370 (IN_ROOT | IN_CONCURRENT_ROOT)); // no root accesses in the heap
371 verify_decorators<expected_mo_decorators | heap_oop_decorators>();
372 }
373
374 static const DecoratorSet load_mo_decorators = MO_UNORDERED | MO_VOLATILE | MO_RELAXED | MO_ACQUIRE | MO_SEQ_CST;
375 static const DecoratorSet store_mo_decorators = MO_UNORDERED | MO_VOLATILE | MO_RELAXED | MO_RELEASE | MO_SEQ_CST;
376 static const DecoratorSet atomic_xchg_mo_decorators = MO_SEQ_CST;
377 static const DecoratorSet atomic_cmpxchg_mo_decorators = MO_RELAXED | MO_SEQ_CST;
378
379 public:
380 // Primitive heap accesses
381 static inline AccessInternal::LoadAtProxy<decorators> load_at(oop base, ptrdiff_t offset) {
382 verify_primitive_decorators<load_mo_decorators>();
383 return AccessInternal::LoadAtProxy<decorators>(base, offset);
384 }
385
386 template <typename T>
387 static inline void store_at(oop base, ptrdiff_t offset, T value) {
388 verify_primitive_decorators<store_mo_decorators>();
389 AccessInternal::store_at<decorators>(base, offset, value);
390 }
391
392 template <typename T>
393 static inline T atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
394 verify_primitive_decorators<atomic_cmpxchg_mo_decorators>();
395 return AccessInternal::atomic_cmpxchg_at<decorators>(new_value, base, offset, compare_value);
396 }
397
398 template <typename T>
399 static inline T atomic_xchg_at(T new_value, oop base, ptrdiff_t offset) {
400 verify_primitive_decorators<atomic_xchg_mo_decorators>();
401 return AccessInternal::atomic_xchg_at<decorators>(new_value, base, offset);
402 }
403
404 template <typename T>
405 static inline void arraycopy(arrayOop src_obj, arrayOop dst_obj, T *src, T *dst, size_t length) {
406 verify_decorators<ARRAYCOPY_DECORATOR_MASK | IN_HEAP |
407 AS_DECORATOR_MASK>();
408 AccessInternal::arraycopy<decorators>(src_obj, dst_obj, src, dst, length);
409 }
410
411 // Oop heap accesses
412 static inline AccessInternal::LoadAtProxy<decorators | INTERNAL_VALUE_IS_OOP> oop_load_at(oop base, ptrdiff_t offset) {
413 verify_heap_oop_decorators<load_mo_decorators>();
414 return AccessInternal::LoadAtProxy<decorators | INTERNAL_VALUE_IS_OOP>(base, offset);
415 }
416
417 template <typename T>
418 static inline void oop_store_at(oop base, ptrdiff_t offset, T value) {
419 verify_heap_oop_decorators<store_mo_decorators>();
420 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
421 OopType oop_value = value;
422 AccessInternal::store_at<decorators | INTERNAL_VALUE_IS_OOP>(base, offset, oop_value);
423 }
424
425 template <typename T>
426 static inline T oop_atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
427 verify_heap_oop_decorators<atomic_cmpxchg_mo_decorators>();
428 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
429 OopType new_oop_value = new_value;
430 OopType compare_oop_value = compare_value;
431 return AccessInternal::atomic_cmpxchg_at<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, base, offset, compare_oop_value);
432 }
433
434 template <typename T>
435 static inline T oop_atomic_xchg_at(T new_value, oop base, ptrdiff_t offset) {
436 verify_heap_oop_decorators<atomic_xchg_mo_decorators>();
437 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
438 OopType new_oop_value = new_value;
439 return AccessInternal::atomic_xchg_at<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, base, offset);
440 }
441
442 template <typename T>
443 static inline bool oop_arraycopy(arrayOop src_obj, arrayOop dst_obj, T *src, T *dst, size_t length) {
444 verify_decorators<ARRAYCOPY_DECORATOR_MASK | IN_HEAP | AS_DECORATOR_MASK>();
445 return AccessInternal::arraycopy<decorators | INTERNAL_VALUE_IS_OOP>(src_obj, dst_obj, src, dst, length);
446 }
447
448 // Clone an object from src to dst
449 static inline void clone(oop src, oop dst, size_t size) {
450 verify_decorators<IN_HEAP>();
451 AccessInternal::clone<decorators>(src, dst, size);
452 }
453
454 // Primitive accesses
455 template <typename P>
456 static inline P load(P* addr) {
457 verify_primitive_decorators<load_mo_decorators>();
458 return AccessInternal::load<decorators, P, P>(addr);
459 }
460
461 template <typename P, typename T>
462 static inline void store(P* addr, T value) {
463 verify_primitive_decorators<store_mo_decorators>();
464 AccessInternal::store<decorators>(addr, value);
465 }
466
467 template <typename P, typename T>
468 static inline T atomic_cmpxchg(T new_value, P* addr, T compare_value) {
469 verify_primitive_decorators<atomic_cmpxchg_mo_decorators>();
470 return AccessInternal::atomic_cmpxchg<decorators>(new_value, addr, compare_value);
471 }
472
473 template <typename P, typename T>
474 static inline T atomic_xchg(T new_value, P* addr) {
475 verify_primitive_decorators<atomic_xchg_mo_decorators>();
476 return AccessInternal::atomic_xchg<decorators>(new_value, addr);
477 }
478
479 // Oop accesses
480 template <typename P>
481 static inline AccessInternal::LoadProxy<P, decorators | INTERNAL_VALUE_IS_OOP> oop_load(P* addr) {
482 verify_oop_decorators<load_mo_decorators>();
483 return AccessInternal::LoadProxy<P, decorators | INTERNAL_VALUE_IS_OOP>(addr);
484 }
485
486 template <typename P, typename T>
487 static inline void oop_store(P* addr, T value) {
488 verify_oop_decorators<store_mo_decorators>();
489 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
490 OopType oop_value = value;
491 AccessInternal::store<decorators | INTERNAL_VALUE_IS_OOP>(addr, oop_value);
492 }
493
494 template <typename P, typename T>
495 static inline T oop_atomic_cmpxchg(T new_value, P* addr, T compare_value) {
496 verify_oop_decorators<atomic_cmpxchg_mo_decorators>();
497 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
498 OopType new_oop_value = new_value;
499 OopType compare_oop_value = compare_value;
500 return AccessInternal::atomic_cmpxchg<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, addr, compare_oop_value);
501 }
502
503 template <typename P, typename T>
504 static inline T oop_atomic_xchg(T new_value, P* addr) {
505 verify_oop_decorators<atomic_xchg_mo_decorators>();
506 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
507 OopType new_oop_value = new_value;
508 return AccessInternal::atomic_xchg<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, addr);
509 }
510
511 static oop resolve(oop obj) {
512 verify_decorators<INTERNAL_EMPTY>();
513 return AccessInternal::resolve<decorators>(obj);
514 }
515 };
516
517 // Helper for performing raw accesses (knows only of memory ordering
518 // atomicity decorators as well as compressed oops)
519 template <DecoratorSet decorators = INTERNAL_EMPTY>
520 class RawAccess: public Access<AS_RAW | decorators> {};
521
522 // Helper for performing normal accesses on the heap. These accesses
523 // may resolve an accessor on a GC barrier set
524 template <DecoratorSet decorators = INTERNAL_EMPTY>
525 class HeapAccess: public Access<IN_HEAP | decorators> {};
526
527 // Helper for performing normal accesses in roots. These accesses
528 // may resolve an accessor on a GC barrier set
529 template <DecoratorSet decorators = INTERNAL_EMPTY>
530 class RootAccess: public Access<IN_ROOT | decorators> {};
531
532 #endif // SHARE_VM_RUNTIME_ACCESS_HPP