1 /*
2 * Copyright (c) 2017, 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
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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
59 typedef uint64_t DecoratorSet;
60
61 // == Internal Decorators - do not use ==
62 // * INTERNAL_EMPTY: This is the name for the empty decorator set (in absence of other decorators).
63 // * INTERNAL_CONVERT_COMPRESSED_OOPS: This is an oop access that will require converting an oop
64 // to a narrowOop or vice versa, if UseCompressedOops is known to be set.
65 // * INTERNAL_VALUE_IS_OOP: Remember that the involved access is on oop rather than primitive.
66 const DecoratorSet INTERNAL_EMPTY = UCONST64(0);
67 const DecoratorSet INTERNAL_CONVERT_COMPRESSED_OOP = UCONST64(1) << 1;
68 const DecoratorSet INTERNAL_VALUE_IS_OOP = UCONST64(1) << 2;
69
70 // == Internal build-time Decorators ==
71 // * INTERNAL_BT_BARRIER_ON_PRIMITIVES: This is set in the barrierSetConfig.hpp file.
72 const DecoratorSet INTERNAL_BT_BARRIER_ON_PRIMITIVES = UCONST64(1) << 3;
73
74 // == Internal run-time Decorators ==
75 // * INTERNAL_RT_USE_COMPRESSED_OOPS: This decorator will be set in runtime resolved
76 // access backends iff UseCompressedOops is true.
77 const DecoratorSet INTERNAL_RT_USE_COMPRESSED_OOPS = UCONST64(1) << 4;
78
79 const DecoratorSet INTERNAL_DECORATOR_MASK = INTERNAL_CONVERT_COMPRESSED_OOP | INTERNAL_VALUE_IS_OOP |
80 INTERNAL_BT_BARRIER_ON_PRIMITIVES | INTERNAL_RT_USE_COMPRESSED_OOPS;
81
82 // == Memory Ordering Decorators ==
83 // The memory ordering decorators can be described in the following way:
84 // === Decorator Rules ===
85 // The different types of memory ordering guarantees have a strict order of strength.
86 // Explicitly specifying the stronger ordering implies that the guarantees of the weaker
87 // property holds too. The names come from the C++11 atomic operations, and typically
88 // have a JMM equivalent property.
89 // The equivalence may be viewed like this:
90 // MO_UNORDERED is equivalent to JMM plain.
91 // MO_VOLATILE has no equivalence in JMM, because it's a C++ thing.
92 // MO_RELAXED is equivalent to JMM opaque.
93 // MO_ACQUIRE is equivalent to JMM acquire.
94 // MO_RELEASE is equivalent to JMM release.
95 // MO_SEQ_CST is equivalent to JMM volatile.
96 //
97 // === Stores ===
98 // * MO_UNORDERED (Default): No guarantees.
99 // - The compiler and hardware are free to reorder aggressively. And they will.
100 // * MO_VOLATILE: Volatile stores (in the C++ sense).
101 // - The stores are not reordered by the compiler (but possibly the HW) w.r.t. other
102 // volatile accesses in program order (but possibly non-volatile accesses).
103 // * MO_RELAXED: Relaxed atomic stores.
104 // - The stores are atomic.
105 // - Guarantees from volatile stores hold.
106 // * MO_RELEASE: Releasing stores.
107 // - The releasing store will make its preceding memory accesses observable to memory accesses
108 // subsequent to an acquiring load observing this releasing store.
109 // - Guarantees from relaxed stores hold.
110 // * MO_SEQ_CST: Sequentially consistent stores.
111 // - The stores are observed in the same order by MO_SEQ_CST loads on other processors
112 // - Preceding loads and stores in program order are not reordered with subsequent loads and stores in program order.
113 // - Guarantees from releasing stores hold.
114 // === Loads ===
115 // * MO_UNORDERED (Default): No guarantees
116 // - The compiler and hardware are free to reorder aggressively. And they will.
117 // * MO_VOLATILE: Volatile loads (in the C++ sense).
118 // - The loads are not reordered by the compiler (but possibly the HW) w.r.t. other
119 // volatile accesses in program order (but possibly non-volatile accesses).
120 // * MO_RELAXED: Relaxed atomic loads.
121 // - The stores are atomic.
122 // - Guarantees from volatile loads hold.
123 // * MO_ACQUIRE: Acquiring loads.
124 // - An acquiring load will make subsequent memory accesses observe the memory accesses
125 // preceding the releasing store that the acquiring load observed.
126 // - Guarantees from relaxed loads hold.
127 // * MO_SEQ_CST: Sequentially consistent loads.
128 // - These loads observe MO_SEQ_CST stores in the same order on other processors
129 // - Preceding loads and stores in program order are not reordered with subsequent loads and stores in program order.
130 // - Guarantees from acquiring loads hold.
131 // === Atomic Cmpxchg ===
132 // * MO_RELAXED: Atomic but relaxed cmpxchg.
133 // - Guarantees from MO_RELAXED loads and MO_RELAXED stores hold unconditionally.
134 // * MO_SEQ_CST: Sequentially consistent cmpxchg.
135 // - Guarantees from MO_SEQ_CST loads and MO_SEQ_CST stores hold unconditionally.
136 // === Atomic Xchg ===
137 // * MO_RELAXED: Atomic but relaxed atomic xchg.
138 // - Guarantees from MO_RELAXED loads and MO_RELAXED stores hold.
139 // * MO_SEQ_CST: Sequentially consistent xchg.
140 // - Guarantees from MO_SEQ_CST loads and MO_SEQ_CST stores hold.
141 const DecoratorSet MO_UNORDERED = UCONST64(1) << 5;
142 const DecoratorSet MO_VOLATILE = UCONST64(1) << 6;
143 const DecoratorSet MO_RELAXED = UCONST64(1) << 7;
144 const DecoratorSet MO_ACQUIRE = UCONST64(1) << 8;
145 const DecoratorSet MO_RELEASE = UCONST64(1) << 9;
146 const DecoratorSet MO_SEQ_CST = UCONST64(1) << 10;
147 const DecoratorSet MO_DECORATOR_MASK = MO_UNORDERED | MO_VOLATILE | MO_RELAXED |
148 MO_ACQUIRE | MO_RELEASE | MO_SEQ_CST;
149
150 // === Barrier Strength Decorators ===
151 // * AS_RAW: The access will translate into a raw memory access, hence ignoring all semantic concerns
152 // except memory ordering and compressed oops. This will bypass runtime function pointer dispatching
153 // in the pipeline and hardwire to raw accesses without going trough the GC access barriers.
154 // - Accesses on oop* translate to raw memory accesses without runtime checks
155 // - Accesses on narrowOop* translate to encoded/decoded memory accesses without runtime checks
156 // - Accesses on HeapWord* translate to a runtime check choosing one of the above
157 // - Accesses on other types translate to raw memory accesses without runtime checks
158 // * AS_NO_KEEPALIVE: The barrier is used only on oop references and will not keep any involved objects
159 // alive, regardless of the type of reference being accessed. It will however perform the memory access
160 // in a consistent way w.r.t. e.g. concurrent compaction, so that the right field is being accessed,
161 // or maintain, e.g. intergenerational or interregional pointers if applicable. This should be used with
162 // extreme caution in isolated scopes.
163 // * AS_NORMAL: The accesses will be resolved to an accessor on the BarrierSet class, giving the
164 // responsibility of performing the access and what barriers to be performed to the GC. This is the default.
165 // Note that primitive accesses will only be resolved on the barrier set if the appropriate build-time
166 // decorator for enabling primitive barriers is enabled for the build.
167 const DecoratorSet AS_RAW = UCONST64(1) << 11;
168 const DecoratorSet AS_NO_KEEPALIVE = UCONST64(1) << 12;
169 const DecoratorSet AS_NORMAL = UCONST64(1) << 13;
170 const DecoratorSet AS_DECORATOR_MASK = AS_RAW | AS_NO_KEEPALIVE | AS_NORMAL;
171
172 // === Reference Strength Decorators ===
173 // These decorators only apply to accesses on oop-like types (oop/narrowOop).
174 // * ON_STRONG_OOP_REF: Memory access is performed on a strongly reachable reference.
175 // * ON_WEAK_OOP_REF: The memory access is performed on a weakly reachable reference.
176 // * ON_PHANTOM_OOP_REF: The memory access is performed on a phantomly reachable reference.
177 // This is the same ring of strength as jweak and weak oops in the VM.
178 // * ON_UNKNOWN_OOP_REF: The memory access is performed on a reference of unknown strength.
179 // This could for example come from the unsafe API.
180 // * Default (no explicit reference strength specified): ON_STRONG_OOP_REF
181 const DecoratorSet ON_STRONG_OOP_REF = UCONST64(1) << 14;
182 const DecoratorSet ON_WEAK_OOP_REF = UCONST64(1) << 15;
183 const DecoratorSet ON_PHANTOM_OOP_REF = UCONST64(1) << 16;
184 const DecoratorSet ON_UNKNOWN_OOP_REF = UCONST64(1) << 17;
185 const DecoratorSet ON_DECORATOR_MASK = ON_STRONG_OOP_REF | ON_WEAK_OOP_REF |
186 ON_PHANTOM_OOP_REF | ON_UNKNOWN_OOP_REF;
187
188 // === Access Location ===
189 // Accesses can take place in, e.g. the heap, old or young generation and different native roots.
190 // The location is important to the GC as it may imply different actions. The following decorators are used:
191 // * IN_HEAP: The access is performed in the heap. Many barriers such as card marking will
192 // be omitted if this decorator is not set.
193 // * IN_HEAP_ARRAY: The access is performed on a heap allocated array. This is sometimes a special case
194 // for some GCs, and implies that it is an IN_HEAP.
195 // * IN_ROOT: The access is performed in an off-heap data structure pointing into the Java heap.
196 // * IN_CONCURRENT_ROOT: The access is performed in an off-heap data structure pointing into the Java heap,
197 // but is notably not scanned during safepoints. This is sometimes a special case for some GCs and
198 // implies that it is also an IN_ROOT.
199 const DecoratorSet IN_HEAP = UCONST64(1) << 18;
200 const DecoratorSet IN_HEAP_ARRAY = UCONST64(1) << 19;
201 const DecoratorSet IN_ROOT = UCONST64(1) << 20;
202 const DecoratorSet IN_CONCURRENT_ROOT = UCONST64(1) << 21;
203 const DecoratorSet IN_DECORATOR_MASK = IN_HEAP | IN_HEAP_ARRAY |
204 IN_ROOT | IN_CONCURRENT_ROOT;
205
206 // == Value Decorators ==
207 // * OOP_NOT_NULL: This property can make certain barriers faster such as compressing oops.
208 const DecoratorSet OOP_NOT_NULL = UCONST64(1) << 22;
209 const DecoratorSet OOP_DECORATOR_MASK = OOP_NOT_NULL;
210
211 // == Arraycopy Decorators ==
212 // * ARRAYCOPY_DEST_NOT_INITIALIZED: This property can be important to e.g. SATB barriers by
213 // marking that the previous value uninitialized nonsense rather than a real value.
214 // * ARRAYCOPY_CHECKCAST: This property means that the class of the objects in source
215 // are not guaranteed to be subclasses of the class of the destination array. This requires
216 // a check-cast barrier during the copying operation. If this is not set, it is assumed
217 // that the array is covariant: (the source array type is-a destination array type)
218 // * ARRAYCOPY_DISJOINT: This property means that it is known that the two array ranges
219 // are disjoint.
220 // * ARRAYCOPY_ARRAYOF: The copy is in the arrayof form.
221 // * ARRAYCOPY_ATOMIC: The accesses have to be atomic over the size of its elements.
222 // * ARRAYCOPY_ALIGNED: The accesses have to be aligned on a HeapWord.
223 const DecoratorSet ARRAYCOPY_DEST_NOT_INITIALIZED = UCONST64(1) << 24;
224 const DecoratorSet ARRAYCOPY_CHECKCAST = UCONST64(1) << 25;
225 const DecoratorSet ARRAYCOPY_DISJOINT = UCONST64(1) << 26;
226 const DecoratorSet ARRAYCOPY_ARRAYOF = UCONST64(1) << 27;
227 const DecoratorSet ARRAYCOPY_ATOMIC = UCONST64(1) << 28;
228 const DecoratorSet ARRAYCOPY_ALIGNED = UCONST64(1) << 29;
229 const DecoratorSet ARRAYCOPY_DECORATOR_MASK = ARRAYCOPY_DEST_NOT_INITIALIZED |
230 ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT |
231 ARRAYCOPY_DISJOINT | ARRAYCOPY_ARRAYOF |
232 ARRAYCOPY_ATOMIC | ARRAYCOPY_ALIGNED;
233
234 // The HasDecorator trait can help at compile-time determining whether a decorator set
235 // has an intersection with a certain other decorator set
236 template <DecoratorSet decorators, DecoratorSet decorator>
237 struct HasDecorator: public IntegralConstant<bool, (decorators & decorator) != 0> {};
238
239 namespace AccessInternal {
240 template <typename T>
241 struct OopOrNarrowOopInternal: AllStatic {
242 typedef oop type;
243 };
244
245 template <>
246 struct OopOrNarrowOopInternal<narrowOop>: AllStatic {
247 typedef narrowOop type;
248 };
249
250 // This metafunction returns a canonicalized oop/narrowOop type for a passed
251 // in oop-like types passed in from oop_* overloads where the user has sworn
252 // that the passed in values should be oop-like (e.g. oop, oopDesc*, arrayOop,
253 // narrowOoop, instanceOopDesc*, and random other things).
254 // In the oop_* overloads, it must hold that if the passed in type T is not
255 // narrowOop, then it by contract has to be one of many oop-like types implicitly
256 // convertible to oop, and hence returns oop as the canonical oop type.
257 // If it turns out it was not, then the implicit conversion to oop will fail
258 // to compile, as desired.
259 template <typename T>
260 struct OopOrNarrowOop: AllStatic {
261 typedef typename OopOrNarrowOopInternal<typename Decay<T>::type>::type type;
262 };
263
264 inline void* field_addr(oop base, ptrdiff_t byte_offset) {
265 return reinterpret_cast<void*>(reinterpret_cast<intptr_t>((void*)base) + byte_offset);
266 }
267
268 template <DecoratorSet decorators, typename T>
269 void store_at(oop base, ptrdiff_t offset, T value);
270
271 template <DecoratorSet decorators, typename T>
272 T load_at(oop base, ptrdiff_t offset);
273
274 template <DecoratorSet decorators, typename T>
275 T atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value);
276
277 template <DecoratorSet decorators, typename T>
278 T atomic_xchg_at(T new_value, oop base, ptrdiff_t offset);
279
280 template <DecoratorSet decorators, typename P, typename T>
281 void store(P* addr, T value);
282
283 template <DecoratorSet decorators, typename P, typename T>
284 T load(P* addr);
285
286 template <DecoratorSet decorators, typename P, typename T>
287 T atomic_cmpxchg(T new_value, P* addr, T compare_value);
288
289 template <DecoratorSet decorators, typename P, typename T>
290 T atomic_xchg(T new_value, P* addr);
291
292 template <DecoratorSet decorators, typename T>
293 bool arraycopy(arrayOop src_obj, arrayOop dst_obj, T *src, T *dst, size_t length);
294
295 template <DecoratorSet decorators>
296 void clone(oop src, oop dst, size_t size);
297
298 // Infer the type that should be returned from a load.
299 template <typename P, DecoratorSet decorators>
300 class LoadProxy: public StackObj {
301 private:
302 P *const _addr;
303 public:
304 LoadProxy(P* addr) : _addr(addr) {}
305
306 template <typename T>
307 inline operator T() {
308 return load<decorators, P, T>(_addr);
309 }
310
311 inline operator P() {
312 return load<decorators, P, P>(_addr);
313 }
314 };
315
316 // Infer the type that should be returned from a load_at.
317 template <DecoratorSet decorators>
318 class LoadAtProxy: public StackObj {
319 private:
320 const oop _base;
321 const ptrdiff_t _offset;
322 public:
323 LoadAtProxy(oop base, ptrdiff_t offset) : _base(base), _offset(offset) {}
324
325 template <typename T>
326 inline operator T() const {
327 return load_at<decorators, T>(_base, _offset);
328 }
329 };
330 }
331
332 template <DecoratorSet decorators = INTERNAL_EMPTY>
333 class Access: public AllStatic {
334 // This function asserts that if an access gets passed in a decorator outside
335 // of the expected_decorators, then something is wrong. It additionally checks
336 // the consistency of the decorators so that supposedly disjoint decorators are indeed
337 // disjoint. For example, an access can not be both in heap and on root at the
338 // same time.
339 template <DecoratorSet expected_decorators>
340 static void verify_decorators();
341
342 template <DecoratorSet expected_mo_decorators>
343 static void verify_primitive_decorators() {
344 const DecoratorSet primitive_decorators = (AS_DECORATOR_MASK ^ AS_NO_KEEPALIVE) | IN_HEAP |
345 IN_HEAP_ARRAY | MO_DECORATOR_MASK;
346 verify_decorators<expected_mo_decorators | primitive_decorators>();
347 }
348
349 template <DecoratorSet expected_mo_decorators>
350 static void verify_oop_decorators() {
351 const DecoratorSet oop_decorators = AS_DECORATOR_MASK | IN_DECORATOR_MASK |
352 (ON_DECORATOR_MASK ^ ON_UNKNOWN_OOP_REF) | // no unknown oop refs outside of the heap
353 OOP_DECORATOR_MASK | MO_DECORATOR_MASK;
354 verify_decorators<expected_mo_decorators | oop_decorators>();
355 }
356
357 template <DecoratorSet expected_mo_decorators>
358 static void verify_heap_oop_decorators() {
359 const DecoratorSet heap_oop_decorators = AS_DECORATOR_MASK | ON_DECORATOR_MASK |
360 OOP_DECORATOR_MASK | (IN_DECORATOR_MASK ^
361 (IN_ROOT ^ IN_CONCURRENT_ROOT)) | // no root accesses in the heap
362 MO_DECORATOR_MASK;
363 verify_decorators<expected_mo_decorators | heap_oop_decorators>();
364 }
365
366 static const DecoratorSet load_mo_decorators = MO_UNORDERED | MO_VOLATILE | MO_RELAXED | MO_ACQUIRE | MO_SEQ_CST;
367 static const DecoratorSet store_mo_decorators = MO_UNORDERED | MO_VOLATILE | MO_RELAXED | MO_RELEASE | MO_SEQ_CST;
368 static const DecoratorSet atomic_xchg_mo_decorators = MO_SEQ_CST;
369 static const DecoratorSet atomic_cmpxchg_mo_decorators = MO_RELAXED | MO_SEQ_CST;
370
371 public:
372 // Primitive heap accesses
373 static inline AccessInternal::LoadAtProxy<decorators> load_at(oop base, ptrdiff_t offset) {
374 verify_primitive_decorators<load_mo_decorators>();
375 return AccessInternal::LoadAtProxy<decorators>(base, offset);
376 }
377
378 template <typename T>
379 static inline void store_at(oop base, ptrdiff_t offset, T value) {
380 verify_primitive_decorators<store_mo_decorators>();
381 AccessInternal::store_at<decorators>(base, offset, value);
382 }
383
384 template <typename T>
385 static inline T atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
386 verify_primitive_decorators<atomic_cmpxchg_mo_decorators>();
387 return AccessInternal::atomic_cmpxchg_at<decorators>(new_value, base, offset, compare_value);
388 }
389
390 template <typename T>
391 static inline T atomic_xchg_at(T new_value, oop base, ptrdiff_t offset) {
392 verify_primitive_decorators<atomic_xchg_mo_decorators>();
393 return AccessInternal::atomic_xchg_at<decorators>(new_value, base, offset);
394 }
395
396 template <typename T>
397 static inline bool arraycopy(arrayOop src_obj, arrayOop dst_obj, T *src, T *dst, size_t length) {
398 verify_decorators<ARRAYCOPY_DECORATOR_MASK | IN_HEAP |
399 AS_DECORATOR_MASK>();
400 return AccessInternal::arraycopy<decorators>(src_obj, dst_obj, src, dst, length);
401 }
402
403 // Oop heap accesses
404 static inline AccessInternal::LoadAtProxy<decorators | INTERNAL_VALUE_IS_OOP> oop_load_at(oop base, ptrdiff_t offset) {
405 verify_heap_oop_decorators<load_mo_decorators>();
406 return AccessInternal::LoadAtProxy<decorators | INTERNAL_VALUE_IS_OOP>(base, offset);
407 }
408
409 template <typename T>
410 static inline void oop_store_at(oop base, ptrdiff_t offset, T value) {
411 verify_heap_oop_decorators<store_mo_decorators>();
412 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
413 OopType oop_value = value;
414 AccessInternal::store_at<decorators | INTERNAL_VALUE_IS_OOP>(base, offset, oop_value);
415 }
416
417 template <typename T>
418 static inline T oop_atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
419 verify_heap_oop_decorators<atomic_cmpxchg_mo_decorators>();
420 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
421 OopType new_oop_value = new_value;
422 OopType compare_oop_value = compare_value;
423 return AccessInternal::atomic_cmpxchg_at<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, base, offset, compare_oop_value);
424 }
425
426 template <typename T>
427 static inline T oop_atomic_xchg_at(T new_value, oop base, ptrdiff_t offset) {
428 verify_heap_oop_decorators<atomic_xchg_mo_decorators>();
429 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
430 OopType new_oop_value = new_value;
431 return AccessInternal::atomic_xchg_at<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, base, offset);
432 }
433
434 template <typename T>
435 static inline bool oop_arraycopy(arrayOop src_obj, arrayOop dst_obj, T *src, T *dst, size_t length) {
436 verify_decorators<ARRAYCOPY_DECORATOR_MASK | IN_HEAP | AS_DECORATOR_MASK>();
437 return AccessInternal::arraycopy<decorators | INTERNAL_VALUE_IS_OOP>(src_obj, dst_obj, src, dst, length);
438 }
439
440 // Clone an object from src to dst
441 static inline void clone(oop src, oop dst, size_t size) {
442 verify_decorators<IN_HEAP>();
443 AccessInternal::clone<decorators>(src, dst, size);
444 }
445
446 // Primitive accesses
447 template <typename P>
448 static inline P load(P* addr) {
449 verify_primitive_decorators<load_mo_decorators>();
450 return AccessInternal::load<decorators, P, P>(addr);
451 }
452
453 template <typename P, typename T>
454 static inline void store(P* addr, T value) {
455 verify_primitive_decorators<store_mo_decorators>();
456 AccessInternal::store<decorators>(addr, value);
457 }
458
459 template <typename P, typename T>
460 static inline T atomic_cmpxchg(T new_value, P* addr, T compare_value) {
461 verify_primitive_decorators<atomic_cmpxchg_mo_decorators>();
462 return AccessInternal::atomic_cmpxchg<decorators>(new_value, addr, compare_value);
463 }
464
465 template <typename P, typename T>
466 static inline T atomic_xchg(T new_value, P* addr) {
467 verify_primitive_decorators<atomic_xchg_mo_decorators>();
468 return AccessInternal::atomic_xchg<decorators>(new_value, addr);
469 }
470
471 // Oop accesses
472 template <typename P>
473 static inline AccessInternal::LoadProxy<P, decorators | INTERNAL_VALUE_IS_OOP> oop_load(P* addr) {
474 verify_oop_decorators<load_mo_decorators>();
475 return AccessInternal::LoadProxy<P, decorators | INTERNAL_VALUE_IS_OOP>(addr);
476 }
477
478 template <typename P, typename T>
479 static inline void oop_store(P* addr, T value) {
480 verify_oop_decorators<store_mo_decorators>();
481 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
482 OopType oop_value = value;
483 AccessInternal::store<decorators | INTERNAL_VALUE_IS_OOP>(addr, oop_value);
484 }
485
486 template <typename P, typename T>
487 static inline T oop_atomic_cmpxchg(T new_value, P* addr, T compare_value) {
488 verify_oop_decorators<atomic_cmpxchg_mo_decorators>();
489 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
490 OopType new_oop_value = new_value;
491 OopType compare_oop_value = compare_value;
492 return AccessInternal::atomic_cmpxchg<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, addr, compare_oop_value);
493 }
494
495 template <typename P, typename T>
496 static inline T oop_atomic_xchg(T new_value, P* addr) {
497 verify_oop_decorators<atomic_xchg_mo_decorators>();
498 typedef typename AccessInternal::OopOrNarrowOop<T>::type OopType;
499 OopType new_oop_value = new_value;
500 return AccessInternal::atomic_xchg<decorators | INTERNAL_VALUE_IS_OOP>(new_oop_value, addr);
501 }
502 };
503
504 // Helper for performing raw accesses (knows only of memory ordering
505 // atomicity decorators as well as compressed oops)
506 template <DecoratorSet decorators = INTERNAL_EMPTY>
507 class RawAccess: public Access<AS_RAW | decorators> {};
508
509 // Helper for performing normal accesses on the heap. These accesses
510 // may resolve an accessor on a GC barrier set
511 template <DecoratorSet decorators = INTERNAL_EMPTY>
512 class HeapAccess: public Access<IN_HEAP | decorators> {};
513
514 // Helper for performing normal accesses in roots. These accesses
515 // may resolve an accessor on a GC barrier set
516 template <DecoratorSet decorators = INTERNAL_EMPTY>
517 class RootAccess: public Access<IN_ROOT | decorators> {};
518
519 #endif // SHARE_VM_RUNTIME_ACCESS_HPP