1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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24
25 #ifndef SHARE_GC_SHARED_BARRIERSET_HPP
26 #define SHARE_GC_SHARED_BARRIERSET_HPP
27
28 #include "gc/shared/barrierSetConfig.hpp"
29 #include "memory/memRegion.hpp"
30 #include "oops/access.hpp"
31 #include "oops/accessBackend.hpp"
32 #include "oops/oopsHierarchy.hpp"
33 #include "utilities/exceptions.hpp"
34 #include "utilities/fakeRttiSupport.hpp"
35 #include "utilities/macros.hpp"
36
37 class BarrierSetAssembler;
38 class BarrierSetC1;
39 class BarrierSetC2;
40 class BarrierSetNMethod;
41 class BarrierSetStackChunk;
42 class JavaThread;
43
44 // This class provides the interface between a barrier implementation and
45 // the rest of the system.
46
47 class BarrierSet: public CHeapObj<mtGC> {
48 friend class VMStructs;
49
50 static BarrierSet* _barrier_set;
51
52 public:
53 enum Name {
54 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
55 FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
56 #undef BARRIER_SET_DECLARE_BS_ENUM
57 UnknownBS
58 };
59
60 protected:
61 // Fake RTTI support. For a derived class T to participate
62 // - T must have a corresponding Name entry.
63 // - GetName<T> must be specialized to return the corresponding Name
64 // entry.
65 // - If T is a base class, the constructor must have a FakeRtti
66 // parameter and pass it up to its base class, with the tag set
67 // augmented with the corresponding Name entry.
68 // - If T is a concrete class, the constructor must create a
69 // FakeRtti object whose tag set includes the corresponding Name
70 // entry, and pass it up to its base class.
71 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
72
73 private:
74 FakeRtti _fake_rtti;
75 BarrierSetAssembler* _barrier_set_assembler;
76 BarrierSetC1* _barrier_set_c1;
77 BarrierSetC2* _barrier_set_c2;
78 BarrierSetNMethod* _barrier_set_nmethod;
79 BarrierSetStackChunk* _barrier_set_stack_chunk;
80
81 public:
82 // Metafunction mapping a class derived from BarrierSet to the
83 // corresponding Name enum tag.
84 template<typename T> struct GetName;
85
86 // Metafunction mapping a Name enum type to the corresponding
87 // lass derived from BarrierSet.
88 template<BarrierSet::Name T> struct GetType;
89
90 // Note: This is not presently the Name corresponding to the
91 // concrete class of this object.
92 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
93
94 // Test whether this object is of the type corresponding to bsn.
95 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
96
97 // End of fake RTTI support.
98
99 protected:
100 BarrierSet(BarrierSetAssembler* barrier_set_assembler,
101 BarrierSetC1* barrier_set_c1,
102 BarrierSetC2* barrier_set_c2,
103 BarrierSetNMethod* barrier_set_nmethod,
104 BarrierSetStackChunk* barrier_set_stack_chunk,
105 const FakeRtti& fake_rtti);
106 ~BarrierSet() { }
107
108 template <class BarrierSetAssemblerT>
109 static BarrierSetAssembler* make_barrier_set_assembler() {
110 return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(nullptr);
111 }
112
113 template <class BarrierSetC1T>
114 static BarrierSetC1* make_barrier_set_c1() {
115 return COMPILER1_PRESENT(new BarrierSetC1T()) NOT_COMPILER1(nullptr);
116 }
117
118 template <class BarrierSetC2T>
119 static BarrierSetC2* make_barrier_set_c2() {
120 return COMPILER2_PRESENT(new BarrierSetC2T()) NOT_COMPILER2(nullptr);
121 }
122
123 static void throw_array_null_pointer_store_exception(arrayOop src, arrayOop dst, TRAPS);
124 static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS);
125
126 public:
127 // Support for optimizing compilers to call the barrier set on slow path allocations
128 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
129 // The allocation is safe to use iff it returns true. If not, the slow-path allocation
130 // is redone until it succeeds. This can e.g. prevent allocations from the slow path
131 // to be in old.
132 virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
133 virtual void on_thread_create(Thread* thread) {}
134 virtual void on_thread_destroy(Thread* thread) {}
135
136 // These perform BarrierSet-related initialization/cleanup before the thread
137 // is added to or removed from the corresponding set of threads. The
138 // argument thread is the current thread. These are called either holding
139 // the Threads_lock (for a JavaThread) and so not at a safepoint, or holding
140 // the NonJavaThreadsList_lock (for a NonJavaThread) locked by the
141 // caller. That locking ensures the operation is "atomic" with the list
142 // modification wrto operations that hold the NJTList_lock and either also
143 // hold the Threads_lock or are at a safepoint.
144 virtual void on_thread_attach(Thread* thread);
145 virtual void on_thread_detach(Thread* thread) {}
146
147 virtual void make_parsable(JavaThread* thread) {}
148
149 public:
150 // Print a description of the memory for the barrier set
151 virtual void print_on(outputStream* st) const = 0;
152
153 static BarrierSet* barrier_set() { return _barrier_set; }
154 static void set_barrier_set(BarrierSet* barrier_set);
155
156 BarrierSetAssembler* barrier_set_assembler() {
157 assert(_barrier_set_assembler != nullptr, "should be set");
158 return _barrier_set_assembler;
159 }
160
161 BarrierSetC1* barrier_set_c1() {
162 assert(_barrier_set_c1 != nullptr, "should be set");
163 return _barrier_set_c1;
164 }
165
166 BarrierSetC2* barrier_set_c2() {
167 assert(_barrier_set_c2 != nullptr, "should be set");
168 return _barrier_set_c2;
169 }
170
171 BarrierSetNMethod* barrier_set_nmethod() {
172 return _barrier_set_nmethod;
173 }
174
175 BarrierSetStackChunk* barrier_set_stack_chunk() {
176 assert(_barrier_set_stack_chunk != nullptr, "should be set");
177 return _barrier_set_stack_chunk;
178 }
179
180 // The AccessBarrier of a BarrierSet subclass is called by the Access API
181 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
182 // may override these default access operations by declaring an
183 // AccessBarrier class in its BarrierSet. Its accessors will then be
184 // automatically resolved at runtime.
185 //
186 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
187 // the following steps should be taken:
188 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
189 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
190 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
191 template <DecoratorSet decorators, typename BarrierSetT>
192 class AccessBarrier: protected RawAccessBarrier<decorators> {
193 private:
194 typedef RawAccessBarrier<decorators> Raw;
195
196 public:
197 // Primitive heap accesses. These accessors get resolved when
198 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
199 // not an oop_* overload, and the barrier strength is AS_NORMAL.
200 template <typename T>
201 static T load_in_heap(T* addr) {
202 return Raw::template load<T>(addr);
203 }
204
205 template <typename T>
206 static T load_in_heap_at(oop base, ptrdiff_t offset) {
207 return Raw::template load_at<T>(base, offset);
208 }
209
210 template <typename T>
211 static void store_in_heap(T* addr, T value) {
212 Raw::store(addr, value);
213 }
214
215 template <typename T>
216 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
217 Raw::store_at(base, offset, value);
218 }
219
220 template <typename T>
221 static T atomic_cmpxchg_in_heap(T* addr, T compare_value, T new_value) {
222 return Raw::atomic_cmpxchg(addr, compare_value, new_value);
223 }
224
225 template <typename T>
226 static T atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, T compare_value, T new_value) {
227 return Raw::atomic_cmpxchg_at(base, offset, compare_value, new_value);
228 }
229
230 template <typename T>
231 static T atomic_xchg_in_heap(T* addr, T new_value) {
232 return Raw::atomic_xchg(addr, new_value);
233 }
234
235 template <typename T>
236 static T atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, T new_value) {
237 return Raw::atomic_xchg_at(base, offset, new_value);
238 }
239
240 template <typename T>
241 static void arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
242 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
243 size_t length) {
244 Raw::arraycopy(src_obj, src_offset_in_bytes, src_raw,
245 dst_obj, dst_offset_in_bytes, dst_raw,
246 length);
247 }
248
249 // Heap oop accesses. These accessors get resolved when
250 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
251 // an oop_* overload, and the barrier strength is AS_NORMAL.
252 template <typename T>
253 static oop oop_load_in_heap(T* addr) {
254 return Raw::template oop_load<oop>(addr);
255 }
256
257 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
258 return Raw::template oop_load_at<oop>(base, offset);
259 }
260
261 template <typename T>
262 static void oop_store_in_heap(T* addr, oop value) {
263 Raw::oop_store(addr, value);
264 }
265
266 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
267 Raw::oop_store_at(base, offset, value);
268 }
269
270 template <typename T>
271 static oop oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
272 return Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
273 }
274
275 static oop oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
276 return Raw::oop_atomic_cmpxchg_at(base, offset, compare_value, new_value);
277 }
278
279 template <typename T>
280 static oop oop_atomic_xchg_in_heap(T* addr, oop new_value) {
281 return Raw::oop_atomic_xchg(addr, new_value);
282 }
283
284 static oop oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
285 return Raw::oop_atomic_xchg_at(base, offset, new_value);
286 }
287
288 template <typename T>
289 static void oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
290 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
291 size_t length);
292
293 // Off-heap oop accesses. These accessors get resolved when
294 // IN_HEAP is not set (e.g. when using the NativeAccess API), it is
295 // an oop* overload, and the barrier strength is AS_NORMAL.
296 template <typename T>
297 static oop oop_load_not_in_heap(T* addr) {
298 return Raw::template oop_load<oop>(addr);
299 }
300
301 template <typename T>
302 static void oop_store_not_in_heap(T* addr, oop value) {
303 Raw::oop_store(addr, value);
304 }
305
306 template <typename T>
307 static oop oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
308 return Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
309 }
310
311 template <typename T>
312 static oop oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
313 return Raw::oop_atomic_xchg(addr, new_value);
314 }
315
316 // Clone barrier support
317 static void clone_in_heap(oop src, oop dst, size_t size) {
318 Raw::clone(src, dst, size);
319 }
320
321 static void value_copy_in_heap(void* src, void* dst, InlineKlass* md) {
322 Raw::value_copy(src, dst, md);
323 }
324
325 };
326 };
327
328 template<typename T>
329 inline T* barrier_set_cast(BarrierSet* bs) {
330 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
331 return static_cast<T*>(bs);
332 }
333
334 #endif // SHARE_GC_SHARED_BARRIERSET_HPP