1 /*
2 * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
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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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).
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23 */
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 JavaThread;
42
43 // This class provides the interface between a barrier implementation and
44 // the rest of the system.
45
46 class BarrierSet: public CHeapObj<mtGC> {
47 friend class VMStructs;
48
49 static BarrierSet* _barrier_set;
50
51 public:
52 enum Name {
53 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
54 FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
55 #undef BARRIER_SET_DECLARE_BS_ENUM
56 UnknownBS
57 };
58
59 protected:
60 // Fake RTTI support. For a derived class T to participate
61 // - T must have a corresponding Name entry.
62 // - GetName<T> must be specialized to return the corresponding Name
63 // entry.
64 // - If T is a base class, the constructor must have a FakeRtti
65 // parameter and pass it up to its base class, with the tag set
66 // augmented with the corresponding Name entry.
67 // - If T is a concrete class, the constructor must create a
68 // FakeRtti object whose tag set includes the corresponding Name
69 // entry, and pass it up to its base class.
70 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
71
72 private:
73 FakeRtti _fake_rtti;
74 BarrierSetAssembler* _barrier_set_assembler;
75 BarrierSetC1* _barrier_set_c1;
76 BarrierSetC2* _barrier_set_c2;
77 BarrierSetNMethod* _barrier_set_nmethod;
78
79 public:
80 // Metafunction mapping a class derived from BarrierSet to the
81 // corresponding Name enum tag.
82 template<typename T> struct GetName;
83
84 // Metafunction mapping a Name enum type to the corresponding
85 // lass derived from BarrierSet.
86 template<BarrierSet::Name T> struct GetType;
87
88 // Note: This is not presently the Name corresponding to the
89 // concrete class of this object.
90 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
91
92 // Test whether this object is of the type corresponding to bsn.
93 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
94
95 // End of fake RTTI support.
96
97 protected:
98 BarrierSet(BarrierSetAssembler* barrier_set_assembler,
99 BarrierSetC1* barrier_set_c1,
100 BarrierSetC2* barrier_set_c2,
101 BarrierSetNMethod* barrier_set_nmethod,
102 const FakeRtti& fake_rtti) :
103 _fake_rtti(fake_rtti),
104 _barrier_set_assembler(barrier_set_assembler),
105 _barrier_set_c1(barrier_set_c1),
106 _barrier_set_c2(barrier_set_c2),
107 _barrier_set_nmethod(barrier_set_nmethod) {}
108 ~BarrierSet() { }
109
110 template <class BarrierSetAssemblerT>
111 static BarrierSetAssembler* make_barrier_set_assembler() {
112 return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(NULL);
113 }
114
115 template <class BarrierSetC1T>
116 static BarrierSetC1* make_barrier_set_c1() {
117 return COMPILER1_PRESENT(new BarrierSetC1T()) NOT_COMPILER1(NULL);
118 }
119
120 template <class BarrierSetC2T>
121 static BarrierSetC2* make_barrier_set_c2() {
122 return COMPILER2_PRESENT(new BarrierSetC2T()) NOT_COMPILER2(NULL);
123 }
124
125 static void throw_array_null_pointer_store_exception(arrayOop src, arrayOop dst, TRAPS);
126 static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS);
127
128 public:
129 // Support for optimizing compilers to call the barrier set on slow path allocations
130 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
131 // The allocation is safe to use iff it returns true. If not, the slow-path allocation
132 // is redone until it succeeds. This can e.g. prevent allocations from the slow path
133 // to be in old.
134 virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
135 virtual void on_thread_create(Thread* thread) {}
136 virtual void on_thread_destroy(Thread* thread) {}
137
138 // These perform BarrierSet-related initialization/cleanup before the thread
139 // is added to or removed from the corresponding set of threads. The
140 // argument thread is the current thread. These are called either holding
141 // the Threads_lock (for a JavaThread) and so not at a safepoint, or holding
142 // the NonJavaThreadsList_lock (for a NonJavaThread) locked by the
143 // caller. That locking ensures the operation is "atomic" with the list
144 // modification wrto operations that hold the NJTList_lock and either also
145 // hold the Threads_lock or are at a safepoint.
146 virtual void on_thread_attach(Thread* thread) {}
147 virtual void on_thread_detach(Thread* thread) {}
148
149 virtual void make_parsable(JavaThread* thread) {}
150
151 #ifdef CHECK_UNHANDLED_OOPS
152 virtual bool oop_equals_operator_allowed() { return true; }
153 #endif
154
155 public:
156 // Print a description of the memory for the barrier set
157 virtual void print_on(outputStream* st) const = 0;
158
159 static BarrierSet* barrier_set() { return _barrier_set; }
160 static void set_barrier_set(BarrierSet* barrier_set);
161
162 BarrierSetAssembler* barrier_set_assembler() {
163 assert(_barrier_set_assembler != NULL, "should be set");
164 return _barrier_set_assembler;
165 }
166
167 BarrierSetC1* barrier_set_c1() {
168 assert(_barrier_set_c1 != NULL, "should be set");
169 return _barrier_set_c1;
170 }
171
172 BarrierSetC2* barrier_set_c2() {
173 assert(_barrier_set_c2 != NULL, "should be set");
174 return _barrier_set_c2;
175 }
176
177 BarrierSetNMethod* barrier_set_nmethod() {
178 return _barrier_set_nmethod;
179 }
180
181 // The AccessBarrier of a BarrierSet subclass is called by the Access API
182 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
183 // may override these default access operations by declaring an
184 // AccessBarrier class in its BarrierSet. Its accessors will then be
185 // automatically resolved at runtime.
186 //
187 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
188 // the following steps should be taken:
189 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
190 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
191 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
192 template <DecoratorSet decorators, typename BarrierSetT>
193 class AccessBarrier: protected RawAccessBarrier<decorators> {
194 private:
195 typedef RawAccessBarrier<decorators> Raw;
196
197 public:
198 // Primitive heap accesses. These accessors get resolved when
199 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
200 // not an oop_* overload, and the barrier strength is AS_NORMAL.
201 template <typename T>
202 static T load_in_heap(T* addr) {
203 return Raw::template load<T>(addr);
204 }
205
206 template <typename T>
207 static T load_in_heap_at(oop base, ptrdiff_t offset) {
208 return Raw::template load_at<T>(base, offset);
209 }
210
211 template <typename T>
212 static void store_in_heap(T* addr, T value) {
213 Raw::store(addr, value);
214 }
215
216 template <typename T>
217 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
218 Raw::store_at(base, offset, value);
219 }
220
221 template <typename T>
222 static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
223 return Raw::atomic_cmpxchg(new_value, addr, compare_value);
224 }
225
226 template <typename T>
227 static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
228 return Raw::atomic_cmpxchg_at(new_value, base, offset, compare_value);
229 }
230
231 template <typename T>
232 static T atomic_xchg_in_heap(T new_value, T* addr) {
233 return Raw::atomic_xchg(new_value, addr);
234 }
235
236 template <typename T>
237 static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
238 return Raw::atomic_xchg_at(new_value, base, offset);
239 }
240
241 template <typename T>
242 static void arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
243 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
244 size_t length) {
245 Raw::arraycopy(src_obj, src_offset_in_bytes, src_raw,
246 dst_obj, dst_offset_in_bytes, dst_raw,
247 length);
248 }
249
250 // Heap oop accesses. These accessors get resolved when
251 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
252 // an oop_* overload, and the barrier strength is AS_NORMAL.
253 template <typename T>
254 static oop oop_load_in_heap(T* addr) {
255 return Raw::template oop_load<oop>(addr);
256 }
257
258 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
259 return Raw::template oop_load_at<oop>(base, offset);
260 }
261
262 template <typename T>
263 static void oop_store_in_heap(T* addr, oop value) {
264 Raw::oop_store(addr, value);
265 }
266
267 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
268 Raw::oop_store_at(base, offset, value);
269 }
270
271 template <typename T>
272 static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
273 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
274 }
275
276 static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
277 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
278 }
279
280 template <typename T>
281 static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
282 return Raw::oop_atomic_xchg(new_value, addr);
283 }
284
285 static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
286 return Raw::oop_atomic_xchg_at(new_value, base, offset);
287 }
288
289 template <typename T>
290 static void oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
291 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
292 size_t length);
293
294 // Off-heap oop accesses. These accessors get resolved when
295 // IN_HEAP is not set (e.g. when using the NativeAccess API), it is
296 // an oop* overload, and the barrier strength is AS_NORMAL.
297 template <typename T>
298 static oop oop_load_not_in_heap(T* addr) {
299 return Raw::template oop_load<oop>(addr);
300 }
301
302 template <typename T>
303 static void oop_store_not_in_heap(T* addr, oop value) {
304 Raw::oop_store(addr, value);
305 }
306
307 template <typename T>
308 static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
309 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
310 }
311
312 template <typename T>
313 static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
314 return Raw::oop_atomic_xchg(new_value, addr);
315 }
316
317 // Clone barrier support
318 static void clone_in_heap(oop src, oop dst, size_t size) {
319 Raw::clone(src, dst, size);
320 }
321
322 static oop resolve(oop obj) {
323 return Raw::resolve(obj);
324 }
325
326 static bool equals(oop o1, oop o2) {
327 return Raw::equals(o1, o2);
328 }
329 };
330 };
331
332 template<typename T>
333 inline T* barrier_set_cast(BarrierSet* bs) {
334 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
335 return static_cast<T*>(bs);
336 }
337
338 #endif // SHARE_GC_SHARED_BARRIERSET_HPP