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.
8 *
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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).
14 *
15 * You should have received a copy of the GNU General Public License version
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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/fakeRttiSupport.hpp"
34 #include "utilities/macros.hpp"
35
36 class BarrierSetAssembler;
37 class BarrierSetC1;
38 class BarrierSetC2;
39 class BarrierSetNMethod;
40 class JavaThread;
41
42 // This class provides the interface between a barrier implementation and
43 // the rest of the system.
44
45 class BarrierSet: public CHeapObj<mtGC> {
46 friend class VMStructs;
47
48 static BarrierSet* _barrier_set;
49
50 public:
51 enum Name {
52 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
53 FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
54 #undef BARRIER_SET_DECLARE_BS_ENUM
55 UnknownBS
56 };
57
58 protected:
59 // Fake RTTI support. For a derived class T to participate
60 // - T must have a corresponding Name entry.
61 // - GetName<T> must be specialized to return the corresponding Name
62 // entry.
63 // - If T is a base class, the constructor must have a FakeRtti
64 // parameter and pass it up to its base class, with the tag set
65 // augmented with the corresponding Name entry.
66 // - If T is a concrete class, the constructor must create a
67 // FakeRtti object whose tag set includes the corresponding Name
68 // entry, and pass it up to its base class.
69 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
70
71 private:
72 FakeRtti _fake_rtti;
73 BarrierSetAssembler* _barrier_set_assembler;
74 BarrierSetC1* _barrier_set_c1;
75 BarrierSetC2* _barrier_set_c2;
76 BarrierSetNMethod* _barrier_set_nmethod;
77
78 public:
79 // Metafunction mapping a class derived from BarrierSet to the
80 // corresponding Name enum tag.
81 template<typename T> struct GetName;
82
83 // Metafunction mapping a Name enum type to the corresponding
84 // lass derived from BarrierSet.
85 template<BarrierSet::Name T> struct GetType;
86
87 // Note: This is not presently the Name corresponding to the
88 // concrete class of this object.
89 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
90
91 // Test whether this object is of the type corresponding to bsn.
92 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
93
94 // End of fake RTTI support.
95
96 protected:
97 BarrierSet(BarrierSetAssembler* barrier_set_assembler,
98 BarrierSetC1* barrier_set_c1,
99 BarrierSetC2* barrier_set_c2,
100 BarrierSetNMethod* barrier_set_nmethod,
101 const FakeRtti& fake_rtti) :
102 _fake_rtti(fake_rtti),
103 _barrier_set_assembler(barrier_set_assembler),
104 _barrier_set_c1(barrier_set_c1),
105 _barrier_set_c2(barrier_set_c2),
106 _barrier_set_nmethod(barrier_set_nmethod) {}
107 ~BarrierSet() { }
108
109 template <class BarrierSetAssemblerT>
110 static BarrierSetAssembler* make_barrier_set_assembler() {
111 return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(NULL);
112 }
113
114 template <class BarrierSetC1T>
115 static BarrierSetC1* make_barrier_set_c1() {
116 return COMPILER1_PRESENT(new BarrierSetC1T()) NOT_COMPILER1(NULL);
117 }
118
119 template <class BarrierSetC2T>
120 static BarrierSetC2* make_barrier_set_c2() {
121 return COMPILER2_PRESENT(new BarrierSetC2T()) NOT_COMPILER2(NULL);
122 }
123
124 public:
125 // Support for optimizing compilers to call the barrier set on slow path allocations
126 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
127 // The allocation is safe to use iff it returns true. If not, the slow-path allocation
128 // is redone until it succeeds. This can e.g. prevent allocations from the slow path
129 // to be in old.
130 virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
131 virtual void on_thread_create(Thread* thread) {}
132 virtual void on_thread_destroy(Thread* thread) {}
133 virtual void on_thread_attach(Thread* thread) {}
134 virtual void on_thread_detach(Thread* thread) {}
135 virtual void make_parsable(JavaThread* thread) {}
136
137 #ifdef CHECK_UNHANDLED_OOPS
138 virtual bool oop_equals_operator_allowed() { return true; }
139 #endif
140
141 public:
142 // Print a description of the memory for the barrier set
143 virtual void print_on(outputStream* st) const = 0;
144
145 static BarrierSet* barrier_set() { return _barrier_set; }
146 static void set_barrier_set(BarrierSet* barrier_set);
147
148 BarrierSetAssembler* barrier_set_assembler() {
149 assert(_barrier_set_assembler != NULL, "should be set");
150 return _barrier_set_assembler;
151 }
152
153 BarrierSetC1* barrier_set_c1() {
154 assert(_barrier_set_c1 != NULL, "should be set");
155 return _barrier_set_c1;
156 }
157
158 BarrierSetC2* barrier_set_c2() {
159 assert(_barrier_set_c2 != NULL, "should be set");
160 return _barrier_set_c2;
161 }
162
163 BarrierSetNMethod* barrier_set_nmethod() {
164 return _barrier_set_nmethod;
165 }
166
167 // The AccessBarrier of a BarrierSet subclass is called by the Access API
168 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
169 // may override these default access operations by declaring an
170 // AccessBarrier class in its BarrierSet. Its accessors will then be
171 // automatically resolved at runtime.
172 //
173 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
174 // the following steps should be taken:
175 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
176 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
177 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
178 template <DecoratorSet decorators, typename BarrierSetT>
179 class AccessBarrier: protected RawAccessBarrier<decorators> {
180 private:
181 typedef RawAccessBarrier<decorators> Raw;
182
183 public:
184 // Primitive heap accesses. These accessors get resolved when
185 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
186 // not an oop_* overload, and the barrier strength is AS_NORMAL.
187 template <typename T>
188 static T load_in_heap(T* addr) {
189 return Raw::template load<T>(addr);
190 }
191
192 template <typename T>
193 static T load_in_heap_at(oop base, ptrdiff_t offset) {
194 return Raw::template load_at<T>(base, offset);
195 }
196
197 template <typename T>
198 static void store_in_heap(T* addr, T value) {
199 Raw::store(addr, value);
200 }
201
202 template <typename T>
203 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
204 Raw::store_at(base, offset, value);
205 }
206
207 template <typename T>
208 static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
209 return Raw::atomic_cmpxchg(new_value, addr, compare_value);
210 }
211
212 template <typename T>
213 static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
214 return Raw::atomic_cmpxchg_at(new_value, base, offset, compare_value);
215 }
216
217 template <typename T>
218 static T atomic_xchg_in_heap(T new_value, T* addr) {
219 return Raw::atomic_xchg(new_value, addr);
220 }
221
222 template <typename T>
223 static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
224 return Raw::atomic_xchg_at(new_value, base, offset);
225 }
226
227 template <typename T>
228 static void arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
229 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
230 size_t length) {
231 Raw::arraycopy(src_obj, src_offset_in_bytes, src_raw,
232 dst_obj, dst_offset_in_bytes, dst_raw,
233 length);
234 }
235
236 // Heap oop accesses. These accessors get resolved when
237 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
238 // an oop_* overload, and the barrier strength is AS_NORMAL.
239 template <typename T>
240 static oop oop_load_in_heap(T* addr) {
241 return Raw::template oop_load<oop>(addr);
242 }
243
244 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
245 return Raw::template oop_load_at<oop>(base, offset);
246 }
247
248 template <typename T>
249 static void oop_store_in_heap(T* addr, oop value) {
250 Raw::oop_store(addr, value);
251 }
252
253 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
254 Raw::oop_store_at(base, offset, value);
255 }
256
257 template <typename T>
258 static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
259 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
260 }
261
262 static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
263 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
264 }
265
266 template <typename T>
267 static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
268 return Raw::oop_atomic_xchg(new_value, addr);
269 }
270
271 static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
272 return Raw::oop_atomic_xchg_at(new_value, base, offset);
273 }
274
275 template <typename T>
276 static bool oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
277 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
278 size_t length);
279
280 // Off-heap oop accesses. These accessors get resolved when
281 // IN_HEAP is not set (e.g. when using the NativeAccess API), it is
282 // an oop* overload, and the barrier strength is AS_NORMAL.
283 template <typename T>
284 static oop oop_load_not_in_heap(T* addr) {
285 return Raw::template oop_load<oop>(addr);
286 }
287
288 template <typename T>
289 static void oop_store_not_in_heap(T* addr, oop value) {
290 Raw::oop_store(addr, value);
291 }
292
293 template <typename T>
294 static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
295 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
296 }
297
298 template <typename T>
299 static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
300 return Raw::oop_atomic_xchg(new_value, addr);
301 }
302
303 // Clone barrier support
304 static void clone_in_heap(oop src, oop dst, size_t size) {
305 Raw::clone(src, dst, size);
306 }
307
308 static oop resolve(oop obj) {
309 return Raw::resolve(obj);
310 }
311
312 static bool equals(oop o1, oop o2) {
313 return Raw::equals(o1, o2);
314 }
315 };
316 };
317
318 template<typename T>
319 inline T* barrier_set_cast(BarrierSet* bs) {
320 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
321 return static_cast<T*>(bs);
322 }
323
324 #endif // SHARE_GC_SHARED_BARRIERSET_HPP