1 /*
2 * Copyright (c) 2000, 2018, 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
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
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
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 #ifndef SHARE_VM_GC_SHARED_BARRIERSET_HPP
26 #define SHARE_VM_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 JavaThread;
37 class BarrierSetAssembler;
38
39 // This class provides the interface between a barrier implementation and
40 // the rest of the system.
41
42 class BarrierSet: public CHeapObj<mtGC> {
43 friend class VMStructs;
44
45 static BarrierSet* _barrier_set;
46
47 public:
48 enum Name {
49 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
50 FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
51 #undef BARRIER_SET_DECLARE_BS_ENUM
52 UnknownBS
53 };
54
55 protected:
56 // Fake RTTI support. For a derived class T to participate
57 // - T must have a corresponding Name entry.
58 // - GetName<T> must be specialized to return the corresponding Name
59 // entry.
60 // - If T is a base class, the constructor must have a FakeRtti
61 // parameter and pass it up to its base class, with the tag set
62 // augmented with the corresponding Name entry.
63 // - If T is a concrete class, the constructor must create a
64 // FakeRtti object whose tag set includes the corresponding Name
65 // entry, and pass it up to its base class.
66 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
67
68 private:
69 FakeRtti _fake_rtti;
70 BarrierSetAssembler* _barrier_set_assembler;
71
72 public:
73 // Metafunction mapping a class derived from BarrierSet to the
74 // corresponding Name enum tag.
75 template<typename T> struct GetName;
76
77 // Metafunction mapping a Name enum type to the corresponding
78 // lass derived from BarrierSet.
79 template<BarrierSet::Name T> struct GetType;
80
81 // Note: This is not presently the Name corresponding to the
82 // concrete class of this object.
83 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
84
85 // Test whether this object is of the type corresponding to bsn.
86 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
87
88 // End of fake RTTI support.
89
90 protected:
91 BarrierSet(BarrierSetAssembler* barrier_set_assembler, const FakeRtti& fake_rtti) :
92 _fake_rtti(fake_rtti),
93 _barrier_set_assembler(barrier_set_assembler) { }
94 ~BarrierSet() { }
95
96 template <class BarrierSetAssemblerT>
97 BarrierSetAssembler* make_barrier_set_assembler() {
98 return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(NULL);
99 }
100
101 public:
102 // Support for optimizing compilers to call the barrier set on slow path allocations
103 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
104 // The allocation is safe to use iff it returns true. If not, the slow-path allocation
105 // is redone until it succeeds. This can e.g. prevent allocations from the slow path
106 // to be in old.
107 virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
108 virtual void on_thread_create(Thread* thread) {}
109 virtual void on_thread_destroy(Thread* thread) {}
110 virtual void on_thread_attach(JavaThread* thread) {}
111 virtual void on_thread_detach(JavaThread* thread) {}
112 virtual void make_parsable(JavaThread* thread) {}
113
114 public:
115 // Print a description of the memory for the barrier set
116 virtual void print_on(outputStream* st) const = 0;
117
118 static BarrierSet* barrier_set() { return _barrier_set; }
119 static void set_barrier_set(BarrierSet* barrier_set);
120
121 BarrierSetAssembler* barrier_set_assembler() {
122 assert(_barrier_set_assembler != NULL, "should be set");
123 return _barrier_set_assembler;
124 }
125
126 // The AccessBarrier of a BarrierSet subclass is called by the Access API
127 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
128 // may override these default access operations by declaring an
129 // AccessBarrier class in its BarrierSet. Its accessors will then be
130 // automatically resolved at runtime.
131 //
132 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
133 // the following steps should be taken:
134 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
135 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
136 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
137 template <DecoratorSet decorators, typename BarrierSetT>
138 class AccessBarrier: protected RawAccessBarrier<decorators> {
139 private:
140 typedef RawAccessBarrier<decorators> Raw;
141
142 public:
143 // Primitive heap accesses. These accessors get resolved when
144 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
145 // not an oop_* overload, and the barrier strength is AS_NORMAL.
146 template <typename T>
147 static T load_in_heap(T* addr) {
148 return Raw::template load<T>(addr);
149 }
150
151 template <typename T>
152 static T load_in_heap_at(oop base, ptrdiff_t offset) {
153 return Raw::template load_at<T>(base, offset);
154 }
155
156 template <typename T>
157 static void store_in_heap(T* addr, T value) {
158 Raw::store(addr, value);
159 }
160
161 template <typename T>
162 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
163 Raw::store_at(base, offset, value);
164 }
165
166 template <typename T>
167 static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
168 return Raw::atomic_cmpxchg(new_value, addr, compare_value);
169 }
170
171 template <typename T>
172 static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
173 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
174 }
175
176 template <typename T>
177 static T atomic_xchg_in_heap(T new_value, T* addr) {
178 return Raw::atomic_xchg(new_value, addr);
179 }
180
181 template <typename T>
182 static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
183 return Raw::atomic_xchg_at(new_value, base, offset);
184 }
185
186 template <typename T>
187 static void arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
188 Raw::arraycopy(src_obj, dst_obj, src, dst, length);
189 }
190
191 // Heap oop accesses. These accessors get resolved when
192 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
193 // an oop_* overload, and the barrier strength is AS_NORMAL.
194 template <typename T>
195 static oop oop_load_in_heap(T* addr) {
196 return Raw::template oop_load<oop>(addr);
197 }
198
199 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
200 return Raw::template oop_load_at<oop>(base, offset);
201 }
202
203 template <typename T>
204 static void oop_store_in_heap(T* addr, oop value) {
205 Raw::oop_store(addr, value);
206 }
207
208 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
209 Raw::oop_store_at(base, offset, value);
210 }
211
212 template <typename T>
213 static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
214 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
215 }
216
217 static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
218 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
219 }
220
221 template <typename T>
222 static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
223 return Raw::oop_atomic_xchg(new_value, addr);
224 }
225
226 static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
227 return Raw::oop_atomic_xchg_at(new_value, base, offset);
228 }
229
230 template <typename T>
231 static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
232 return Raw::oop_arraycopy(src_obj, dst_obj, src, dst, length);
233 }
234
235 // Off-heap oop accesses. These accessors get resolved when
236 // IN_HEAP is not set (e.g. when using the RootAccess API), it is
237 // an oop* overload, and the barrier strength is AS_NORMAL.
238 template <typename T>
239 static oop oop_load_not_in_heap(T* addr) {
240 return Raw::template oop_load<oop>(addr);
241 }
242
243 template <typename T>
244 static void oop_store_not_in_heap(T* addr, oop value) {
245 Raw::oop_store(addr, value);
246 }
247
248 template <typename T>
249 static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
250 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
251 }
252
253 template <typename T>
254 static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
255 return Raw::oop_atomic_xchg(new_value, addr);
256 }
257
258 // Clone barrier support
259 static void clone_in_heap(oop src, oop dst, size_t size) {
260 Raw::clone(src, dst, size);
261 }
262
263 static oop resolve(oop obj) {
264 return Raw::resolve(obj);
265 }
266
267 static bool equals(oop o1, oop o2) {
268 return Raw::equals(o1, o2);
269 }
270 };
271 };
272
273 template<typename T>
274 inline T* barrier_set_cast(BarrierSet* bs) {
275 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
276 return static_cast<T*>(bs);
277 }
278
279 #endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP