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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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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* _bs;
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 static BarrierSet* barrier_set() { return _bs; }
56
57 protected:
58 // Fake RTTI support. For a derived class T to participate
59 // - T must have a corresponding Name entry.
60 // - GetName<T> must be specialized to return the corresponding Name
61 // entry.
62 // - If T is a base class, the constructor must have a FakeRtti
63 // parameter and pass it up to its base class, with the tag set
64 // augmented with the corresponding Name entry.
65 // - If T is a concrete class, the constructor must create a
66 // FakeRtti object whose tag set includes the corresponding Name
67 // entry, and pass it up to its base class.
68 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
69
70 private:
71 FakeRtti _fake_rtti;
72 BarrierSetAssembler* _barrier_set_assembler;
73
74 public:
75 // Metafunction mapping a class derived from BarrierSet to the
76 // corresponding Name enum tag.
77 template<typename T> struct GetName;
78
79 // Metafunction mapping a Name enum type to the corresponding
80 // lass derived from BarrierSet.
81 template<BarrierSet::Name T> struct GetType;
82
83 // Note: This is not presently the Name corresponding to the
84 // concrete class of this object.
85 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
86
87 // Test whether this object is of the type corresponding to bsn.
88 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
89
90 // End of fake RTTI support.
91
92 protected:
93 BarrierSet(BarrierSetAssembler* barrier_set_assembler, const FakeRtti& fake_rtti) :
94 _fake_rtti(fake_rtti),
95 _barrier_set_assembler(barrier_set_assembler) { }
96 ~BarrierSet() { }
97
98 template <class BarrierSetAssemblerT>
99 BarrierSetAssembler* make_barrier_set_assembler() {
100 return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(NULL);
101 }
102
103 public:
104 // Support for optimizing compilers to call the barrier set on slow path allocations
105 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
106 // The allocation is safe to use iff it returns true. If not, the slow-path allocation
107 // is redone until it succeeds. This can e.g. prevent allocations from the slow path
108 // to be in old.
109 virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
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 void set_bs(BarrierSet* bs) { _bs = bs; }
119
120 BarrierSetAssembler* barrier_set_assembler() {
121 assert(_barrier_set_assembler != NULL, "should be set");
122 return _barrier_set_assembler;
123 }
124
125 // The AccessBarrier of a BarrierSet subclass is called by the Access API
126 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
127 // may override these default access operations by declaring an
128 // AccessBarrier class in its BarrierSet. Its accessors will then be
129 // automatically resolved at runtime.
130 //
131 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
132 // the following steps should be taken:
133 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
134 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
135 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
136 template <DecoratorSet decorators, typename BarrierSetT>
137 class AccessBarrier: protected RawAccessBarrier<decorators> {
138 private:
139 typedef RawAccessBarrier<decorators> Raw;
140
141 public:
142 // Primitive heap accesses. These accessors get resolved when
143 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
144 // not an oop_* overload, and the barrier strength is AS_NORMAL.
145 template <typename T>
146 static T load_in_heap(T* addr) {
147 return Raw::template load<T>(addr);
148 }
149
150 template <typename T>
151 static T load_in_heap_at(oop base, ptrdiff_t offset) {
152 return Raw::template load_at<T>(base, offset);
153 }
154
155 template <typename T>
156 static void store_in_heap(T* addr, T value) {
157 Raw::store(addr, value);
158 }
159
160 template <typename T>
161 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
162 Raw::store_at(base, offset, value);
163 }
164
165 template <typename T>
166 static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
167 return Raw::atomic_cmpxchg(new_value, addr, compare_value);
168 }
169
170 template <typename T>
171 static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
172 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
173 }
174
175 template <typename T>
176 static T atomic_xchg_in_heap(T new_value, T* addr) {
177 return Raw::atomic_xchg(new_value, addr);
178 }
179
180 template <typename T>
181 static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
182 return Raw::atomic_xchg_at(new_value, base, offset);
183 }
184
185 template <typename T>
186 static void arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
187 Raw::arraycopy(src_obj, dst_obj, src, dst, length);
188 }
189
190 // Heap oop accesses. These accessors get resolved when
191 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
192 // an oop_* overload, and the barrier strength is AS_NORMAL.
193 template <typename T>
194 static oop oop_load_in_heap(T* addr) {
195 return Raw::template oop_load<oop>(addr);
196 }
197
198 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
199 return Raw::template oop_load_at<oop>(base, offset);
200 }
201
202 template <typename T>
203 static void oop_store_in_heap(T* addr, oop value) {
204 Raw::oop_store(addr, value);
205 }
206
207 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
208 Raw::oop_store_at(base, offset, value);
209 }
210
211 template <typename T>
212 static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
213 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
214 }
215
216 static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
217 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
218 }
219
220 template <typename T>
221 static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
222 return Raw::oop_atomic_xchg(new_value, addr);
223 }
224
225 static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
226 return Raw::oop_atomic_xchg_at(new_value, base, offset);
227 }
228
229 template <typename T>
230 static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
231 return Raw::oop_arraycopy(src_obj, dst_obj, src, dst, length);
232 }
233
234 // Off-heap oop accesses. These accessors get resolved when
235 // IN_HEAP is not set (e.g. when using the RootAccess API), it is
236 // an oop* overload, and the barrier strength is AS_NORMAL.
237 template <typename T>
238 static oop oop_load_not_in_heap(T* addr) {
239 return Raw::template oop_load<oop>(addr);
240 }
241
242 template <typename T>
243 static void oop_store_not_in_heap(T* addr, oop value) {
244 Raw::oop_store(addr, value);
245 }
246
247 template <typename T>
248 static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
249 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
250 }
251
252 template <typename T>
253 static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
254 return Raw::oop_atomic_xchg(new_value, addr);
255 }
256
257 // Clone barrier support
258 static void clone_in_heap(oop src, oop dst, size_t size) {
259 Raw::clone(src, dst, size);
260 }
261
262 static oop resolve(oop obj) {
263 return Raw::resolve(obj);
264 }
265
266 static bool equals(oop o1, oop o2) {
267 return Raw::equals(o1, o2);
268 }
269 };
270 };
271
272 template<typename T>
273 inline T* barrier_set_cast(BarrierSet* bs) {
274 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
275 return static_cast<T*>(bs);
276 }
277
278 #endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP