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
35 class JavaThread;
36 class BarrierSetCodeGen;
37
38 // This class provides the interface between a barrier implementation and
39 // the rest of the system.
40
41 class BarrierSet: public CHeapObj<mtGC> {
42 friend class VMStructs;
43
44 static BarrierSet* _bs;
45
46 public:
47 enum Name {
48 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
49 FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
50 #undef BARRIER_SET_DECLARE_BS_ENUM
51 UnknownBS
52 };
53
54 static BarrierSet* barrier_set() { return _bs; }
55
56 protected:
57 // Fake RTTI support. For a derived class T to participate
58 // - T must have a corresponding Name entry.
59 // - GetName<T> must be specialized to return the corresponding Name
60 // entry.
61 // - If T is a base class, the constructor must have a FakeRtti
62 // parameter and pass it up to its base class, with the tag set
63 // augmented with the corresponding Name entry.
64 // - If T is a concrete class, the constructor must create a
65 // FakeRtti object whose tag set includes the corresponding Name
66 // entry, and pass it up to its base class.
67 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
68
69 private:
70 FakeRtti _fake_rtti;
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(const FakeRtti& fake_rtti) : _fake_rtti(fake_rtti), _code_gen(NULL) { }
92 ~BarrierSet() { }
93 BarrierSetCodeGen* _code_gen;
94 virtual BarrierSetCodeGen* make_code_gen() = 0;
95
96 public:
97 // Support for optimizing compilers to call the barrier set on slow path allocations
98 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
99 // The allocation is safe to use iff it returns true. If not, the slow-path allocation
100 // is redone until it succeeds. This can e.g. prevent allocations from the slow path
101 // to be in old.
102 virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
103 virtual void on_thread_attach(JavaThread* thread) {}
104 virtual void on_thread_detach(JavaThread* thread) {}
105 virtual void make_parsable(JavaThread* thread) {}
106
107 public:
108 // Print a description of the memory for the barrier set
109 virtual void print_on(outputStream* st) const = 0;
110
111 static void set_bs(BarrierSet* bs) { _bs = bs; }
112
113 virtual void initialize();
114
115 BarrierSetCodeGen* code_gen() {
116 assert(_code_gen != NULL, "should be set");
117 return _code_gen;
118 }
119
120 // The AccessBarrier of a BarrierSet subclass is called by the Access API
121 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
122 // may override these default access operations by declaring an
123 // AccessBarrier class in its BarrierSet. Its accessors will then be
124 // automatically resolved at runtime.
125 //
126 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
127 // the following steps should be taken:
128 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
129 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
130 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
131 template <DecoratorSet decorators, typename BarrierSetT>
132 class AccessBarrier: protected RawAccessBarrier<decorators> {
133 private:
134 typedef RawAccessBarrier<decorators> Raw;
135
136 public:
137 // Primitive heap accesses. These accessors get resolved when
138 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
139 // not an oop_* overload, and the barrier strength is AS_NORMAL.
140 template <typename T>
141 static T load_in_heap(T* addr) {
142 return Raw::template load<T>(addr);
143 }
144
145 template <typename T>
146 static T load_in_heap_at(oop base, ptrdiff_t offset) {
147 return Raw::template load_at<T>(base, offset);
148 }
149
150 template <typename T>
151 static void store_in_heap(T* addr, T value) {
152 Raw::store(addr, value);
153 }
154
155 template <typename T>
156 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
157 Raw::store_at(base, offset, value);
158 }
159
160 template <typename T>
161 static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
162 return Raw::atomic_cmpxchg(new_value, addr, compare_value);
163 }
164
165 template <typename T>
166 static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
167 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
168 }
169
170 template <typename T>
171 static T atomic_xchg_in_heap(T new_value, T* addr) {
172 return Raw::atomic_xchg(new_value, addr);
173 }
174
175 template <typename T>
176 static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
177 return Raw::atomic_xchg_at(new_value, base, offset);
178 }
179
180 template <typename T>
181 static bool arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
182 return Raw::arraycopy(src_obj, dst_obj, src, dst, length);
183 }
184
185 // Heap oop accesses. These accessors get resolved when
186 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
187 // an oop_* overload, and the barrier strength is AS_NORMAL.
188 template <typename T>
189 static oop oop_load_in_heap(T* addr) {
190 return Raw::template oop_load<oop>(addr);
191 }
192
193 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
194 return Raw::template oop_load_at<oop>(base, offset);
195 }
196
197 template <typename T>
198 static void oop_store_in_heap(T* addr, oop value) {
199 Raw::oop_store(addr, value);
200 }
201
202 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
203 Raw::oop_store_at(base, offset, value);
204 }
205
206 template <typename T>
207 static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
208 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
209 }
210
211 static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
212 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
213 }
214
215 template <typename T>
216 static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
217 return Raw::oop_atomic_xchg(new_value, addr);
218 }
219
220 static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
221 return Raw::oop_atomic_xchg_at(new_value, base, offset);
222 }
223
224 template <typename T>
225 static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
226 return Raw::oop_arraycopy(src_obj, dst_obj, src, dst, length);
227 }
228
229 // Off-heap oop accesses. These accessors get resolved when
230 // IN_HEAP is not set (e.g. when using the RootAccess API), it is
231 // an oop* overload, and the barrier strength is AS_NORMAL.
232 template <typename T>
233 static oop oop_load_not_in_heap(T* addr) {
234 return Raw::template oop_load<oop>(addr);
235 }
236
237 template <typename T>
238 static void oop_store_not_in_heap(T* addr, oop value) {
239 Raw::oop_store(addr, value);
240 }
241
242 template <typename T>
243 static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
244 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
245 }
246
247 template <typename T>
248 static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
249 return Raw::oop_atomic_xchg(new_value, addr);
250 }
251
252 // Clone barrier support
253 static void clone_in_heap(oop src, oop dst, size_t size) {
254 Raw::clone(src, dst, size);
255 }
256
257 static oop resolve(oop obj) {
258 return Raw::resolve(obj);
259 }
260 };
261 };
262
263 template<typename T>
264 inline T* barrier_set_cast(BarrierSet* bs) {
265 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
266 return static_cast<T*>(bs);
267 }
268
269 #endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP