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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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
134 // These perform BarrierSet-related initialization/cleanup before the thread
135 // is added to or removed from the corresponding set of threads. The
136 // argument thread is the current thread. These are called either holding
137 // the Threads_lock (for a JavaThread) and so not at a safepoint, or holding
138 // the NonJavaThreadsList_lock (for a NonJavaThread) locked by the
139 // caller. That locking ensures the operation is "atomic" with the list
140 // modification wrto operations that hold the NJTList_lock and either also
141 // hold the Threads_lock or are at a safepoint.
142 virtual void on_thread_attach(Thread* thread) {}
143 virtual void on_thread_detach(Thread* thread) {}
144
145 virtual void make_parsable(JavaThread* thread) {}
146
147 #ifdef CHECK_UNHANDLED_OOPS
148 virtual bool oop_equals_operator_allowed() { return true; }
149 #endif
150
151 public:
152 // Print a description of the memory for the barrier set
153 virtual void print_on(outputStream* st) const = 0;
154
155 static BarrierSet* barrier_set() { return _barrier_set; }
156 static void set_barrier_set(BarrierSet* barrier_set);
157
158 BarrierSetAssembler* barrier_set_assembler() {
159 assert(_barrier_set_assembler != NULL, "should be set");
160 return _barrier_set_assembler;
161 }
162
163 BarrierSetC1* barrier_set_c1() {
164 assert(_barrier_set_c1 != NULL, "should be set");
165 return _barrier_set_c1;
166 }
167
168 BarrierSetC2* barrier_set_c2() {
169 assert(_barrier_set_c2 != NULL, "should be set");
170 return _barrier_set_c2;
171 }
172
173 BarrierSetNMethod* barrier_set_nmethod() {
174 return _barrier_set_nmethod;
175 }
176
177 // The AccessBarrier of a BarrierSet subclass is called by the Access API
178 // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
179 // may override these default access operations by declaring an
180 // AccessBarrier class in its BarrierSet. Its accessors will then be
181 // automatically resolved at runtime.
182 //
183 // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
184 // the following steps should be taken:
185 // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
186 // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
187 // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
188 template <DecoratorSet decorators, typename BarrierSetT>
189 class AccessBarrier: protected RawAccessBarrier<decorators> {
190 private:
191 typedef RawAccessBarrier<decorators> Raw;
192
193 public:
194 // Primitive heap accesses. These accessors get resolved when
195 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
196 // not an oop_* overload, and the barrier strength is AS_NORMAL.
197 template <typename T>
198 static T load_in_heap(T* addr) {
199 return Raw::template load<T>(addr);
200 }
201
202 template <typename T>
203 static T load_in_heap_at(oop base, ptrdiff_t offset) {
204 return Raw::template load_at<T>(base, offset);
205 }
206
207 template <typename T>
208 static void store_in_heap(T* addr, T value) {
209 Raw::store(addr, value);
210 }
211
212 template <typename T>
213 static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
214 Raw::store_at(base, offset, value);
215 }
216
217 template <typename T>
218 static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
219 return Raw::atomic_cmpxchg(new_value, addr, compare_value);
220 }
221
222 template <typename T>
223 static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
224 return Raw::atomic_cmpxchg_at(new_value, base, offset, compare_value);
225 }
226
227 template <typename T>
228 static T atomic_xchg_in_heap(T new_value, T* addr) {
229 return Raw::atomic_xchg(new_value, addr);
230 }
231
232 template <typename T>
233 static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
234 return Raw::atomic_xchg_at(new_value, base, offset);
235 }
236
237 template <typename T>
238 static void arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
239 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
240 size_t length) {
241 Raw::arraycopy(src_obj, src_offset_in_bytes, src_raw,
242 dst_obj, dst_offset_in_bytes, dst_raw,
243 length);
244 }
245
246 // Heap oop accesses. These accessors get resolved when
247 // IN_HEAP is set (e.g. when using the HeapAccess API), it is
248 // an oop_* overload, and the barrier strength is AS_NORMAL.
249 template <typename T>
250 static oop oop_load_in_heap(T* addr) {
251 return Raw::template oop_load<oop>(addr);
252 }
253
254 static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
255 return Raw::template oop_load_at<oop>(base, offset);
256 }
257
258 template <typename T>
259 static void oop_store_in_heap(T* addr, oop value) {
260 Raw::oop_store(addr, value);
261 }
262
263 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
264 Raw::oop_store_at(base, offset, value);
265 }
266
267 template <typename T>
268 static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
269 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
270 }
271
272 static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
273 return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
274 }
275
276 template <typename T>
277 static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
278 return Raw::oop_atomic_xchg(new_value, addr);
279 }
280
281 static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
282 return Raw::oop_atomic_xchg_at(new_value, base, offset);
283 }
284
285 template <typename T>
286 static bool oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
287 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
288 size_t length);
289
290 // Off-heap oop accesses. These accessors get resolved when
291 // IN_HEAP is not set (e.g. when using the NativeAccess API), it is
292 // an oop* overload, and the barrier strength is AS_NORMAL.
293 template <typename T>
294 static oop oop_load_not_in_heap(T* addr) {
295 return Raw::template oop_load<oop>(addr);
296 }
297
298 template <typename T>
299 static void oop_store_not_in_heap(T* addr, oop value) {
300 Raw::oop_store(addr, value);
301 }
302
303 template <typename T>
304 static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
305 return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
306 }
307
308 template <typename T>
309 static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
310 return Raw::oop_atomic_xchg(new_value, addr);
311 }
312
313 // Clone barrier support
314 static void clone_in_heap(oop src, oop dst, size_t size) {
315 Raw::clone(src, dst, size);
316 }
317
318 static oop resolve(oop obj) {
319 return Raw::resolve(obj);
320 }
321
322 static bool equals(oop o1, oop o2) {
323 return Raw::equals(o1, o2);
324 }
325 };
326 };
327
328 template<typename T>
329 inline T* barrier_set_cast(BarrierSet* bs) {
330 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
331 return static_cast<T*>(bs);
332 }
333
334 #endif // SHARE_GC_SHARED_BARRIERSET_HPP