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 21 * questions. 22 * 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