1 /*
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  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
  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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 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/exceptions.hpp"
 34 #include "utilities/fakeRttiSupport.hpp"
 35 #include "utilities/macros.hpp"
 36 
 37 class BarrierSetAssembler;
 38 class BarrierSetC1;
 39 class BarrierSetC2;
 40 class BarrierSetNMethod;
 41 class JavaThread;
 42 
 43 // This class provides the interface between a barrier implementation and
 44 // the rest of the system.
 45 
 46 class BarrierSet: public CHeapObj<mtGC> {
 47   friend class VMStructs;
 48 
 49   static BarrierSet* _barrier_set;
 50 
 51 public:
 52   enum Name {
 53 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
 54     FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
 55 #undef BARRIER_SET_DECLARE_BS_ENUM
 56     UnknownBS
 57   };
 58 
 59 protected:
 60   // Fake RTTI support.  For a derived class T to participate
 61   // - T must have a corresponding Name entry.
 62   // - GetName<T> must be specialized to return the corresponding Name
 63   //   entry.
 64   // - If T is a base class, the constructor must have a FakeRtti
 65   //   parameter and pass it up to its base class, with the tag set
 66   //   augmented with the corresponding Name entry.
 67   // - If T is a concrete class, the constructor must create a
 68   //   FakeRtti object whose tag set includes the corresponding Name
 69   //   entry, and pass it up to its base class.
 70   typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
 71 
 72 private:
 73   FakeRtti _fake_rtti;
 74   BarrierSetAssembler* _barrier_set_assembler;
 75   BarrierSetC1* _barrier_set_c1;
 76   BarrierSetC2* _barrier_set_c2;
 77   BarrierSetNMethod* _barrier_set_nmethod;
 78 
 79 public:
 80   // Metafunction mapping a class derived from BarrierSet to the
 81   // corresponding Name enum tag.
 82   template<typename T> struct GetName;
 83 
 84   // Metafunction mapping a Name enum type to the corresponding
 85   // lass derived from BarrierSet.
 86   template<BarrierSet::Name T> struct GetType;
 87 
 88   // Note: This is not presently the Name corresponding to the
 89   // concrete class of this object.
 90   BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
 91 
 92   // Test whether this object is of the type corresponding to bsn.
 93   bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
 94 
 95   // End of fake RTTI support.
 96 
 97 protected:
 98   BarrierSet(BarrierSetAssembler* barrier_set_assembler,
 99              BarrierSetC1* barrier_set_c1,
100              BarrierSetC2* barrier_set_c2,
101              BarrierSetNMethod* barrier_set_nmethod,
102              const FakeRtti& fake_rtti) :
103     _fake_rtti(fake_rtti),
104     _barrier_set_assembler(barrier_set_assembler),
105     _barrier_set_c1(barrier_set_c1),
106     _barrier_set_c2(barrier_set_c2),
107     _barrier_set_nmethod(barrier_set_nmethod) {}
108   ~BarrierSet() { }
109 
110   template <class BarrierSetAssemblerT>
111   static BarrierSetAssembler* make_barrier_set_assembler() {
112     return NOT_ZERO(new BarrierSetAssemblerT()) ZERO_ONLY(NULL);
113   }
114 
115   template <class BarrierSetC1T>
116   static BarrierSetC1* make_barrier_set_c1() {
117     return COMPILER1_PRESENT(new BarrierSetC1T()) NOT_COMPILER1(NULL);
118   }
119 
120   template <class BarrierSetC2T>
121   static BarrierSetC2* make_barrier_set_c2() {
122     return COMPILER2_PRESENT(new BarrierSetC2T()) NOT_COMPILER2(NULL);
123   }
124 
125   static void throw_array_null_pointer_store_exception(arrayOop src, arrayOop dst, TRAPS);
126   static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS);
127 
128 public:
129   // Support for optimizing compilers to call the barrier set on slow path allocations
130   // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
131   // The allocation is safe to use iff it returns true. If not, the slow-path allocation
132   // is redone until it succeeds. This can e.g. prevent allocations from the slow path
133   // to be in old.
134   virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
135   virtual void on_thread_create(Thread* thread) {}
136   virtual void on_thread_destroy(Thread* thread) {}
137 
138   // These perform BarrierSet-related initialization/cleanup before the thread
139   // is added to or removed from the corresponding set of threads. The
140   // argument thread is the current thread. These are called either holding
141   // the Threads_lock (for a JavaThread) and so not at a safepoint, or holding
142   // the NonJavaThreadsList_lock (for a NonJavaThread) locked by the
143   // caller. That locking ensures the operation is "atomic" with the list
144   // modification wrto operations that hold the NJTList_lock and either also
145   // hold the Threads_lock or are at a safepoint.
146   virtual void on_thread_attach(Thread* thread) {}
147   virtual void on_thread_detach(Thread* thread) {}
148 
149   virtual void make_parsable(JavaThread* thread) {}
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* addr, T compare_value, T new_value) {
219       return Raw::atomic_cmpxchg(addr, compare_value, new_value);
220     }
221 
222     template <typename T>
223     static T atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, T compare_value, T new_value) {
224       return Raw::atomic_cmpxchg_at(base, offset, compare_value, new_value);
225     }
226 
227     template <typename T>
228     static T atomic_xchg_in_heap(T* addr, T new_value) {
229       return Raw::atomic_xchg(addr, new_value);
230     }
231 
232     template <typename T>
233     static T atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, T new_value) {
234       return Raw::atomic_xchg_at(base, offset, new_value);
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(T* addr, oop compare_value, oop new_value) {
269       return Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
270     }
271 
272     static oop oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
273       return Raw::oop_atomic_cmpxchg_at(base, offset, compare_value, new_value);
274     }
275 
276     template <typename T>
277     static oop oop_atomic_xchg_in_heap(T* addr, oop new_value) {
278       return Raw::oop_atomic_xchg(addr, new_value);
279     }
280 
281     static oop oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
282       return Raw::oop_atomic_xchg_at(base, offset, new_value);
283     }
284 
285     template <typename T>
286     static void 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(T* addr, oop compare_value, oop new_value) {
305       return Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
306     }
307 
308     template <typename T>
309     static oop oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
310       return Raw::oop_atomic_xchg(addr, new_value);
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 void value_copy_in_heap(void* src, void* dst, InlineKlass* md) {
319       Raw::value_copy(src, dst, md);
320     }
321 
322   };
323 };
324 
325 template<typename T>
326 inline T* barrier_set_cast(BarrierSet* bs) {
327   assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
328   return static_cast<T*>(bs);
329 }
330 
331 #endif // SHARE_GC_SHARED_BARRIERSET_HPP