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1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_RUNTIME_MIRROR_ARRAY_INL_H_
18 #define ART_RUNTIME_MIRROR_ARRAY_INL_H_
19 
20 #include "array.h"
21 
22 #include "class.h"
23 #include "gc/heap-inl.h"
24 #include "thread.h"
25 #include "utils.h"
26 
27 namespace art {
28 namespace mirror {
29 
ClassSize()30 inline uint32_t Array::ClassSize() {
31   uint32_t vtable_entries = Object::kVTableLength;
32   return Class::ComputeClassSize(true, vtable_entries, 0, 0, 0);
33 }
34 
35 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
SizeOf()36 inline size_t Array::SizeOf() {
37   // This is safe from overflow because the array was already allocated, so we know it's sane.
38   size_t component_size =
39       GetClass<kVerifyFlags, kReadBarrierOption>()->template GetComponentSize<kReadBarrierOption>();
40   // Don't need to check this since we already check this in GetClass.
41   int32_t component_count =
42       GetLength<static_cast<VerifyObjectFlags>(kVerifyFlags & ~kVerifyThis)>();
43   size_t header_size = DataOffset(component_size).SizeValue();
44   size_t data_size = component_count * component_size;
45   return header_size + data_size;
46 }
47 
48 template<VerifyObjectFlags kVerifyFlags>
CheckIsValidIndex(int32_t index)49 inline bool Array::CheckIsValidIndex(int32_t index) {
50   if (UNLIKELY(static_cast<uint32_t>(index) >=
51                static_cast<uint32_t>(GetLength<kVerifyFlags>()))) {
52     ThrowArrayIndexOutOfBoundsException(index);
53     return false;
54   }
55   return true;
56 }
57 
ComputeArraySize(Thread * self,Class * array_class,int32_t component_count,size_t component_size)58 static inline size_t ComputeArraySize(Thread* self, Class* array_class, int32_t component_count,
59                                       size_t component_size)
60     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
61   DCHECK(array_class != NULL);
62   DCHECK_GE(component_count, 0);
63   DCHECK(array_class->IsArrayClass());
64 
65   size_t header_size = Array::DataOffset(component_size).SizeValue();
66   size_t data_size = component_count * component_size;
67   size_t size = header_size + data_size;
68 
69   // Check for overflow and throw OutOfMemoryError if this was an unreasonable request.
70   size_t component_shift = sizeof(size_t) * 8 - 1 - CLZ(component_size);
71   if (UNLIKELY(data_size >> component_shift != size_t(component_count) || size < data_size)) {
72     self->ThrowOutOfMemoryError(StringPrintf("%s of length %d would overflow",
73                                              PrettyDescriptor(array_class).c_str(),
74                                              component_count).c_str());
75     return 0;  // failure
76   }
77   return size;
78 }
79 
80 // Used for setting the array length in the allocation code path to ensure it is guarded by a
81 // StoreStore fence.
82 class SetLengthVisitor {
83  public:
SetLengthVisitor(int32_t length)84   explicit SetLengthVisitor(int32_t length) : length_(length) {
85   }
86 
operator()87   void operator()(Object* obj, size_t usable_size) const
88       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
89     UNUSED(usable_size);
90     // Avoid AsArray as object is not yet in live bitmap or allocation stack.
91     Array* array = down_cast<Array*>(obj);
92     // DCHECK(array->IsArrayInstance());
93     array->SetLength(length_);
94   }
95 
96  private:
97   const int32_t length_;
98 
99   DISALLOW_COPY_AND_ASSIGN(SetLengthVisitor);
100 };
101 
102 // Similar to SetLengthVisitor, used for setting the array length to fill the usable size of an
103 // array.
104 class SetLengthToUsableSizeVisitor {
105  public:
SetLengthToUsableSizeVisitor(int32_t min_length,size_t header_size,size_t component_size)106   SetLengthToUsableSizeVisitor(int32_t min_length, size_t header_size, size_t component_size) :
107       minimum_length_(min_length), header_size_(header_size), component_size_(component_size) {
108   }
109 
operator()110   void operator()(Object* obj, size_t usable_size) const
111       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
112     // Avoid AsArray as object is not yet in live bitmap or allocation stack.
113     Array* array = down_cast<Array*>(obj);
114     // DCHECK(array->IsArrayInstance());
115     int32_t length = (usable_size - header_size_) / component_size_;
116     DCHECK_GE(length, minimum_length_);
117     byte* old_end = reinterpret_cast<byte*>(array->GetRawData(component_size_, minimum_length_));
118     byte* new_end = reinterpret_cast<byte*>(array->GetRawData(component_size_, length));
119     // Ensure space beyond original allocation is zeroed.
120     memset(old_end, 0, new_end - old_end);
121     array->SetLength(length);
122   }
123 
124  private:
125   const int32_t minimum_length_;
126   const size_t header_size_;
127   const size_t component_size_;
128 
129   DISALLOW_COPY_AND_ASSIGN(SetLengthToUsableSizeVisitor);
130 };
131 
132 template <bool kIsInstrumented>
Alloc(Thread * self,Class * array_class,int32_t component_count,size_t component_size,gc::AllocatorType allocator_type,bool fill_usable)133 inline Array* Array::Alloc(Thread* self, Class* array_class, int32_t component_count,
134                            size_t component_size, gc::AllocatorType allocator_type,
135                            bool fill_usable) {
136   DCHECK(allocator_type != gc::kAllocatorTypeLOS);
137   size_t size = ComputeArraySize(self, array_class, component_count, component_size);
138   if (UNLIKELY(size == 0)) {
139     return nullptr;
140   }
141   gc::Heap* heap = Runtime::Current()->GetHeap();
142   Array* result;
143   if (!fill_usable) {
144     SetLengthVisitor visitor(component_count);
145     result = down_cast<Array*>(
146         heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, array_class, size,
147                                                               allocator_type, visitor));
148   } else {
149     SetLengthToUsableSizeVisitor visitor(component_count, DataOffset(component_size).SizeValue(),
150                                          component_size);
151     result = down_cast<Array*>(
152         heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, array_class, size,
153                                                               allocator_type, visitor));
154   }
155   if (kIsDebugBuild && result != nullptr && Runtime::Current()->IsStarted()) {
156     array_class = result->GetClass();  // In case the array class moved.
157     CHECK_EQ(array_class->GetComponentSize(), component_size);
158     if (!fill_usable) {
159       CHECK_EQ(result->SizeOf(), size);
160     } else {
161       CHECK_GE(result->SizeOf(), size);
162     }
163   }
164   return result;
165 }
166 
167 template<class T>
VisitRoots(RootCallback * callback,void * arg)168 inline void PrimitiveArray<T>::VisitRoots(RootCallback* callback, void* arg) {
169   if (!array_class_.IsNull()) {
170     array_class_.VisitRoot(callback, arg, 0, kRootStickyClass);
171   }
172 }
173 
174 template<typename T>
Alloc(Thread * self,size_t length)175 inline PrimitiveArray<T>* PrimitiveArray<T>::Alloc(Thread* self, size_t length) {
176   Array* raw_array = Array::Alloc<true>(self, GetArrayClass(), length, sizeof(T),
177                                         Runtime::Current()->GetHeap()->GetCurrentAllocator());
178   return down_cast<PrimitiveArray<T>*>(raw_array);
179 }
180 
181 template<typename T>
Get(int32_t i)182 inline T PrimitiveArray<T>::Get(int32_t i) {
183   if (!CheckIsValidIndex(i)) {
184     DCHECK(Thread::Current()->IsExceptionPending());
185     return T(0);
186   }
187   return GetWithoutChecks(i);
188 }
189 
190 template<typename T>
Set(int32_t i,T value)191 inline void PrimitiveArray<T>::Set(int32_t i, T value) {
192   if (Runtime::Current()->IsActiveTransaction()) {
193     Set<true>(i, value);
194   } else {
195     Set<false>(i, value);
196   }
197 }
198 
199 template<typename T>
200 template<bool kTransactionActive, bool kCheckTransaction>
Set(int32_t i,T value)201 inline void PrimitiveArray<T>::Set(int32_t i, T value) {
202   if (CheckIsValidIndex(i)) {
203     SetWithoutChecks<kTransactionActive, kCheckTransaction>(i, value);
204   } else {
205     DCHECK(Thread::Current()->IsExceptionPending());
206   }
207 }
208 
209 template<typename T>
210 template<bool kTransactionActive, bool kCheckTransaction>
SetWithoutChecks(int32_t i,T value)211 inline void PrimitiveArray<T>::SetWithoutChecks(int32_t i, T value) {
212   if (kCheckTransaction) {
213     DCHECK_EQ(kTransactionActive, Runtime::Current()->IsActiveTransaction());
214   }
215   if (kTransactionActive) {
216     Runtime::Current()->RecordWriteArray(this, i, GetWithoutChecks(i));
217   }
218   DCHECK(CheckIsValidIndex(i));
219   GetData()[i] = value;
220 }
221 // Backward copy where elements are of aligned appropriately for T. Count is in T sized units.
222 // Copies are guaranteed not to tear when the sizeof T is less-than 64bit.
223 template<typename T>
ArrayBackwardCopy(T * d,const T * s,int32_t count)224 static inline void ArrayBackwardCopy(T* d, const T* s, int32_t count) {
225   d += count;
226   s += count;
227   for (int32_t i = 0; i < count; ++i) {
228     d--;
229     s--;
230     *d = *s;
231   }
232 }
233 
234 // Forward copy where elements are of aligned appropriately for T. Count is in T sized units.
235 // Copies are guaranteed not to tear when the sizeof T is less-than 64bit.
236 template<typename T>
ArrayForwardCopy(T * d,const T * s,int32_t count)237 static inline void ArrayForwardCopy(T* d, const T* s, int32_t count) {
238   for (int32_t i = 0; i < count; ++i) {
239     *d = *s;
240     d++;
241     s++;
242   }
243 }
244 
245 template<class T>
Memmove(int32_t dst_pos,PrimitiveArray<T> * src,int32_t src_pos,int32_t count)246 inline void PrimitiveArray<T>::Memmove(int32_t dst_pos, PrimitiveArray<T>* src, int32_t src_pos,
247                                        int32_t count) {
248   if (UNLIKELY(count == 0)) {
249     return;
250   }
251   DCHECK_GE(dst_pos, 0);
252   DCHECK_GE(src_pos, 0);
253   DCHECK_GT(count, 0);
254   DCHECK(src != nullptr);
255   DCHECK_LT(dst_pos, GetLength());
256   DCHECK_LE(dst_pos, GetLength() - count);
257   DCHECK_LT(src_pos, src->GetLength());
258   DCHECK_LE(src_pos, src->GetLength() - count);
259 
260   // Note for non-byte copies we can't rely on standard libc functions like memcpy(3) and memmove(3)
261   // in our implementation, because they may copy byte-by-byte.
262   if (LIKELY(src != this)) {
263     // Memcpy ok for guaranteed non-overlapping distinct arrays.
264     Memcpy(dst_pos, src, src_pos, count);
265   } else {
266     // Handle copies within the same array using the appropriate direction copy.
267     void* dst_raw = GetRawData(sizeof(T), dst_pos);
268     const void* src_raw = src->GetRawData(sizeof(T), src_pos);
269     if (sizeof(T) == sizeof(uint8_t)) {
270       uint8_t* d = reinterpret_cast<uint8_t*>(dst_raw);
271       const uint8_t* s = reinterpret_cast<const uint8_t*>(src_raw);
272       memmove(d, s, count);
273     } else {
274       const bool copy_forward = (dst_pos < src_pos) || (dst_pos - src_pos >= count);
275       if (sizeof(T) == sizeof(uint16_t)) {
276         uint16_t* d = reinterpret_cast<uint16_t*>(dst_raw);
277         const uint16_t* s = reinterpret_cast<const uint16_t*>(src_raw);
278         if (copy_forward) {
279           ArrayForwardCopy<uint16_t>(d, s, count);
280         } else {
281           ArrayBackwardCopy<uint16_t>(d, s, count);
282         }
283       } else if (sizeof(T) == sizeof(uint32_t)) {
284         uint32_t* d = reinterpret_cast<uint32_t*>(dst_raw);
285         const uint32_t* s = reinterpret_cast<const uint32_t*>(src_raw);
286         if (copy_forward) {
287           ArrayForwardCopy<uint32_t>(d, s, count);
288         } else {
289           ArrayBackwardCopy<uint32_t>(d, s, count);
290         }
291       } else {
292         DCHECK_EQ(sizeof(T), sizeof(uint64_t));
293         uint64_t* d = reinterpret_cast<uint64_t*>(dst_raw);
294         const uint64_t* s = reinterpret_cast<const uint64_t*>(src_raw);
295         if (copy_forward) {
296           ArrayForwardCopy<uint64_t>(d, s, count);
297         } else {
298           ArrayBackwardCopy<uint64_t>(d, s, count);
299         }
300       }
301     }
302   }
303 }
304 
305 template<class T>
Memcpy(int32_t dst_pos,PrimitiveArray<T> * src,int32_t src_pos,int32_t count)306 inline void PrimitiveArray<T>::Memcpy(int32_t dst_pos, PrimitiveArray<T>* src, int32_t src_pos,
307                                       int32_t count) {
308   if (UNLIKELY(count == 0)) {
309     return;
310   }
311   DCHECK_GE(dst_pos, 0);
312   DCHECK_GE(src_pos, 0);
313   DCHECK_GT(count, 0);
314   DCHECK(src != nullptr);
315   DCHECK_LT(dst_pos, GetLength());
316   DCHECK_LE(dst_pos, GetLength() - count);
317   DCHECK_LT(src_pos, src->GetLength());
318   DCHECK_LE(src_pos, src->GetLength() - count);
319 
320   // Note for non-byte copies we can't rely on standard libc functions like memcpy(3) and memmove(3)
321   // in our implementation, because they may copy byte-by-byte.
322   void* dst_raw = GetRawData(sizeof(T), dst_pos);
323   const void* src_raw = src->GetRawData(sizeof(T), src_pos);
324   if (sizeof(T) == sizeof(uint8_t)) {
325     memcpy(dst_raw, src_raw, count);
326   } else if (sizeof(T) == sizeof(uint16_t)) {
327     uint16_t* d = reinterpret_cast<uint16_t*>(dst_raw);
328     const uint16_t* s = reinterpret_cast<const uint16_t*>(src_raw);
329     ArrayForwardCopy<uint16_t>(d, s, count);
330   } else if (sizeof(T) == sizeof(uint32_t)) {
331     uint32_t* d = reinterpret_cast<uint32_t*>(dst_raw);
332     const uint32_t* s = reinterpret_cast<const uint32_t*>(src_raw);
333     ArrayForwardCopy<uint32_t>(d, s, count);
334   } else {
335     DCHECK_EQ(sizeof(T), sizeof(uint64_t));
336     uint64_t* d = reinterpret_cast<uint64_t*>(dst_raw);
337     const uint64_t* s = reinterpret_cast<const uint64_t*>(src_raw);
338     ArrayForwardCopy<uint64_t>(d, s, count);
339   }
340 }
341 
342 }  // namespace mirror
343 }  // namespace art
344 
345 #endif  // ART_RUNTIME_MIRROR_ARRAY_INL_H_
346