runtime/mirror/array-inl.h - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #ifndef ART_RUNTIME_MIRROR_ARRAY_INL_H_
 #define ART_RUNTIME_MIRROR_ARRAY_INL_H_

 #include "array.h"

 #include "android-base/stringprintf.h"

 #include "base/bit_utils.h"
 #include "base/casts.h"
 #include "base/logging.h"
 #include "class-inl.h"
 #include "gc/heap-inl.h"
 #include "obj_ptr-inl.h"
 #include "thread.h"

 namespace art {
 namespace mirror {

 inline uint32_t Array::ClassSize(PointerSize pointer_size) {
   uint32_t vtable_entries = Object::kVTableLength;
   return Class::ComputeClassSize(true, vtable_entries, 0, 0, 0, 0, 0, pointer_size);
 }

 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
 inline size_t Array::SizeOf() {
   // This is safe from overflow because the array was already allocated, so we know it's sane.
   size_t component_size_shift = GetClass<kVerifyFlags, kReadBarrierOption>()->
       template GetComponentSizeShift<kReadBarrierOption>();
   // Don't need to check this since we already check this in GetClass.
   int32_t component_count =
       GetLength<static_cast<VerifyObjectFlags>(kVerifyFlags & ~kVerifyThis)>();
   size_t header_size = DataOffset(1U << component_size_shift).SizeValue();
   size_t data_size = component_count << component_size_shift;
   return header_size + data_size;
 }

 inline MemberOffset Array::DataOffset(size_t component_size) {
   DCHECK(IsPowerOfTwo(component_size)) << component_size;
   size_t data_offset = RoundUp(OFFSETOF_MEMBER(Array, first_element_), component_size);
   DCHECK_EQ(RoundUp(data_offset, component_size), data_offset)
       << "Array data offset isn't aligned with component size";
   return MemberOffset(data_offset);
 }

 template<VerifyObjectFlags kVerifyFlags>
 inline bool Array::CheckIsValidIndex(int32_t index) {
   if (UNLIKELY(static_cast<uint32_t>(index) >=
                static_cast<uint32_t>(GetLength<kVerifyFlags>()))) {
     ThrowArrayIndexOutOfBoundsException(index);
     return false;
   }
   return true;
 }

 static inline size_t ComputeArraySize(int32_t component_count, size_t component_size_shift) {
   DCHECK_GE(component_count, 0);

   size_t component_size = 1U << component_size_shift;
   size_t header_size = Array::DataOffset(component_size).SizeValue();
   size_t data_size = static_cast<size_t>(component_count) << component_size_shift;
   size_t size = header_size + data_size;

   // Check for size_t overflow if this was an unreasonable request
   // but let the caller throw OutOfMemoryError.
 #ifdef __LP64__
   // 64-bit. No overflow as component_count is 32-bit and the maximum
   // component size is 8.
   DCHECK_LE((1U << component_size_shift), 8U);
 #else
   // 32-bit.
   DCHECK_NE(header_size, 0U);
   DCHECK_EQ(RoundUp(header_size, component_size), header_size);
   // The array length limit (exclusive).
   const size_t length_limit = (0U - header_size) >> component_size_shift;
   if (UNLIKELY(length_limit <= static_cast<size_t>(component_count))) {
     return 0;  // failure
   }
 #endif
   return size;
 }

 // Used for setting the array length in the allocation code path to ensure it is guarded by a
 // StoreStore fence.
 class SetLengthVisitor {
  public:
   explicit SetLengthVisitor(int32_t length) : length_(length) {
   }

   void operator()(ObjPtr<Object> obj, size_t usable_size ATTRIBUTE_UNUSED) const
       REQUIRES_SHARED(Locks::mutator_lock_) {
     // Avoid AsArray as object is not yet in live bitmap or allocation stack.
     ObjPtr<Array> array = ObjPtr<Array>::DownCast(obj);
     // DCHECK(array->IsArrayInstance());
     array->SetLength(length_);
   }

  private:
   const int32_t length_;

   DISALLOW_COPY_AND_ASSIGN(SetLengthVisitor);
 };

 // Similar to SetLengthVisitor, used for setting the array length to fill the usable size of an
 // array.
 class SetLengthToUsableSizeVisitor {
  public:
   SetLengthToUsableSizeVisitor(int32_t min_length, size_t header_size,
                                size_t component_size_shift) :
       minimum_length_(min_length), header_size_(header_size),
       component_size_shift_(component_size_shift) {
   }

   void operator()(ObjPtr<Object> obj, size_t usable_size) const
       REQUIRES_SHARED(Locks::mutator_lock_) {
     // Avoid AsArray as object is not yet in live bitmap or allocation stack.
     ObjPtr<Array> array = ObjPtr<Array>::DownCast(obj);
     // DCHECK(array->IsArrayInstance());
     int32_t length = (usable_size - header_size_) >> component_size_shift_;
     DCHECK_GE(length, minimum_length_);
     uint8_t* old_end = reinterpret_cast<uint8_t*>(array->GetRawData(1U << component_size_shift_,
                                                                     minimum_length_));
     uint8_t* new_end = reinterpret_cast<uint8_t*>(array->GetRawData(1U << component_size_shift_,
                                                                     length));
     // Ensure space beyond original allocation is zeroed.
     memset(old_end, 0, new_end - old_end);
     array->SetLength(length);
   }

  private:
   const int32_t minimum_length_;
   const size_t header_size_;
   const size_t component_size_shift_;

   DISALLOW_COPY_AND_ASSIGN(SetLengthToUsableSizeVisitor);
 };

 template <bool kIsInstrumented, bool kFillUsable>
 inline Array* Array::Alloc(Thread* self,
                            ObjPtr<Class> array_class,
                            int32_t component_count,
                            size_t component_size_shift,
                            gc::AllocatorType allocator_type) {
   DCHECK(allocator_type != gc::kAllocatorTypeLOS);
   DCHECK(array_class != nullptr);
   DCHECK(array_class->IsArrayClass());
   DCHECK_EQ(array_class->GetComponentSizeShift(), component_size_shift);
   DCHECK_EQ(array_class->GetComponentSize(), (1U << component_size_shift));
   size_t size = ComputeArraySize(component_count, component_size_shift);
 #ifdef __LP64__
   // 64-bit. No size_t overflow.
   DCHECK_NE(size, 0U);
 #else
   // 32-bit.
   if (UNLIKELY(size == 0)) {
     self->ThrowOutOfMemoryError(android::base::StringPrintf("%s of length %d would overflow",
                                                             array_class->PrettyDescriptor().c_str(),
                                                             component_count).c_str());
     return nullptr;
   }
 #endif
   gc::Heap* heap = Runtime::Current()->GetHeap();
   Array* result;
   if (!kFillUsable) {
     SetLengthVisitor visitor(component_count);
     result = down_cast<Array*>(
         heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, array_class, size,
                                                               allocator_type, visitor));
   } else {
     SetLengthToUsableSizeVisitor visitor(component_count,
                                          DataOffset(1U << component_size_shift).SizeValue(),
                                          component_size_shift);
     result = down_cast<Array*>(
         heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, array_class, size,
                                                               allocator_type, visitor));
   }
   if (kIsDebugBuild && result != nullptr && Runtime::Current()->IsStarted()) {
     array_class = result->GetClass();  // In case the array class moved.
     CHECK_EQ(array_class->GetComponentSize(), 1U << component_size_shift);
     if (!kFillUsable) {
       CHECK_EQ(result->SizeOf(), size);
     } else {
       CHECK_GE(result->SizeOf(), size);
     }
   }
   return result;
 }

 template<class T>
 inline void PrimitiveArray<T>::VisitRoots(RootVisitor* visitor) {
   array_class_.VisitRootIfNonNull(visitor, RootInfo(kRootStickyClass));
 }

 template<typename T>
 inline PrimitiveArray<T>* PrimitiveArray<T>::Alloc(Thread* self, size_t length) {
   Array* raw_array = Array::Alloc<true>(self,
                                         GetArrayClass(),
                                         length,
                                         ComponentSizeShiftWidth(sizeof(T)),
                                         Runtime::Current()->GetHeap()->GetCurrentAllocator());
   return down_cast<PrimitiveArray<T>*>(raw_array);
 }

 template<typename T>
 inline T PrimitiveArray<T>::Get(int32_t i) {
   if (!CheckIsValidIndex(i)) {
     DCHECK(Thread::Current()->IsExceptionPending());
     return T(0);
   }
   return GetWithoutChecks(i);
 }

 template<typename T>
 inline void PrimitiveArray<T>::Set(int32_t i, T value) {
   if (Runtime::Current()->IsActiveTransaction()) {
     Set<true>(i, value);
   } else {
     Set<false>(i, value);
   }
 }

 template<typename T>
 template<bool kTransactionActive, bool kCheckTransaction>
 inline void PrimitiveArray<T>::Set(int32_t i, T value) {
   if (CheckIsValidIndex(i)) {
     SetWithoutChecks<kTransactionActive, kCheckTransaction>(i, value);
   } else {
     DCHECK(Thread::Current()->IsExceptionPending());
   }
 }

 template<typename T>
 template<bool kTransactionActive, bool kCheckTransaction, VerifyObjectFlags kVerifyFlags>
 inline void PrimitiveArray<T>::SetWithoutChecks(int32_t i, T value) {
   if (kCheckTransaction) {
     DCHECK_EQ(kTransactionActive, Runtime::Current()->IsActiveTransaction());
   }
   if (kTransactionActive) {
     Runtime::Current()->RecordWriteArray(this, i, GetWithoutChecks(i));
   }
   DCHECK(CheckIsValidIndex<kVerifyFlags>(i));
   GetData()[i] = value;
 }
 // Backward copy where elements are of aligned appropriately for T. Count is in T sized units.
 // Copies are guaranteed not to tear when the sizeof T is less-than 64bit.
 template<typename T>
 static inline void ArrayBackwardCopy(T* d, const T* s, int32_t count) {
   d += count;
   s += count;
   for (int32_t i = 0; i < count; ++i) {
     d--;
     s--;
     *d = *s;
   }
 }

 // Forward copy where elements are of aligned appropriately for T. Count is in T sized units.
 // Copies are guaranteed not to tear when the sizeof T is less-than 64bit.
 template<typename T>
 static inline void ArrayForwardCopy(T* d, const T* s, int32_t count) {
   for (int32_t i = 0; i < count; ++i) {
     *d = *s;
     d++;
     s++;
   }
 }

 template<class T>
 inline void PrimitiveArray<T>::Memmove(int32_t dst_pos,
                                        ObjPtr<PrimitiveArray<T>> src,
                                        int32_t src_pos,
                                        int32_t count) {
   if (UNLIKELY(count == 0)) {
     return;
   }
   DCHECK_GE(dst_pos, 0);
   DCHECK_GE(src_pos, 0);
   DCHECK_GT(count, 0);
   DCHECK(src != nullptr);
   DCHECK_LT(dst_pos, GetLength());
   DCHECK_LE(dst_pos, GetLength() - count);
   DCHECK_LT(src_pos, src->GetLength());
   DCHECK_LE(src_pos, src->GetLength() - count);

   // Note for non-byte copies we can't rely on standard libc functions like memcpy(3) and memmove(3)
   // in our implementation, because they may copy byte-by-byte.
   if (LIKELY(src != this)) {
     // Memcpy ok for guaranteed non-overlapping distinct arrays.
     Memcpy(dst_pos, src, src_pos, count);
   } else {
     // Handle copies within the same array using the appropriate direction copy.
     void* dst_raw = GetRawData(sizeof(T), dst_pos);
     const void* src_raw = src->GetRawData(sizeof(T), src_pos);
     if (sizeof(T) == sizeof(uint8_t)) {
       uint8_t* d = reinterpret_cast<uint8_t*>(dst_raw);
       const uint8_t* s = reinterpret_cast<const uint8_t*>(src_raw);
       memmove(d, s, count);
     } else {
       const bool copy_forward = (dst_pos < src_pos) || (dst_pos - src_pos >= count);
       if (sizeof(T) == sizeof(uint16_t)) {
         uint16_t* d = reinterpret_cast<uint16_t*>(dst_raw);
         const uint16_t* s = reinterpret_cast<const uint16_t*>(src_raw);
         if (copy_forward) {
           ArrayForwardCopy<uint16_t>(d, s, count);
         } else {
           ArrayBackwardCopy<uint16_t>(d, s, count);
         }
       } else if (sizeof(T) == sizeof(uint32_t)) {
         uint32_t* d = reinterpret_cast<uint32_t*>(dst_raw);
         const uint32_t* s = reinterpret_cast<const uint32_t*>(src_raw);
         if (copy_forward) {
           ArrayForwardCopy<uint32_t>(d, s, count);
         } else {
           ArrayBackwardCopy<uint32_t>(d, s, count);
         }
       } else {
         DCHECK_EQ(sizeof(T), sizeof(uint64_t));
         uint64_t* d = reinterpret_cast<uint64_t*>(dst_raw);
         const uint64_t* s = reinterpret_cast<const uint64_t*>(src_raw);
         if (copy_forward) {
           ArrayForwardCopy<uint64_t>(d, s, count);
         } else {
           ArrayBackwardCopy<uint64_t>(d, s, count);
         }
       }
     }
   }
 }

 template<class T>
 inline void PrimitiveArray<T>::Memcpy(int32_t dst_pos,
                                       ObjPtr<PrimitiveArray<T>> src,
                                       int32_t src_pos,
                                       int32_t count) {
   if (UNLIKELY(count == 0)) {
     return;
   }
   DCHECK_GE(dst_pos, 0);
   DCHECK_GE(src_pos, 0);
   DCHECK_GT(count, 0);
   DCHECK(src != nullptr);
   DCHECK_LT(dst_pos, GetLength());
   DCHECK_LE(dst_pos, GetLength() - count);
   DCHECK_LT(src_pos, src->GetLength());
   DCHECK_LE(src_pos, src->GetLength() - count);

   // Note for non-byte copies we can't rely on standard libc functions like memcpy(3) and memmove(3)
   // in our implementation, because they may copy byte-by-byte.
   void* dst_raw = GetRawData(sizeof(T), dst_pos);
   const void* src_raw = src->GetRawData(sizeof(T), src_pos);
   if (sizeof(T) == sizeof(uint8_t)) {
     memcpy(dst_raw, src_raw, count);
   } else if (sizeof(T) == sizeof(uint16_t)) {
     uint16_t* d = reinterpret_cast<uint16_t*>(dst_raw);
     const uint16_t* s = reinterpret_cast<const uint16_t*>(src_raw);
     ArrayForwardCopy<uint16_t>(d, s, count);
   } else if (sizeof(T) == sizeof(uint32_t)) {
     uint32_t* d = reinterpret_cast<uint32_t*>(dst_raw);
     const uint32_t* s = reinterpret_cast<const uint32_t*>(src_raw);
     ArrayForwardCopy<uint32_t>(d, s, count);
   } else {
     DCHECK_EQ(sizeof(T), sizeof(uint64_t));
     uint64_t* d = reinterpret_cast<uint64_t*>(dst_raw);
     const uint64_t* s = reinterpret_cast<const uint64_t*>(src_raw);
     ArrayForwardCopy<uint64_t>(d, s, count);
   }
 }

 template<typename T, VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
 inline T PointerArray::GetElementPtrSize(uint32_t idx, PointerSize ptr_size) {
   // C style casts here since we sometimes have T be a pointer, or sometimes an integer
   // (for stack traces).
   if (ptr_size == PointerSize::k64) {
     return (T)static_cast<uintptr_t>(
         AsLongArray<kVerifyFlags, kReadBarrierOption>()->GetWithoutChecks(idx));
   }
   return (T)static_cast<uintptr_t>(
       AsIntArray<kVerifyFlags, kReadBarrierOption>()->GetWithoutChecks(idx));
 }

 template<bool kTransactionActive, bool kUnchecked>
 inline void PointerArray::SetElementPtrSize(uint32_t idx, uint64_t element, PointerSize ptr_size) {
   if (ptr_size == PointerSize::k64) {
     (kUnchecked ? down_cast<LongArray*>(static_cast<Object*>(this)) : AsLongArray())->
         SetWithoutChecks<kTransactionActive>(idx, element);
   } else {
     DCHECK_LE(element, static_cast<uint64_t>(0xFFFFFFFFu));
     (kUnchecked ? down_cast<IntArray*>(static_cast<Object*>(this)) : AsIntArray())
         ->SetWithoutChecks<kTransactionActive>(idx, static_cast<uint32_t>(element));
   }
 }

 template<bool kTransactionActive, bool kUnchecked, typename T>
 inline void PointerArray::SetElementPtrSize(uint32_t idx, T* element, PointerSize ptr_size) {
   SetElementPtrSize<kTransactionActive, kUnchecked>(idx,
                                                     reinterpret_cast<uintptr_t>(element),
                                                     ptr_size);
 }

 template <VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption, typename Visitor>
 inline void PointerArray::Fixup(mirror::PointerArray* dest,
                                 PointerSize pointer_size,
                                 const Visitor& visitor) {
   for (size_t i = 0, count = GetLength(); i < count; ++i) {
     void* ptr = GetElementPtrSize<void*, kVerifyFlags, kReadBarrierOption>(i, pointer_size);
     void* new_ptr = visitor(ptr);
     if (ptr != new_ptr) {
       dest->SetElementPtrSize<false, true>(i, new_ptr, pointer_size);
     }
   }
 }

 template<bool kUnchecked>
 void PointerArray::Memcpy(int32_t dst_pos,
                           ObjPtr<PointerArray> src,
                           int32_t src_pos,
                           int32_t count,
                           PointerSize ptr_size) {
   DCHECK(!Runtime::Current()->IsActiveTransaction());
   DCHECK(!src.IsNull());
   if (ptr_size == PointerSize::k64) {
     LongArray* l_this = (kUnchecked ? down_cast<LongArray*>(static_cast<Object*>(this))
                                     : AsLongArray());
     LongArray* l_src = (kUnchecked ? down_cast<LongArray*>(static_cast<Object*>(src.Ptr()))
                                    : src->AsLongArray());
     l_this->Memcpy(dst_pos, l_src, src_pos, count);
   } else {
     IntArray* i_this = (kUnchecked ? down_cast<IntArray*>(static_cast<Object*>(this))
                                    : AsIntArray());
     IntArray* i_src = (kUnchecked ? down_cast<IntArray*>(static_cast<Object*>(src.Ptr()))
                                   : src->AsIntArray());
     i_this->Memcpy(dst_pos, i_src, src_pos, count);
   }
 }

 template<typename T>
 inline void PrimitiveArray<T>::SetArrayClass(ObjPtr<Class> array_class) {
   CHECK(array_class_.IsNull());
   CHECK(array_class != nullptr);
   array_class_ = GcRoot<Class>(array_class);
 }

 }  // namespace mirror
 }  // namespace art

 #endif  // ART_RUNTIME_MIRROR_ARRAY_INL_H_
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#ifndef ART_RUNTIME_MIRROR_ARRAY_INL_H_
	#define ART_RUNTIME_MIRROR_ARRAY_INL_H_

	#include "array.h"

	#include "android-base/stringprintf.h"

	#include "base/bit_utils.h"
	#include "base/casts.h"
	#include "base/logging.h"
	#include "class-inl.h"
	#include "gc/heap-inl.h"
	#include "obj_ptr-inl.h"
	#include "thread.h"

	namespace art {
	namespace mirror {

	inline uint32_t Array::ClassSize(PointerSize pointer_size) {
	uint32_t vtable_entries = Object::kVTableLength;
	return Class::ComputeClassSize(true, vtable_entries, 0, 0, 0, 0, 0, pointer_size);
	}

	template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
	inline size_t Array::SizeOf() {
	// This is safe from overflow because the array was already allocated, so we know it's sane.
	size_t component_size_shift = GetClass<kVerifyFlags, kReadBarrierOption>()->
	template GetComponentSizeShift<kReadBarrierOption>();
	// Don't need to check this since we already check this in GetClass.
	int32_t component_count =
	GetLength<static_cast<VerifyObjectFlags>(kVerifyFlags & ~kVerifyThis)>();
	size_t header_size = DataOffset(1U << component_size_shift).SizeValue();
	size_t data_size = component_count << component_size_shift;
	return header_size + data_size;
	}

	inline MemberOffset Array::DataOffset(size_t component_size) {
	DCHECK(IsPowerOfTwo(component_size)) << component_size;
	size_t data_offset = RoundUp(OFFSETOF_MEMBER(Array, first_element_), component_size);
	DCHECK_EQ(RoundUp(data_offset, component_size), data_offset)
	<< "Array data offset isn't aligned with component size";
	return MemberOffset(data_offset);
	}

	template<VerifyObjectFlags kVerifyFlags>
	inline bool Array::CheckIsValidIndex(int32_t index) {
	if (UNLIKELY(static_cast<uint32_t>(index) >=
	static_cast<uint32_t>(GetLength<kVerifyFlags>()))) {
	ThrowArrayIndexOutOfBoundsException(index);
	return false;
	}
	return true;
	}

	static inline size_t ComputeArraySize(int32_t component_count, size_t component_size_shift) {
	DCHECK_GE(component_count, 0);

	size_t component_size = 1U << component_size_shift;
	size_t header_size = Array::DataOffset(component_size).SizeValue();
	size_t data_size = static_cast<size_t>(component_count) << component_size_shift;
	size_t size = header_size + data_size;

	// Check for size_t overflow if this was an unreasonable request
	// but let the caller throw OutOfMemoryError.
	#ifdef __LP64__
	// 64-bit. No overflow as component_count is 32-bit and the maximum
	// component size is 8.
	DCHECK_LE((1U << component_size_shift), 8U);
	#else
	// 32-bit.
	DCHECK_NE(header_size, 0U);
	DCHECK_EQ(RoundUp(header_size, component_size), header_size);
	// The array length limit (exclusive).
	const size_t length_limit = (0U - header_size) >> component_size_shift;
	if (UNLIKELY(length_limit <= static_cast<size_t>(component_count))) {
	return 0; // failure
	}
	#endif
	return size;
	}

	// Used for setting the array length in the allocation code path to ensure it is guarded by a
	// StoreStore fence.
	class SetLengthVisitor {
	public:
	explicit SetLengthVisitor(int32_t length) : length_(length) {
	}

	void operator()(ObjPtr<Object> obj, size_t usable_size ATTRIBUTE_UNUSED) const
	REQUIRES_SHARED(Locks::mutator_lock_) {
	// Avoid AsArray as object is not yet in live bitmap or allocation stack.
	ObjPtr<Array> array = ObjPtr<Array>::DownCast(obj);
	// DCHECK(array->IsArrayInstance());
	array->SetLength(length_);
	}

	private:
	const int32_t length_;

	DISALLOW_COPY_AND_ASSIGN(SetLengthVisitor);
	};

	// Similar to SetLengthVisitor, used for setting the array length to fill the usable size of an
	// array.
	class SetLengthToUsableSizeVisitor {
	public:
	SetLengthToUsableSizeVisitor(int32_t min_length, size_t header_size,
	size_t component_size_shift) :
	minimum_length_(min_length), header_size_(header_size),
	component_size_shift_(component_size_shift) {
	}

	void operator()(ObjPtr<Object> obj, size_t usable_size) const
	REQUIRES_SHARED(Locks::mutator_lock_) {
	// Avoid AsArray as object is not yet in live bitmap or allocation stack.
	ObjPtr<Array> array = ObjPtr<Array>::DownCast(obj);
	// DCHECK(array->IsArrayInstance());
	int32_t length = (usable_size - header_size_) >> component_size_shift_;
	DCHECK_GE(length, minimum_length_);
	uint8_t* old_end = reinterpret_cast<uint8_t*>(array->GetRawData(1U << component_size_shift_,
	minimum_length_));
	uint8_t* new_end = reinterpret_cast<uint8_t*>(array->GetRawData(1U << component_size_shift_,
	length));
	// Ensure space beyond original allocation is zeroed.
	memset(old_end, 0, new_end - old_end);
	array->SetLength(length);
	}

	private:
	const int32_t minimum_length_;
	const size_t header_size_;
	const size_t component_size_shift_;

	DISALLOW_COPY_AND_ASSIGN(SetLengthToUsableSizeVisitor);
	};

	template <bool kIsInstrumented, bool kFillUsable>
	inline Array* Array::Alloc(Thread* self,
	ObjPtr<Class> array_class,
	int32_t component_count,
	size_t component_size_shift,
	gc::AllocatorType allocator_type) {
	DCHECK(allocator_type != gc::kAllocatorTypeLOS);
	DCHECK(array_class != nullptr);
	DCHECK(array_class->IsArrayClass());
	DCHECK_EQ(array_class->GetComponentSizeShift(), component_size_shift);
	DCHECK_EQ(array_class->GetComponentSize(), (1U << component_size_shift));
	size_t size = ComputeArraySize(component_count, component_size_shift);
	#ifdef __LP64__
	// 64-bit. No size_t overflow.
	DCHECK_NE(size, 0U);
	#else
	// 32-bit.
	if (UNLIKELY(size == 0)) {
	self->ThrowOutOfMemoryError(android::base::StringPrintf("%s of length %d would overflow",
	array_class->PrettyDescriptor().c_str(),
	component_count).c_str());
	return nullptr;
	}
	#endif
	gc::Heap* heap = Runtime::Current()->GetHeap();
	Array* result;
	if (!kFillUsable) {
	SetLengthVisitor visitor(component_count);
	result = down_cast<Array*>(
	heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, array_class, size,
	allocator_type, visitor));
	} else {
	SetLengthToUsableSizeVisitor visitor(component_count,
	DataOffset(1U << component_size_shift).SizeValue(),
	component_size_shift);
	result = down_cast<Array*>(
	heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, array_class, size,
	allocator_type, visitor));
	}
	if (kIsDebugBuild && result != nullptr && Runtime::Current()->IsStarted()) {
	array_class = result->GetClass(); // In case the array class moved.
	CHECK_EQ(array_class->GetComponentSize(), 1U << component_size_shift);
	if (!kFillUsable) {
	CHECK_EQ(result->SizeOf(), size);
	} else {
	CHECK_GE(result->SizeOf(), size);
	}
	}
	return result;
	}

	template<class T>
	inline void PrimitiveArray<T>::VisitRoots(RootVisitor* visitor) {
	array_class_.VisitRootIfNonNull(visitor, RootInfo(kRootStickyClass));
	}

	template<typename T>
	inline PrimitiveArray<T>* PrimitiveArray<T>::Alloc(Thread* self, size_t length) {
	Array* raw_array = Array::Alloc<true>(self,
	GetArrayClass(),
	length,
	ComponentSizeShiftWidth(sizeof(T)),
	Runtime::Current()->GetHeap()->GetCurrentAllocator());
	return down_cast<PrimitiveArray<T>*>(raw_array);
	}

	template<typename T>
	inline T PrimitiveArray<T>::Get(int32_t i) {
	if (!CheckIsValidIndex(i)) {
	DCHECK(Thread::Current()->IsExceptionPending());
	return T(0);
	}
	return GetWithoutChecks(i);
	}

	template<typename T>
	inline void PrimitiveArray<T>::Set(int32_t i, T value) {
	if (Runtime::Current()->IsActiveTransaction()) {
	Set<true>(i, value);
	} else {
	Set<false>(i, value);
	}
	}

	template<typename T>
	template<bool kTransactionActive, bool kCheckTransaction>
	inline void PrimitiveArray<T>::Set(int32_t i, T value) {
	if (CheckIsValidIndex(i)) {
	SetWithoutChecks<kTransactionActive, kCheckTransaction>(i, value);
	} else {
	DCHECK(Thread::Current()->IsExceptionPending());
	}
	}

	template<typename T>
	template<bool kTransactionActive, bool kCheckTransaction, VerifyObjectFlags kVerifyFlags>
	inline void PrimitiveArray<T>::SetWithoutChecks(int32_t i, T value) {
	if (kCheckTransaction) {
	DCHECK_EQ(kTransactionActive, Runtime::Current()->IsActiveTransaction());
	}
	if (kTransactionActive) {
	Runtime::Current()->RecordWriteArray(this, i, GetWithoutChecks(i));
	}
	DCHECK(CheckIsValidIndex<kVerifyFlags>(i));
	GetData()[i] = value;
	}
	// Backward copy where elements are of aligned appropriately for T. Count is in T sized units.
	// Copies are guaranteed not to tear when the sizeof T is less-than 64bit.
	template<typename T>
	static inline void ArrayBackwardCopy(T* d, const T* s, int32_t count) {
	d += count;
	s += count;
	for (int32_t i = 0; i < count; ++i) {
	d--;
	s--;
	d = s;
	}
	}

	// Forward copy where elements are of aligned appropriately for T. Count is in T sized units.
	// Copies are guaranteed not to tear when the sizeof T is less-than 64bit.
	template<typename T>
	static inline void ArrayForwardCopy(T* d, const T* s, int32_t count) {
	for (int32_t i = 0; i < count; ++i) {
	d = s;
	d++;
	s++;
	}
	}

	template<class T>
	inline void PrimitiveArray<T>::Memmove(int32_t dst_pos,
	ObjPtr<PrimitiveArray<T>> src,
	int32_t src_pos,
	int32_t count) {
	if (UNLIKELY(count == 0)) {
	return;
	}
	DCHECK_GE(dst_pos, 0);
	DCHECK_GE(src_pos, 0);
	DCHECK_GT(count, 0);
	DCHECK(src != nullptr);
	DCHECK_LT(dst_pos, GetLength());
	DCHECK_LE(dst_pos, GetLength() - count);
	DCHECK_LT(src_pos, src->GetLength());
	DCHECK_LE(src_pos, src->GetLength() - count);

	// Note for non-byte copies we can't rely on standard libc functions like memcpy(3) and memmove(3)
	// in our implementation, because they may copy byte-by-byte.
	if (LIKELY(src != this)) {
	// Memcpy ok for guaranteed non-overlapping distinct arrays.
	Memcpy(dst_pos, src, src_pos, count);
	} else {
	// Handle copies within the same array using the appropriate direction copy.
	void* dst_raw = GetRawData(sizeof(T), dst_pos);
	const void* src_raw = src->GetRawData(sizeof(T), src_pos);
	if (sizeof(T) == sizeof(uint8_t)) {
	uint8_t* d = reinterpret_cast<uint8_t*>(dst_raw);
	const uint8_t* s = reinterpret_cast<const uint8_t*>(src_raw);
	memmove(d, s, count);
	} else {
	const bool copy_forward = (dst_pos < src_pos) \|\| (dst_pos - src_pos >= count);
	if (sizeof(T) == sizeof(uint16_t)) {
	uint16_t* d = reinterpret_cast<uint16_t*>(dst_raw);
	const uint16_t* s = reinterpret_cast<const uint16_t*>(src_raw);
	if (copy_forward) {
	ArrayForwardCopy<uint16_t>(d, s, count);
	} else {
	ArrayBackwardCopy<uint16_t>(d, s, count);
	}
	} else if (sizeof(T) == sizeof(uint32_t)) {
	uint32_t* d = reinterpret_cast<uint32_t*>(dst_raw);
	const uint32_t* s = reinterpret_cast<const uint32_t*>(src_raw);
	if (copy_forward) {
	ArrayForwardCopy<uint32_t>(d, s, count);
	} else {
	ArrayBackwardCopy<uint32_t>(d, s, count);
	}
	} else {
	DCHECK_EQ(sizeof(T), sizeof(uint64_t));
	uint64_t* d = reinterpret_cast<uint64_t*>(dst_raw);
	const uint64_t* s = reinterpret_cast<const uint64_t*>(src_raw);
	if (copy_forward) {
	ArrayForwardCopy<uint64_t>(d, s, count);
	} else {
	ArrayBackwardCopy<uint64_t>(d, s, count);
	}
	}
	}
	}
	}

	template<class T>
	inline void PrimitiveArray<T>::Memcpy(int32_t dst_pos,
	ObjPtr<PrimitiveArray<T>> src,
	int32_t src_pos,
	int32_t count) {
	if (UNLIKELY(count == 0)) {
	return;
	}
	DCHECK_GE(dst_pos, 0);
	DCHECK_GE(src_pos, 0);
	DCHECK_GT(count, 0);
	DCHECK(src != nullptr);
	DCHECK_LT(dst_pos, GetLength());
	DCHECK_LE(dst_pos, GetLength() - count);
	DCHECK_LT(src_pos, src->GetLength());
	DCHECK_LE(src_pos, src->GetLength() - count);

	// Note for non-byte copies we can't rely on standard libc functions like memcpy(3) and memmove(3)
	// in our implementation, because they may copy byte-by-byte.
	void* dst_raw = GetRawData(sizeof(T), dst_pos);
	const void* src_raw = src->GetRawData(sizeof(T), src_pos);
	if (sizeof(T) == sizeof(uint8_t)) {
	memcpy(dst_raw, src_raw, count);
	} else if (sizeof(T) == sizeof(uint16_t)) {
	uint16_t* d = reinterpret_cast<uint16_t*>(dst_raw);
	const uint16_t* s = reinterpret_cast<const uint16_t*>(src_raw);
	ArrayForwardCopy<uint16_t>(d, s, count);
	} else if (sizeof(T) == sizeof(uint32_t)) {
	uint32_t* d = reinterpret_cast<uint32_t*>(dst_raw);
	const uint32_t* s = reinterpret_cast<const uint32_t*>(src_raw);
	ArrayForwardCopy<uint32_t>(d, s, count);
	} else {
	DCHECK_EQ(sizeof(T), sizeof(uint64_t));
	uint64_t* d = reinterpret_cast<uint64_t*>(dst_raw);
	const uint64_t* s = reinterpret_cast<const uint64_t*>(src_raw);
	ArrayForwardCopy<uint64_t>(d, s, count);
	}
	}

	template<typename T, VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
	inline T PointerArray::GetElementPtrSize(uint32_t idx, PointerSize ptr_size) {
	// C style casts here since we sometimes have T be a pointer, or sometimes an integer
	// (for stack traces).
	if (ptr_size == PointerSize::k64) {
	return (T)static_cast<uintptr_t>(
	AsLongArray<kVerifyFlags, kReadBarrierOption>()->GetWithoutChecks(idx));
	}
	return (T)static_cast<uintptr_t>(
	AsIntArray<kVerifyFlags, kReadBarrierOption>()->GetWithoutChecks(idx));
	}

	template<bool kTransactionActive, bool kUnchecked>
	inline void PointerArray::SetElementPtrSize(uint32_t idx, uint64_t element, PointerSize ptr_size) {
	if (ptr_size == PointerSize::k64) {
	(kUnchecked ? down_cast<LongArray>(static_cast<Object>(this)) : AsLongArray())->
	SetWithoutChecks<kTransactionActive>(idx, element);
	} else {
	DCHECK_LE(element, static_cast<uint64_t>(0xFFFFFFFFu));
	(kUnchecked ? down_cast<IntArray>(static_cast<Object>(this)) : AsIntArray())
	->SetWithoutChecks<kTransactionActive>(idx, static_cast<uint32_t>(element));
	}
	}

	template<bool kTransactionActive, bool kUnchecked, typename T>
	inline void PointerArray::SetElementPtrSize(uint32_t idx, T* element, PointerSize ptr_size) {
	SetElementPtrSize<kTransactionActive, kUnchecked>(idx,
	reinterpret_cast<uintptr_t>(element),
	ptr_size);
	}

	template <VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption, typename Visitor>
	inline void PointerArray::Fixup(mirror::PointerArray* dest,
	PointerSize pointer_size,
	const Visitor& visitor) {
	for (size_t i = 0, count = GetLength(); i < count; ++i) {
	void* ptr = GetElementPtrSize<void*, kVerifyFlags, kReadBarrierOption>(i, pointer_size);
	void* new_ptr = visitor(ptr);
	if (ptr != new_ptr) {
	dest->SetElementPtrSize<false, true>(i, new_ptr, pointer_size);
	}
	}
	}

	template<bool kUnchecked>
	void PointerArray::Memcpy(int32_t dst_pos,
	ObjPtr<PointerArray> src,
	int32_t src_pos,
	int32_t count,
	PointerSize ptr_size) {
	DCHECK(!Runtime::Current()->IsActiveTransaction());
	DCHECK(!src.IsNull());
	if (ptr_size == PointerSize::k64) {
	LongArray* l_this = (kUnchecked ? down_cast<LongArray>(static_cast<Object>(this))
	: AsLongArray());
	LongArray* l_src = (kUnchecked ? down_cast<LongArray>(static_cast<Object>(src.Ptr()))
	: src->AsLongArray());
	l_this->Memcpy(dst_pos, l_src, src_pos, count);
	} else {
	IntArray* i_this = (kUnchecked ? down_cast<IntArray>(static_cast<Object>(this))
	: AsIntArray());
	IntArray* i_src = (kUnchecked ? down_cast<IntArray>(static_cast<Object>(src.Ptr()))
	: src->AsIntArray());
	i_this->Memcpy(dst_pos, i_src, src_pos, count);
	}
	}

	template<typename T>
	inline void PrimitiveArray<T>::SetArrayClass(ObjPtr<Class> array_class) {
	CHECK(array_class_.IsNull());
	CHECK(array_class != nullptr);
	array_class_ = GcRoot<Class>(array_class);
	}

	} // namespace mirror
	} // namespace art

	#endif // ART_RUNTIME_MIRROR_ARRAY_INL_H_