runtime/mirror/string-inl.h - platform/art - Git at Google

 /*
  * 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_STRING_INL_H_
 #define ART_RUNTIME_MIRROR_STRING_INL_H_

 #include "array.h"
 #include "base/bit_utils.h"
 #include "class.h"
 #include "gc/heap-inl.h"
 #include "globals.h"
 #include "intern_table.h"
 #include "runtime.h"
 #include "string.h"
 #include "thread.h"
 #include "utf.h"
 #include "utils.h"

 namespace art {
 namespace mirror {

 inline uint32_t String::ClassSize(size_t pointer_size) {
   uint32_t vtable_entries = Object::kVTableLength + 53;
   return Class::ComputeClassSize(true, vtable_entries, 0, 2, 0, 1, 2, pointer_size);
 }

 // Sets string count in the allocation code path to ensure it is guarded by a CAS.
 class SetStringCountVisitor {
  public:
   explicit SetStringCountVisitor(int32_t count) : count_(count) {
   }

   void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
       SHARED_REQUIRES(Locks::mutator_lock_) {
     // Avoid AsString as object is not yet in live bitmap or allocation stack.
     String* string = down_cast<String*>(obj);
     string->SetCount(count_);
   }

  private:
   const int32_t count_;
 };

 // Sets string count and value in the allocation code path to ensure it is guarded by a CAS.
 class SetStringCountAndBytesVisitor {
  public:
   SetStringCountAndBytesVisitor(int32_t count, Handle<ByteArray> src_array, int32_t offset,
                                 int32_t high_byte)
       : count_(count), src_array_(src_array), offset_(offset), high_byte_(high_byte) {
   }

   void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
       SHARED_REQUIRES(Locks::mutator_lock_) {
     // Avoid AsString as object is not yet in live bitmap or allocation stack.
     String* string = down_cast<String*>(obj);
     string->SetCount(count_);
     uint16_t* value = string->GetValue();
     const uint8_t* const src = reinterpret_cast<uint8_t*>(src_array_->GetData()) + offset_;
     for (int i = 0; i < count_; i++) {
       value[i] = high_byte_ + (src[i] & 0xFF);
     }
   }

  private:
   const int32_t count_;
   Handle<ByteArray> src_array_;
   const int32_t offset_;
   const int32_t high_byte_;
 };

 // Sets string count and value in the allocation code path to ensure it is guarded by a CAS.
 class SetStringCountAndValueVisitorFromCharArray {
  public:
   SetStringCountAndValueVisitorFromCharArray(int32_t count, Handle<CharArray> src_array,
                                              int32_t offset) :
     count_(count), src_array_(src_array), offset_(offset) {
   }

   void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
       SHARED_REQUIRES(Locks::mutator_lock_) {
     // Avoid AsString as object is not yet in live bitmap or allocation stack.
     String* string = down_cast<String*>(obj);
     string->SetCount(count_);
     const uint16_t* const src = src_array_->GetData() + offset_;
     memcpy(string->GetValue(), src, count_ * sizeof(uint16_t));
   }

  private:
   const int32_t count_;
   Handle<CharArray> src_array_;
   const int32_t offset_;
 };

 // Sets string count and value in the allocation code path to ensure it is guarded by a CAS.
 class SetStringCountAndValueVisitorFromString {
  public:
   SetStringCountAndValueVisitorFromString(int32_t count, Handle<String> src_string,
                                           int32_t offset) :
     count_(count), src_string_(src_string), offset_(offset) {
   }

   void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
       SHARED_REQUIRES(Locks::mutator_lock_) {
     // Avoid AsString as object is not yet in live bitmap or allocation stack.
     String* string = down_cast<String*>(obj);
     string->SetCount(count_);
     const uint16_t* const src = src_string_->GetValue() + offset_;
     memcpy(string->GetValue(), src, count_ * sizeof(uint16_t));
   }

  private:
   const int32_t count_;
   Handle<String> src_string_;
   const int32_t offset_;
 };

 inline String* String::Intern() {
   return Runtime::Current()->GetInternTable()->InternWeak(this);
 }

 inline uint16_t String::CharAt(int32_t index) {
   int32_t count = GetField32(OFFSET_OF_OBJECT_MEMBER(String, count_));
   if (UNLIKELY((index < 0) || (index >= count))) {
     Thread* self = Thread::Current();
     self->ThrowNewExceptionF("Ljava/lang/StringIndexOutOfBoundsException;",
                              "length=%i; index=%i", count, index);
     return 0;
   }
   return GetValue()[index];
 }

 template<VerifyObjectFlags kVerifyFlags>
 inline size_t String::SizeOf() {
   size_t size = sizeof(String) + (sizeof(uint16_t) * GetLength<kVerifyFlags>());
   // String.equals() intrinsics assume zero-padding up to kObjectAlignment,
   // so make sure the zero-padding is actually copied around if GC compaction
   // chooses to copy only SizeOf() bytes.
   // http://b/23528461
   return RoundUp(size, kObjectAlignment);
 }

 template <bool kIsInstrumented, typename PreFenceVisitor>
 inline String* String::Alloc(Thread* self, int32_t utf16_length, gc::AllocatorType allocator_type,
                              const PreFenceVisitor& pre_fence_visitor) {
   constexpr size_t header_size = sizeof(String);
   static_assert(sizeof(utf16_length) <= sizeof(size_t),
                 "static_cast<size_t>(utf16_length) must not lose bits.");
   size_t length = static_cast<size_t>(utf16_length);
   size_t data_size = sizeof(uint16_t) * length;
   size_t size = header_size + data_size;
   // String.equals() intrinsics assume zero-padding up to kObjectAlignment,
   // so make sure the allocator clears the padding as well.
   // http://b/23528461
   size_t alloc_size = RoundUp(size, kObjectAlignment);
   Class* string_class = GetJavaLangString();

   // Check for overflow and throw OutOfMemoryError if this was an unreasonable request.
   // Do this by comparing with the maximum length that will _not_ cause an overflow.
   constexpr size_t overflow_length = (-header_size) / sizeof(uint16_t);  // Unsigned arithmetic.
   constexpr size_t max_alloc_length = overflow_length - 1u;
   static_assert(IsAligned<sizeof(uint16_t)>(kObjectAlignment),
                 "kObjectAlignment must be at least as big as Java char alignment");
   constexpr size_t max_length = RoundDown(max_alloc_length, kObjectAlignment / sizeof(uint16_t));
   if (UNLIKELY(length > max_length)) {
     self->ThrowOutOfMemoryError(StringPrintf("%s of length %d would overflow",
                                              PrettyDescriptor(string_class).c_str(),
                                              utf16_length).c_str());
     return nullptr;
   }

   gc::Heap* heap = Runtime::Current()->GetHeap();
   return down_cast<String*>(
       heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, string_class, alloc_size,
                                                             allocator_type, pre_fence_visitor));
 }

 template <bool kIsInstrumented>
 inline String* String::AllocFromByteArray(Thread* self, int32_t byte_length,
                                           Handle<ByteArray> array, int32_t offset,
                                           int32_t high_byte, gc::AllocatorType allocator_type) {
   SetStringCountAndBytesVisitor visitor(byte_length, array, offset, high_byte << 8);
   String* string = Alloc<kIsInstrumented>(self, byte_length, allocator_type, visitor);
   return string;
 }

 template <bool kIsInstrumented>
 inline String* String::AllocFromCharArray(Thread* self, int32_t count,
                                           Handle<CharArray> array, int32_t offset,
                                           gc::AllocatorType allocator_type) {
   // It is a caller error to have a count less than the actual array's size.
   DCHECK_GE(array->GetLength(), count);
   SetStringCountAndValueVisitorFromCharArray visitor(count, array, offset);
   String* new_string = Alloc<kIsInstrumented>(self, count, allocator_type, visitor);
   return new_string;
 }

 template <bool kIsInstrumented>
 inline String* String::AllocFromString(Thread* self, int32_t string_length, Handle<String> string,
                                        int32_t offset, gc::AllocatorType allocator_type) {
   SetStringCountAndValueVisitorFromString visitor(string_length, string, offset);
   String* new_string = Alloc<kIsInstrumented>(self, string_length, allocator_type, visitor);
   return new_string;
 }

 inline int32_t String::GetHashCode() {
   int32_t result = GetField32(OFFSET_OF_OBJECT_MEMBER(String, hash_code_));
   if (UNLIKELY(result == 0)) {
     result = ComputeHashCode();
   }
   DCHECK(result != 0 || ComputeUtf16Hash(GetValue(), GetLength()) == 0)
       << ToModifiedUtf8() << " " << result;
   return result;
 }

 }  // namespace mirror
 }  // namespace art

 #endif  // ART_RUNTIME_MIRROR_STRING_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_STRING_INL_H_
	#define ART_RUNTIME_MIRROR_STRING_INL_H_

	#include "array.h"
	#include "base/bit_utils.h"
	#include "class.h"
	#include "gc/heap-inl.h"
	#include "globals.h"
	#include "intern_table.h"
	#include "runtime.h"
	#include "string.h"
	#include "thread.h"
	#include "utf.h"
	#include "utils.h"

	namespace art {
	namespace mirror {

	inline uint32_t String::ClassSize(size_t pointer_size) {
	uint32_t vtable_entries = Object::kVTableLength + 53;
	return Class::ComputeClassSize(true, vtable_entries, 0, 2, 0, 1, 2, pointer_size);
	}

	// Sets string count in the allocation code path to ensure it is guarded by a CAS.
	class SetStringCountVisitor {
	public:
	explicit SetStringCountVisitor(int32_t count) : count_(count) {
	}

	void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
	SHARED_REQUIRES(Locks::mutator_lock_) {
	// Avoid AsString as object is not yet in live bitmap or allocation stack.
	String* string = down_cast<String*>(obj);
	string->SetCount(count_);
	}

	private:
	const int32_t count_;
	};

	// Sets string count and value in the allocation code path to ensure it is guarded by a CAS.
	class SetStringCountAndBytesVisitor {
	public:
	SetStringCountAndBytesVisitor(int32_t count, Handle<ByteArray> src_array, int32_t offset,
	int32_t high_byte)
	: count_(count), src_array_(src_array), offset_(offset), high_byte_(high_byte) {
	}

	void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
	SHARED_REQUIRES(Locks::mutator_lock_) {
	// Avoid AsString as object is not yet in live bitmap or allocation stack.
	String* string = down_cast<String*>(obj);
	string->SetCount(count_);
	uint16_t* value = string->GetValue();
	const uint8_t* const src = reinterpret_cast<uint8_t*>(src_array_->GetData()) + offset_;
	for (int i = 0; i < count_; i++) {
	value[i] = high_byte_ + (src[i] & 0xFF);
	}
	}

	private:
	const int32_t count_;
	Handle<ByteArray> src_array_;
	const int32_t offset_;
	const int32_t high_byte_;
	};

	// Sets string count and value in the allocation code path to ensure it is guarded by a CAS.
	class SetStringCountAndValueVisitorFromCharArray {
	public:
	SetStringCountAndValueVisitorFromCharArray(int32_t count, Handle<CharArray> src_array,
	int32_t offset) :
	count_(count), src_array_(src_array), offset_(offset) {
	}

	void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
	SHARED_REQUIRES(Locks::mutator_lock_) {
	// Avoid AsString as object is not yet in live bitmap or allocation stack.
	String* string = down_cast<String*>(obj);
	string->SetCount(count_);
	const uint16_t* const src = src_array_->GetData() + offset_;
	memcpy(string->GetValue(), src, count_ * sizeof(uint16_t));
	}

	private:
	const int32_t count_;
	Handle<CharArray> src_array_;
	const int32_t offset_;
	};

	// Sets string count and value in the allocation code path to ensure it is guarded by a CAS.
	class SetStringCountAndValueVisitorFromString {
	public:
	SetStringCountAndValueVisitorFromString(int32_t count, Handle<String> src_string,
	int32_t offset) :
	count_(count), src_string_(src_string), offset_(offset) {
	}

	void operator()(Object* obj, size_t usable_size ATTRIBUTE_UNUSED) const
	SHARED_REQUIRES(Locks::mutator_lock_) {
	// Avoid AsString as object is not yet in live bitmap or allocation stack.
	String* string = down_cast<String*>(obj);
	string->SetCount(count_);
	const uint16_t* const src = src_string_->GetValue() + offset_;
	memcpy(string->GetValue(), src, count_ * sizeof(uint16_t));
	}

	private:
	const int32_t count_;
	Handle<String> src_string_;
	const int32_t offset_;
	};

	inline String* String::Intern() {
	return Runtime::Current()->GetInternTable()->InternWeak(this);
	}

	inline uint16_t String::CharAt(int32_t index) {
	int32_t count = GetField32(OFFSET_OF_OBJECT_MEMBER(String, count_));
	if (UNLIKELY((index < 0) \|\| (index >= count))) {
	Thread* self = Thread::Current();
	self->ThrowNewExceptionF("Ljava/lang/StringIndexOutOfBoundsException;",
	"length=%i; index=%i", count, index);
	return 0;
	}
	return GetValue()[index];
	}

	template<VerifyObjectFlags kVerifyFlags>
	inline size_t String::SizeOf() {
	size_t size = sizeof(String) + (sizeof(uint16_t) * GetLength<kVerifyFlags>());
	// String.equals() intrinsics assume zero-padding up to kObjectAlignment,
	// so make sure the zero-padding is actually copied around if GC compaction
	// chooses to copy only SizeOf() bytes.
	// http://b/23528461
	return RoundUp(size, kObjectAlignment);
	}

	template <bool kIsInstrumented, typename PreFenceVisitor>
	inline String* String::Alloc(Thread* self, int32_t utf16_length, gc::AllocatorType allocator_type,
	const PreFenceVisitor& pre_fence_visitor) {
	constexpr size_t header_size = sizeof(String);
	static_assert(sizeof(utf16_length) <= sizeof(size_t),
	"static_cast<size_t>(utf16_length) must not lose bits.");
	size_t length = static_cast<size_t>(utf16_length);
	size_t data_size = sizeof(uint16_t) * length;
	size_t size = header_size + data_size;
	// String.equals() intrinsics assume zero-padding up to kObjectAlignment,
	// so make sure the allocator clears the padding as well.
	// http://b/23528461
	size_t alloc_size = RoundUp(size, kObjectAlignment);
	Class* string_class = GetJavaLangString();

	// Check for overflow and throw OutOfMemoryError if this was an unreasonable request.
	// Do this by comparing with the maximum length that will _not_ cause an overflow.
	constexpr size_t overflow_length = (-header_size) / sizeof(uint16_t); // Unsigned arithmetic.
	constexpr size_t max_alloc_length = overflow_length - 1u;
	static_assert(IsAligned<sizeof(uint16_t)>(kObjectAlignment),
	"kObjectAlignment must be at least as big as Java char alignment");
	constexpr size_t max_length = RoundDown(max_alloc_length, kObjectAlignment / sizeof(uint16_t));
	if (UNLIKELY(length > max_length)) {
	self->ThrowOutOfMemoryError(StringPrintf("%s of length %d would overflow",
	PrettyDescriptor(string_class).c_str(),
	utf16_length).c_str());
	return nullptr;
	}

	gc::Heap* heap = Runtime::Current()->GetHeap();
	return down_cast<String*>(
	heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, string_class, alloc_size,
	allocator_type, pre_fence_visitor));
	}

	template <bool kIsInstrumented>
	inline String* String::AllocFromByteArray(Thread* self, int32_t byte_length,
	Handle<ByteArray> array, int32_t offset,
	int32_t high_byte, gc::AllocatorType allocator_type) {
	SetStringCountAndBytesVisitor visitor(byte_length, array, offset, high_byte << 8);
	String* string = Alloc<kIsInstrumented>(self, byte_length, allocator_type, visitor);
	return string;
	}

	template <bool kIsInstrumented>
	inline String* String::AllocFromCharArray(Thread* self, int32_t count,
	Handle<CharArray> array, int32_t offset,
	gc::AllocatorType allocator_type) {
	// It is a caller error to have a count less than the actual array's size.
	DCHECK_GE(array->GetLength(), count);
	SetStringCountAndValueVisitorFromCharArray visitor(count, array, offset);
	String* new_string = Alloc<kIsInstrumented>(self, count, allocator_type, visitor);
	return new_string;
	}

	template <bool kIsInstrumented>
	inline String* String::AllocFromString(Thread* self, int32_t string_length, Handle<String> string,
	int32_t offset, gc::AllocatorType allocator_type) {
	SetStringCountAndValueVisitorFromString visitor(string_length, string, offset);
	String* new_string = Alloc<kIsInstrumented>(self, string_length, allocator_type, visitor);
	return new_string;
	}

	inline int32_t String::GetHashCode() {
	int32_t result = GetField32(OFFSET_OF_OBJECT_MEMBER(String, hash_code_));
	if (UNLIKELY(result == 0)) {
	result = ComputeHashCode();
	}
	DCHECK(result != 0 \|\| ComputeUtf16Hash(GetValue(), GetLength()) == 0)
	<< ToModifiedUtf8() << " " << result;
	return result;
	}

	} // namespace mirror
	} // namespace art

	#endif // ART_RUNTIME_MIRROR_STRING_INL_H_