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 "class.h"
#include "gc/heap-inl.h"
#include "thread.h"
#include "utils.h"

namespace art {
namespace mirror {

inline size_t Array::SizeOf() const {
  // This is safe from overflow because the array was already allocated, so we know it's sane.
  size_t component_size = GetClass()->GetComponentSize();
  int32_t component_count = GetLength();
  size_t header_size = sizeof(Object) + (component_size == sizeof(int64_t) ? 8 : 4);
  size_t data_size = component_count * component_size;
  return header_size + data_size;
}

static inline size_t ComputeArraySize(Thread* self, Class* array_class, int32_t component_count,
                                      size_t component_size)
    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
  DCHECK(array_class != NULL);
  DCHECK_GE(component_count, 0);
  DCHECK(array_class->IsArrayClass());

  size_t header_size = sizeof(Object) + (component_size == sizeof(int64_t) ? 8 : 4);
  size_t data_size = component_count * component_size;
  size_t size = header_size + data_size;

  // Check for overflow and throw OutOfMemoryError if this was an unreasonable request.
  size_t component_shift = sizeof(size_t) * 8 - 1 - CLZ(component_size);
  if (UNLIKELY(data_size >> component_shift != size_t(component_count) || size < data_size)) {
    self->ThrowOutOfMemoryError(StringPrintf("%s of length %d would overflow",
                                             PrettyDescriptor(array_class).c_str(),
                                             component_count).c_str());
    return 0;  // failure
  }
  return size;
}

static inline Array* SetArrayLength(Array* array, size_t length) {
  if (LIKELY(array != NULL)) {
    DCHECK(array->IsArrayInstance());
    array->SetLength(length);
  }
  return array;
}

inline Array* Array::AllocInstrumented(Thread* self, Class* array_class, int32_t component_count,
                                       size_t component_size) {
  size_t size = ComputeArraySize(self, array_class, component_count, component_size);
  if (UNLIKELY(size == 0)) {
    return NULL;
  }
  gc::Heap* heap = Runtime::Current()->GetHeap();
  Array* array = down_cast<Array*>(heap->AllocObjectInstrumented(self, array_class, size));
  return SetArrayLength(array, component_count);
}

inline Array* Array::AllocUninstrumented(Thread* self, Class* array_class, int32_t component_count,
                                         size_t component_size) {
  size_t size = ComputeArraySize(self, array_class, component_count, component_size);
  if (UNLIKELY(size == 0)) {
    return NULL;
  }
  gc::Heap* heap = Runtime::Current()->GetHeap();
  Array* array = down_cast<Array*>(heap->AllocObjectUninstrumented(self, array_class, size));
  return SetArrayLength(array, component_count);
}

inline Array* Array::AllocInstrumented(Thread* self, Class* array_class, int32_t component_count) {
  DCHECK(array_class->IsArrayClass());
  return AllocInstrumented(self, array_class, component_count, array_class->GetComponentSize());
}

inline Array* Array::AllocUninstrumented(Thread* self, Class* array_class, int32_t component_count) {
  DCHECK(array_class->IsArrayClass());
  return AllocUninstrumented(self, array_class, component_count, array_class->GetComponentSize());
}

}  // namespace mirror
}  // namespace art

#endif  // ART_RUNTIME_MIRROR_ARRAY_INL_H_