runtime/lambda/leaking_allocator.h

/*
 * Copyright (C) 2015 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_LAMBDA_LEAKING_ALLOCATOR_H_
#define ART_RUNTIME_LAMBDA_LEAKING_ALLOCATOR_H_

#include <utility>  // std::forward

namespace art {
class Thread;  // forward declaration

namespace lambda {

// Temporary class to centralize all the leaking allocations.
// Allocations made through this class are never freed, but it is a placeholder
// that means that the calling code needs to be rewritten to properly:
//
// (a) Have a lifetime scoped to some other entity.
// (b) Not be allocated over and over again if it was already allocated once (immutable data).
//
// TODO: do all of the above a/b for each callsite, and delete this class.
class LeakingAllocator {
 public:
  // Allocate byte_size bytes worth of memory. Never freed.
  static void* AllocateMemory(Thread* self, size_t byte_size);

  // Make a new instance of T, flexibly sized, in-place at newly allocated memory. Never freed.
  template <typename T, typename... Args>
  static T* MakeFlexibleInstance(Thread* self, size_t byte_size, Args&&... args) {
    return new (AllocateMemory(self, byte_size)) T(std::forward<Args>(args)...);
  }

  // Make a new instance of T in-place at newly allocated memory. Never freed.
  template <typename T, typename... Args>
  static T* MakeInstance(Thread* self, Args&&... args) {
    return new (AllocateMemory(self, sizeof(T))) T(std::forward<Args>(args)...);
  }
};

}  // namespace lambda
}  // namespace art

#endif  // ART_RUNTIME_LAMBDA_LEAKING_ALLOCATOR_H_