include/llvm/Support/RecyclingAllocator.h

//==- llvm/Support/RecyclingAllocator.h - Recycling Allocator ----*- C++ -*-==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the RecyclingAllocator class.  See the doxygen comment for
// RecyclingAllocator for more details on the implementation.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_RECYCLINGALLOCATOR_H
#define LLVM_SUPPORT_RECYCLINGALLOCATOR_H

#include "llvm/Support/Recycler.h"

namespace llvm {

/// RecyclingAllocator - This class wraps an Allocator, adding the
/// functionality of recycling deleted objects.
///
template <class AllocatorType, class T, size_t Size = sizeof(T),
          size_t Align = alignof(T)>
class RecyclingAllocator {
private:
  /// Base - Implementation details.
  ///
  Recycler<T, Size, Align> Base;

  /// Allocator - The wrapped allocator.
  ///
  AllocatorType Allocator;

public:
  ~RecyclingAllocator() { Base.clear(Allocator); }

  /// Allocate - Return a pointer to storage for an object of type
  /// SubClass. The storage may be either newly allocated or recycled.
  ///
  template<class SubClass>
  SubClass *Allocate() { return Base.template Allocate<SubClass>(Allocator); }

  T *Allocate() { return Base.Allocate(Allocator); }

  /// Deallocate - Release storage for the pointed-to object. The
  /// storage will be kept track of and may be recycled.
  ///
  template<class SubClass>
  void Deallocate(SubClass* E) { return Base.Deallocate(Allocator, E); }

  void PrintStats() {
    Allocator.PrintStats();
    Base.PrintStats();
  }
};

}

template<class AllocatorType, class T, size_t Size, size_t Align>
inline void *operator new(size_t size,
                          llvm::RecyclingAllocator<AllocatorType,
                                                   T, Size, Align> &Allocator) {
  assert(size <= Size && "allocation size exceeded");
  return Allocator.Allocate();
}

template<class AllocatorType, class T, size_t Size, size_t Align>
inline void operator delete(void *E,
                            llvm::RecyclingAllocator<AllocatorType,
                                                     T, Size, Align> &A) {
  A.Deallocate(E);
}

#endif