synchronized_allocator.h

// Copyright 2024 The Pigweed Authors
//
// 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
//
//     https://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.
#pragma once
 
#include <cstddef>
#include <mutex>
 
#include "pw_allocator/allocator.h"
#include "pw_sync/borrow.h"
#include "pw_sync/lock_annotations.h"
 
namespace pw::allocator {
 
template <typename LockType>
class SynchronizedAllocator : public Allocator {
 private:
  using Pointer = sync::BorrowedPointer<Allocator, LockType>;
 
 public:
  SynchronizedAllocator(Allocator& allocator) noexcept
      : Allocator(allocator.capabilities()),
        allocator_(allocator),
        borrowable_(allocator_, lock_) {}
 
  Pointer Borrow() const { return borrowable_.acquire(); }
 
 private:
  void* DoAllocate(Layout layout) override {
    std::lock_guard lock(lock_);
    return allocator_.Allocate(layout);
  }
 
  void DoDeallocate(void* ptr) override {
    std::lock_guard lock(lock_);
    return allocator_.Deallocate(ptr);
  }
 
  void DoDeallocate(void* ptr, Layout) override { DoDeallocate(ptr); }
 
  bool DoResize(void* ptr, size_t new_size) override {
    std::lock_guard lock(lock_);
    return allocator_.Resize(ptr, new_size);
  }
 
  void* DoReallocate(void* ptr, Layout new_layout) override {
    std::lock_guard lock(lock_);
    return allocator_.Reallocate(ptr, new_layout);
  }
 
  size_t DoGetAllocated() const override {
    std::lock_guard lock(lock_);
    return allocator_.GetAllocated();
  }
 
  Result<Layout> DoGetInfo(InfoType info_type, const void* ptr) const override {
    std::lock_guard lock(lock_);
    return GetInfo(allocator_, info_type, ptr);
  }
 
  Allocator& allocator_ PW_GUARDED_BY(lock_);
  mutable LockType lock_;
  sync::Borrowable<Allocator, LockType> borrowable_;
};
 
struct NoSync {
  constexpr void lock() {}
  constexpr void unlock() {}
};
 
}  // namespace pw::allocator