folly/folly/memory/ThreadCachedArena.h

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * 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.
 */

#pragma once

#include <type_traits>

#include <folly/Likely.h>
#include <folly/Synchronized.h>
#include <folly/ThreadLocal.h>
#include <folly/memory/Arena.h>

namespace folly {

/**
 * Thread-caching arena: allocate memory which gets freed when the arena gets
 * destroyed.
 *
 * The arena itself allocates memory using malloc() in blocks of
 * at least minBlockSize bytes.
 *
 * For speed, each thread gets its own Arena (see Arena.h); when threads
 * exit, the Arena gets merged into a "zombie" Arena, which will be deallocated
 * when the ThreadCachedArena object is destroyed.
 */
class ThreadCachedArena { … };

template <>
struct AllocatorHasTrivialDeallocate<ThreadCachedArena> : std::true_type { … };

ThreadCachedArenaAllocator;

} // namespace folly