folly/folly/io/async/DelayedDestruction.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 <memory>

#include <folly/io/async/DelayedDestructionBase.h>

namespace folly {

/**
 * DelayedDestruction is a helper class to ensure objects are not deleted
 * while they still have functions executing in a higher stack frame.
 *
 * This is useful for objects that invoke callback functions, to ensure that a
 * callback does not destroy the calling object.
 *
 * Classes needing this functionality should:
 * - derive from DelayedDestruction
 * - make their destructor private or protected, so it cannot be called
 *   directly
 * - create a DestructorGuard object on the stack in each public method that
 *   may invoke a callback
 *
 * DelayedDestruction does not perform any locking.  It is intended to be used
 * only from a single thread.
 */
class DelayedDestruction : public DelayedDestructionBase { … };

DelayedDestructionUniquePtr;

template <typename T, typename... A>
DelayedDestructionUniquePtr<T> makeDelayedDestructionUniquePtr(A&&... a) { … }

} // namespace folly