folly/folly/concurrency/memory/ReadMostlySharedPtr.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 <atomic>

#include <folly/Function.h>
#include <folly/concurrency/memory/TLRefCount.h>

namespace folly {

template <typename T, typename RefCount>
class ReadMostlyMainPtr;
template <typename T, typename RefCount>
class ReadMostlyWeakPtr;
template <typename T, typename RefCount>
class ReadMostlySharedPtr;
template <typename RefCount>
class ReadMostlyMainPtrDeleter;

DefaultRefCount;

namespace detail {

template <typename RefCount = DefaultRefCount>
class ReadMostlySharedPtrCore { … };

} // namespace detail

template <typename T, typename RefCount = DefaultRefCount>
class ReadMostlyMainPtr { … };

template <typename T, typename RefCount = DefaultRefCount>
class ReadMostlyWeakPtr { … };

template <typename T, typename RefCount = DefaultRefCount>
class ReadMostlySharedPtr { … };

/**
 * This can be used to destroy multiple ReadMostlyMainPtrs at once.
 */
template <typename RefCount = DefaultRefCount>
class ReadMostlyMainPtrDeleter { … };

template <typename T, typename RefCount>
inline bool operator==(
    const ReadMostlyMainPtr<T, RefCount>& ptr, std::nullptr_t) { … }

template <typename T, typename RefCount>
inline bool operator==(
    std::nullptr_t, const ReadMostlyMainPtr<T, RefCount>& ptr) { … }

template <typename T, typename RefCount>
inline bool operator==(
    const ReadMostlySharedPtr<T, RefCount>& ptr, std::nullptr_t) { … }

template <typename T, typename RefCount>
inline bool operator==(
    std::nullptr_t, const ReadMostlySharedPtr<T, RefCount>& ptr) { … }

template <typename T, typename RefCount>
inline bool operator!=(
    const ReadMostlyMainPtr<T, RefCount>& ptr, std::nullptr_t) { … }

template <typename T, typename RefCount>
inline bool operator!=(
    std::nullptr_t, const ReadMostlyMainPtr<T, RefCount>& ptr) { … }

template <typename T, typename RefCount>
inline bool operator!=(
    const ReadMostlySharedPtr<T, RefCount>& ptr, std::nullptr_t) { … }

template <typename T, typename RefCount>
inline bool operator!=(
    std::nullptr_t, const ReadMostlySharedPtr<T, RefCount>& ptr) { … }
} // namespace folly