folly/folly/Executor.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 <cassert>
#include <climits>
#include <utility>

#include <folly/Function.h>
#include <folly/Optional.h>
#include <folly/Range.h>
#include <folly/Utility.h>
#include <folly/lang/Exception.h>

namespace folly {

Func;

namespace detail {

class ExecutorKeepAliveBase { … };

} // namespace detail

/// An Executor accepts units of work with add(), which should be
/// threadsafe.
class Executor { … };

/// Returns a keep-alive token which guarantees that Executor will keep
/// processing tasks until the token is released (if supported by Executor).
/// KeepAlive always contains a valid pointer to an Executor.
template <typename ExecutorT>
Executor::KeepAlive<ExecutorT> getKeepAliveToken(ExecutorT* executor) { … }

template <typename ExecutorT>
Executor::KeepAlive<ExecutorT> getKeepAliveToken(ExecutorT& executor) { … }

template <typename ExecutorT>
Executor::KeepAlive<ExecutorT> getKeepAliveToken(
    Executor::KeepAlive<ExecutorT>& ka) { … }

struct ExecutorBlockingContext { … };
static_assert …;

struct ExecutorBlockingList { … };
static_assert …;

class ExecutorBlockingGuard { … };

Optional<ExecutorBlockingContext> getExecutorBlockingContext() noexcept;

} // namespace folly