folly/folly/executors/ExecutionObserver.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 <cstdint>

#include <boost/intrusive/list.hpp>

namespace folly {

/**
 * Observes the execution of a task. Multiple execution observers can be chained
 * together. As a caveat, execution observers should not remove themselves from
 * the list of observers during execution
 */
class ExecutionObserver
    : public boost::intrusive::list_base_hook<
          boost::intrusive::link_mode<boost::intrusive::auto_unlink>> { … };

class ExecutionObserverScopeGuard { … };

} // namespace folly