folly/folly/executors/QueueObserver.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 <stdint.h>
#include <sys/types.h>
#include <memory>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include <folly/Function.h>
#include <folly/Portability.h>
#include <folly/Synchronized.h>
#include <folly/portability/SysTypes.h>

namespace folly {

class RequestContext;

/**
 * WorkerProvider is a simple interface that can be used
 * to collect information about worker threads that are pulling work
 * from a given queue.
 */
class WorkerProvider { … };

/**
 * Interface for executors that provide a WorkerProvider to collect thread ids.
 */
class GetThreadIdCollector { … };

class ThreadIdWorkerProvider : public WorkerProvider { … };

class QueueObserver { … };

class QueueObserverFactory { … };

MakeQueueObserverFactory;
#if FOLLY_HAVE_WEAK_SYMBOLS
FOLLY_ATTR_WEAK MakeQueueObserverFactory make_queue_observer_factory;
#else
constexpr MakeQueueObserverFactory* make_queue_observer_factory = …;
#endif

struct QueueInfo { … };
LaggingQueueInfoFunc;
} // namespace folly