1/*
2 * Copyright 2015-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16#pragma once
17
18#include <cstdint>
19
20namespace folly {
21
22/**
23 * Observes the execution of a task.
24 */
25class ExecutionObserver {
26 public:
27 virtual ~ExecutionObserver() {}
28
29 /**
30 * Called when a task is about to start executing.
31 *
32 * @param id Unique id for the task which is starting.
33 */
34 virtual void starting(uintptr_t id) noexcept = 0;
35
36 /**
37 * Called when a task is ready to run.
38 *
39 * @param id Unique id for the task which is ready to run.
40 */
41 virtual void runnable(uintptr_t id) noexcept = 0;
42
43 /**
44 * Called just after a task stops executing.
45 *
46 * @param id Unique id for the task which stopped.
47 */
48 virtual void stopped(uintptr_t id) noexcept = 0;
49};
50
51} // namespace folly
52