1 
2 /**
3  *    Copyright (C) 2018-present MongoDB, Inc.
4  *
5  *    This program is free software: you can redistribute it and/or modify
6  *    it under the terms of the Server Side Public License, version 1,
7  *    as published by MongoDB, Inc.
8  *
9  *    This program is distributed in the hope that it will be useful,
10  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *    Server Side Public License for more details.
13  *
14  *    You should have received a copy of the Server Side Public License
15  *    along with this program. If not, see
16  *    <http://www.mongodb.com/licensing/server-side-public-license>.
17  *
18  *    As a special exception, the copyright holders give permission to link the
19  *    code of portions of this program with the OpenSSL library under certain
20  *    conditions as described in each individual source file and distribute
21  *    linked combinations including the program with the OpenSSL library. You
22  *    must comply with the Server Side Public License in all respects for
23  *    all of the code used other than as permitted herein. If you modify file(s)
24  *    with this exception, you may extend this exception to your version of the
25  *    file(s), but you are not obligated to do so. If you do not wish to do so,
26  *    delete this exception statement from your version. If you delete this
27  *    exception statement from all source files in the program, then also delete
28  *    it in the license file.
29  */
30 
31 #pragma once
32 
33 #include <cstdint>
34 #include <vector>
35 
36 #include "mongo/stdx/condition_variable.h"
37 #include "mongo/stdx/mutex.h"
38 #include "mongo/util/concurrency/thread_pool_interface.h"
39 
40 namespace mongo {
41 namespace executor {
42 
43 class NetworkInterface;
44 
45 /**
46  * A Thread Pool implementation based on running tasks on the background thread
47  * of some Network Interface.
48  *
49  * The basic idea is to triage tasks, running them immediately if we're invoked
50  * from on the network interface thread, and queueing them up to be drained by
51  * a setAlarm if not.
52  */
53 class NetworkInterfaceThreadPool final : public ThreadPoolInterface {
54 public:
55     NetworkInterfaceThreadPool(NetworkInterface* net);
56     ~NetworkInterfaceThreadPool() override;
57 
58     void startup() override;
59     void shutdown() override;
60     void join() override;
61     Status schedule(Task task) override;
62 
63 private:
64     void consumeTasks(stdx::unique_lock<stdx::mutex> lk);
65     void dtorImpl();
66 
67     NetworkInterface* const _net;
68 
69     // Protects all of the pool state below
70     stdx::mutex _mutex;
71     stdx::condition_variable _joiningCondition;
72     std::vector<Task> _tasks;
73     bool _started = false;
74     bool _inShutdown = false;
75     bool _joining = false;
76     bool _registeredAlarm = false;
77     bool _consumingTasks = false;
78 };
79 
80 }  // namespace executor
81 }  // namespace mongo
82