1 /* -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /*
3  *     Copyright 2016 Couchbase, Inc.
4  *
5  *   Licensed under the Apache License, Version 2.0 (the "License");
6  *   you may not use this file except in compliance with the License.
7  *   You may obtain a copy of the License at
8  *
9  *       http://www.apache.org/licenses/LICENSE-2.0
10  *
11  *   Unless required by applicable law or agreed to in writing, software
12  *   distributed under the License is distributed on an "AS IS" BASIS,
13  *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  *   See the License for the specific language governing permissions and
15  *   limitations under the License.
16  */
17 #include "scrubber_task.h"
18 
19 #include "default_engine_internal.h"
20 #include "engine_manager.h"
21 
scrubber_task_main(void* arg)22 static void scrubber_task_main(void* arg) {
23     ScrubberTask* task = reinterpret_cast<ScrubberTask*>(arg);
24     task->run();
25 }
26 
ScrubberTask(EngineManager& manager)27 ScrubberTask::ScrubberTask(EngineManager& manager)
28     : state(State::Idle),
29       shuttingdown(false),
30       engineManager(manager) {
31     std::unique_lock<std::mutex> lck(lock);
32     if (cb_create_named_thread(&scrubberThread, &scrubber_task_main, this, 0,
33                                "mc:item scrub") != 0) {
34         throw std::runtime_error("Error creating 'mc:item scrub' thread");
35     }
36 }
37 
shutdown()38 void ScrubberTask::shutdown() {
39     std::unique_lock<std::mutex> lck(lock);
40     shuttingdown = true;
41     // Serialize with ::run
42     cvar.notify_one();
43 }
44 
joinThread()45 void ScrubberTask::joinThread() {
46     cb_join_thread(scrubberThread);
47 }
48 
placeOnWorkQueue(struct default_engine* engine, bool destroy)49 void ScrubberTask::placeOnWorkQueue(struct default_engine* engine,
50                                     bool destroy) {
51     std::lock_guard<std::mutex> lck(lock);
52     if (!shuttingdown) {
53         engine->scrubber.force_delete = destroy;
54         workQueue.push_back(std::make_pair(engine, destroy));
55         cvar.notify_one();
56     }
57 }
58 
run()59 void ScrubberTask::run() {
60     std::unique_lock<std::mutex> lck(lock);
61     while (!shuttingdown) {
62         if (!workQueue.empty()) {
63             auto engine = workQueue.front();
64             workQueue.pop_front();
65             state = State::Scrubbing;
66             lck.unlock();
67             // Run the task without holding the lock
68             item_scrubber_main(engine.first);
69             engineManager.notifyScrubComplete(engine.first, engine.second);
70 
71             // relock so lck can safely unlock when destroyed at loop end.
72             lck.lock();
73         } else {
74             state = State::Idle;
75             cvar.wait(lck);
76         }
77     }
78     state = State::Stopped;
79 }
80