1 /*
2  * Copyright (C) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include "media_scan_executor.h"
17 #include <thread>
18 
19 namespace OHOS {
20 namespace Media {
Commit(std::unique_ptr<MediaScannerObj> scanner)21 int32_t MediaScanExecutor::Commit(std::unique_ptr<MediaScannerObj> scanner)
22 {
23     std::lock_guard<std::mutex> lock(queueMutex_);
24     queue_.push(move(scanner));
25     if (activeThread_ < MAX_THREAD) {
26         thread(&MediaScanExecutor::HandleScanExecution, this).detach();
27         activeThread_++;
28     }
29     return 0;
30 }
31 
HandleScanExecution()32 void MediaScanExecutor::HandleScanExecution()
33 {
34     std::string name("HandleScanExecution");
35     pthread_setname_np(pthread_self(), name.c_str());
36     std::unique_ptr<MediaScannerObj> scanner;
37     while (true) {
38         {
39             std::lock_guard<std::mutex> lock(queueMutex_);
40             if (queue_.empty()) {
41                 activeThread_--;
42                 break;
43             }
44 
45             scanner = std::move(queue_.front());
46             queue_.pop();
47         }
48 
49         scanner->SetStopFlag(stopFlag_);
50         (void)scanner->Scan();
51     }
52 }
53 
54 /* race condition is avoided by the ability life cycle */
Start()55 void MediaScanExecutor::Start()
56 {
57     *stopFlag_ = false;
58 }
59 
Stop()60 void MediaScanExecutor::Stop()
61 {
62     *stopFlag_ = true;
63 
64     /* wait for async scan theads to stop */
65     std::this_thread::sleep_for(std::chrono::milliseconds(sleepTime_));
66 
67     /* clear all tasks in the queue */
68     std::lock_guard<std::mutex> lock(queueMutex_);
69     std::queue<std::unique_ptr<MediaScannerObj>> emptyQueue;
70     queue_.swap(emptyQueue);
71 }
72 } // namespace Media
73 } // namespace OHOS
74