1 /*
2  * Copyright (C) 2018 The Android Open Source Project
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 
17 #include <bufferhub/BufferHubIdGenerator.h>
18 #include <log/log.h>
19 
20 namespace android {
21 namespace frameworks {
22 namespace bufferhub {
23 namespace V1_0 {
24 namespace implementation {
25 
getInstance()26 BufferHubIdGenerator& BufferHubIdGenerator::getInstance() {
27     static BufferHubIdGenerator generator;
28 
29     return generator;
30 }
31 
getId()32 int BufferHubIdGenerator::getId() {
33     std::lock_guard<std::mutex> lock(mIdsInUseMutex);
34 
35     do {
36         if (++mLastId >= std::numeric_limits<int>::max()) {
37             mLastId = 0;
38         }
39     } while (mIdsInUse.find(mLastId) != mIdsInUse.end());
40 
41     mIdsInUse.insert(mLastId);
42     return mLastId;
43 }
44 
freeId(int id)45 void BufferHubIdGenerator::freeId(int id) {
46     std::lock_guard<std::mutex> lock(mIdsInUseMutex);
47     auto iter = mIdsInUse.find(id);
48     if (iter != mIdsInUse.end()) {
49         mIdsInUse.erase(iter);
50     } else {
51         ALOGW("%s: Cannot free nonexistent id #%d", __FUNCTION__, id);
52     }
53 }
54 
55 } // namespace implementation
56 } // namespace V1_0
57 } // namespace bufferhub
58 } // namespace frameworks
59 } // namespace android
60