1 /*
2  * Copyright (C) 2024 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 #pragma once
18 
19 #include <future>
20 
21 namespace gfxstream {
22 
23 enum class CancelableFutureStatus {
24     kUnknown,
25     kSuccess,
26     kCanceled,
27 };
28 
29 using CancelableFuture = std::shared_future<CancelableFutureStatus>;
30 
31 class AutoCancelingPromise {
32    public:
33     AutoCancelingPromise() = default;
34 
35     AutoCancelingPromise(AutoCancelingPromise& rhs) = delete;
36     AutoCancelingPromise& operator=(AutoCancelingPromise& rhs) = delete;
37 
38     AutoCancelingPromise(AutoCancelingPromise&& rhs) = default;
39     AutoCancelingPromise& operator=(AutoCancelingPromise&& rhs) = default;
40 
~AutoCancelingPromise()41     ~AutoCancelingPromise() {
42         if (!mValueWasSet) {
43             mPromise.set_value(CancelableFutureStatus::kCanceled);
44         }
45     }
46 
GetFuture()47     CancelableFuture GetFuture() { return mPromise.get_future().share(); }
48 
MarkComplete()49     void MarkComplete() {
50         mValueWasSet = true;
51         mPromise.set_value(CancelableFutureStatus::kSuccess);
52     }
53 
54    private:
55     bool mValueWasSet = false;
56     std::promise<CancelableFutureStatus> mPromise;
57 };
58 
59 }  // namespace gfxstream