1 /*
2  * Copyright (C) 2013 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 #ifndef ANDROID_HWUI_FUTURE_H
18 #define ANDROID_HWUI_FUTURE_H
19 
20 #include <utils/RefBase.h>
21 
22 #include "Barrier.h"
23 
24 namespace android {
25 namespace uirenderer {
26 
27 template<typename T>
28 class Future: public LightRefBase<Future<T> > {
29 public:
mBarrier(type)30     Future(Condition::WakeUpType type = Condition::WAKE_UP_ONE): mBarrier(type), mResult() { }
~Future()31     ~Future() { }
32 
33     /**
34      * Returns the result of this future, blocking if
35      * the result is not available yet.
36      */
get()37     T get() const {
38         mBarrier.wait();
39         return mResult;
40     }
41 
42     /**
43      * This method must be called only once.
44      */
produce(T result)45     void produce(T result) {
46         mResult = result;
47         mBarrier.open();
48     }
49 
50 private:
51     Barrier mBarrier;
52     T mResult;
53 };
54 
55 }; // namespace uirenderer
56 }; // namespace android
57 
58 #endif // ANDROID_HWUI_FUTURE_H
59