1 /*
2  * Copyright (C) 2019 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 package com.android.systemui.util.concurrency;
18 
19 import java.util.concurrent.Executor;
20 import java.util.concurrent.TimeUnit;
21 
22 /**
23  * A sub-class of {@link Executor} that allows scheduling commands to execute periodically.
24  */
25 public interface RepeatableExecutor extends Executor {
26 
27     /**
28      * Execute supplied Runnable on the Executors thread after initial delay, and subsequently with
29      * the given delay between the termination of one execution and the commencement of the next.
30      *
31      * Each invocation of the supplied Runnable will be scheduled after the previous invocation
32      * completes. For example, if you schedule the Runnable with a 60 second delay, and the Runnable
33      * itself takes 1 second, the effective delay will be 61 seconds between each invocation.
34      *
35      * See {@link java.util.concurrent.ScheduledExecutorService#scheduleRepeatedly(Runnable,
36      * long, long)}
37      *
38      * @return A Runnable that, when run, removes the supplied argument from the Executor queue.
39      */
executeRepeatedly(Runnable r, long initialDelayMillis, long delayMillis)40     default Runnable executeRepeatedly(Runnable r, long initialDelayMillis, long delayMillis) {
41         return executeRepeatedly(r, initialDelayMillis, delayMillis, TimeUnit.MILLISECONDS);
42     }
43 
44     /**
45      * Execute supplied Runnable on the Executors thread after initial delay, and subsequently with
46      * the given delay between the termination of one execution and the commencement of the next..
47      *
48      * See {@link java.util.concurrent.ScheduledExecutorService#scheduleRepeatedly(Runnable,
49      * long, long)}
50      *
51      * @return A Runnable that, when run, removes the supplied argument from the Executor queue.
52      */
executeRepeatedly(Runnable r, long initialDelay, long delay, TimeUnit unit)53     Runnable executeRepeatedly(Runnable r, long initialDelay, long delay, TimeUnit unit);
54 }
55