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.google.android.setupcompat.internal;
18 
19 /**
20  * A time source; returns a time value representing the number of nanoseconds elapsed since some
21  * fixed but arbitrary point in time.
22  *
23  * <p><b>Warning:</b> this interface can only be used to measure elapsed time, not wall time.
24  */
25 public interface Ticker {
26 
27   /** Returns the number of nanoseconds elapsed since this ticker's fixed point of reference. */
read()28   long read();
29 }
30