1 /*
2  * Copyright 2021 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 androidx.camera.camera2.pipe.core
18 
19 /** A token is used to track access to underlying resources. Implementations must be thread-safe. */
20 internal interface Token {
21     val released: Boolean
22 
23     /**
24      * Release this token instance. Return true if this is the first time release has been called on
25      * this token.
26      */
releasenull27     fun release(): Boolean
28 }
29