1 /*
2  * Copyright 2025 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.tracing.driver
18 
19 import androidx.annotation.RestrictTo
20 
21 internal const val QUEUE_CAPACITY = 64
22 
23 /** An actual thread safe queue implementation. */
24 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
25 public class Queue<T>(capacity: Int = QUEUE_CAPACITY) {
26     private val queue: ArrayDeque<T> = ArrayDeque(capacity)
27 
isEmptynull28     public fun isEmpty(): Boolean {
29         return synchronized(queue) { queue.isEmpty() }
30     }
31 
isNotEmptynull32     public fun isNotEmpty(): Boolean {
33         return synchronized(queue) { queue.isNotEmpty() }
34     }
35 
36     public val size: Int
37         get() {
<lambda>null38             return synchronized(queue) { queue.size }
39         }
40 
addLastnull41     public fun addLast(value: T) {
42         synchronized(queue) { queue.addLast(value) }
43     }
44 
removeFirstOrNullnull45     public fun removeFirstOrNull(): T? {
46         return synchronized(queue) { queue.removeFirstOrNull() }
47     }
48 }
49