1 /*
2  * Copyright (C) 2024 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.intentresolver.util
18 
19 import android.os.CancellationSignal
20 import kotlinx.coroutines.CoroutineStart
21 import kotlinx.coroutines.awaitCancellation
22 import kotlinx.coroutines.coroutineScope
23 import kotlinx.coroutines.launch
24 
25 /**
26  * Invokes [block] with a [CancellationSignal] that is bound to this coroutine's lifetime; if this
27  * coroutine is cancelled, then [CancellationSignal.cancel] is promptly invoked.
28  */
withCancellationSignalnull29 suspend fun <R> withCancellationSignal(block: suspend (signal: CancellationSignal) -> R): R =
30     coroutineScope {
31         val signal = CancellationSignal()
32         val signalJob =
33             launch(start = CoroutineStart.UNDISPATCHED) {
34                 try {
35                     awaitCancellation()
36                 } finally {
37                     signal.cancel()
38                 }
39             }
40         block(signal).also { signalJob.cancel() }
41     }
42