1 /* 2 * Copyright (C) 2022 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.kotlin 18 19 import kotlinx.coroutines.CompletableDeferred 20 import kotlinx.coroutines.coroutineScope 21 import kotlinx.coroutines.launch 22 23 /** 24 * Runs the given [blocks] in parallel, returning the result of the first one to complete, and 25 * cancelling all others. 26 */ <lambda>null27suspend fun <R> race(vararg blocks: suspend () -> R): R = coroutineScope { 28 val completion = CompletableDeferred<R>() 29 val raceJob = launch { 30 for (block in blocks) { 31 launch { completion.complete(block()) } 32 } 33 } 34 completion.await().also { raceJob.cancel() } 35 } 36