| Dustin Lam | 60c7905 | 2019-11-01 13:43:57 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2018 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 | @file:Suppress("NOTHING_TO_INLINE") |
| 18 | |
| 19 | package androidx.work |
| 20 | |
| 21 | import androidx.annotation.RestrictTo |
| 22 | import com.google.common.util.concurrent.ListenableFuture |
| 23 | import kotlinx.coroutines.suspendCancellableCoroutine |
| 24 | import java.util.concurrent.CancellationException |
| 25 | import java.util.concurrent.ExecutionException |
| 26 | import kotlin.coroutines.resume |
| 27 | import kotlin.coroutines.resumeWithException |
| 28 | |
| 29 | /** |
| 30 | * Awaits for the completion of the [ListenableFuture] without blocking a thread. |
| 31 | * |
| 32 | * @return R The result from the [ListenableFuture] |
| 33 | * |
| 34 | * @hide |
| 35 | */ |
| 36 | @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) |
| 37 | suspend inline fun <R> ListenableFuture<R>.await(): R { |
| 38 | // Fast path |
| 39 | if (isDone) { |
| 40 | try { |
| 41 | return get() |
| 42 | } catch (e: ExecutionException) { |
| 43 | throw e.cause ?: e |
| 44 | } |
| 45 | } |
| 46 | return suspendCancellableCoroutine { cancellableContinuation -> |
| 47 | addListener(Runnable { |
| 48 | try { |
| 49 | cancellableContinuation.resume(get()) |
| 50 | } catch (throwable: Throwable) { |
| 51 | val cause = throwable.cause ?: throwable |
| 52 | when (throwable) { |
| 53 | is CancellationException -> cancellableContinuation.cancel(cause) |
| 54 | else -> cancellableContinuation.resumeWithException(cause) |
| 55 | } |
| 56 | } |
| 57 | }, DirectExecutor.INSTANCE) |
| 58 | } |
| 59 | } |
