Roman Elizarov | d82b3a9 | 2017-06-23 21:52:08 +0300 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2016-2017 JetBrains s.r.o. |
| 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 kotlinx.coroutines.experimental |
| 18 | |
| 19 | import kotlin.coroutines.experimental.Continuation |
| 20 | import kotlin.coroutines.experimental.CoroutineContext |
| 21 | |
| 22 | /** |
| 23 | * Abstract class to simplify writing of coroutine completion objects that |
| 24 | * implement completion [Continuation], [Job], and [CoroutineScope] interfaces. |
| 25 | * It stores the result of continuation in the state of the job. |
| 26 | * |
| 27 | * @param active when `true` coroutine is created in _active_ state, when `false` in _new_ state. See [Job] for details. |
| 28 | * @suppress **This is unstable API and it is subject to change.** |
| 29 | */ |
| 30 | public abstract class AbstractCoroutine<in T>( |
| 31 | private val parentContext: CoroutineContext, |
| 32 | active: Boolean |
| 33 | ) : JobSupport(active), Continuation<T>, CoroutineScope { |
| 34 | @Suppress("LeakingThis") |
| 35 | public final override val context: CoroutineContext = parentContext + this |
| 36 | |
| 37 | final override val hasCancellingState: Boolean get() = true |
| 38 | |
| 39 | final override fun resume(value: T) { |
| 40 | lockFreeLoopOnState { state -> |
| 41 | when (state) { |
| 42 | is Incomplete -> if (updateState(state, value, MODE_ATOMIC_DEFAULT)) return |
| 43 | is Cancelled -> return // ignore resumes on cancelled continuation |
| 44 | else -> error("Already resumed, but got value $value") |
| 45 | } |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | final override fun resumeWithException(exception: Throwable) { |
| 50 | lockFreeLoopOnState { state -> |
| 51 | when (state) { |
| 52 | is Incomplete -> { |
| 53 | if (updateState(state, CompletedExceptionally(exception), MODE_ATOMIC_DEFAULT)) return |
| 54 | } |
| 55 | is Cancelled -> { |
| 56 | // ignore resumes on cancelled continuation, but handle exception if a different one is here |
| 57 | if (exception != state.exception) handleCoroutineException(context, exception) |
| 58 | return |
| 59 | } |
| 60 | else -> throw IllegalStateException("Already resumed, but got exception $exception", exception) |
| 61 | } |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | final override fun handleException(exception: Throwable) { |
| 66 | handleCoroutineException(parentContext, exception) |
| 67 | } |
| 68 | } |