| /* |
| * Copyright 2016-2017 JetBrains s.r.o. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package kotlinx.coroutines.experimental |
| |
| import kotlin.coroutines.experimental.Continuation |
| import kotlin.coroutines.experimental.CoroutineContext |
| |
| /** |
| * Receiver interface for generic coroutine builders, so that the code inside coroutine has a convenient access |
| * to its [context] and cancellation status via [isActive]. |
| */ |
| public interface CoroutineScope { |
| /** |
| * Returns `true` when this coroutine is still active (was not cancelled). |
| */ |
| public val isActive: Boolean |
| |
| /** |
| * Returns the context of this coroutine. |
| */ |
| public val context: CoroutineContext |
| } |
| |
| /** |
| * Abstract class to simplify writing of coroutine completion objects that |
| * implements [Continuation] and [Job] interfaces. |
| * It stores the result of continuation in the state of the job. |
| */ |
| @Suppress("LeakingThis") |
| internal abstract class AbstractCoroutine<in T>(context: CoroutineContext) : JobSupport(), Continuation<T>, CoroutineScope { |
| override val context: CoroutineContext = context + this // merges this job into this context |
| |
| final override fun resume(value: T) { |
| while (true) { // lock-free loop on state |
| val state = getState() // atomic read |
| when (state) { |
| is Active -> if (updateState(state, value)) return |
| is Cancelled -> return // ignore resumes on cancelled continuation |
| else -> throw IllegalStateException("Already resumed, but got value $value") |
| } |
| } |
| } |
| |
| final override fun resumeWithException(exception: Throwable) { |
| while (true) { // lock-free loop on state |
| val state = getState() // atomic read |
| when (state) { |
| is Active -> if (updateState(state, Failed(exception))) return |
| is Cancelled -> { |
| // ignore resumes on cancelled continuation, but handle exception if a different one is here |
| if (exception != state.exception) handleCoroutineException(context, exception) |
| return |
| } |
| else -> throw IllegalStateException("Already resumed, but got exception $exception", exception) |
| } |
| } |
| } |
| |
| final override fun handleCompletionException(closeException: Throwable) { |
| handleCoroutineException(context, closeException) |
| } |
| } |