| 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) |
| } |
| } |