| /* |
| * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license. |
| */ |
| |
| package kotlinx.coroutines |
| |
| import kotlin.coroutines.* |
| import kotlin.jvm.* |
| |
| /** |
| * A coroutine dispatcher that is not confined to any specific thread. |
| */ |
| internal object Unconfined : CoroutineDispatcher() { |
| override fun isDispatchNeeded(context: CoroutineContext): Boolean = false |
| |
| override fun dispatch(context: CoroutineContext, block: Runnable) { |
| // It can only be called by the "yield" function. See also code of "yield" function. |
| val yieldContext = context[YieldContext] |
| if (yieldContext != null) { |
| // report to "yield" that it is an unconfined dispatcher and don't call "block.run()" |
| yieldContext.dispatcherWasUnconfined = true |
| return |
| } |
| throw UnsupportedOperationException("Dispatchers.Unconfined.dispatch function can only be used by the yield function. " + |
| "If you wrap Unconfined dispatcher in your code, make sure you properly delegate " + |
| "isDispatchNeeded and dispatch calls.") |
| } |
| |
| override fun toString(): String = "Dispatchers.Unconfined" |
| } |
| |
| /** |
| * Used to detect calls to [Unconfined.dispatch] from [yield] function. |
| */ |
| internal class YieldContext : AbstractCoroutineContextElement(Key) { |
| companion object Key : CoroutineContext.Key<YieldContext> |
| |
| @JvmField |
| var dispatcherWasUnconfined = false |
| } |