kotlinx-coroutines-core / kotlinx.coroutines.experimental / NonCancellable

NonCancellable

object NonCancellable : AbstractCoroutineContextElement, Job (source)

A non-cancelable job that is always active. It is designed for withContext function to prevent cancellation of code blocks that need to be executed without cancellation.

Use it like this:

withContext(NonCancellable) {
    // this code will not be cancelled
}

Properties

children	`val children: Sequence<Job>` Always returns emptySequence.
isActive	`val isActive: Boolean` Always returns `true`.
isCancelled	`val isCancelled: Boolean` Always returns `false`.
isCompleted	`val isCompleted: Boolean` Always returns `false`.
onJoin	`val onJoin: SelectClause0` Clause for select expression of join suspending function that selects when the job is complete. This clause never fails, even if the job completes exceptionally.

Functions

attachChild	`fun attachChild(child: Job): DisposableHandle` Always returns NonDisposableHandle and does not do anything.
cancel	`fun cancel(cause: Throwable?): Boolean` Always returns `false`.
cancelChildren	`fun cancelChildren(cause: Throwable?): Unit` Does not do anything.
getCancellationException	`fun getCancellationException(): CancellationException` Always throws IllegalStateException.
invokeOnCompletion	`fun invokeOnCompletion( handler: CompletionHandler ): DisposableHandle` `fun invokeOnCompletion( handler: CompletionHandler, onCancelling: Boolean ): DisposableHandle` `fun invokeOnCompletion( onCancelling_: Boolean, handler: CompletionHandler ): DisposableHandle` `fun invokeOnCompletion( onCancelling: Boolean, invokeImmediately: Boolean, handler: CompletionHandler ): DisposableHandle` Always returns NonDisposableHandle.
join	`suspend fun join(): Unit` Always throws UnsupportedOperationException.
start	`fun start(): Boolean` Always returns `false`.

Extension Functions

cancel	`fun CoroutineContext.cancel( cause: Throwable? = null ): Boolean` Cancels Job of this context with an optional cancellation cause. The result is `true` if the job was cancelled as a result of this invocation and `false` if there is no job in the context or if it was already cancelled or completed. See Job.cancel for details.
cancelAndJoin	`suspend fun Job.cancelAndJoin(): Unit` Cancels the job and suspends invoking coroutine until the cancelled job is complete.
cancelFutureOnCompletion	`fun Job.cancelFutureOnCompletion( future: Future<*> ): DisposableHandle` Cancels a specified future when this job is complete.
disposeOnCompletion	`fun Job.disposeOnCompletion( handle: DisposableHandle ): DisposableHandle` Disposes a specified handle when this job is complete.
joinChildren	`suspend fun Job.joinChildren(): Unit` Suspends coroutine until all children of this job are complete using Job.join for all of them. Unlike Job.join on this job as a whole, it does not wait until this job is complete.