kotlinx.coroutines

Class JobKt

kotlinx.coroutines.JobKt

public class JobKt

Method Summary

Modifier and Type	Method and Description
static Job	Job(Job parent) Creates a new job object in an active state. A failure of any child of this job immediately causes this job to fail, too, and cancels the rest of its children.
static void	cancel(NonExistentClass $receiver) Cancels interface Job of this context. See Job.cancel for details.
static java.lang.Object	cancelAndJoin(Job $receiver, kotlin.coroutines.experimental.Continuation<? super kotlin.Unit> p) Cancels the job and suspends invoking coroutine until the cancelled job is complete.
static void	cancelChildren(NonExistentClass $receiver) Cancels all children of the interface Job in this context, without touching the the state of this job itself. It does not do anything if there is no job in the context or it has no children.
static void	cancelChildren(NonExistentClass $receiver, java.lang.Throwable cause) Deprecated.
static void	cancelChildren(Job $receiver) Cancels all Job.getChildren jobs of this coroutine using Job.cancel for all of them. Unlike Job.cancel on this job as a whole, the state of this job itself is not affected.
static void	cancelFutureOnCancellation(CancellableContinuation<?> $receiver, java.util.concurrent.Future<?> future) Cancels a specified future when this job is cancelled. This is a shortcut for the following code with slightly more efficient implementation (one fewer object created).
static boolean	isActive(NonExistentClass $receiver) Returns true when the interface Job of the coroutine in this context is still active (has not completed and was not cancelled yet).

Method Detail

isActive

public static boolean isActive(NonExistentClass $receiver)

Returns true when the interface Job of the coroutine in this context is still active (has not completed and was not cancelled yet).

Check this property in long-running computation loops to support cancellation when CoroutineScopeKt.isActive is not available:

while (coroutineContext.isActive) {
    // do some computation
}

The coroutineContext.isActive expression is a shortcut for coroutineContext[Job]?.isActive == true. See Job.isActive.

See Also:

interface Job, CoroutineScopeKt.isActive, Job.isActive

Job

public static Job Job(Job parent)

Creates a new job object in an active state. A failure of any child of this job immediately causes this job to fail, too, and cancels the rest of its children.

To handle children failure independently of each other use SupervisorKt.SupervisorJob.

If parent job is specified, then this job becomes a child job of its parent and is cancelled when its parent fails or is cancelled. All this job's children are cancelled in this case, too. The invocation of Job.cancel with exception (other than CancellationException) on this job also cancels parent.

Parameters:

parent - an optional parent job.

See Also:

SupervisorKt.SupervisorJob, Job.cancel

cancel

public static void cancel(NonExistentClass $receiver)

Cancels interface Job of this context. See Job.cancel for details.

See Also:

interface Job, Job.cancel

cancelAndJoin

public static java.lang.Object cancelAndJoin(Job $receiver,
                                             kotlin.coroutines.experimental.Continuation<? super kotlin.Unit> p)

Cancels the job and suspends invoking coroutine until the cancelled job is complete.

This suspending function is cancellable and always checks for the cancellation of invoking coroutine's Job. If the interface Job of the invoking coroutine is cancelled or completed when this suspending function is invoked or while it is suspended, this function throws CancellationException.

In particular, it means that a parent coroutine invoking cancelAndJoin on a child coroutine that was started using launch(coroutineContext) { ... } builder throws CancellationException if the child had crashed, unless a non-standard interface CoroutineExceptionHandler is installed in the context.

This is a shortcut for the invocation of Job.cancel followed by Job.join.

See Also:

interface Job, interface CoroutineExceptionHandler, Job.cancel, Job.join

cancelChildren

public static void cancelChildren(NonExistentClass $receiver)

Cancels all children of the interface Job in this context, without touching the the state of this job itself. It does not do anything if there is no job in the context or it has no children.

See Also:

interface Job

cancelChildren

public static void cancelChildren(NonExistentClass $receiver,
                                  java.lang.Throwable cause)

Deprecated.

cancelChildren

public static void cancelChildren(Job $receiver)

Cancels all Job.getChildren jobs of this coroutine using Job.cancel for all of them. Unlike Job.cancel on this job as a whole, the state of this job itself is not affected.

See Also:

Job.getChildren, Job.cancel, Job.cancel

cancelFutureOnCancellation

public static void cancelFutureOnCancellation(CancellableContinuation<?> $receiver,
                                              java.util.concurrent.Future<?> future)

Cancels a specified future when this job is cancelled. This is a shortcut for the following code with slightly more efficient implementation (one fewer object created).

invokeOnCancellation { future.cancel(false) }