Module swim.concurrent

Package swim.concurrent

Interface Task

All Superinterfaces:

TaskFunction

All Known Implementing Classes:

AbstractTask, AgentModel, AgentNode, MetaEdgeAgent, MetaHostAgent, MetaLaneAgent, MetaMeshAgent, MetaPartAgent

public interface Task
extends TaskFunction

Stateful TaskFunction to invoke as a sequential process on a concurrent execution Stage, with lifecycle callbacks, and a TaskContext for self-management. Use Stage.task(TaskFunction) to bind a new Task to a Stage, and invoke TaskRef.cue() to schedule the concurrent execution of the sequential task.

Blocking

Task implementations should not perform long running or blocking operations, if possible. If a Task does need to block, it should return true from taskWillBlock() to avoid thread starvation of the execution Stage.

See Also:

• AbstractTask
• Stage

Method Summary

Modifier and Type	Method	Description
void	runTask()	Executes this sequential process.
void	setTaskContext(TaskContext taskContext)	Sets the context used to managed this Task.
TaskContext	taskContext()	Returns the context used to managed this Task.
void	taskDidCancel()	Lifecycle callback invoked after this Task is explicitly cancelled.
boolean	taskWillBlock()	Returns true if this Task might block its thread of execution when running; returns false if this Task will never block.
void	taskWillCue()	Lifecycle callback invoked before this Task is scheduled for execution.

Method Details

taskContext

TaskContext taskContext()

Returns the context used to managed this Task. Returns null if this Task is not bound to a Stage.

setTaskContext

void setTaskContext(TaskContext taskContext)

Sets the context used to managed this Task. A TaskContext is assigned when binding this Task to a Stage.

runTask

void runTask()

Executes this sequential process. Only one thread at a time will execute runTask for this Task.

Specified by:

runTask in interface TaskFunction

taskWillBlock

boolean taskWillBlock()

Returns true if this Task might block its thread of execution when running; returns false if this Task will never block. Used by the execution Stage to prevent thread starvation when concurrently running many blocking tasks.

taskWillCue

void taskWillCue()

Lifecycle callback invoked before this Task is scheduled for execution.

taskDidCancel

void taskDidCancel()

Lifecycle callback invoked after this Task is explicitly cancelled.