org.apache.gobblin.util.concurrent

Class TaskScheduler<K,T extends ScheduledTask<K>>

java.lang.Object

org.apache.gobblin.util.concurrent.TaskScheduler<K,T>

All Implemented Interfaces:

Closeable, AutoCloseable

public abstract class TaskScheduler<K,T extends ScheduledTask<K>>
extends Object
implements Closeable

Base class for a task scheduler that can run ScheduledTasks periodically. Subclasses can implement startImpl(Optional) and closeImpl().

Implementations of this interface are expected to be thread-safe, and can be safely accessed by multiple concurrent threads.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TaskScheduler()

Method Summary

Modifier and Type	Method and Description
boolean	cancel(T task) Attempts to cancel the specified ScheduledTask.
void	close() Closes this TaskScheduler, ensuring that new tasks cannot be created and cancelling existing tasks.
com.google.common.base.Optional<T>	getScheduledTask(K key) Gets the ScheduledTask with the specified key.
Iterable<T>	getScheduledTasks() Gets all ScheduledTasks.
void	schedule(T task, long period, TimeUnit unit) Schedules a subclass of ScheduledTask to run periodically.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TaskScheduler

protected TaskScheduler()

Method Detail

schedule

public final void schedule(T task,
                           long period,
                           TimeUnit unit)
                    throws IOException

Schedules a subclass of ScheduledTask to run periodically.

Parameters:

task - the subclass of ScheduledTask to run every period

period - the period between successive executions of the task

unit - the time unit of the initialDelay and period parameters

Throws:

IOException

getScheduledTasks

public final Iterable<T> getScheduledTasks()

Gets all ScheduledTasks.

Returns:

the ScheduledTasks

getScheduledTask

public final com.google.common.base.Optional<T> getScheduledTask(K key)

Gets the ScheduledTask with the specified key.

Returns:

the ScheduledTask

cancel

public boolean cancel(T task)

Attempts to cancel the specified ScheduledTask.

Parameters:

task - the ScheduledTask to cancel

Returns:

true if the ScheduledTask was canceled; otherwise, false

close

public final void close()
                 throws IOException

Closes this TaskScheduler, ensuring that new tasks cannot be created and cancelling existing tasks.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException - if an I/O error occurs