Package org.elasticsearch.threadpool

Interface Scheduler

All Known Implementing Classes:

ThreadPool

public interface Scheduler

Scheduler that allows to schedule one-shot and periodic commands.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	Scheduler.Cancellable	This interface represents an object whose execution may be cancelled during runtime.
static final class	Scheduler.ReschedulingRunnable	This class encapsulates the scheduling of a Runnable that needs to be repeated on a interval.
static class	Scheduler.SafeScheduledThreadPoolExecutor	This subclass ensures to properly bubble up Throwable instances of both type Error and Exception thrown in submitted/scheduled tasks to the uncaught exception handler
static interface	Scheduler.ScheduledCancellable	A scheduled cancellable allow cancelling and reading the remaining delay of a scheduled task.

Method Summary

Modifier and Type	Method	Description
static boolean	awaitTermination(ScheduledThreadPoolExecutor scheduledThreadPoolExecutor, long timeout, TimeUnit timeUnit)
static ScheduledThreadPoolExecutor	initScheduler(Settings settings, String schedulerName)	Create a scheduler that can be used client side.
Scheduler.ScheduledCancellable	schedule(Runnable command, TimeValue delay, String executor)	Schedules a one-shot command to be run after a given delay.
default Scheduler.Cancellable	scheduleWithFixedDelay(Runnable command, TimeValue interval, String executor)	Schedules a periodic action that runs on scheduler thread.
static boolean	terminate(ScheduledThreadPoolExecutor scheduledThreadPoolExecutor, long timeout, TimeUnit timeUnit)
static Scheduler.Cancellable	wrapAsCancellable(Future<?> future)	Utility method to wrap a Future as a Cancellable
static Scheduler.ScheduledCancellable	wrapAsScheduledCancellable(ScheduledFuture<?> scheduledFuture)	Utility method to wrap a ScheduledFuture as a ScheduledCancellable

Method Details

initScheduler

static ScheduledThreadPoolExecutor initScheduler(Settings settings,
 String schedulerName)

Create a scheduler that can be used client side. Server side, please use ThreadPool.schedule instead. Notice that if any scheduled jobs fail with an exception, these will bubble up to the uncaught exception handler where they will be logged as a warning. This includes jobs started using execute, submit and schedule.

Parameters:

settings - the settings to use

schedulerName - a string that identifies the threads belonging to this scheduler

Returns:

executor

terminate

static boolean terminate(ScheduledThreadPoolExecutor scheduledThreadPoolExecutor,
 long timeout,
 TimeUnit timeUnit)

awaitTermination

static boolean awaitTermination(ScheduledThreadPoolExecutor scheduledThreadPoolExecutor,
 long timeout,
 TimeUnit timeUnit)

schedule

Scheduler.ScheduledCancellable schedule(Runnable command,
 TimeValue delay,
 String executor)

Schedules a one-shot command to be run after a given delay. The command is run in the context of the calling thread. The command runs on scheduler thread. Do not run blocking calls on the scheduler thread. Subclasses may allow to execute on a different executor, in which case blocking calls are allowed.

Parameters:

command - the command to run

delay - delay before the task executes

executor - the name of the executor that has to execute this task. Ignored in the default implementation but can be used by subclasses that support multiple executors.

Returns:

a ScheduledFuture who's get will return when the task has been added to its target thread pool and throws an exception if the task is canceled before it was added to its target thread pool. Once the task has been added to its target thread pool the ScheduledFuture cannot interact with it.

Throws:

EsRejectedExecutionException - if the task cannot be scheduled for execution

scheduleWithFixedDelay

default Scheduler.Cancellable scheduleWithFixedDelay(Runnable command,
 TimeValue interval,
 String executor)

Schedules a periodic action that runs on scheduler thread. Do not run blocking calls on the scheduler thread. Subclasses may allow to execute on a different executor, in which case blocking calls are allowed.

Parameters:

command - the action to take

interval - the delay interval

executor - the name of the executor that has to execute this task. Ignored in the default implementation but can be used by subclasses that support multiple executors.

Returns:

a Scheduler.Cancellable that can be used to cancel the subsequent runs of the command. If the command is running, it will not be interrupted.

wrapAsCancellable

static Scheduler.Cancellable wrapAsCancellable(Future<?> future)

Utility method to wrap a Future as a Cancellable

Parameters:

future - the future to wrap

Returns:

a cancellable delegating to the future

wrapAsScheduledCancellable

static Scheduler.ScheduledCancellable wrapAsScheduledCancellable(ScheduledFuture<?> scheduledFuture)

Utility method to wrap a ScheduledFuture as a ScheduledCancellable

Parameters:

scheduledFuture - the scheduled future to wrap

Returns:

a SchedulecCancellable delegating to the scheduledFuture