com.j_spaces.kernel.threadpool.monitor

Interface FutureExecutorService

All Known Implementing Classes:

TimeoutObserverExecutorService

public interface FutureExecutorService

ExecutorService limited to methods using Future.

Since:

7.0.2

Author:

Moran Avigdor

Method Summary

Modifier and Type	Method and Description
<T> List<Future<T>>	invokeAll(Collection<Callable<T>> tasks) Executes the given tasks, returning a list of Futures holding their status and results when all complete.
<T> List<Future<T>>	invokeAll(Collection<Callable<T>> tasks, long timeout, TimeUnit unit) Executes the given tasks, returning a list of Futures holding their status and results when all complete or the timeout expires, whichever happens first.
void	shutdown() Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted.
List<Runnable>	shutdownNow() Attempts to stop all actively executing tasks, halts the processing of waiting tasks, and returns a list of the tasks that were awaiting execution.
<T> Future<T>	submit(Callable<T> task) Submits a value-returning task for execution and returns a Future representing the pending results of the task.
Future<?>	submit(Runnable task) Submits a Runnable task for execution and returns a Future representing that task.
<T> Future<T>	submit(Runnable task, T result) Submits a Runnable task for execution and returns a Future representing that task that will upon completion return the given result

Method Detail

shutdown

void shutdown()

Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted. Invocation has no additional effect if already shut down.

Throws:

SecurityException - if a security manager exists and shutting down this ExecutorService may manipulate threads that the caller is not permitted to modify because it does not hold RuntimePermission("modifyThread"), or the security manager's checkAccess method denies access.

shutdownNow

List<Runnable> shutdownNow()

Attempts to stop all actively executing tasks, halts the processing of waiting tasks, and returns a list of the tasks that were awaiting execution.

There are no guarantees beyond best-effort attempts to stop processing actively executing tasks. For example, typical implementations will cancel via Thread.interrupt(), so if any tasks mask or fail to respond to interrupts, they may never terminate.

Returns:

list of tasks that never commenced execution

Throws:

SecurityException - if a security manager exists and shutting down this ExecutorService may manipulate threads that the caller is not permitted to modify because it does not hold RuntimePermission("modifyThread"), or the security manager's checkAccess method denies access.

submit

<T> Future<T> submit(Callable<T> task)

Submits a value-returning task for execution and returns a Future representing the pending results of the task.

If you would like to immediately block waiting for a task, you can use constructions of the form result = exec.submit(aCallable).get();

Note: The Executors class includes a set of methods that can convert some other common closure-like objects, for example, PrivilegedAction to Callable form so they can be submitted.

Parameters:

task - the task to submit

Returns:

a Future representing pending completion of the task

Throws:

RejectedExecutionException - if task cannot be scheduled for execution

NullPointerException - if task null

submit

<T> Future<T> submit(Runnable task,
                     T result)

Submits a Runnable task for execution and returns a Future representing that task that will upon completion return the given result

Parameters:

task - the task to submit

result - the result to return

Returns:

a Future representing pending completion of the task, and whose get() method will return the given result upon completion.

Throws:

RejectedExecutionException - if task cannot be scheduled for execution

NullPointerException - if task null

submit

Future<?> submit(Runnable task)

Submits a Runnable task for execution and returns a Future representing that task.

Parameters:

task - the task to submit

Returns:

a Future representing pending completion of the task, and whose get() method will return null upon completion.

Throws:

RejectedExecutionException - if task cannot be scheduled for execution

NullPointerException - if task null

invokeAll

<T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
                       throws InterruptedException

Executes the given tasks, returning a list of Futures holding their status and results when all complete. Future.isDone() is true for each element of the returned list. Note that a completed task could have terminated either normally or by throwing an exception. The results of this method are undefined if the given collection is modified while this operation is in progress.

Parameters:

tasks - the collection of tasks

Returns:

A list of Futures representing the tasks, in the same sequential order as produced by the iterator for the given task list, each of which has completed.

Throws:

InterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelled.

NullPointerException - if tasks or any of its elements are null

RejectedExecutionException - if any task cannot be scheduled for execution

invokeAll

<T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks,
                              long timeout,
                              TimeUnit unit)
                       throws InterruptedException

Executes the given tasks, returning a list of Futures holding their status and results when all complete or the timeout expires, whichever happens first. Future.isDone() is true for each element of the returned list. Upon return, tasks that have not completed are cancelled. Note that a completed task could have terminated either normally or by throwing an exception. The results of this method are undefined if the given collection is modified while this operation is in progress.

Parameters:

tasks - the collection of tasks

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

A list of Futures representing the tasks, in the same sequential order as produced by the iterator for the given task list. If the operation did not time out, each task will have completed. If it did time out, some of these tasks will not have completed.

Throws:

InterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelled.

NullPointerException - if tasks, any of its elements, or unit are null

RejectedExecutionException - if any task cannot be scheduled for execution