broadwick.concurrent

Class LocalPoolExecutor

java.lang.Object

broadwick.concurrent.LocalPoolExecutor

All Implemented Interfaces:

Executor

public class LocalPoolExecutor
extends Object
implements Executor

This Executor controls the execution of several threads using a fixed thread pool. Several instances of the callable object are added to the execution pool which monitors their execution, if any fails, i.e. any of the jobs throws an exception, then all non-running jobs are canceled and currently running jobs are terminated.

Nested Class Summary

Nested classes/interfaces inherited from interface broadwick.concurrent.Executor

Executor.Status

Field Summary

Fields

Modifier and Type	Field and Description
private Callable<?>	job
private int	numRuns
private boolean	ok
private int	poolSize
private ExecutorService	service
private Executor.Status	status

Constructor Summary

Constructors

Constructor and Description
LocalPoolExecutor(int threadPoolSize, int numInstancesToRun, Callable<?> callable) Create the Callable executor that will run a supplied number of instances of a supplied callable, canceling the execution if a thread throws an exception.
LocalPoolExecutor(int threadPoolSize, List<Callable<?>> jobs) Create the Callable executor that will run each callable in a collection, canceling the execution if a thread throws an exception.

Method Summary

Modifier and Type	Method and Description
Executor.Status	getStatus() Get the current status of the jobs in the executor.
void	run() Run the required number of jobs, checking for thrown exceptions once each task has completed.
private void	shutdown() Shutdown the ExecutionService, blocking until ALL the threads have finished before returning.
private void	stopAllTasks(List<Future<?>> tasks) Send a message to all the futures to cancel their execution.

Methods inherited from class java.lang.Object

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

Field Detail

poolSize

private final int poolSize

numRuns

private final int numRuns

job

private final Callable<?> job

service

private final ExecutorService service

status

private Executor.Status status

ok

private boolean ok

Constructor Detail

LocalPoolExecutor

public LocalPoolExecutor(int threadPoolSize,
                         int numInstancesToRun,
                         Callable<?> callable)

Create the Callable executor that will run a supplied number of instances of a supplied callable, canceling the execution if a thread throws an exception.

Parameters:

threadPoolSize - the number of concurrent threads to be run (the size of the thread pool)

numInstancesToRun - the number of threads to be run.

callable - the actual Callable instance that is to be executed in the pool.

LocalPoolExecutor

public LocalPoolExecutor(int threadPoolSize,
                         List<Callable<?>> jobs)

Create the Callable executor that will run each callable in a collection, canceling the execution if a thread throws an exception.

Parameters:

threadPoolSize - the number of concurrent threads to be run (the size of the thread pool)

jobs - a collection of [Callable] jobs to be run.

Method Detail

getStatus

public final Executor.Status getStatus()

Description copied from interface: Executor

Get the current status of the jobs in the executor. The status is for the batch of jobs which can be wating to be started, running. completed or terminated (completed with errors).

Specified by:

getStatus in interface Executor

Returns:

the status of the jobs in the executor.

run

public final void run()

Description copied from interface: Executor

Run the required number of jobs, checking for thrown exceptions once each task has completed. On detection of an exception subsequent tasks will be cancelled.

Specified by:

run in interface Executor

stopAllTasks

private void stopAllTasks(List<Future<?>> tasks)

Send a message to all the futures to cancel their execution. On completion the status of the executor is set to Executor.Status.TERMINATED.

Parameters:

tasks - a collection of future object that are to be stopped.

shutdown

private void shutdown()

Shutdown the ExecutionService, blocking until ALL the threads have finished before returning.