Class DefaultTaskExecutor

java.lang.Object

net.imglib2.parallel.DefaultTaskExecutor

All Implemented Interfaces:

AutoCloseable, TaskExecutor

public class DefaultTaskExecutor
extends Object
implements TaskExecutor

A TaskExecutor that wraps around a given ExecutorService.

Field Summary

Fields

Modifier and Type	Field	Description
private final ExecutorService	executorService

Constructor Summary

Constructors

Constructor	Description
DefaultTaskExecutor(ExecutorService executorService)

Method Summary

Modifier and Type	Method	Description
void	close()
private <T> T[]	concatenate(T[] a, T[] b)
<T> void	forEach(List<? extends T> parameters, Consumer<? super T> task)	Like TaskExecutor.runAll(List) but - instead of a list of tasks - it takes a list of parameters and a function that is called for each of the parameters.
<T,R> List<R>	forEachApply(List<? extends T> parameters, Function<? super T, ? extends R> task)	Like TaskExecutor.forEach(List, Consumer) but collects the results.
ExecutorService	getExecutorService()	Get the underlying ExecutorService.
int	getParallelism()	Get the number of threads that are used for execution.
private void	invokeAllIgnoreResults(List<Callable<Object>> callables)
void	runAll(List<Runnable> tasks)	This method will execute the given list of tasks.
int	suggestNumberOfTasks()	If there is a big task that could be split into sub tasks for parallelization, this method gives you a reasonable number of sub tasks.
private RuntimeException	unwrapExecutionException(Throwable e)	ExecutorService wrap all exceptions thrown by any task into a ExecutionException, this makes the stack traces rather hard to read.

Methods inherited from class Object

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

Field Details

executorService

private final ExecutorService executorService

Constructor Details

DefaultTaskExecutor

public DefaultTaskExecutor(ExecutorService executorService)

Method Details

getExecutorService

public ExecutorService getExecutorService()

Description copied from interface: TaskExecutor

Get the underlying ExecutorService. This is not always a fully functional ExecutorService: Especially the methods ExecutorService.shutdown() and ExecutorService.awaitTermination(long, TimeUnit) must not be used.

Specified by:

getExecutorService in interface TaskExecutor

getParallelism

public int getParallelism()

Description copied from interface: TaskExecutor

Get the number of threads that are used for execution.

Specified by:

getParallelism in interface TaskExecutor

runAll

public void runAll(List<Runnable> tasks)

Description copied from interface: TaskExecutor

This method will execute the given list of tasks. A single threaded TaskExecutor will execute the tasks one after the other. A multi threaded TaskExecutor will distribute the tasks to the threads. The method blocks until all tasks are completed.

Specified by:

runAll in interface TaskExecutor

suggestNumberOfTasks

public int suggestNumberOfTasks()

Description copied from interface: TaskExecutor

If there is a big task that could be split into sub tasks for parallelization, this method gives you a reasonable number of sub tasks.

A single threaded TaskExecutor will return 1. A multi threaded TaskExecutor will usually return 4 times the number of threads.

Specified by:

suggestNumberOfTasks in interface TaskExecutor

forEach

public <T> void forEach(List<? extends T> parameters,
 Consumer<? super T> task)

Description copied from interface: TaskExecutor

Like TaskExecutor.runAll(List) but - instead of a list of tasks - it takes a list of parameters and a function that is called for each of the parameters.

Specified by:

forEach in interface TaskExecutor

forEachApply

public <T,R> List<R> forEachApply(List<? extends T> parameters,
 Function<? super T, ? extends R> task)

Description copied from interface: TaskExecutor

Like TaskExecutor.forEach(List, Consumer) but collects the results.

Specified by:

forEachApply in interface TaskExecutor

invokeAllIgnoreResults

private void invokeAllIgnoreResults(List<Callable<Object>> callables)

unwrapExecutionException

private RuntimeException unwrapExecutionException(Throwable e)

ExecutorService wrap all exceptions thrown by any task into a ExecutionException, this makes the stack traces rather hard to read. This method unwraps the ExecutionException and thereby reveals the original exception, and ensures it's complete stack trace.

concatenate

private <T> T[] concatenate(T[] a,
 T[] b)

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface TaskExecutor