Package org.onlab.util

Class PredictableExecutor

java.lang.Object

java.util.concurrent.AbstractExecutorService

org.onlab.util.PredictableExecutor

All Implemented Interfaces:

Executor, ExecutorService

public class PredictableExecutor
extends AbstractExecutorService
implements ExecutorService

(Somewhat) predictable ExecutorService.

ExecutorService which behaves similar to the one created by Executors.newFixedThreadPool(int, ThreadFactory), but assigns command to specific thread based on it's PredictableExecutor.PickyTask.hint(), Object.hashCode(), or hint value explicitly specified when the command was passed to this PredictableExecutor.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	PredictableExecutor.PickyCallable<T>	Callable also implementing PredictableExecutor.PickyTask.
static class	PredictableExecutor.PickyFutureTask<T>	A FutureTask implementing PredictableExecutor.PickyTask.
static interface	PredictableExecutor.PickyRunnable	Runnable also implementing PredictableExecutor.PickyTask.
static interface	PredictableExecutor.PickyTask	Abstraction to give a task a way to express it's preference to run on certain thread.

Constructor Summary

Constructors

Constructor	Description
PredictableExecutor(int buckets, ThreadFactory threadFactory)	Creates PredictableExecutor instance.
PredictableExecutor(int buckets, ThreadFactory threadFactory, boolean directExec)	Creates PredictableExecutor instance.
PredictableExecutor(ThreadFactory threadFactory)	Creates PredictableExecutor instance with bucket size set to number of available processors.

Method Summary

Modifier and Type	Method	Description
boolean	awaitTermination(long timeout, TimeUnit unit)
protected ExecutorService	backendExecutorService(ThreadFactory threadFactory, boolean direct)	Creates a single thread ExecutorService to use in the backend.
void	execute(Runnable command)
void	execute(Runnable command, int hint)	Executes given command at some time in the future.
void	execute(Runnable command, Function<Runnable,Integer> hintFunction)	Executes given command at some time in the future.
boolean	isShutdown()
boolean	isTerminated()
static PredictableExecutor	newPredictableExecutor(int buckets, ThreadFactory threadFactory)	Creates PredictableExecutor instance.
protected <T> PredictableExecutor.PickyFutureTask<T>	newTaskFor(Runnable runnable, T value)
protected <T> PredictableExecutor.PickyFutureTask<T>	newTaskFor(Callable<T> callable)
static PredictableExecutor.PickyRunnable	picky(Runnable runnable, int hint)	Wraps the given Runnable into PredictableExecutor.PickyRunnable returning supplied hint.
static PredictableExecutor.PickyRunnable	picky(Runnable runnable, Function<Runnable,Integer> hint)	Wraps the given Runnable into PredictableExecutor.PickyRunnable returning supplied hint.
static <T> PredictableExecutor.PickyCallable<T>	picky(Callable<T> callable, int hint)	Wraps the given Callable into PredictableExecutor.PickyCallable returning supplied hint.
static <T> PredictableExecutor.PickyCallable<T>	picky(Callable<T> callable, Function<Callable<T>,Integer> hint)	Wraps the given Callable into PredictableExecutor.PickyCallable returning supplied hint.
void	shutdown()
List<Runnable>	shutdownNow()
CompletableFuture<Void>	submit(Runnable command, int hint)	Submits a value-returning task for execution and returns a Future representing the pending results of the task.
CompletableFuture<Void>	submit(Runnable command, Function<Runnable,Integer> hintFunction)	Submits a value-returning task for execution and returns a Future representing the pending results of the task.

Methods inherited from class java.util.concurrent.AbstractExecutorService

invokeAll, invokeAll, invokeAny, invokeAny, submit, submit, submit

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.concurrent.ExecutorService

invokeAll, invokeAll, invokeAny, invokeAny, submit, submit, submit

Constructor Detail

PredictableExecutor

public PredictableExecutor(int buckets,
                           ThreadFactory threadFactory)

Creates PredictableExecutor instance.

Parameters:

buckets - number of buckets or 0 to match available processors

threadFactory - ThreadFactory to use to create threads

PredictableExecutor

public PredictableExecutor(int buckets,
                           ThreadFactory threadFactory,
                           boolean directExec)

Creates PredictableExecutor instance. Meant for testing purposes.

Parameters:

buckets - number of buckets or 0 to match available processors

threadFactory - ThreadFactory to use to create threads

directExec - direct executors

PredictableExecutor

public PredictableExecutor(ThreadFactory threadFactory)

Creates PredictableExecutor instance with bucket size set to number of available processors.

Parameters:

threadFactory - ThreadFactory to use to create threads

Method Detail

newPredictableExecutor

public static PredictableExecutor newPredictableExecutor(int buckets,
                                                         ThreadFactory threadFactory)

Creates PredictableExecutor instance.

Parameters:

buckets - number of buckets or 0 to match available processors

threadFactory - ThreadFactory to use to create threads

Returns:

PredictableExecutor

backendExecutorService

protected ExecutorService backendExecutorService(ThreadFactory threadFactory,
                                                 boolean direct)

Creates a single thread ExecutorService to use in the backend.

Parameters:

threadFactory - ThreadFactory to use to create threads

direct - direct executors

Returns:

single thread ExecutorService or direct executor

execute

public void execute(Runnable command,
                    int hint)

Executes given command at some time in the future.

Parameters:

command - the Runnable task

hint - value to pick thread to run on.

execute

public void execute(Runnable command,
                    Function<Runnable,Integer> hintFunction)

Executes given command at some time in the future.

Parameters:

command - the Runnable task

hintFunction - Function to compute hint value

submit

public CompletableFuture<Void> submit(Runnable command,
                                      int hint)

Submits a value-returning task for execution and returns a Future representing the pending results of the task. The Future's get method will return the task's result upon successful completion.

Parameters:

command - the Runnable task

hint - value to pick thread to run on.

Returns:

completable future representing the pending results

submit

public CompletableFuture<Void> submit(Runnable command,
                                      Function<Runnable,Integer> hintFunction)

Submits a value-returning task for execution and returns a Future representing the pending results of the task. The Future's get method will return the task's result upon successful completion.

Parameters:

command - the Runnable task

hintFunction - Function to compute hint value

Returns:

completable future representing the pending results

execute

public void execute(Runnable command)

Specified by:

execute in interface Executor

shutdown

public void shutdown()

Specified by:

shutdown in interface ExecutorService

shutdownNow

public List<Runnable> shutdownNow()

Specified by:

shutdownNow in interface ExecutorService

isShutdown

public boolean isShutdown()

Specified by:

isShutdown in interface ExecutorService

isTerminated

public boolean isTerminated()

Specified by:

isTerminated in interface ExecutorService

awaitTermination

public boolean awaitTermination(long timeout,
                                TimeUnit unit)
                         throws InterruptedException

Note: It'll try, but is not assured that the method will return by specified timeout.

Specified by:

awaitTermination in interface ExecutorService

Throws:

InterruptedException

newTaskFor

protected <T> PredictableExecutor.PickyFutureTask<T> newTaskFor(Callable<T> callable)

Overrides:

newTaskFor in class AbstractExecutorService

newTaskFor

protected <T> PredictableExecutor.PickyFutureTask<T> newTaskFor(Runnable runnable,
                                                                T value)

Overrides:

newTaskFor in class AbstractExecutorService

picky

public static PredictableExecutor.PickyRunnable picky(Runnable runnable,
                                                      int hint)

Wraps the given Runnable into PredictableExecutor.PickyRunnable returning supplied hint.

Parameters:

runnable - Runnable

hint - hint value

Returns:

PredictableExecutor.PickyRunnable

picky

public static PredictableExecutor.PickyRunnable picky(Runnable runnable,
                                                      Function<Runnable,Integer> hint)

Wraps the given Runnable into PredictableExecutor.PickyRunnable returning supplied hint.

Parameters:

runnable - Runnable

hint - hint function

Returns:

PredictableExecutor.PickyRunnable

picky

public static <T> PredictableExecutor.PickyCallable<T> picky(Callable<T> callable,
                                                             int hint)

Wraps the given Callable into PredictableExecutor.PickyCallable returning supplied hint.

Type Parameters:

T - entity type

Parameters:

callable - Callable

hint - hint value

Returns:

PredictableExecutor.PickyCallable

picky

public static <T> PredictableExecutor.PickyCallable<T> picky(Callable<T> callable,
                                                             Function<Callable<T>,Integer> hint)

Wraps the given Callable into PredictableExecutor.PickyCallable returning supplied hint.

Type Parameters:

T - entity type

Parameters:

callable - Callable

hint - hint function

Returns:

PredictableExecutor.PickyCallable