org.shared.parallel

Class Engine<T>

java.lang.Object

org.shared.parallel.Engine<T>

Type Parameters:

T - the input type.

public class Engine<T>
extends Object

An execution engine class for pushing data through the guts of some parallel computation given as a directed, acyclic graph.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	Engine.EngineEdge<O> An output-input relationship between two Engine.EngineNodes.
protected class	Engine.EngineNode<I,O> A computation node that is part of some topology of nodes.
protected static class	Engine.ThrowableReferenceHandler A subclass of AtomicReference that doubles as an Thread.UncaughtExceptionHandler.

Constructor Summary

Constructors

Constructor and Description
Engine() Alternate constructor.
Engine(int nThreads) Alternate constructor.
Engine(int nThreads, TraversalPolicy<Engine.EngineNode<?,?>,Engine.EngineEdge<?>> policy) Default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
<I,O> Handle<O>	add(Calculator<I,O> calc, boolean hasOutput, Collection<? extends Calculator<?,? extends I>> calcDeps) Adds a Calculator along with its dependencies.
<I,O> void	add(Calculator<I,O> calc, Calculator<?,? extends I>... calcDeps) Adds a non-output Calculator along with its dependencies.
protected <O> void	addEdge(Engine.EngineNode<?,? extends O> u, Engine.EngineNode<? super O,?> v) Links two Engine.EngineNodes by an Engine.EngineEdge.
<I,O> Handle<O>	addOutput(Calculator<I,O> calc, Calculator<?,? extends I>... calcDeps) Adds an output Calculator along with its dependencies.
void	execute(T engineInput) Executes with the given input.
Calculator<? super Object,? extends T>	getInput() Gets the initial Calculator, which does nothing aside from repeating input given to it.
protected void	invalidate() Invalidates the current traversal ordering.
String	toString() Outputs human-readable directives for Dot graph generation.
protected void	validate() Computes a traversal ordering over the current configuration of Engine.EngineNodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

Engine

public Engine()

Alternate constructor. Creates an engine with the number of threads set to Runtime.availableProcessors() and LimitedMemoryPolicy for its TraversalPolicy.

Engine

public Engine(int nThreads)

Alternate constructor. Creates an engine with LimitedMemoryPolicy for its TraversalPolicy.

Parameters:

nThreads - the number of threads.

Engine

public Engine(int nThreads,
      TraversalPolicy<Engine.EngineNode<?,?>,Engine.EngineEdge<?>> policy)

Default constructor.

Parameters:

nThreads - the number of threads.

policy - the TraversalPolicy to apply when ordering nodes.

Method Detail

getInput

public Calculator<? super Object,? extends T> getInput()

Gets the initial Calculator, which does nothing aside from repeating input given to it.

add

public <I,O> void add(Calculator<I,O> calc,
             Calculator<?,? extends I>... calcDeps)

Adds a non-output Calculator along with its dependencies.

See Also:

add(Calculator, boolean, Collection)

addOutput

public <I,O> Handle<O> addOutput(Calculator<I,O> calc,
                        Calculator<?,? extends I>... calcDeps)

Adds an output Calculator along with its dependencies.

Returns:

a Handle from which potential output can be retrieved.

See Also:

add(Calculator, boolean, Collection)

add

public <I,O> Handle<O> add(Calculator<I,O> calc,
                  boolean hasOutput,
                  Collection<? extends Calculator<?,? extends I>> calcDeps)

Adds a Calculator along with its dependencies.

Type Parameters:

I - the Calculator input type.

O - the Calculator output type.

Parameters:

calc - the Calculator.

hasOutput - whether this node has observable output.

calcDeps - the dependencies.

Returns:

a Handle from which potential output can be retrieved.

execute

public void execute(T engineInput)

Executes with the given input.

Parameters:

engineInput - the input.

toString

public String toString()

Outputs human-readable directives for Dot graph generation.

Overrides:

toString in class Object

validate

protected void validate()

Computes a traversal ordering over the current configuration of Engine.EngineNodes.

invalidate

protected void invalidate()

Invalidates the current traversal ordering.

addEdge

protected <O> void addEdge(Engine.EngineNode<?,? extends O> u,
               Engine.EngineNode<? super O,?> v)

Links two Engine.EngineNodes by an Engine.EngineEdge.

Type Parameters:

O - the output-input type.