org.semanticweb.elk.util.concurrent.computation

Class ConcurrentComputation<I,F extends InputProcessorFactory<I,?>>

java.lang.Object

org.semanticweb.elk.util.concurrent.computation.SimpleInterrupter

org.semanticweb.elk.util.concurrent.computation.ConcurrentComputation<I,F>

Type Parameters:

I - the type of the input to be processed.

F - the type of the factory for the input processors

All Implemented Interfaces:

Interrupter

public class ConcurrentComputation<I,F extends InputProcessorFactory<I,?>>
extends SimpleInterrupter

An class for concurrent processing of a number of tasks. The input for the tasks are submitted, buffered, and processed by concurrent workers using the the InputProcessor objects created by the supplied InputProcessorFactory. The implementation is loosely based on a producer-consumer framework with one producer and many consumers. The processing of the input should start by calling the start() method, following by submit(Object) method for submitting input to be processed. The workers will always wait for new input, unless interrupted or finish() method is called. If finish() is called then no further input can be submitted and the workers will terminate when all input has been processed or they are interrupted earlier, whichever is earlier.

Author:

"Yevgeny Kazakov"

Constructor Summary

Constructors

Constructor and Description
ConcurrentComputation(F inputProcessorFactory, ComputationExecutor executor, int maxWorkers) Creating a ConcurrentComputation instance.
ConcurrentComputation(F inputProcessorFactory, ComputationExecutor executor, int maxWorkers, int bufferCapacity) Creating a ConcurrentComputation instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	finish() Marks the end of the input and requests all workers to terminate when all currently submitted input has been processed.
F	getInputProcessorFactory()
void	setInterrupt(boolean flag) Set interrupt flag to the given value.
boolean	start() Starts the workers to process the input.
boolean	submit(I input) Submitting a new input for processing.
protected void	waitWorkers() Wait until all currently running workers stop; no input can be submitted after calling this method.

Methods inherited from class org.semanticweb.elk.util.concurrent.computation.SimpleInterrupter

isInterrupted

Methods inherited from class java.lang.Object

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

Constructor Detail

ConcurrentComputation

public ConcurrentComputation(F inputProcessorFactory,
                     ComputationExecutor executor,
                     int maxWorkers,
                     int bufferCapacity)

Creating a ConcurrentComputation instance.

Parameters:

inputProcessorFactory - the factory for input processors

executor - the executor used internally to run the jobs

maxWorkers - the maximal number of concurrent workers processing the jobs

bufferCapacity - the size of the buffer for scheduled jobs; if the buffer is full, submitting new jobs will block until new space is available

ConcurrentComputation

public ConcurrentComputation(F inputProcessorFactory,
                     ComputationExecutor executor,
                     int maxWorkers)

Creating a ConcurrentComputation instance.

Parameters:

inputProcessorFactory - the factory for input processors

executor - the executor used internally to run the jobs

maxWorkers - the maximal number of concurrent workers processing the jobs

Method Detail

getInputProcessorFactory

public F getInputProcessorFactory()

Returns:

the InputProcessorFactory used by this ConcurrentComputation

start

public boolean start()

Starts the workers to process the input.

Returns:

true if the operation was successful

submit

public boolean submit(I input)
               throws InterruptedException

Submitting a new input for processing. Submitted input jobs are first buffered, and then concurrently processed by workers. If the buffer is full, the method blocks until new space is available.

Parameters:

input - the input to be processed

Returns:

true if the input has been successfully submitted for computation; the input cannot be submitted if finish() was called or the computation has been terminated

Throws:

InterruptedException - thrown if interrupted during waiting for space to be available

setInterrupt

public final void setInterrupt(boolean flag)

Description copied from interface: Interrupter

Set interrupt flag to the given value. After calling this method Interrupter.isInterrupted() should return this value

Specified by:

setInterrupt in interface Interrupter

Overrides:

setInterrupt in class SimpleInterrupter

Parameters:

flag - true if interrupt is requested false if not

waitWorkers

protected void waitWorkers()
                    throws InterruptedException

Wait until all currently running workers stop; no input can be submitted after calling this method. When this method returns, no worker should be running.

Throws:

InterruptedException

finish

public void finish()
            throws InterruptedException

Marks the end of the input and requests all workers to terminate when all currently submitted input has been processed. After calling this method, no new input can be submitted anymore, i.e., calling submit(Object) will always return false. The method blocks until all workers have been stopped. If interrupted while blocked, this method can be called again in order to complete the termination request.

Throws:

InterruptedException - if interrupted during waiting for finish request