edu.stanford.nlp.util.concurrent

Class MulticoreWrapper<I,O>

java.lang.Object

edu.stanford.nlp.util.concurrent.MulticoreWrapper<I,O>

Type Parameters:

I - input type

O - output type

Direct Known Subclasses:

InterruptibleMulticoreWrapper

public class MulticoreWrapper<I,O>
extends Object

Provides convenient multicore processing for threadsafe objects. Objects that can be wrapped by MulticoreWrapper must implement the ThreadsafeProcessor interface. See edu.stanford.nlp.util.concurrent.MulticoreWrapperTest and edu.stanford.nlp.tagger.maxent.documentation.MulticoreWrapperDemo for examples of use. TODO(spenceg): This code does **not** support multiple consumers, i.e., multi-threaded calls to peek() and poll().

Author:

Spence Green

Constructor Summary

Constructors

Constructor and Description
MulticoreWrapper(int nThreads, ThreadsafeProcessor<I,O> processor) Constructor.
MulticoreWrapper(int numThreads, ThreadsafeProcessor<I,O> processor, boolean orderResults) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected ThreadPoolExecutor	buildThreadPool(int nThreads)
void	join() Wait for all threads to finish, then destroy the pool of worker threads so that the main thread can shutdown.
void	join(boolean destroyThreadpool) Wait for all threads to finish.
boolean	peek() Indicates whether or not a new result is available.
O	poll() Returns the next available result.
void	put(I item) Allocate instance to a process and return.
String	toString() Return status information about the underlying threadpool.

Methods inherited from class java.lang.Object

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

Constructor Detail

MulticoreWrapper

public MulticoreWrapper(int nThreads,
                ThreadsafeProcessor<I,O> processor)

Constructor.

Parameters:

nThreads - If less than or equal to 0, then automatically determine the number of threads. Otherwise, the size of the underlying threadpool.

processor -

MulticoreWrapper

public MulticoreWrapper(int numThreads,
                ThreadsafeProcessor<I,O> processor,
                boolean orderResults)

Constructor.

Parameters:

numThreads - -- if less than or equal to 0, then automatically determine the number of threads. Otherwise, the size of the underlying threadpool.

processor -

orderResults - -- If true, return results in the order submitted. Otherwise, return results as they become available.

Method Detail

buildThreadPool

protected ThreadPoolExecutor buildThreadPool(int nThreads)

toString

public String toString()

Return status information about the underlying threadpool.

Overrides:

toString in class Object

put

public void put(I item)
         throws RejectedExecutionException

Allocate instance to a process and return. This call blocks until item can be assigned to a thread.

Parameters:

item - Input to a Processor

Throws:

RejectedExecutionException - -- A RuntimeException when there is an uncaught exception in the queue. Resolution is for the calling class to shutdown the wrapper and create a new threadpool.

join

public void join()

Wait for all threads to finish, then destroy the pool of worker threads so that the main thread can shutdown.

join

public void join(boolean destroyThreadpool)

Wait for all threads to finish.

Parameters:

destroyThreadpool - -- if true, then destroy the worker threads so that the main thread can shutdown.

peek

public boolean peek()

Indicates whether or not a new result is available.

Returns:

true if a new result is available, false otherwise.

poll

public O poll()

Returns the next available result.

Returns:

the next completed result, or null if no result is available