groovyx.gpars
Class GParsExecutorsPoolUtil

java.lang.Object
  groovyx.gpars.GParsExecutorsPoolUtil

class GParsExecutorsPoolUtil

This class forms the core of the DSL initialized by GParsExecutorsPool. The static methods of GParsExecutorsPoolUtil get attached to their first arguments (the Groovy Category mechanism) and can be then invoked as if they were part of the argument classes.

Authors:

Vaclav Pech Date: Oct 23, 2008

See Also:

GParsExecutorsPool

timer

private static final java.util.Timer timer

Allows timeouts for async operations

GParsExecutorsPoolUtil

GParsExecutorsPoolUtil()

anyParallel

public static boolean anyParallel(java.lang.Object collection, groovy.lang.Closure cl)

Performs the any() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. After this method returns, all the closures have been finished and the caller can safely use the result. The anyParallel() method is lazy and once a positive answer has been given by at least one element, it avoids running the supplied closure on subsequent elements. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> assert service.anyParallel([1, 2, 3, 4, 5]){Number number -> number > 2}* assert !service.anyParallel([1, 2, 3, 4, 5]){Number number -> number > 6}*}* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new anyParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> assert [1, 2, 3, 4, 5].anyParallel{Number number -> number > 2}* assert ![1, 2, 3, 4, 5].anyParallel{Number number -> number > 6}*}*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

anyParallel

public static boolean anyParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel any on a map

async

public static groovy.lang.Closure async(groovy.lang.Closure cl)

Creates an asynchronous variant of the supplied closure, which, when invoked returns a future for the potential return value

callAsync

public static java.util.concurrent.Future callAsync(groovy.lang.Closure cl, java.lang.Object args)

Calls a closure in a separate thread supplying the given arguments, returning a future for the potential return value.

callParallel

private static java.util.concurrent.Future callParallel(groovy.lang.Closure task)

schedules the supplied closure for processing in the underlying thread pool.

callTimeoutAsync

public static java.util.concurrent.Future callTimeoutAsync(groovy.lang.Closure cl, long timeout, java.lang.Object args)

Calls a closure in a separate thread supplying the given arguments, returning a future for the potential return value. Also allows the asynchronous calculation to be cancelled after a given timeout. In order to allow cancellation, the asynchronously running code must keep checking the _interrupted_ flag of its own thread and cease the calculation once the flag is set to true.

Parameters:

timeout - The timeout in milliseconds to wait before the calculation gets cancelled.

callTimeoutAsync

public static java.util.concurrent.Future callTimeoutAsync(groovy.lang.Closure cl, groovy.time.Duration timeout, java.lang.Object args)

Calls a closure in a separate thread supplying the given arguments, returning a future for the potential return value. Also allows the asynchronous calculation to be cancelled after a given timeout. In order to allow cancellation, the asynchronously running code must keep checking the _interrupted_ flag of its own thread and cease the calculation once the flag is set to true.

Parameters:

timeout - The timeout to wait before the calculation gets cancelled.

collectParallel

public static java.lang.Object collectParallel(java.lang.Object collection, groovy.lang.Closure cl)

Iterates over a collection/object with the collect() method using an asynchronous variant of the supplied closure to evaluate each collection's element. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = service.collectParallel([1, 2, 3, 4, 5]){Number number -> number * 10}* assertEquals(new HashSet([10, 20, 30, 40, 50]), new HashSet((Collection)result)) }* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new collectParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = [1, 2, 3, 4, 5].collectParallel{Number number -> number * 10}* assertEquals(new HashSet([10, 20, 30, 40, 50]), new HashSet((Collection)result)) }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

collectParallel

public static java.util.Collection collectParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel collect on a map

eachParallel

public static java.lang.Object eachParallel(java.lang.Object collection, groovy.lang.Closure cl)

Iterates over a collection/object with the each() method using an asynchronous variant of the supplied closure to evaluate each collection's element. A Semaphore is used to make the calling thread wait for all the results. After this method returns, all the closures have been finished and all the potential shared resources have been updated by the threads. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. Example: GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = Collections.synchronizedSet(new HashSet()) service.eachParallel([1, 2, 3, 4, 5]) {Number number -> result.add(number * 10)}* assertEquals(new HashSet([10, 20, 30, 40, 50]), result) }* Note that the result variable is synchronized to prevent race conditions between multiple threads. Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new eachParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = Collections.synchronizedSet(new HashSet()) [1, 2, 3, 4, 5].eachParallel { Number number -> result.add(number * 10) }* assertEquals(new HashSet([10, 20, 30, 40, 50]), result) }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

eachParallel

public static java.lang.Object eachParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel each on maps

eachWithIndexParallel

public static java.lang.Object eachWithIndexParallel(java.lang.Object collection, groovy.lang.Closure cl)

Iterates over a collection/object with the eachWithIndex() method using an asynchronous variant of the supplied closure to evaluate each collection's element. A Semaphore is used to make the calling thread wait for all the results. After this method returns, all the closures have been finished and all the potential shared resources have been updated by the threads. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. Example: GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = Collections.synchronizedSet(new HashSet()) service.eachWithIndexParallel([1, 2, 3, 4, 5]) {Number number -> result.add(number * 10)}* assertEquals(new HashSet([10, 20, 30, 40, 50]), result) }* Note that the result variable is synchronized to prevent race conditions between multiple threads. Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new eachParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = Collections.synchronizedSet(new HashSet()) [1, 2, 3, 4, 5].eachWithIndexParallel { Number number, int index -> result.add(number * 10) }* assertEquals(new HashSet([10, 20, 30, 40, 50]), result) }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

eachWithIndexParallel

public static java.lang.Object eachWithIndexParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel eachWithIndex on maps

everyParallel

public static boolean everyParallel(java.lang.Object collection, groovy.lang.Closure cl)

Performs the all() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> assert service.everyParallel([1, 2, 3, 4, 5]){Number number -> number > 0}* assert !service.everyParallel([1, 2, 3, 4, 5]){Number number -> number > 2}*}* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new findAllParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> assert [1, 2, 3, 4, 5].everyParallel{Number number -> number > 0}* assert ![1, 2, 3, 4, 5].everyParallel{Number number -> number > 2}*}*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

everyParallel

public static boolean everyParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel every on a map

findAllParallel

public static java.lang.Object findAllParallel(java.lang.Object collection, groovy.lang.Closure cl)

Performs the findAll() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = service.findAllParallel([1, 2, 3, 4, 5]){Number number -> number > 2}* assertEquals(new HashSet([3, 4, 5]), new HashSet((Collection)result)) }* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new findAllParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = [1, 2, 3, 4, 5].findAllParallel{Number number -> number > 2}* assertEquals(new HashSet([3, 4, 5]), new HashSet((Collection)result)) }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

findAllParallel

public static java.util.Map findAllParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel findAll on a map returning a map of found items

findAnyParallel

public static java.lang.Object findAnyParallel(java.lang.Object collection, groovy.lang.Closure cl)

Performs the find() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. Unlike with the find method, findAnyParallel() does not guarantee that the a matching element with the lowest index is returned. The findAnyParallel() method evaluates elements lazily and stops processing further elements of the collection once a match has been found. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = service.findParallel([1, 2, 3, 4, 5]){Number number -> number > 2}* assert result in [3, 4, 5] }* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new findAllParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = [1, 2, 3, 4, 5].findParallel{Number number -> number > 2}* assert result in [3, 4, 5] }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

findAnyParallel

public static java.lang.Object findAnyParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel findAny on a map

findParallel

public static java.lang.Object findParallel(java.lang.Object collection, groovy.lang.Closure cl)

Performs the find() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = service.findParallel([1, 2, 3, 4, 5]){Number number -> number > 2}* assert result in [3, 4, 5] }* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new findAllParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = [1, 2, 3, 4, 5].findParallel{Number number -> number > 2}* assert result in [3, 4, 5] }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

findParallel

public static java.lang.Object findParallel(java.util.Map collection, groovy.lang.Closure cl)

Does parallel find on a map

grepParallel

public static java.lang.Object grepParallel(java.lang.Object collection, java.lang.Object filter)

Performs the grep()() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = service.grepParallel([1, 2, 3, 4, 5])(3..6) assertEquals(new HashSet([3, 4, 5]), new HashSet((Collection)result)) }* Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new findAllParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> def result = [1, 2, 3, 4, 5].grepParallel(3..6) assertEquals(new HashSet([3, 4, 5]), new HashSet((Collection)result)) }*

throws:

AsyncException If any of the collection's elements causes the closure to throw an exception. The original exceptions will be stored in the AsyncException's concurrentExceptions field.

grepParallel

public static java.util.Map grepParallel(java.util.Map collection, java.lang.Object filter)

Does parallel grep on a map

groupByParallel

public static java.util.Map groupByParallel(java.lang.Object collection, groovy.lang.Closure cl)

Performs the groupBy() operation using an asynchronous variant of the supplied closure to evaluate each collection's/object's element. After this method returns, all the closures have been finished and the caller can safely use the result. It's important to protect any shared resources used by the supplied closure from race conditions caused by multi-threaded access. GParsExecutorsPool.withPool(5) {ExecutorService service -> assert service.groupByParallel(([1, 2, 3, 4, 5]){Number number -> number % 2}).size() == 2 Alternatively a DSL can be used to simplify the code. All collections/objects within the withPool block have a new groupByParallel(Closure cl) method, which delegates to the GParsExecutorsPoolUtil class. GParsExecutorsPool.withPool(5) {ExecutorService service -> assert ([1, 2, 3, 4, 5].groupByParallel{Number number -> number % 2}).size() == 2

leftShift

public static java.util.concurrent.Future leftShift(java.util.concurrent.ExecutorService executorService, groovy.lang.Closure task)

Submits the task for asynchronous processing returning the Future received from the executor service. Allows for the following syntax:

 executorService << {println 'Inside parallel task'}* 

processResult

public static java.util.List processResult(java.util.List futures)

Copyright © 2008–2010 Václav Pech. All Rights Reserved.