/*
 * Copyright (c) 2021 Goldman Sachs.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompany this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */

package org.eclipse.collections.impl.parallel;

import java.util.concurrent.Executor;

import org.eclipse.collections.api.block.procedure.Procedure;
import org.eclipse.collections.impl.utility.ArrayIterate;

import static org.eclipse.collections.impl.factory.Iterables.iList;

The ParallelArrayIterate class contains a parallel forEach algorithm that work with Java arrays. The forEach algorithm employs a batching fork and join approach approach. All Collections that are not array based use ParallelArrayIterate to parallelize, by converting themselves to an array using toArray().
/** * The ParallelArrayIterate class contains a parallel forEach algorithm that work with Java arrays. The forEach * algorithm employs a batching fork and join approach approach. All Collections that are not array based use * ParallelArrayIterate to parallelize, by converting themselves to an array using toArray(). */
public final class ParallelArrayIterate { private ParallelArrayIterate() { throw new AssertionError("Suppress default constructor for noninstantiability"); } public static <T, BT extends Procedure<? super T>> void forEach( T[] array, ProcedureFactory<BT> procedureFactory, Combiner<BT> combiner) { int taskCount = Math.max(ParallelIterate.DEFAULT_PARALLEL_TASK_COUNT, array.length / ParallelIterate.DEFAULT_MIN_FORK_SIZE); ParallelArrayIterate.forEach(array, procedureFactory, combiner, ParallelIterate.DEFAULT_MIN_FORK_SIZE, taskCount); } public static <T, BT extends Procedure<? super T>> void forEach( T[] array, ProcedureFactory<BT> procedureFactory, Combiner<BT> combiner, int minForkSize, int taskCount) { ParallelArrayIterate.forEachOn(array, procedureFactory, combiner, minForkSize, taskCount, ParallelIterate.EXECUTOR_SERVICE); } public static <T, BT extends Procedure<? super T>> void forEachOn( T[] array, ProcedureFactory<BT> procedureFactory, Combiner<BT> combiner, int minForkSize, int taskCount, Executor executor) { if (ArrayIterate.notEmpty(array)) { int size = array.length; if (size < minForkSize) { BT procedure = procedureFactory.create(); ArrayIterate.forEach(array, procedure); ParallelArrayIterate.combineSingleProcedure(combiner, procedure); } else { int threadCount = Math.min(size, taskCount); new ArrayProcedureFJTaskRunner<>(combiner, threadCount).executeAndCombine(executor, procedureFactory, array); } } } private static <T, BT extends Procedure<? super T>> void combineSingleProcedure(Combiner<BT> combiner, BT procedure) { if (combiner.useCombineOne()) { combiner.combineOne(procedure); } else { combiner.combineAll(iList(procedure)); } } }