org.apache.sysml.runtime.util.CommonThreadPool.java Source code

Introduction

Here is the source code for org.apache.sysml.runtime.util.CommonThreadPool.java

Source

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.sysml.runtime.util;

import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import org.apache.commons.lang.NotImplementedException;
import org.apache.sysml.runtime.controlprogram.parfor.stat.InfrastructureAnalyzer;

/**
 * This common thread pool provides an abstraction to obtain a shared
 * thread pool, specifically the ForkJoinPool.commonPool, for all requests
 * of the maximum degree of parallelism. If pools of different size are
 * requested, we create new pool instances of FixedThreadPool.
 */
public class CommonThreadPool implements ExecutorService {
    //shared thread pool used system-wide, potentially by concurrent parfor workers
    //we use the ForkJoinPool.commonPool() to avoid explicit cleanup, including
    //unnecessary initialization (e.g., problematic in jmlc) and because this commonPool
    //resulted in better performance than a dedicated fixed thread pool.
    private static final int size = InfrastructureAnalyzer.getLocalParallelism();
    private static final ExecutorService shared = ForkJoinPool.commonPool();
    private final ExecutorService _pool;

    public CommonThreadPool(ExecutorService pool) {
        _pool = pool;
    }

    public static ExecutorService get(int k) {
        return new CommonThreadPool((size == k) ? shared : Executors.newFixedThreadPool(k));
    }

    public static void shutdownShared() {
        shared.shutdownNow();
    }

    public void shutdown() {
        if (_pool != shared)
            _pool.shutdown();
    }

    public List<Runnable> shutdownNow() {
        return (_pool != shared) ? _pool.shutdownNow() : null;
    }

    public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) throws InterruptedException {
        return _pool.invokeAll(tasks);
    }

    public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
            throws InterruptedException {
        return _pool.invokeAll(tasks, timeout, unit);
    }

    public void execute(Runnable command) {
        _pool.execute(command);
    }

    public <T> Future<T> submit(Callable<T> task) {
        return _pool.submit(task);
    }

    public <T> Future<T> submit(Runnable task, T result) {
        return _pool.submit(task, result);
    }

    public Future<?> submit(Runnable task) {
        return _pool.submit(task);
    }

    //unnecessary methods required for API compliance

    public boolean isShutdown() {
        throw new NotImplementedException();
    }

    public boolean isTerminated() {
        throw new NotImplementedException();
    }

    public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
        throw new NotImplementedException();
    }

    public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
            throws InterruptedException, ExecutionException {
        throw new NotImplementedException();
    }

    public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
            throws InterruptedException, ExecutionException, TimeoutException {
        throw new NotImplementedException();
    }
}