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Java example source code file (JavacTestingAbstractThreadedTest.java)

This example Java source code file (JavacTestingAbstractThreadedTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

assertionerror, atomicinteger, executorservice, interruptedexception, javactestingabstractthreadedtest, override, printwriter, standardjavafilemanager, stringwriter, thread, threadfactory, threading, threadlocal, threads, throwable, total

The JavacTestingAbstractThreadedTest.java Java example source code

/*
 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import javax.tools.JavaCompiler;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

/**
 * An abstract superclass for threaded tests.
 *
 * This class will try to read a property named test.concurrency.
 * The property can be provided by passing this option to jtreg:
 * -javaoption:-Dtest.concurrency=#
 *
 * If the property is not set the class will use a heuristic to determine the
 * maximum number of threads that can be fired to execute a given test.
 *
 * This code will have to be revisited if jprt starts using concurrency for
 * for running jtreg tests.
 */
public abstract class JavacTestingAbstractThreadedTest {

    protected static AtomicInteger numberOfThreads = new AtomicInteger();

    protected static int getThreadPoolSize() {
        Integer testConc = Integer.getInteger("test.concurrency");
        if (testConc != null) return testConc;
        int cores = Runtime.getRuntime().availableProcessors();
        numberOfThreads.set(Math.max(2, Math.min(8, cores / 2)));
        return numberOfThreads.get();
    }

    protected static void checkAfterExec() throws InterruptedException {
        checkAfterExec(true);
    };

    protected static boolean throwAssertionOnError = true;

    protected static boolean printAll = false;

    protected static StringWriter errSWriter = new StringWriter();
    protected static PrintWriter errWriter = new PrintWriter(errSWriter);

    protected static StringWriter outSWriter = new StringWriter();
    protected static PrintWriter outWriter = new PrintWriter(outSWriter);

    protected static void checkAfterExec(boolean printCheckCount)
            throws InterruptedException {
        pool.shutdown();
        pool.awaitTermination(15, TimeUnit.MINUTES);
        if (errCount.get() > 0) {
            if (throwAssertionOnError) {
                closePrinters();
                System.err.println(errSWriter.toString());
                throw new AssertionError(
                    String.format("%d errors found", errCount.get()));
            } else {
                System.err.println(
                        String.format("%d errors found", errCount.get()));
            }
        } else if (printCheckCount) {
            outWriter.println("Total check executed: " + checkCount.get());
        }
        /*
         * This output is for supporting debugging. It does not mean that a given
         * test had executed that number of threads concurrently. The value printed
         * here is the maximum possible amount.
         */
        closePrinters();
        if (printAll) {
            System.out.println(errSWriter.toString());
            System.out.println(outSWriter.toString());
        }
        System.out.println("Total number of threads in thread pool: " +
                numberOfThreads.get());
    }

    protected static void closePrinters() {
        errWriter.close();
        outWriter.close();
    }

    protected static void processException(Throwable t) {
        errCount.incrementAndGet();
        t.printStackTrace(errWriter);
        pool.shutdown();
    }

    //number of checks executed
    protected static AtomicInteger checkCount = new AtomicInteger();

    //number of errors found while running combo tests
    protected static AtomicInteger errCount = new AtomicInteger();

    //create default shared JavaCompiler - reused across multiple compilations
    protected static JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

    protected static ExecutorService pool = Executors.newFixedThreadPool(
            getThreadPoolSize(), new ThreadFactory() {
        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(r);
            t.setUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
                @Override
                public void uncaughtException(Thread t, Throwable e) {
                    pool.shutdown();
                    errCount.incrementAndGet();
                    e.printStackTrace(System.err);
                }
            });
            return t;
        }
    });

    /*
     * File manager is not thread-safe so it cannot be re-used across multiple
     * threads. However we cache per-thread FileManager to avoid excessive
     * object creation
     */
    protected static final ThreadLocal<StandardJavaFileManager> fm =
        new ThreadLocal<StandardJavaFileManager>() {
            @Override protected StandardJavaFileManager initialValue() {
                return comp.getStandardFileManager(null, null, null);
            }
        };

}

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