util/Collection/IteratorMicroBenchmark.java

/*
 * Copyright (c) 2007, 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.
 */

/*
 * @test
 * @summary micro-benchmark correctness mode
 * @run main IteratorMicroBenchmark iterations=1 size=8 warmup=0
 */

import static java.util.stream.Collectors.summingInt;
import static java.util.stream.Collectors.toCollection;

import java.lang.ref.WeakReference;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.PriorityQueue;
import java.util.Spliterator;
import java.util.Vector;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ConcurrentLinkedDeque;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.LongAdder;
import java.util.function.UnaryOperator;
import java.util.regex.Pattern;
import java.util.stream.Stream;

/**
 * Usage: [iterations=N] [size=N] [filter=REGEXP] [warmup=SECONDS]
 *
 * To run this in micro-benchmark mode, simply run as a normal java program.
 * Be patient; this program runs for a very long time.
 * For faster runs, restrict execution using command line args.
 *
 * This is an interface based version of ArrayList/IteratorMicroBenchmark
 *
 * @author Martin Buchholz
 */
public class IteratorMicroBenchmark {
    abstract static class Job {
        private final String name;
        public Job(String name) { this.name = name; }
        public String name() { return name; }
        public abstract void work() throws Throwable;
        public void run() {
            try { work(); }
            catch (Throwable ex) {
                // current job cannot always be deduced from stacktrace.
                throw new RuntimeException("Job failed: " + name(), ex);
            }
        }
    }

    final int iterations;
    final int size;             // number of elements in collections
    final double warmupSeconds;
    final long warmupNanos;
    final Pattern nameFilter;   // select subset of Jobs to run
    final boolean reverse;      // reverse order of Jobs
    final boolean shuffle;      // randomize order of Jobs

    IteratorMicroBenchmark(String[] args) {
        iterations    = intArg(args, "iterations", 10_000);
        size          = intArg(args, "size", 1000);
        warmupSeconds = doubleArg(args, "warmup", 7.0);
        nameFilter    = patternArg(args, "filter");
        reverse       = booleanArg(args, "reverse");
        shuffle       = booleanArg(args, "shuffle");

        warmupNanos = (long) (warmupSeconds * (1000L * 1000L * 1000L));
    }

    // --------------- GC finalization infrastructure ---------------

    /** No guarantees, but effective in practice. */
    static void forceFullGc() {
        CountDownLatch finalizeDone = new CountDownLatch(1);
        WeakReference<?> ref = new WeakReference<Object>(new Object() {
            @SuppressWarnings("deprecation")
            protected void finalize() { finalizeDone.countDown(); }});
        try {
            for (int i = 0; i < 10; i++) {
                System.gc();
                if (finalizeDone.await(1L, TimeUnit.SECONDS) && ref.get() == null) {
                    System.runFinalization(); // try to pick up stragglers
                    return;
                }
            }
        } catch (InterruptedException unexpected) {
            throw new AssertionError("unexpected InterruptedException");
        }
        throw new AssertionError("failed to do a \"full\" gc");
    }

    /**
     * Runs each job for long enough that all the runtime compilers
     * have had plenty of time to warm up, i.e. get around to
     * compiling everything worth compiling.
     * Returns array of average times per job per run.
     */
    long[] time0(List<Job> jobs) {
        final int size = jobs.size();
        long[] nanoss = new long[size];
        for (int i = 0; i < size; i++) {
            if (warmupNanos > 0) forceFullGc();
            Job job = jobs.get(i);
            long totalTime;
            int runs = 0;
            long startTime = System.nanoTime();
            do { job.run(); runs++; }
            while ((totalTime = System.nanoTime() - startTime) < warmupNanos);
            nanoss[i] = totalTime/runs;
        }
        return nanoss;
    }

    void time(List<Job> jobs) throws Throwable {
        if (warmupNanos > 0) time0(jobs); // Warm up run
        final int size = jobs.size();
        final long[] nanoss = time0(jobs); // Real timing run
        final long[] milliss = new long[size];
        final double[] ratios = new double[size];

        final String nameHeader   = "Method";
        final String millisHeader = "Millis";
        final String ratioHeader  = "Ratio";

        int nameWidth   = nameHeader.length();
        int millisWidth = millisHeader.length();
        int ratioWidth  = ratioHeader.length();

        for (int i = 0; i < size; i++) {
            nameWidth = Math.max(nameWidth, jobs.get(i).name().length());

            milliss[i] = nanoss[i]/(1000L * 1000L);
            millisWidth = Math.max(millisWidth,
                                   String.format("%d", milliss[i]).length());

            ratios[i] = (double) nanoss[i] / (double) nanoss[0];
            ratioWidth = Math.max(ratioWidth,
                                  String.format("%.3f", ratios[i]).length());
        }

        String format = String.format("%%-%ds %%%dd %%%d.3f%%n",
                                      nameWidth, millisWidth, ratioWidth);
        String headerFormat = String.format("%%-%ds %%%ds %%%ds%%n",
                                            nameWidth, millisWidth, ratioWidth);
        System.out.printf(headerFormat, "Method", "Millis", "Ratio");

        // Print out absolute and relative times, calibrated against first job
        for (int i = 0; i < size; i++)
            System.out.printf(format, jobs.get(i).name(), milliss[i], ratios[i]);
    }

    private static String keywordValue(String[] args, String keyword) {
        for (String arg : args)
            if (arg.startsWith(keyword))
                return arg.substring(keyword.length() + 1);
        return null;
    }

    private static int intArg(String[] args, String keyword, int defaultValue) {
        String val = keywordValue(args, keyword);
        return (val == null) ? defaultValue : Integer.parseInt(val);
    }

    private static double doubleArg(String[] args, String keyword, double defaultValue) {
        String val = keywordValue(args, keyword);
        return (val == null) ? defaultValue : Double.parseDouble(val);
    }

    private static Pattern patternArg(String[] args, String keyword) {
        String val = keywordValue(args, keyword);
        return (val == null) ? null : Pattern.compile(val);
    }

    private static boolean booleanArg(String[] args, String keyword) {
        String val = keywordValue(args, keyword);
        if (val == null || val.equals("false")) return false;
        if (val.equals("true")) return true;
        throw new IllegalArgumentException(val);
    }

    private static void deoptimize(int sum) {
        if (sum == 42)
            System.out.println("the answer");
    }

    private static <T> Iterable<T> backwards(final List<T> list) {
        return new Iterable<T>() {
            public Iterator<T> iterator() {
                return new Iterator<T>() {
                    final ListIterator<T> it = list.listIterator(list.size());
                    public boolean hasNext() { return it.hasPrevious(); }
                    public T next()          { return it.previous(); }
                    public void remove()     {        it.remove(); }};}};
    }

    // Checks for correctness *and* prevents loop optimizations
    static class Check {
        private int sum;
        public void sum(int sum) {
            if (this.sum == 0)
                this.sum = sum;
            if (this.sum != sum)
                throw new AssertionError("Sum mismatch");
        }
    }
    volatile Check check = new Check();

    public static void main(String[] args) throws Throwable {
        new IteratorMicroBenchmark(args).run();
    }

    HashMap<Class<?>, String> goodClassName = new HashMap<>();

    String goodClassName(Class<?> klazz) {
        return goodClassName.computeIfAbsent(
            klazz,
            k -> {
                String simple = k.getSimpleName();
                return (simple.equals("SubList")) // too simple!
                    ? k.getName().replaceFirst(".*\\.", "")
                    : simple;
            });
    }

    static List<Integer> makeSubList(List<Integer> list) {
        final ThreadLocalRandom rnd = ThreadLocalRandom.current();
        int size = list.size();
        if (size <= 2) return list.subList(0, size);
        List<Integer> subList = list.subList(rnd.nextInt(0, 2),
                                             size - rnd.nextInt(0, 2));
        List<Integer> copy = new ArrayList<>(list);
        subList.clear();
        subList.addAll(copy);
        return subList;
    }

    void run() throws Throwable {
        final ArrayList<Integer> al = new ArrayList<>(size);

        // Populate collections with random data
        final ThreadLocalRandom rnd = ThreadLocalRandom.current();
        for (int i = 0; i < size; i++)
            al.add(rnd.nextInt(size));

        final ArrayDeque<Integer> ad = new ArrayDeque<>(al);
        final ArrayBlockingQueue<Integer> abq = new ArrayBlockingQueue<>(al.size());
        abq.addAll(al);

        // shuffle circular array elements so they wrap
        for (int i = 0, n = rnd.nextInt(size); i < n; i++) {
            ad.addLast(ad.removeFirst());
            abq.add(abq.remove());
        }

        ArrayList<Job> jobs = Stream.<Collection<Integer>>of(
                al, ad, abq,
                makeSubList(new ArrayList<>(al)),
                new LinkedList<>(al),
                makeSubList(new LinkedList<>(al)),
                new PriorityQueue<>(al),
                new Vector<>(al),
                makeSubList(new Vector<>(al)),
                new CopyOnWriteArrayList<>(al),
                makeSubList(new CopyOnWriteArrayList<>(al)),
                new ConcurrentLinkedQueue<>(al),
                new ConcurrentLinkedDeque<>(al),
                new LinkedBlockingQueue<>(al),
                new LinkedBlockingDeque<>(al),
                new LinkedTransferQueue<>(al),
                new PriorityBlockingQueue<>(al))
            .flatMap(x -> jobs(x))
            .filter(job ->
                nameFilter == null || nameFilter.matcher(job.name()).find())
            .collect(toCollection(ArrayList::new));

        if (reverse) Collections.reverse(jobs);
        if (shuffle) Collections.shuffle(jobs);

        time(jobs);
    }

    @SafeVarargs @SuppressWarnings("varargs")
    private <T> Stream<T> concatStreams(Stream<T> ... streams) {
        return Stream.of(streams).flatMap(s -> s);
    }

    Stream<Job> jobs(Collection<Integer> x) {
        return concatStreams(
            collectionJobs(x),

            (x instanceof Deque)
            ? dequeJobs((Deque<Integer>)x)
            : Stream.empty(),

            (x instanceof List)
            ? listJobs((List<Integer>)x)
            : Stream.empty());
    }

    Object sneakyAdder(int[] sneakySum) {
        return new Object() {
            public int hashCode() { throw new AssertionError(); }
            public boolean equals(Object z) {
                sneakySum[0] += (int) z; return false; }};
    }

    Stream<Job> collectionJobs(Collection<Integer> x) {
        final String klazz = goodClassName(x.getClass());
        return Stream.of(
            new Job(klazz + " iterate for loop") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        int sum = 0;
                        for (Integer n : x)
                            sum += n;
                        check.sum(sum);}}},
            new Job(klazz + " iterator().forEachRemaining()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.iterator().forEachRemaining(n -> sum[0] += n);
                        check.sum(sum[0]);}}},
            new Job(klazz + " spliterator().tryAdvance()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        Spliterator<Integer> spliterator = x.spliterator();
                        do {} while (spliterator.tryAdvance(n -> sum[0] += n));
                        check.sum(sum[0]);}}},
            new Job(klazz + " spliterator().forEachRemaining()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.spliterator().forEachRemaining(n -> sum[0] += n);
                        check.sum(sum[0]);}}},
            new Job(klazz + " removeIf") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        if (x.removeIf(n -> { sum[0] += n; return false; }))
                            throw new AssertionError();
                        check.sum(sum[0]);}}},
            new Job(klazz + " contains") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    Object sneakyAdder = sneakyAdder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        if (x.contains(sneakyAdder)) throw new AssertionError();
                        check.sum(sum[0]);}}},
            new Job(klazz + " remove(Object)") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    Object sneakyAdder = sneakyAdder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        if (x.remove(sneakyAdder)) throw new AssertionError();
                        check.sum(sum[0]);}}},
            new Job(klazz + " forEach") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.forEach(n -> sum[0] += n);
                        check.sum(sum[0]);}}},
            new Job(klazz + " toArray()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        for (Object o : x.toArray())
                            sum[0] += (Integer) o;
                        check.sum(sum[0]);}}},
            new Job(klazz + " toArray(a)") {
                public void work() throws Throwable {
                    Integer[] a = new Integer[x.size()];
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.toArray(a);
                        for (Object o : a)
                            sum[0] += (Integer) o;
                        check.sum(sum[0]);}}},
            new Job(klazz + " toArray(empty)") {
                public void work() throws Throwable {
                    Integer[] empty = new Integer[0];
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        for (Integer o : x.toArray(empty))
                            sum[0] += o;
                        check.sum(sum[0]);}}},
            new Job(klazz + " stream().forEach") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.stream().forEach(n -> sum[0] += n);
                        check.sum(sum[0]);}}},
            new Job(klazz + " stream().mapToInt") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        check.sum(x.stream().mapToInt(e -> e).sum());}}},
            new Job(klazz + " stream().collect") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        check.sum(x.stream()
                                  .collect(summingInt(e -> e)));}}},
            new Job(klazz + " stream()::iterator") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        for (Integer o : (Iterable<Integer>) x.stream()::iterator)
                            sum[0] += o;
                        check.sum(sum[0]);}}},
            new Job(klazz + " parallelStream().forEach") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        LongAdder sum = new LongAdder();
                        x.parallelStream().forEach(n -> sum.add(n));
                        check.sum((int) sum.sum());}}},
            new Job(klazz + " parallelStream().mapToInt") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        check.sum(x.parallelStream().mapToInt(e -> e).sum());}}},
            new Job(klazz + " parallelStream().collect") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        check.sum(x.parallelStream()
                                  .collect(summingInt(e -> e)));}}},
            new Job(klazz + " parallelStream()::iterator") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        for (Integer o : (Iterable<Integer>) x.parallelStream()::iterator)
                            sum[0] += o;
                        check.sum(sum[0]);}}});
    }

    Stream<Job> dequeJobs(Deque<Integer> x) {
        String klazz = goodClassName(x.getClass());
        return Stream.of(
            new Job(klazz + " descendingIterator() loop") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        int sum = 0;
                        Iterator<Integer> it = x.descendingIterator();
                        while (it.hasNext())
                            sum += it.next();
                        check.sum(sum);}}},
            new Job(klazz + " descendingIterator().forEachRemaining()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.descendingIterator().forEachRemaining(n -> sum[0] += n);
                        check.sum(sum[0]);}}});
    }

    Stream<Job> listJobs(List<Integer> x) {
        final String klazz = goodClassName(x.getClass());
        return Stream.of(
            new Job(klazz + " listIterator forward loop") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        int sum = 0;
                        ListIterator<Integer> it = x.listIterator();
                        while (it.hasNext())
                            sum += it.next();
                        check.sum(sum);}}},
            new Job(klazz + " listIterator backward loop") {
                public void work() throws Throwable {
                    for (int i = 0; i < iterations; i++) {
                        int sum = 0;
                        ListIterator<Integer> it = x.listIterator(x.size());
                        while (it.hasPrevious())
                            sum += it.previous();
                        check.sum(sum);}}},
            new Job(klazz + " indexOf") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    Object sneakyAdder = sneakyAdder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        if (x.indexOf(sneakyAdder) != -1)
                            throw new AssertionError();
                        check.sum(sum[0]);}}},
            new Job(klazz + " lastIndexOf") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    Object sneakyAdder = sneakyAdder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        if (x.lastIndexOf(sneakyAdder) != -1)
                            throw new AssertionError();
                        check.sum(sum[0]);}}},
            new Job(klazz + " replaceAll") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    UnaryOperator<Integer> sneakyAdder =
                        x -> { sum[0] += x; return x; };
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.replaceAll(sneakyAdder);
                        check.sum(sum[0]);}}});
    }
}
Revision:	1.42
Committed:	Thu Apr 5 05:23:16 2018 UTC (6 years, 1 month ago) by jsr166
Branch:	MAIN
Changes since 1.41:	+10 -0 lines
Log Message:	add Job for replaceAll
#	User	Rev	Content
1	jsr166	1.1	/*
2			* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
3			* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4			*
5			* This code is free software; you can redistribute it and/or modify it
6			* under the terms of the GNU General Public License version 2 only, as
7			* published by the Free Software Foundation.
8			*
9			* This code is distributed in the hope that it will be useful, but WITHOUT
10			* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11			* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12			* version 2 for more details (a copy is included in the LICENSE file that
13			* accompanied this code).
14			*
15			* You should have received a copy of the GNU General Public License version
16			* 2 along with this work; if not, write to the Free Software Foundation,
17			* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18			*
19			* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20			* or visit www.oracle.com if you need additional information or have any
21			* questions.
22			*/
23
24			/*
25			* @test
26			* @summary micro-benchmark correctness mode
27			* @run main IteratorMicroBenchmark iterations=1 size=8 warmup=0
28			*/
29
30	jsr166	1.12	import static java.util.stream.Collectors.summingInt;
31	jsr166	1.31	import static java.util.stream.Collectors.toCollection;
32	jsr166	1.12
33	jsr166	1.1	import java.lang.ref.WeakReference;
34			import java.util.ArrayDeque;
35			import java.util.ArrayList;
36			import java.util.Collection;
37	jsr166	1.10	import java.util.Collections;
38	jsr166	1.1	import java.util.Deque;
39	jsr166	1.36	import java.util.HashMap;
40	jsr166	1.1	import java.util.Iterator;
41	jsr166	1.13	import java.util.LinkedList;
42	jsr166	1.1	import java.util.List;
43			import java.util.ListIterator;
44	jsr166	1.8	import java.util.PriorityQueue;
45	jsr166	1.1	import java.util.Spliterator;
46			import java.util.Vector;
47			import java.util.concurrent.ArrayBlockingQueue;
48			import java.util.concurrent.ConcurrentLinkedDeque;
49			import java.util.concurrent.ConcurrentLinkedQueue;
50	jsr166	1.30	import java.util.concurrent.CopyOnWriteArrayList;
51	jsr166	1.1	import java.util.concurrent.LinkedBlockingDeque;
52			import java.util.concurrent.LinkedBlockingQueue;
53			import java.util.concurrent.LinkedTransferQueue;
54	jsr166	1.8	import java.util.concurrent.PriorityBlockingQueue;
55	jsr166	1.1	import java.util.concurrent.CountDownLatch;
56			import java.util.concurrent.ThreadLocalRandom;
57			import java.util.concurrent.TimeUnit;
58	jsr166	1.19	import java.util.concurrent.atomic.LongAdder;
59	jsr166	1.42	import java.util.function.UnaryOperator;
60	jsr166	1.1	import java.util.regex.Pattern;
61	jsr166	1.30	import java.util.stream.Stream;
62	jsr166	1.1
63			/**
64			* Usage: [iterations=N] [size=N] [filter=REGEXP] [warmup=SECONDS]
65			*
66			* To run this in micro-benchmark mode, simply run as a normal java program.
67			* Be patient; this program runs for a very long time.
68			* For faster runs, restrict execution using command line args.
69			*
70			* This is an interface based version of ArrayList/IteratorMicroBenchmark
71			*
72			* @author Martin Buchholz
73			*/
74			public class IteratorMicroBenchmark {
75			abstract static class Job {
76			private final String name;
77			public Job(String name) { this.name = name; }
78			public String name() { return name; }
79			public abstract void work() throws Throwable;
80	jsr166	1.38	public void run() {
81			try { work(); }
82			catch (Throwable ex) {
83			// current job cannot always be deduced from stacktrace.
84			throw new RuntimeException("Job failed: " + name(), ex);
85			}
86			}
87	jsr166	1.1	}
88
89	jsr166	1.11	final int iterations;
90			final int size; // number of elements in collections
91			final double warmupSeconds;
92			final long warmupNanos;
93	jsr166	1.31	final Pattern nameFilter; // select subset of Jobs to run
94	jsr166	1.11	final boolean reverse; // reverse order of Jobs
95			final boolean shuffle; // randomize order of Jobs
96
97			IteratorMicroBenchmark(String[] args) {
98			iterations = intArg(args, "iterations", 10_000);
99			size = intArg(args, "size", 1000);
100			warmupSeconds = doubleArg(args, "warmup", 7.0);
101	jsr166	1.31	nameFilter = patternArg(args, "filter");
102	jsr166	1.11	reverse = booleanArg(args, "reverse");
103			shuffle = booleanArg(args, "shuffle");
104
105			warmupNanos = (long) (warmupSeconds * (1000L * 1000L * 1000L));
106			}
107	jsr166	1.1
108			// --------------- GC finalization infrastructure ---------------
109
110			/** No guarantees, but effective in practice. */
111			static void forceFullGc() {
112			CountDownLatch finalizeDone = new CountDownLatch(1);
113			WeakReference<?> ref = new WeakReference<Object>(new Object() {
114	jsr166	1.36	@SuppressWarnings("deprecation")
115	jsr166	1.1	protected void finalize() { finalizeDone.countDown(); }});
116			try {
117			for (int i = 0; i < 10; i++) {
118			System.gc();
119			if (finalizeDone.await(1L, TimeUnit.SECONDS) && ref.get() == null) {
120			System.runFinalization(); // try to pick up stragglers
121			return;
122			}
123			}
124			} catch (InterruptedException unexpected) {
125			throw new AssertionError("unexpected InterruptedException");
126			}
127			throw new AssertionError("failed to do a \"full\" gc");
128			}
129
130			/**
131			* Runs each job for long enough that all the runtime compilers
132			* have had plenty of time to warm up, i.e. get around to
133			* compiling everything worth compiling.
134			* Returns array of average times per job per run.
135			*/
136	jsr166	1.38	long[] time0(List<Job> jobs) {
137	jsr166	1.1	final int size = jobs.size();
138			long[] nanoss = new long[size];
139			for (int i = 0; i < size; i++) {
140			if (warmupNanos > 0) forceFullGc();
141	jsr166	1.9	Job job = jobs.get(i);
142			long totalTime;
143			int runs = 0;
144			long startTime = System.nanoTime();
145	jsr166	1.38	do { job.run(); runs++; }
146	jsr166	1.9	while ((totalTime = System.nanoTime() - startTime) < warmupNanos);
147			nanoss[i] = totalTime/runs;
148	jsr166	1.1	}
149			return nanoss;
150			}
151
152			void time(List<Job> jobs) throws Throwable {
153	jsr166	1.9	if (warmupNanos > 0) time0(jobs); // Warm up run
154	jsr166	1.1	final int size = jobs.size();
155			final long[] nanoss = time0(jobs); // Real timing run
156			final long[] milliss = new long[size];
157			final double[] ratios = new double[size];
158
159			final String nameHeader = "Method";
160			final String millisHeader = "Millis";
161			final String ratioHeader = "Ratio";
162
163			int nameWidth = nameHeader.length();
164			int millisWidth = millisHeader.length();
165			int ratioWidth = ratioHeader.length();
166
167			for (int i = 0; i < size; i++) {
168			nameWidth = Math.max(nameWidth, jobs.get(i).name().length());
169
170			milliss[i] = nanoss[i]/(1000L * 1000L);
171			millisWidth = Math.max(millisWidth,
172			String.format("%d", milliss[i]).length());
173
174			ratios[i] = (double) nanoss[i] / (double) nanoss[0];
175			ratioWidth = Math.max(ratioWidth,
176			String.format("%.3f", ratios[i]).length());
177			}
178
179			String format = String.format("%%-%ds %%%dd %%%d.3f%%n",
180			nameWidth, millisWidth, ratioWidth);
181			String headerFormat = String.format("%%-%ds %%%ds %%%ds%%n",
182			nameWidth, millisWidth, ratioWidth);
183			System.out.printf(headerFormat, "Method", "Millis", "Ratio");
184
185			// Print out absolute and relative times, calibrated against first job
186			for (int i = 0; i < size; i++)
187			System.out.printf(format, jobs.get(i).name(), milliss[i], ratios[i]);
188			}
189
190			private static String keywordValue(String[] args, String keyword) {
191			for (String arg : args)
192			if (arg.startsWith(keyword))
193			return arg.substring(keyword.length() + 1);
194			return null;
195			}
196
197			private static int intArg(String[] args, String keyword, int defaultValue) {
198			String val = keywordValue(args, keyword);
199			return (val == null) ? defaultValue : Integer.parseInt(val);
200			}
201
202			private static double doubleArg(String[] args, String keyword, double defaultValue) {
203			String val = keywordValue(args, keyword);
204			return (val == null) ? defaultValue : Double.parseDouble(val);
205			}
206
207			private static Pattern patternArg(String[] args, String keyword) {
208			String val = keywordValue(args, keyword);
209			return (val == null) ? null : Pattern.compile(val);
210			}
211
212	jsr166	1.10	private static boolean booleanArg(String[] args, String keyword) {
213			String val = keywordValue(args, keyword);
214			if (val == null \|\| val.equals("false")) return false;
215			if (val.equals("true")) return true;
216			throw new IllegalArgumentException(val);
217			}
218
219	jsr166	1.1	private static void deoptimize(int sum) {
220			if (sum == 42)
221			System.out.println("the answer");
222			}
223
224			private static <T> Iterable<T> backwards(final List<T> list) {
225			return new Iterable<T>() {
226			public Iterator<T> iterator() {
227			return new Iterator<T>() {
228			final ListIterator<T> it = list.listIterator(list.size());
229			public boolean hasNext() { return it.hasPrevious(); }
230			public T next() { return it.previous(); }
231			public void remove() { it.remove(); }};}};
232			}
233
234			// Checks for correctness and prevents loop optimizations
235	jsr166	1.25	static class Check {
236	jsr166	1.1	private int sum;
237			public void sum(int sum) {
238			if (this.sum == 0)
239			this.sum = sum;
240			if (this.sum != sum)
241			throw new AssertionError("Sum mismatch");
242			}
243			}
244	jsr166	1.2	volatile Check check = new Check();
245	jsr166	1.1
246			public static void main(String[] args) throws Throwable {
247	jsr166	1.11	new IteratorMicroBenchmark(args).run();
248	jsr166	1.1	}
249
250	jsr166	1.36	HashMap<Class<?>, String> goodClassName = new HashMap<>();
251
252			String goodClassName(Class<?> klazz) {
253			return goodClassName.computeIfAbsent(
254			klazz,
255			k -> {
256			String simple = k.getSimpleName();
257			return (simple.equals("SubList")) // too simple!
258			? k.getName().replaceFirst(".*\\.", "")
259			: simple;
260			});
261			}
262
263			static List<Integer> makeSubList(List<Integer> list) {
264			final ThreadLocalRandom rnd = ThreadLocalRandom.current();
265			int size = list.size();
266			if (size <= 2) return list.subList(0, size);
267			List<Integer> subList = list.subList(rnd.nextInt(0, 2),
268			size - rnd.nextInt(0, 2));
269			List<Integer> copy = new ArrayList<>(list);
270			subList.clear();
271			subList.addAll(copy);
272			return subList;
273			}
274
275	jsr166	1.11	void run() throws Throwable {
276	jsr166	1.17	final ArrayList<Integer> al = new ArrayList<>(size);
277	jsr166	1.1
278			// Populate collections with random data
279			final ThreadLocalRandom rnd = ThreadLocalRandom.current();
280	jsr166	1.3	for (int i = 0; i < size; i++)
281	jsr166	1.1	al.add(rnd.nextInt(size));
282
283			final ArrayDeque<Integer> ad = new ArrayDeque<>(al);
284			final ArrayBlockingQueue<Integer> abq = new ArrayBlockingQueue<>(al.size());
285			abq.addAll(al);
286
287			// shuffle circular array elements so they wrap
288			for (int i = 0, n = rnd.nextInt(size); i < n; i++) {
289			ad.addLast(ad.removeFirst());
290			abq.add(abq.remove());
291			}
292
293	jsr166	1.31	ArrayList<Job> jobs = Stream.<Collection<Integer>>of(
294			al, ad, abq,
295	jsr166	1.36	makeSubList(new ArrayList<>(al)),
296	jsr166	1.31	new LinkedList<>(al),
297	jsr166	1.36	makeSubList(new LinkedList<>(al)),
298	jsr166	1.31	new PriorityQueue<>(al),
299			new Vector<>(al),
300	jsr166	1.36	makeSubList(new Vector<>(al)),
301	jsr166	1.31	new CopyOnWriteArrayList<>(al),
302	jsr166	1.36	makeSubList(new CopyOnWriteArrayList<>(al)),
303	jsr166	1.31	new ConcurrentLinkedQueue<>(al),
304			new ConcurrentLinkedDeque<>(al),
305			new LinkedBlockingQueue<>(al),
306			new LinkedBlockingDeque<>(al),
307			new LinkedTransferQueue<>(al),
308			new PriorityBlockingQueue<>(al))
309			.flatMap(x -> jobs(x))
310	jsr166	1.33	.filter(job ->
311			nameFilter == null \|\| nameFilter.matcher(job.name()).find())
312	jsr166	1.31	.collect(toCollection(ArrayList::new));
313	jsr166	1.1
314	jsr166	1.11	if (reverse) Collections.reverse(jobs);
315	jsr166	1.10	if (shuffle) Collections.shuffle(jobs);
316
317	jsr166	1.31	time(jobs);
318			}
319
320	jsr166	1.32	@SafeVarargs @SuppressWarnings("varargs")
321			private <T> Stream<T> concatStreams(Stream<T> ... streams) {
322			return Stream.of(streams).flatMap(s -> s);
323			}
324	jsr166	1.34
325	jsr166	1.31	Stream<Job> jobs(Collection<Integer> x) {
326	jsr166	1.32	return concatStreams(
327			collectionJobs(x),
328	jsr166	1.40
329	jsr166	1.32	(x instanceof Deque)
330			? dequeJobs((Deque<Integer>)x)
331			: Stream.empty(),
332	jsr166	1.40
333	jsr166	1.32	(x instanceof List)
334			? listJobs((List<Integer>)x)
335			: Stream.empty());
336	jsr166	1.1	}
337
338	jsr166	1.36	Object sneakyAdder(int[] sneakySum) {
339			return new Object() {
340			public int hashCode() { throw new AssertionError(); }
341			public boolean equals(Object z) {
342			sneakySum[0] += (int) z; return false; }};
343			}
344
345	jsr166	1.31	Stream<Job> collectionJobs(Collection<Integer> x) {
346	jsr166	1.36	final String klazz = goodClassName(x.getClass());
347	jsr166	1.31	return Stream.of(
348	jsr166	1.5	new Job(klazz + " iterate for loop") {
349	jsr166	1.1	public void work() throws Throwable {
350			for (int i = 0; i < iterations; i++) {
351			int sum = 0;
352			for (Integer n : x)
353			sum += n;
354			check.sum(sum);}}},
355	jsr166	1.18	new Job(klazz + " iterator().forEachRemaining()") {
356	jsr166	1.1	public void work() throws Throwable {
357			int[] sum = new int[1];
358			for (int i = 0; i < iterations; i++) {
359			sum[0] = 0;
360			x.iterator().forEachRemaining(n -> sum[0] += n);
361			check.sum(sum[0]);}}},
362	jsr166	1.18	new Job(klazz + " spliterator().tryAdvance()") {
363	jsr166	1.1	public void work() throws Throwable {
364			int[] sum = new int[1];
365			for (int i = 0; i < iterations; i++) {
366			sum[0] = 0;
367			Spliterator<Integer> spliterator = x.spliterator();
368			do {} while (spliterator.tryAdvance(n -> sum[0] += n));
369			check.sum(sum[0]);}}},
370	jsr166	1.18	new Job(klazz + " spliterator().forEachRemaining()") {
371	jsr166	1.1	public void work() throws Throwable {
372			int[] sum = new int[1];
373			for (int i = 0; i < iterations; i++) {
374			sum[0] = 0;
375			x.spliterator().forEachRemaining(n -> sum[0] += n);
376			check.sum(sum[0]);}}},
377	jsr166	1.18	new Job(klazz + " removeIf") {
378	jsr166	1.1	public void work() throws Throwable {
379			int[] sum = new int[1];
380			for (int i = 0; i < iterations; i++) {
381			sum[0] = 0;
382	jsr166	1.16	if (x.removeIf(n -> { sum[0] += n; return false; }))
383			throw new AssertionError();
384	jsr166	1.1	check.sum(sum[0]);}}},
385	jsr166	1.18	new Job(klazz + " contains") {
386	jsr166	1.14	public void work() throws Throwable {
387			int[] sum = new int[1];
388	jsr166	1.36	Object sneakyAdder = sneakyAdder(sum);
389	jsr166	1.14	for (int i = 0; i < iterations; i++) {
390			sum[0] = 0;
391	jsr166	1.36	if (x.contains(sneakyAdder)) throw new AssertionError();
392	jsr166	1.16	check.sum(sum[0]);}}},
393	jsr166	1.18	new Job(klazz + " remove(Object)") {
394	jsr166	1.16	public void work() throws Throwable {
395			int[] sum = new int[1];
396	jsr166	1.36	Object sneakyAdder = sneakyAdder(sum);
397	jsr166	1.16	for (int i = 0; i < iterations; i++) {
398			sum[0] = 0;
399	jsr166	1.36	if (x.remove(sneakyAdder)) throw new AssertionError();
400	jsr166	1.14	check.sum(sum[0]);}}},
401	jsr166	1.18	new Job(klazz + " forEach") {
402	jsr166	1.1	public void work() throws Throwable {
403			int[] sum = new int[1];
404			for (int i = 0; i < iterations; i++) {
405			sum[0] = 0;
406			x.forEach(n -> sum[0] += n);
407	jsr166	1.6	check.sum(sum[0]);}}},
408	jsr166	1.18	new Job(klazz + " toArray()") {
409	jsr166	1.6	public void work() throws Throwable {
410			int[] sum = new int[1];
411			for (int i = 0; i < iterations; i++) {
412			sum[0] = 0;
413			for (Object o : x.toArray())
414			sum[0] += (Integer) o;
415			check.sum(sum[0]);}}},
416	jsr166	1.18	new Job(klazz + " toArray(a)") {
417	jsr166	1.6	public void work() throws Throwable {
418			Integer[] a = new Integer[x.size()];
419			int[] sum = new int[1];
420			for (int i = 0; i < iterations; i++) {
421			sum[0] = 0;
422			x.toArray(a);
423			for (Object o : a)
424			sum[0] += (Integer) o;
425	jsr166	1.7	check.sum(sum[0]);}}},
426	jsr166	1.18	new Job(klazz + " toArray(empty)") {
427	jsr166	1.7	public void work() throws Throwable {
428			Integer[] empty = new Integer[0];
429			int[] sum = new int[1];
430			for (int i = 0; i < iterations; i++) {
431			sum[0] = 0;
432			for (Integer o : x.toArray(empty))
433			sum[0] += o;
434	jsr166	1.12	check.sum(sum[0]);}}},
435	jsr166	1.19	new Job(klazz + " stream().forEach") {
436			public void work() throws Throwable {
437			int[] sum = new int[1];
438			for (int i = 0; i < iterations; i++) {
439			sum[0] = 0;
440			x.stream().forEach(n -> sum[0] += n);
441			check.sum(sum[0]);}}},
442			new Job(klazz + " stream().mapToInt") {
443			public void work() throws Throwable {
444			for (int i = 0; i < iterations; i++) {
445			check.sum(x.stream().mapToInt(e -> e).sum());}}},
446	jsr166	1.18	new Job(klazz + " stream().collect") {
447	jsr166	1.12	public void work() throws Throwable {
448			for (int i = 0; i < iterations; i++) {
449			check.sum(x.stream()
450			.collect(summingInt(e -> e)));}}},
451	jsr166	1.21	new Job(klazz + " stream()::iterator") {
452	jsr166	1.20	public void work() throws Throwable {
453			int[] sum = new int[1];
454			for (int i = 0; i < iterations; i++) {
455			sum[0] = 0;
456			for (Integer o : (Iterable<Integer>) x.stream()::iterator)
457			sum[0] += o;
458			check.sum(sum[0]);}}},
459	jsr166	1.19	new Job(klazz + " parallelStream().forEach") {
460			public void work() throws Throwable {
461			for (int i = 0; i < iterations; i++) {
462			LongAdder sum = new LongAdder();
463			x.parallelStream().forEach(n -> sum.add(n));
464			check.sum((int) sum.sum());}}},
465			new Job(klazz + " parallelStream().mapToInt") {
466			public void work() throws Throwable {
467			for (int i = 0; i < iterations; i++) {
468			check.sum(x.parallelStream().mapToInt(e -> e).sum());}}},
469	jsr166	1.18	new Job(klazz + " parallelStream().collect") {
470	jsr166	1.12	public void work() throws Throwable {
471			for (int i = 0; i < iterations; i++) {
472			check.sum(x.parallelStream()
473	jsr166	1.20	.collect(summingInt(e -> e)));}}},
474	jsr166	1.21	new Job(klazz + " parallelStream()::iterator") {
475	jsr166	1.20	public void work() throws Throwable {
476			int[] sum = new int[1];
477			for (int i = 0; i < iterations; i++) {
478			sum[0] = 0;
479			for (Integer o : (Iterable<Integer>) x.parallelStream()::iterator)
480			sum[0] += o;
481			check.sum(sum[0]);}}});
482	jsr166	1.1	}
483
484	jsr166	1.31	Stream<Job> dequeJobs(Deque<Integer> x) {
485	jsr166	1.36	String klazz = goodClassName(x.getClass());
486	jsr166	1.31	return Stream.of(
487	jsr166	1.18	new Job(klazz + " descendingIterator() loop") {
488	jsr166	1.1	public void work() throws Throwable {
489			for (int i = 0; i < iterations; i++) {
490			int sum = 0;
491			Iterator<Integer> it = x.descendingIterator();
492			while (it.hasNext())
493			sum += it.next();
494			check.sum(sum);}}},
495	jsr166	1.18	new Job(klazz + " descendingIterator().forEachRemaining()") {
496	jsr166	1.1	public void work() throws Throwable {
497			int[] sum = new int[1];
498			for (int i = 0; i < iterations; i++) {
499			sum[0] = 0;
500			x.descendingIterator().forEachRemaining(n -> sum[0] += n);
501			check.sum(sum[0]);}}});
502			}
503	jsr166	1.30
504	jsr166	1.31	Stream<Job> listJobs(List<Integer> x) {
505	jsr166	1.36	final String klazz = goodClassName(x.getClass());
506	jsr166	1.31	return Stream.of(
507	jsr166	1.41	new Job(klazz + " listIterator forward loop") {
508			public void work() throws Throwable {
509			for (int i = 0; i < iterations; i++) {
510			int sum = 0;
511			ListIterator<Integer> it = x.listIterator();
512			while (it.hasNext())
513			sum += it.next();
514			check.sum(sum);}}},
515			new Job(klazz + " listIterator backward loop") {
516			public void work() throws Throwable {
517			for (int i = 0; i < iterations; i++) {
518			int sum = 0;
519			ListIterator<Integer> it = x.listIterator(x.size());
520			while (it.hasPrevious())
521			sum += it.previous();
522			check.sum(sum);}}},
523	jsr166	1.39	new Job(klazz + " indexOf") {
524			public void work() throws Throwable {
525			int[] sum = new int[1];
526			Object sneakyAdder = sneakyAdder(sum);
527			for (int i = 0; i < iterations; i++) {
528			sum[0] = 0;
529			if (x.indexOf(sneakyAdder) != -1)
530			throw new AssertionError();
531			check.sum(sum[0]);}}},
532			new Job(klazz + " lastIndexOf") {
533			public void work() throws Throwable {
534			int[] sum = new int[1];
535			Object sneakyAdder = sneakyAdder(sum);
536			for (int i = 0; i < iterations; i++) {
537			sum[0] = 0;
538			if (x.lastIndexOf(sneakyAdder) != -1)
539			throw new AssertionError();
540	jsr166	1.42	check.sum(sum[0]);}}},
541			new Job(klazz + " replaceAll") {
542			public void work() throws Throwable {
543			int[] sum = new int[1];
544			UnaryOperator<Integer> sneakyAdder =
545			x -> { sum[0] += x; return x; };
546			for (int i = 0; i < iterations; i++) {
547			sum[0] = 0;
548			x.replaceAll(sneakyAdder);
549	jsr166	1.39	check.sum(sum[0]);}}});
550	jsr166	1.30	}
551	jsr166	1.1	}