util/Collection/RemoveMicroBenchmark.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 RemoveMicroBenchmark iterations=1 size=8 warmup=0
 */

import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.stream.Collectors.toCollection;

import java.lang.ref.ReferenceQueue;
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.Queue;
import java.util.Vector;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentLinkedDeque;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
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.
 *
 * @author Martin Buchholz
 */
public class RemoveMicroBenchmark {
    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

    final ArrayList<Integer> elements; // contains size random Integers

    RemoveMicroBenchmark(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));

        elements = ThreadLocalRandom.current().ints(size)
            .mapToObj(x -> x)
            .collect(toCollection(ArrayList::new));
    }

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

    /** No guarantees, but effective in practice. */
    static void forceFullGc() {
        long timeoutMillis = 1000L;
        CountDownLatch finalized = new CountDownLatch(1);
        ReferenceQueue<Object> queue = new ReferenceQueue<>();
        WeakReference<Object> ref = new WeakReference<>(
            new Object() { protected void finalize() { finalized.countDown(); }},
            queue);
        try {
            for (int tries = 3; tries--> 0; ) {
                System.gc();
                if (finalized.await(timeoutMillis, MILLISECONDS)
                    && queue.remove(timeoutMillis) != null
                    && ref.get() == null) {
                    System.runFinalization(); // try to pick up stragglers
                    return;
                }
                timeoutMillis *= 4;
            }
        } 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 RemoveMicroBenchmark(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;
            });
    }

    String goodClassName(Object x) {
        return goodClassName(x.getClass());
    }

    static List<Integer> makeSubList(List<Integer> list) {
        final ThreadLocalRandom rnd = ThreadLocalRandom.current();
        int size = rnd.nextInt(4);
        for (int i = size; i--> 0; )
            list.add(rnd.nextInt());
        int index = rnd.nextInt(size + 1);
        return list.subList(index, index);
    }

    private static <T> List<T> asSubList(List<T> list) {
        return list.subList(0, list.size());
    }

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

    Class<?> topLevelClass(Object x) {
        for (Class<?> k = x.getClass();; ) {
            Class<?> enclosing = k.getEnclosingClass();
            if (enclosing == null)
                return k;
            k = enclosing;
        }
    }

    void run() throws Throwable {
        ArrayList<Job> jobs = Stream.<Collection<Integer>>of(
                new ArrayList<>(),
                makeSubList(new ArrayList<>()),
                new LinkedList<>(),
                makeSubList(new LinkedList<>()),
                new Vector<>(),
                makeSubList(new Vector<>()),
                new CopyOnWriteArrayList<>(),
                makeSubList(new CopyOnWriteArrayList<>()),
                new ArrayDeque<>(),
                new PriorityQueue<>(),
                new ArrayBlockingQueue<>(elements.size()),
                new ConcurrentLinkedQueue<>(),
                new ConcurrentLinkedDeque<>(),
                new LinkedBlockingQueue<>(),
                new LinkedBlockingDeque<>(),
                new LinkedTransferQueue<>(),
                new PriorityBlockingQueue<>())
            .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);
    }

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

            (CopyOnWriteArrayList.class.isAssignableFrom(topLevelClass(x)))
            ? Stream.empty()
            : iteratorRemoveJobs(x),

            (x instanceof Queue)
            ? queueJobs((Queue<Integer>)x)
            : Stream.empty(),

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

            (x instanceof BlockingQueue)
            ? blockingQueueJobs((BlockingQueue<Integer>)x)
            : Stream.empty(),

            (x instanceof BlockingDeque)
            ? blockingDequeJobs((BlockingDeque<Integer>)x)
            : Stream.empty());
    }

    Collection<Integer> universeRecorder(int[] sum) {
        return new ArrayList<>() {
            public boolean contains(Object x) {
                sum[0] += (Integer) x;
                return true;
            }};
    }

    Collection<Integer> emptyRecorder(int[] sum) {
        return new ArrayList<>() {
            public boolean contains(Object x) {
                sum[0] += (Integer) x;
                return false;
            }};
    }

    Stream<Job> collectionJobs(Collection<Integer> x) {
        final String klazz = goodClassName(x);
        return Stream.of(
            new Job(klazz + " removeIf") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        x.removeIf(n -> { sum[0] += n; return true; });
                        check.sum(sum[0]);}}},
            new Job(klazz + " removeIf rnd-two-pass") {
                public void work() throws Throwable {
                    ThreadLocalRandom rnd = ThreadLocalRandom.current();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        x.removeIf(n -> {
                            boolean b = rnd.nextBoolean();
                            if (b) sum[0] += n;
                            return b; });
                        x.removeIf(n -> { sum[0] += n; return true; });
                        check.sum(sum[0]);}}},
            new Job(klazz + " removeAll") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    Collection<Integer> universe = universeRecorder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        x.removeAll(universe);
                        check.sum(sum[0]);}}},
            new Job(klazz + " retainAll") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    Collection<Integer> empty = emptyRecorder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        x.retainAll(empty);
                        check.sum(sum[0]);}}},
            new Job(klazz + " clear") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        x.forEach(e -> sum[0] += e);
                        x.clear();
                        check.sum(sum[0]);}}});
    }

    Stream<Job> iteratorRemoveJobs(Collection<Integer> x) {
        final String klazz = goodClassName(x);
        return Stream.of(
             new Job(klazz + " Iterator.remove") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        Iterator<Integer> it = x.iterator();
                        while (it.hasNext()) {
                            sum[0] += it.next();
                            it.remove();
                        }
                        check.sum(sum[0]);}}},
            new Job(klazz + " Iterator.remove-rnd-two-pass") {
                public void work() throws Throwable {
                    ThreadLocalRandom rnd = ThreadLocalRandom.current();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Iterator<Integer> it = x.iterator();
                             it.hasNext(); ) {
                            Integer e = it.next();
                            if (rnd.nextBoolean()) {
                                sum[0] += e;
                                it.remove();
                            }
                        }
                        for (Iterator<Integer> it = x.iterator();
                             it.hasNext(); ) {
                            sum[0] += it.next();
                            it.remove();
                        }
                        check.sum(sum[0]);}}});
    }

    Stream<Job> queueJobs(Queue<Integer> x) {
        final String klazz = goodClassName(x);
        return Stream.of(
            new Job(klazz + " poll()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Integer e; (e = x.poll()) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}});
    }

    Stream<Job> dequeJobs(Deque<Integer> x) {
        final String klazz = goodClassName(x);
        return Stream.of(
            new Job(klazz + " descendingIterator().remove") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        Iterator<Integer> it = x.descendingIterator();
                        while (it.hasNext()) {
                            sum[0] += it.next();
                            it.remove();
                        }
                        check.sum(sum[0]);}}},
            new Job(klazz + " pollFirst()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Integer e; (e = x.pollFirst()) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}},
            new Job(klazz + " pollLast()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Integer e; (e = x.pollLast()) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}});
    }

    Stream<Job> blockingQueueJobs(BlockingQueue<Integer> x) {
        final String klazz = goodClassName(x);
        return Stream.of(
            new Job(klazz + " timed poll()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Integer e; (e = x.poll(0L, TimeUnit.DAYS)) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}},
            new Job(klazz + " drainTo(sink)") {
                public void work() throws Throwable {
                    ArrayList<Integer> sink = new ArrayList<>();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        sink.clear();
                        x.addAll(elements);
                        x.drainTo(sink);
                        sink.forEach(e -> sum[0] += e);
                        check.sum(sum[0]);}}},
            new Job(klazz + " drainTo(sink, n)") {
                public void work() throws Throwable {
                    ArrayList<Integer> sink = new ArrayList<>();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        sink.clear();
                        x.addAll(elements);
                        x.drainTo(sink, elements.size());
                        sink.forEach(e -> sum[0] += e);
                        check.sum(sum[0]);}}});
    }

    Stream<Job> blockingDequeJobs(BlockingDeque<Integer> x) {
        final String klazz = goodClassName(x);
        return Stream.of(
            new Job(klazz + " timed pollFirst()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Integer e; (e = x.pollFirst(0L, TimeUnit.DAYS)) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}},
            new Job(klazz + " timed pollLast()") {
                public void work() throws Throwable {
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(elements);
                        for (Integer e; (e = x.pollLast(0L, TimeUnit.DAYS)) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}});
    }
}
Revision:	1.26
Committed:	Thu Jan 10 16:46:56 2019 UTC (5 years, 4 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.25:	+10 -6 lines
Log Message:	support sublists of immutable lists plus cosmetic improvements
#	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 RemoveMicroBenchmark iterations=1 size=8 warmup=0
28			*/
29
30	jsr166	1.24	import static java.util.concurrent.TimeUnit.MILLISECONDS;
31	jsr166	1.22	import static java.util.stream.Collectors.toCollection;
32	jsr166	1.20
33	jsr166	1.24	import java.lang.ref.ReferenceQueue;
34	jsr166	1.1	import java.lang.ref.WeakReference;
35			import java.util.ArrayDeque;
36			import java.util.ArrayList;
37			import java.util.Collection;
38	jsr166	1.5	import java.util.Collections;
39	jsr166	1.1	import java.util.Deque;
40	jsr166	1.22	import java.util.HashMap;
41	jsr166	1.1	import java.util.Iterator;
42			import java.util.LinkedList;
43			import java.util.List;
44			import java.util.ListIterator;
45	jsr166	1.2	import java.util.PriorityQueue;
46	jsr166	1.8	import java.util.Queue;
47	jsr166	1.1	import java.util.Vector;
48			import java.util.concurrent.ArrayBlockingQueue;
49	jsr166	1.7	import java.util.concurrent.BlockingDeque;
50	jsr166	1.3	import java.util.concurrent.BlockingQueue;
51	jsr166	1.1	import java.util.concurrent.ConcurrentLinkedDeque;
52			import java.util.concurrent.ConcurrentLinkedQueue;
53	jsr166	1.22	import java.util.concurrent.CopyOnWriteArrayList;
54	jsr166	1.2	import java.util.concurrent.CountDownLatch;
55	jsr166	1.1	import java.util.concurrent.LinkedBlockingDeque;
56			import java.util.concurrent.LinkedBlockingQueue;
57			import java.util.concurrent.LinkedTransferQueue;
58	jsr166	1.2	import java.util.concurrent.PriorityBlockingQueue;
59	jsr166	1.1	import java.util.concurrent.ThreadLocalRandom;
60			import java.util.concurrent.TimeUnit;
61			import java.util.regex.Pattern;
62	jsr166	1.22	import java.util.stream.Stream;
63	jsr166	1.1
64			/**
65			* Usage: [iterations=N] [size=N] [filter=REGEXP] [warmup=SECONDS]
66			*
67			* To run this in micro-benchmark mode, simply run as a normal java program.
68			* Be patient; this program runs for a very long time.
69			* For faster runs, restrict execution using command line args.
70			*
71			* @author Martin Buchholz
72			*/
73			public class RemoveMicroBenchmark {
74			abstract static class Job {
75			private final String name;
76			public Job(String name) { this.name = name; }
77			public String name() { return name; }
78			public abstract void work() throws Throwable;
79	jsr166	1.21	public void run() {
80			try { work(); }
81			catch (Throwable ex) {
82			// current job cannot always be deduced from stacktrace.
83			throw new RuntimeException("Job failed: " + name(), ex);
84			}
85			}
86	jsr166	1.1	}
87
88	jsr166	1.5	final int iterations;
89			final int size; // number of elements in collections
90			final double warmupSeconds;
91			final long warmupNanos;
92	jsr166	1.22	final Pattern nameFilter; // select subset of Jobs to run
93	jsr166	1.5	final boolean reverse; // reverse order of Jobs
94			final boolean shuffle; // randomize order of Jobs
95
96	jsr166	1.22	final ArrayList<Integer> elements; // contains size random Integers
97
98	jsr166	1.5	RemoveMicroBenchmark(String[] args) {
99			iterations = intArg(args, "iterations", 10_000);
100			size = intArg(args, "size", 1000);
101			warmupSeconds = doubleArg(args, "warmup", 7.0);
102	jsr166	1.22	nameFilter = patternArg(args, "filter");
103	jsr166	1.5	reverse = booleanArg(args, "reverse");
104			shuffle = booleanArg(args, "shuffle");
105
106			warmupNanos = (long) (warmupSeconds * (1000L * 1000L * 1000L));
107	jsr166	1.22
108			elements = ThreadLocalRandom.current().ints(size)
109			.mapToObj(x -> x)
110			.collect(toCollection(ArrayList::new));
111	jsr166	1.5	}
112	jsr166	1.1
113			// --------------- GC finalization infrastructure ---------------
114
115			/** No guarantees, but effective in practice. */
116			static void forceFullGc() {
117	jsr166	1.24	long timeoutMillis = 1000L;
118			CountDownLatch finalized = new CountDownLatch(1);
119			ReferenceQueue<Object> queue = new ReferenceQueue<>();
120			WeakReference<Object> ref = new WeakReference<>(
121			new Object() { protected void finalize() { finalized.countDown(); }},
122			queue);
123	jsr166	1.1	try {
124	jsr166	1.24	for (int tries = 3; tries--> 0; ) {
125	jsr166	1.1	System.gc();
126	jsr166	1.24	if (finalized.await(timeoutMillis, MILLISECONDS)
127			&& queue.remove(timeoutMillis) != null
128			&& ref.get() == null) {
129	jsr166	1.1	System.runFinalization(); // try to pick up stragglers
130			return;
131			}
132	jsr166	1.24	timeoutMillis *= 4;
133	jsr166	1.1	}
134			} catch (InterruptedException unexpected) {
135			throw new AssertionError("unexpected InterruptedException");
136			}
137			throw new AssertionError("failed to do a \"full\" gc");
138			}
139
140			/**
141			* Runs each job for long enough that all the runtime compilers
142			* have had plenty of time to warm up, i.e. get around to
143			* compiling everything worth compiling.
144			* Returns array of average times per job per run.
145			*/
146	jsr166	1.21	long[] time0(List<Job> jobs) {
147	jsr166	1.1	final int size = jobs.size();
148			long[] nanoss = new long[size];
149			for (int i = 0; i < size; i++) {
150			if (warmupNanos > 0) forceFullGc();
151	jsr166	1.4	Job job = jobs.get(i);
152			long totalTime;
153			int runs = 0;
154			long startTime = System.nanoTime();
155	jsr166	1.21	do { job.run(); runs++; }
156	jsr166	1.4	while ((totalTime = System.nanoTime() - startTime) < warmupNanos);
157			nanoss[i] = totalTime/runs;
158	jsr166	1.1	}
159			return nanoss;
160			}
161
162			void time(List<Job> jobs) throws Throwable {
163	jsr166	1.4	if (warmupNanos > 0) time0(jobs); // Warm up run
164	jsr166	1.1	final int size = jobs.size();
165			final long[] nanoss = time0(jobs); // Real timing run
166			final long[] milliss = new long[size];
167			final double[] ratios = new double[size];
168
169			final String nameHeader = "Method";
170			final String millisHeader = "Millis";
171			final String ratioHeader = "Ratio";
172
173			int nameWidth = nameHeader.length();
174			int millisWidth = millisHeader.length();
175			int ratioWidth = ratioHeader.length();
176
177			for (int i = 0; i < size; i++) {
178			nameWidth = Math.max(nameWidth, jobs.get(i).name().length());
179
180			milliss[i] = nanoss[i]/(1000L * 1000L);
181			millisWidth = Math.max(millisWidth,
182			String.format("%d", milliss[i]).length());
183
184			ratios[i] = (double) nanoss[i] / (double) nanoss[0];
185			ratioWidth = Math.max(ratioWidth,
186			String.format("%.3f", ratios[i]).length());
187			}
188
189			String format = String.format("%%-%ds %%%dd %%%d.3f%%n",
190			nameWidth, millisWidth, ratioWidth);
191			String headerFormat = String.format("%%-%ds %%%ds %%%ds%%n",
192			nameWidth, millisWidth, ratioWidth);
193			System.out.printf(headerFormat, "Method", "Millis", "Ratio");
194
195			// Print out absolute and relative times, calibrated against first job
196			for (int i = 0; i < size; i++)
197			System.out.printf(format, jobs.get(i).name(), milliss[i], ratios[i]);
198			}
199
200			private static String keywordValue(String[] args, String keyword) {
201			for (String arg : args)
202			if (arg.startsWith(keyword))
203			return arg.substring(keyword.length() + 1);
204			return null;
205			}
206
207			private static int intArg(String[] args, String keyword, int defaultValue) {
208			String val = keywordValue(args, keyword);
209			return (val == null) ? defaultValue : Integer.parseInt(val);
210			}
211
212			private static double doubleArg(String[] args, String keyword, double defaultValue) {
213			String val = keywordValue(args, keyword);
214			return (val == null) ? defaultValue : Double.parseDouble(val);
215			}
216
217			private static Pattern patternArg(String[] args, String keyword) {
218			String val = keywordValue(args, keyword);
219			return (val == null) ? null : Pattern.compile(val);
220			}
221
222	jsr166	1.5	private static boolean booleanArg(String[] args, String keyword) {
223			String val = keywordValue(args, keyword);
224			if (val == null \|\| val.equals("false")) return false;
225			if (val.equals("true")) return true;
226			throw new IllegalArgumentException(val);
227			}
228
229	jsr166	1.1	private static void deoptimize(int sum) {
230			if (sum == 42)
231			System.out.println("the answer");
232			}
233
234			private static <T> Iterable<T> backwards(final List<T> list) {
235			return new Iterable<T>() {
236			public Iterator<T> iterator() {
237			return new Iterator<T>() {
238			final ListIterator<T> it = list.listIterator(list.size());
239			public boolean hasNext() { return it.hasPrevious(); }
240			public T next() { return it.previous(); }
241			public void remove() { it.remove(); }};}};
242			}
243
244			// Checks for correctness and prevents loop optimizations
245	jsr166	1.18	static class Check {
246	jsr166	1.1	private int sum;
247			public void sum(int sum) {
248			if (this.sum == 0)
249			this.sum = sum;
250			if (this.sum != sum)
251			throw new AssertionError("Sum mismatch");
252			}
253			}
254			volatile Check check = new Check();
255
256			public static void main(String[] args) throws Throwable {
257	jsr166	1.5	new RemoveMicroBenchmark(args).run();
258	jsr166	1.1	}
259
260	jsr166	1.22	HashMap<Class<?>, String> goodClassName = new HashMap<>();
261	jsr166	1.1
262	jsr166	1.22	String goodClassName(Class<?> klazz) {
263			return goodClassName.computeIfAbsent(
264			klazz,
265			k -> {
266			String simple = k.getSimpleName();
267			return (simple.equals("SubList")) // too simple!
268			? k.getName().replaceFirst(".*\\.", "")
269			: simple;
270			});
271			}
272	jsr166	1.1
273	jsr166	1.26	String goodClassName(Object x) {
274			return goodClassName(x.getClass());
275			}
276
277	jsr166	1.22	static List<Integer> makeSubList(List<Integer> list) {
278	jsr166	1.1	final ThreadLocalRandom rnd = ThreadLocalRandom.current();
279	jsr166	1.22	int size = rnd.nextInt(4);
280			for (int i = size; i--> 0; )
281			list.add(rnd.nextInt());
282			int index = rnd.nextInt(size + 1);
283			return list.subList(index, index);
284			}
285
286			private static <T> List<T> asSubList(List<T> list) {
287			return list.subList(0, list.size());
288			}
289
290			@SafeVarargs @SuppressWarnings("varargs")
291	jsr166	1.25	private static <T> Stream<T> concatStreams(Stream<T> ... streams) {
292	jsr166	1.22	return Stream.of(streams).flatMap(s -> s);
293			}
294	jsr166	1.1
295	jsr166	1.22	Class<?> topLevelClass(Object x) {
296			for (Class<?> k = x.getClass();; ) {
297			Class<?> enclosing = k.getEnclosingClass();
298			if (enclosing == null)
299			return k;
300			k = enclosing;
301			}
302			}
303	jsr166	1.1
304	jsr166	1.22	void run() throws Throwable {
305			ArrayList<Job> jobs = Stream.<Collection<Integer>>of(
306			new ArrayList<>(),
307			makeSubList(new ArrayList<>()),
308			new LinkedList<>(),
309			makeSubList(new LinkedList<>()),
310			new Vector<>(),
311			makeSubList(new Vector<>()),
312			new CopyOnWriteArrayList<>(),
313			makeSubList(new CopyOnWriteArrayList<>()),
314			new ArrayDeque<>(),
315			new PriorityQueue<>(),
316			new ArrayBlockingQueue<>(elements.size()),
317			new ConcurrentLinkedQueue<>(),
318			new ConcurrentLinkedDeque<>(),
319			new LinkedBlockingQueue<>(),
320			new LinkedBlockingDeque<>(),
321			new LinkedTransferQueue<>(),
322			new PriorityBlockingQueue<>())
323			.flatMap(x -> jobs(x))
324			.filter(job ->
325			nameFilter == null \|\| nameFilter.matcher(job.name()).find())
326			.collect(toCollection(ArrayList::new));
327	jsr166	1.1
328	jsr166	1.5	if (reverse) Collections.reverse(jobs);
329			if (shuffle) Collections.shuffle(jobs);
330
331	jsr166	1.22	time(jobs);
332			}
333
334			Stream<Job> jobs(Collection<Integer> x) {
335			return concatStreams(
336			collectionJobs(x),
337
338			(CopyOnWriteArrayList.class.isAssignableFrom(topLevelClass(x)))
339			? Stream.empty()
340			: iteratorRemoveJobs(x),
341
342			(x instanceof Queue)
343			? queueJobs((Queue<Integer>)x)
344			: Stream.empty(),
345
346			(x instanceof Deque)
347			? dequeJobs((Deque<Integer>)x)
348			: Stream.empty(),
349
350			(x instanceof BlockingQueue)
351			? blockingQueueJobs((BlockingQueue<Integer>)x)
352			: Stream.empty(),
353
354			(x instanceof BlockingDeque)
355			? blockingDequeJobs((BlockingDeque<Integer>)x)
356			: Stream.empty());
357	jsr166	1.1	}
358
359			Collection<Integer> universeRecorder(int[] sum) {
360			return new ArrayList<>() {
361			public boolean contains(Object x) {
362			sum[0] += (Integer) x;
363			return true;
364			}};
365			}
366
367			Collection<Integer> emptyRecorder(int[] sum) {
368			return new ArrayList<>() {
369			public boolean contains(Object x) {
370			sum[0] += (Integer) x;
371			return false;
372			}};
373			}
374
375	jsr166	1.22	Stream<Job> collectionJobs(Collection<Integer> x) {
376	jsr166	1.26	final String klazz = goodClassName(x);
377	jsr166	1.22	return Stream.of(
378			new Job(klazz + " removeIf") {
379	jsr166	1.1	public void work() throws Throwable {
380			int[] sum = new int[1];
381			for (int i = 0; i < iterations; i++) {
382			sum[0] = 0;
383	jsr166	1.22	x.addAll(elements);
384	jsr166	1.1	x.removeIf(n -> { sum[0] += n; return true; });
385			check.sum(sum[0]);}}},
386	jsr166	1.22	new Job(klazz + " removeIf rnd-two-pass") {
387	jsr166	1.9	public void work() throws Throwable {
388			ThreadLocalRandom rnd = ThreadLocalRandom.current();
389			int[] sum = new int[1];
390			for (int i = 0; i < iterations; i++) {
391			sum[0] = 0;
392	jsr166	1.22	x.addAll(elements);
393	jsr166	1.9	x.removeIf(n -> {
394			boolean b = rnd.nextBoolean();
395			if (b) sum[0] += n;
396			return b; });
397			x.removeIf(n -> { sum[0] += n; return true; });
398			check.sum(sum[0]);}}},
399	jsr166	1.22	new Job(klazz + " removeAll") {
400	jsr166	1.1	public void work() throws Throwable {
401			int[] sum = new int[1];
402			Collection<Integer> universe = universeRecorder(sum);
403			for (int i = 0; i < iterations; i++) {
404			sum[0] = 0;
405	jsr166	1.22	x.addAll(elements);
406	jsr166	1.1	x.removeAll(universe);
407			check.sum(sum[0]);}}},
408	jsr166	1.22	new Job(klazz + " retainAll") {
409	jsr166	1.1	public void work() throws Throwable {
410			int[] sum = new int[1];
411			Collection<Integer> empty = emptyRecorder(sum);
412			for (int i = 0; i < iterations; i++) {
413			sum[0] = 0;
414	jsr166	1.22	x.addAll(elements);
415	jsr166	1.1	x.retainAll(empty);
416			check.sum(sum[0]);}}},
417	jsr166	1.22	new Job(klazz + " clear") {
418			public void work() throws Throwable {
419			int[] sum = new int[1];
420			for (int i = 0; i < iterations; i++) {
421			sum[0] = 0;
422			x.addAll(elements);
423			x.forEach(e -> sum[0] += e);
424			x.clear();
425			check.sum(sum[0]);}}});
426			}
427
428			Stream<Job> iteratorRemoveJobs(Collection<Integer> x) {
429	jsr166	1.26	final String klazz = goodClassName(x);
430	jsr166	1.22	return Stream.of(
431			new Job(klazz + " Iterator.remove") {
432	jsr166	1.1	public void work() throws Throwable {
433			int[] sum = new int[1];
434			for (int i = 0; i < iterations; i++) {
435			sum[0] = 0;
436	jsr166	1.22	x.addAll(elements);
437	jsr166	1.1	Iterator<Integer> it = x.iterator();
438			while (it.hasNext()) {
439			sum[0] += it.next();
440			it.remove();
441			}
442			check.sum(sum[0]);}}},
443	jsr166	1.22	new Job(klazz + " Iterator.remove-rnd-two-pass") {
444	jsr166	1.10	public void work() throws Throwable {
445			ThreadLocalRandom rnd = ThreadLocalRandom.current();
446			int[] sum = new int[1];
447			for (int i = 0; i < iterations; i++) {
448			sum[0] = 0;
449	jsr166	1.22	x.addAll(elements);
450	jsr166	1.12	for (Iterator<Integer> it = x.iterator();
451			it.hasNext(); ) {
452			Integer e = it.next();
453	jsr166	1.10	if (rnd.nextBoolean()) {
454	jsr166	1.12	sum[0] += e;
455	jsr166	1.10	it.remove();
456			}
457			}
458	jsr166	1.12	for (Iterator<Integer> it = x.iterator();
459			it.hasNext(); ) {
460	jsr166	1.10	sum[0] += it.next();
461			it.remove();
462			}
463	jsr166	1.1	check.sum(sum[0]);}}});
464			}
465
466	jsr166	1.22	Stream<Job> queueJobs(Queue<Integer> x) {
467	jsr166	1.26	final String klazz = goodClassName(x);
468	jsr166	1.22	return Stream.of(
469			new Job(klazz + " poll()") {
470	jsr166	1.8	public void work() throws Throwable {
471			int[] sum = new int[1];
472			for (int i = 0; i < iterations; i++) {
473			sum[0] = 0;
474	jsr166	1.22	x.addAll(elements);
475	jsr166	1.8	for (Integer e; (e = x.poll()) != null; )
476			sum[0] += e;
477			check.sum(sum[0]);}}});
478			}
479
480	jsr166	1.22	Stream<Job> dequeJobs(Deque<Integer> x) {
481	jsr166	1.26	final String klazz = goodClassName(x);
482	jsr166	1.22	return Stream.of(
483			new Job(klazz + " descendingIterator().remove") {
484	jsr166	1.1	public void work() throws Throwable {
485			int[] sum = new int[1];
486			for (int i = 0; i < iterations; i++) {
487			sum[0] = 0;
488	jsr166	1.22	x.addAll(elements);
489	jsr166	1.1	Iterator<Integer> it = x.descendingIterator();
490			while (it.hasNext()) {
491			sum[0] += it.next();
492			it.remove();
493			}
494	jsr166	1.6	check.sum(sum[0]);}}},
495	jsr166	1.22	new Job(klazz + " pollFirst()") {
496	jsr166	1.6	public void work() throws Throwable {
497			int[] sum = new int[1];
498			for (int i = 0; i < iterations; i++) {
499			sum[0] = 0;
500	jsr166	1.22	x.addAll(elements);
501	jsr166	1.6	for (Integer e; (e = x.pollFirst()) != null; )
502			sum[0] += e;
503			check.sum(sum[0]);}}},
504	jsr166	1.22	new Job(klazz + " pollLast()") {
505	jsr166	1.6	public void work() throws Throwable {
506			int[] sum = new int[1];
507			for (int i = 0; i < iterations; i++) {
508			sum[0] = 0;
509	jsr166	1.22	x.addAll(elements);
510	jsr166	1.6	for (Integer e; (e = x.pollLast()) != null; )
511			sum[0] += e;
512	jsr166	1.1	check.sum(sum[0]);}}});
513			}
514	jsr166	1.3
515	jsr166	1.22	Stream<Job> blockingQueueJobs(BlockingQueue<Integer> x) {
516	jsr166	1.26	final String klazz = goodClassName(x);
517	jsr166	1.22	return Stream.of(
518	jsr166	1.23	new Job(klazz + " timed poll()") {
519			public void work() throws Throwable {
520			int[] sum = new int[1];
521			for (int i = 0; i < iterations; i++) {
522			sum[0] = 0;
523			x.addAll(elements);
524			for (Integer e; (e = x.poll(0L, TimeUnit.DAYS)) != null; )
525			sum[0] += e;
526			check.sum(sum[0]);}}},
527	jsr166	1.22	new Job(klazz + " drainTo(sink)") {
528	jsr166	1.3	public void work() throws Throwable {
529			ArrayList<Integer> sink = new ArrayList<>();
530			int[] sum = new int[1];
531			for (int i = 0; i < iterations; i++) {
532			sum[0] = 0;
533			sink.clear();
534	jsr166	1.22	x.addAll(elements);
535	jsr166	1.3	x.drainTo(sink);
536			sink.forEach(e -> sum[0] += e);
537			check.sum(sum[0]);}}},
538	jsr166	1.22	new Job(klazz + " drainTo(sink, n)") {
539	jsr166	1.3	public void work() throws Throwable {
540			ArrayList<Integer> sink = new ArrayList<>();
541			int[] sum = new int[1];
542			for (int i = 0; i < iterations; i++) {
543			sum[0] = 0;
544			sink.clear();
545	jsr166	1.22	x.addAll(elements);
546			x.drainTo(sink, elements.size());
547	jsr166	1.3	sink.forEach(e -> sum[0] += e);
548			check.sum(sum[0]);}}});
549			}
550	jsr166	1.7
551	jsr166	1.22	Stream<Job> blockingDequeJobs(BlockingDeque<Integer> x) {
552	jsr166	1.26	final String klazz = goodClassName(x);
553	jsr166	1.22	return Stream.of(
554			new Job(klazz + " timed pollFirst()") {
555	jsr166	1.7	public void work() throws Throwable {
556			int[] sum = new int[1];
557			for (int i = 0; i < iterations; i++) {
558			sum[0] = 0;
559	jsr166	1.22	x.addAll(elements);
560	jsr166	1.7	for (Integer e; (e = x.pollFirst(0L, TimeUnit.DAYS)) != null; )
561			sum[0] += e;
562			check.sum(sum[0]);}}},
563	jsr166	1.22	new Job(klazz + " timed pollLast()") {
564	jsr166	1.7	public void work() throws Throwable {
565			int[] sum = new int[1];
566			for (int i = 0; i < iterations; i++) {
567			sum[0] = 0;
568	jsr166	1.22	x.addAll(elements);
569	jsr166	1.7	for (Integer e; (e = x.pollLast(0L, TimeUnit.DAYS)) != null; )
570			sum[0] += e;
571			check.sum(sum[0]);}}});
572			}
573	jsr166	1.1	}