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 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.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.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.function.Supplier;

/**
 * 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;
    }

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

    RemoveMicroBenchmark(String[] args) {
        iterations    = intArg(args, "iterations", 10_000);
        size          = intArg(args, "size", 1000);
        warmupSeconds = doubleArg(args, "warmup", 7.0);
        filter        = 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() {
            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) throws Throwable {
        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.work(); 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 List<Job> filter(Pattern filter, List<Job> jobs) {
        if (filter == null) return jobs;
        ArrayList<Job> newJobs = new ArrayList<>();
        for (Job job : jobs)
            if (filter.matcher(job.name()).find())
                newJobs.add(job);
        return newJobs;
    }

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

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

    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();
    }

    void run() throws Throwable {
//         System.out.printf(
//             "iterations=%d size=%d, warmup=%1g, filter=\"%s\"%n",
//             iterations, size, warmupSeconds, filter);

        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));

        ArrayList<Job> jobs = new ArrayList<>();

        List.<Collection<Integer>>of(
            new ArrayList<>(),
            new LinkedList<>(),
            new Vector<>(),
            new ArrayDeque<>(),
            new PriorityQueue<>(),
            new ArrayBlockingQueue<>(al.size()),
            new ConcurrentLinkedQueue<>(),
            new ConcurrentLinkedDeque<>(),
            new LinkedBlockingQueue<>(),
            new LinkedBlockingDeque<>(),
            new LinkedTransferQueue<>(),
            new PriorityBlockingQueue<>()).forEach(
                x -> {
                    String klazz = x.getClass().getSimpleName();
                    jobs.addAll(collectionJobs(klazz, () -> x, al));
                    if (x instanceof Queue) {
                        Queue<Integer> queue = (Queue<Integer>) x;
                        jobs.addAll(queueJobs(klazz, () -> queue, al));
                    }
                    if (x instanceof Deque) {
                        Deque<Integer> deque = (Deque<Integer>) x;
                        jobs.addAll(dequeJobs(klazz, () -> deque, al));
                    }
                    if (x instanceof BlockingQueue) {
                        BlockingQueue<Integer> q = (BlockingQueue<Integer>) x;
                        jobs.addAll(blockingQueueJobs(klazz, () -> q, al));
                    }
                    if (x instanceof BlockingDeque) {
                        BlockingDeque<Integer> q = (BlockingDeque<Integer>) x;
                        jobs.addAll(blockingDequeJobs(klazz, () -> q, al));
                    }
                    if (x instanceof List) {
                        List<Integer> list = (List<Integer>) x;
                        jobs.addAll(
                            collectionJobs(
                                klazz + " subList",
                                () -> list.subList(0, x.size()),
                                al));
                    }
                });

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

        time(filter(filter, jobs));
    }

    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;
            }};
    }

    List<Job> collectionJobs(
        String description,
        Supplier<Collection<Integer>> supplier,
        ArrayList<Integer> al) {
        return List.of(
            new Job(description + " removeIf") {
                public void work() throws Throwable {
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        x.removeIf(n -> { sum[0] += n; return true; });
                        check.sum(sum[0]);}}},
            new Job(description + " removeIf rnd-two-pass") {
                public void work() throws Throwable {
                    ThreadLocalRandom rnd = ThreadLocalRandom.current();
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        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(description + " removeAll") {
                public void work() throws Throwable {
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    Collection<Integer> universe = universeRecorder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        x.removeAll(universe);
                        check.sum(sum[0]);}}},
            new Job(description + " retainAll") {
                public void work() throws Throwable {
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    Collection<Integer> empty = emptyRecorder(sum);
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        x.retainAll(empty);
                        check.sum(sum[0]);}}},
            new Job(description + " Iterator.remove") {
                public void work() throws Throwable {
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        Iterator<Integer> it = x.iterator();
                        while (it.hasNext()) {
                            sum[0] += it.next();
                            it.remove();
                        }
                        check.sum(sum[0]);}}},
            new Job(description + " Iterator.remove-rnd-two-pass") {
                public void work() throws Throwable {
                    ThreadLocalRandom rnd = ThreadLocalRandom.current();
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        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]);}}},
            new Job(description + " clear") {
                public void work() throws Throwable {
                    Collection<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        x.forEach(e -> sum[0] += e);
                        x.clear();
                        check.sum(sum[0]);}}});
    }

    List<Job> queueJobs(
        String description,
        Supplier<Queue<Integer>> supplier,
        ArrayList<Integer> al) {
        return List.of(
            new Job(description + " poll()") {
                public void work() throws Throwable {
                    Queue<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        for (Integer e; (e = x.poll()) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}});
    }

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

    List<Job> blockingQueueJobs(
        String description,
        Supplier<BlockingQueue<Integer>> supplier,
        ArrayList<Integer> al) {
        return List.of(
            new Job(description + " drainTo(sink)") {
                public void work() throws Throwable {
                    BlockingQueue<Integer> x = supplier.get();
                    ArrayList<Integer> sink = new ArrayList<>();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        sink.clear();
                        x.addAll(al);
                        x.drainTo(sink);
                        sink.forEach(e -> sum[0] += e);
                        check.sum(sum[0]);}}},
            new Job(description + " drainTo(sink, n)") {
                public void work() throws Throwable {
                    BlockingQueue<Integer> x = supplier.get();
                    ArrayList<Integer> sink = new ArrayList<>();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        sink.clear();
                        x.addAll(al);
                        x.drainTo(sink, al.size());
                        sink.forEach(e -> sum[0] += e);
                        check.sum(sum[0]);}}});
    }

    List<Job> blockingDequeJobs(
        String description,
        Supplier<BlockingDeque<Integer>> supplier,
        ArrayList<Integer> al) {
        return List.of(
            new Job(description + " timed pollFirst()") {
                public void work() throws Throwable {
                    BlockingDeque<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        for (Integer e; (e = x.pollFirst(0L, TimeUnit.DAYS)) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}},
            new Job(description + " timed pollLast()") {
                public void work() throws Throwable {
                    BlockingDeque<Integer> x = supplier.get();
                    int[] sum = new int[1];
                    for (int i = 0; i < iterations; i++) {
                        sum[0] = 0;
                        x.addAll(al);
                        for (Integer e; (e = x.pollLast(0L, TimeUnit.DAYS)) != null; )
                            sum[0] += e;
                        check.sum(sum[0]);}}});
    }
}
Revision:	1.19
Committed:	Sun Jan 7 20:19:00 2018 UTC (6 years, 5 months ago) by jsr166
Branch:	MAIN
Changes since 1.18:	+1 -2 lines
Log Message:	simplify c.stream().forEach to c.forEach
#	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			import java.lang.ref.WeakReference;
31			import java.util.ArrayDeque;
32			import java.util.ArrayList;
33			import java.util.Collection;
34	jsr166	1.5	import java.util.Collections;
35	jsr166	1.1	import java.util.Deque;
36			import java.util.Iterator;
37			import java.util.LinkedList;
38			import java.util.List;
39			import java.util.ListIterator;
40	jsr166	1.2	import java.util.PriorityQueue;
41	jsr166	1.8	import java.util.Queue;
42	jsr166	1.1	import java.util.Vector;
43			import java.util.concurrent.ArrayBlockingQueue;
44	jsr166	1.7	import java.util.concurrent.BlockingDeque;
45	jsr166	1.3	import java.util.concurrent.BlockingQueue;
46	jsr166	1.1	import java.util.concurrent.ConcurrentLinkedDeque;
47			import java.util.concurrent.ConcurrentLinkedQueue;
48	jsr166	1.2	import java.util.concurrent.CountDownLatch;
49	jsr166	1.1	import java.util.concurrent.LinkedBlockingDeque;
50			import java.util.concurrent.LinkedBlockingQueue;
51			import java.util.concurrent.LinkedTransferQueue;
52	jsr166	1.2	import java.util.concurrent.PriorityBlockingQueue;
53	jsr166	1.1	import java.util.concurrent.ThreadLocalRandom;
54			import java.util.concurrent.TimeUnit;
55			import java.util.regex.Pattern;
56			import java.util.function.Supplier;
57
58			/**
59			* Usage: [iterations=N] [size=N] [filter=REGEXP] [warmup=SECONDS]
60			*
61			* To run this in micro-benchmark mode, simply run as a normal java program.
62			* Be patient; this program runs for a very long time.
63			* For faster runs, restrict execution using command line args.
64			*
65			* @author Martin Buchholz
66			*/
67			public class RemoveMicroBenchmark {
68			abstract static class Job {
69			private final String name;
70			public Job(String name) { this.name = name; }
71			public String name() { return name; }
72			public abstract void work() throws Throwable;
73			}
74
75	jsr166	1.5	final int iterations;
76			final int size; // number of elements in collections
77			final double warmupSeconds;
78			final long warmupNanos;
79			final Pattern filter; // select subset of Jobs to run
80			final boolean reverse; // reverse order of Jobs
81			final boolean shuffle; // randomize order of Jobs
82
83			RemoveMicroBenchmark(String[] args) {
84			iterations = intArg(args, "iterations", 10_000);
85			size = intArg(args, "size", 1000);
86			warmupSeconds = doubleArg(args, "warmup", 7.0);
87			filter = patternArg(args, "filter");
88			reverse = booleanArg(args, "reverse");
89			shuffle = booleanArg(args, "shuffle");
90
91			warmupNanos = (long) (warmupSeconds * (1000L * 1000L * 1000L));
92			}
93	jsr166	1.1
94			// --------------- GC finalization infrastructure ---------------
95
96			/** No guarantees, but effective in practice. */
97			static void forceFullGc() {
98			CountDownLatch finalizeDone = new CountDownLatch(1);
99			WeakReference<?> ref = new WeakReference<Object>(new Object() {
100			protected void finalize() { finalizeDone.countDown(); }});
101			try {
102			for (int i = 0; i < 10; i++) {
103			System.gc();
104			if (finalizeDone.await(1L, TimeUnit.SECONDS) && ref.get() == null) {
105			System.runFinalization(); // try to pick up stragglers
106			return;
107			}
108			}
109			} catch (InterruptedException unexpected) {
110			throw new AssertionError("unexpected InterruptedException");
111			}
112			throw new AssertionError("failed to do a \"full\" gc");
113			}
114
115			/**
116			* Runs each job for long enough that all the runtime compilers
117			* have had plenty of time to warm up, i.e. get around to
118			* compiling everything worth compiling.
119			* Returns array of average times per job per run.
120			*/
121			long[] time0(List<Job> jobs) throws Throwable {
122			final int size = jobs.size();
123			long[] nanoss = new long[size];
124			for (int i = 0; i < size; i++) {
125			if (warmupNanos > 0) forceFullGc();
126	jsr166	1.4	Job job = jobs.get(i);
127			long totalTime;
128			int runs = 0;
129			long startTime = System.nanoTime();
130			do { job.work(); runs++; }
131			while ((totalTime = System.nanoTime() - startTime) < warmupNanos);
132			nanoss[i] = totalTime/runs;
133	jsr166	1.1	}
134			return nanoss;
135			}
136
137			void time(List<Job> jobs) throws Throwable {
138	jsr166	1.4	if (warmupNanos > 0) time0(jobs); // Warm up run
139	jsr166	1.1	final int size = jobs.size();
140			final long[] nanoss = time0(jobs); // Real timing run
141			final long[] milliss = new long[size];
142			final double[] ratios = new double[size];
143
144			final String nameHeader = "Method";
145			final String millisHeader = "Millis";
146			final String ratioHeader = "Ratio";
147
148			int nameWidth = nameHeader.length();
149			int millisWidth = millisHeader.length();
150			int ratioWidth = ratioHeader.length();
151
152			for (int i = 0; i < size; i++) {
153			nameWidth = Math.max(nameWidth, jobs.get(i).name().length());
154
155			milliss[i] = nanoss[i]/(1000L * 1000L);
156			millisWidth = Math.max(millisWidth,
157			String.format("%d", milliss[i]).length());
158
159			ratios[i] = (double) nanoss[i] / (double) nanoss[0];
160			ratioWidth = Math.max(ratioWidth,
161			String.format("%.3f", ratios[i]).length());
162			}
163
164			String format = String.format("%%-%ds %%%dd %%%d.3f%%n",
165			nameWidth, millisWidth, ratioWidth);
166			String headerFormat = String.format("%%-%ds %%%ds %%%ds%%n",
167			nameWidth, millisWidth, ratioWidth);
168			System.out.printf(headerFormat, "Method", "Millis", "Ratio");
169
170			// Print out absolute and relative times, calibrated against first job
171			for (int i = 0; i < size; i++)
172			System.out.printf(format, jobs.get(i).name(), milliss[i], ratios[i]);
173			}
174
175			private static String keywordValue(String[] args, String keyword) {
176			for (String arg : args)
177			if (arg.startsWith(keyword))
178			return arg.substring(keyword.length() + 1);
179			return null;
180			}
181
182			private static int intArg(String[] args, String keyword, int defaultValue) {
183			String val = keywordValue(args, keyword);
184			return (val == null) ? defaultValue : Integer.parseInt(val);
185			}
186
187			private static double doubleArg(String[] args, String keyword, double defaultValue) {
188			String val = keywordValue(args, keyword);
189			return (val == null) ? defaultValue : Double.parseDouble(val);
190			}
191
192			private static Pattern patternArg(String[] args, String keyword) {
193			String val = keywordValue(args, keyword);
194			return (val == null) ? null : Pattern.compile(val);
195			}
196
197	jsr166	1.5	private static boolean booleanArg(String[] args, String keyword) {
198			String val = keywordValue(args, keyword);
199			if (val == null \|\| val.equals("false")) return false;
200			if (val.equals("true")) return true;
201			throw new IllegalArgumentException(val);
202			}
203
204	jsr166	1.1	private static List<Job> filter(Pattern filter, List<Job> jobs) {
205			if (filter == null) return jobs;
206			ArrayList<Job> newJobs = new ArrayList<>();
207			for (Job job : jobs)
208			if (filter.matcher(job.name()).find())
209			newJobs.add(job);
210			return newJobs;
211			}
212
213			private static void deoptimize(int sum) {
214			if (sum == 42)
215			System.out.println("the answer");
216			}
217
218			private static <T> List<T> asSubList(List<T> list) {
219			return list.subList(0, list.size());
220			}
221
222			private static <T> Iterable<T> backwards(final List<T> list) {
223			return new Iterable<T>() {
224			public Iterator<T> iterator() {
225			return new Iterator<T>() {
226			final ListIterator<T> it = list.listIterator(list.size());
227			public boolean hasNext() { return it.hasPrevious(); }
228			public T next() { return it.previous(); }
229			public void remove() { it.remove(); }};}};
230			}
231
232			// Checks for correctness and prevents loop optimizations
233	jsr166	1.18	static class Check {
234	jsr166	1.1	private int sum;
235			public void sum(int sum) {
236			if (this.sum == 0)
237			this.sum = sum;
238			if (this.sum != sum)
239			throw new AssertionError("Sum mismatch");
240			}
241			}
242			volatile Check check = new Check();
243
244			public static void main(String[] args) throws Throwable {
245	jsr166	1.5	new RemoveMicroBenchmark(args).run();
246	jsr166	1.1	}
247
248	jsr166	1.5	void run() throws Throwable {
249	jsr166	1.1	// System.out.printf(
250			// "iterations=%d size=%d, warmup=%1g, filter=\"%s\"%n",
251			// iterations, size, warmupSeconds, filter);
252
253	jsr166	1.13	final ArrayList<Integer> al = new ArrayList<>(size);
254	jsr166	1.1
255			// Populate collections with random data
256			final ThreadLocalRandom rnd = ThreadLocalRandom.current();
257			for (int i = 0; i < size; i++)
258			al.add(rnd.nextInt(size));
259
260			ArrayList<Job> jobs = new ArrayList<>();
261
262			List.<Collection<Integer>>of(
263			new ArrayList<>(),
264			new LinkedList<>(),
265			new Vector<>(),
266			new ArrayDeque<>(),
267	jsr166	1.2	new PriorityQueue<>(),
268	jsr166	1.1	new ArrayBlockingQueue<>(al.size()),
269			new ConcurrentLinkedQueue<>(),
270			new ConcurrentLinkedDeque<>(),
271			new LinkedBlockingQueue<>(),
272			new LinkedBlockingDeque<>(),
273	jsr166	1.2	new LinkedTransferQueue<>(),
274	jsr166	1.19	new PriorityBlockingQueue<>()).forEach(
275	jsr166	1.1	x -> {
276			String klazz = x.getClass().getSimpleName();
277			jobs.addAll(collectionJobs(klazz, () -> x, al));
278	jsr166	1.8	if (x instanceof Queue) {
279			Queue<Integer> queue = (Queue<Integer>) x;
280			jobs.addAll(queueJobs(klazz, () -> queue, al));
281			}
282	jsr166	1.1	if (x instanceof Deque) {
283			Deque<Integer> deque = (Deque<Integer>) x;
284			jobs.addAll(dequeJobs(klazz, () -> deque, al));
285			}
286	jsr166	1.3	if (x instanceof BlockingQueue) {
287			BlockingQueue<Integer> q = (BlockingQueue<Integer>) x;
288			jobs.addAll(blockingQueueJobs(klazz, () -> q, al));
289			}
290	jsr166	1.7	if (x instanceof BlockingDeque) {
291			BlockingDeque<Integer> q = (BlockingDeque<Integer>) x;
292			jobs.addAll(blockingDequeJobs(klazz, () -> q, al));
293			}
294	jsr166	1.1	if (x instanceof List) {
295			List<Integer> list = (List<Integer>) x;
296			jobs.addAll(
297			collectionJobs(
298			klazz + " subList",
299			() -> list.subList(0, x.size()),
300			al));
301			}
302			});
303
304	jsr166	1.5	if (reverse) Collections.reverse(jobs);
305			if (shuffle) Collections.shuffle(jobs);
306
307	jsr166	1.1	time(filter(filter, jobs));
308			}
309
310			Collection<Integer> universeRecorder(int[] sum) {
311			return new ArrayList<>() {
312			public boolean contains(Object x) {
313			sum[0] += (Integer) x;
314			return true;
315			}};
316			}
317
318			Collection<Integer> emptyRecorder(int[] sum) {
319			return new ArrayList<>() {
320			public boolean contains(Object x) {
321			sum[0] += (Integer) x;
322			return false;
323			}};
324			}
325
326			List<Job> collectionJobs(
327			String description,
328			Supplier<Collection<Integer>> supplier,
329			ArrayList<Integer> al) {
330			return List.of(
331	jsr166	1.14	new Job(description + " removeIf") {
332	jsr166	1.1	public void work() throws Throwable {
333			Collection<Integer> x = supplier.get();
334			int[] sum = new int[1];
335			for (int i = 0; i < iterations; i++) {
336			sum[0] = 0;
337			x.addAll(al);
338			x.removeIf(n -> { sum[0] += n; return true; });
339			check.sum(sum[0]);}}},
340	jsr166	1.14	new Job(description + " removeIf rnd-two-pass") {
341	jsr166	1.9	public void work() throws Throwable {
342			ThreadLocalRandom rnd = ThreadLocalRandom.current();
343			Collection<Integer> x = supplier.get();
344			int[] sum = new int[1];
345			for (int i = 0; i < iterations; i++) {
346			sum[0] = 0;
347			x.addAll(al);
348			x.removeIf(n -> {
349			boolean b = rnd.nextBoolean();
350			if (b) sum[0] += n;
351			return b; });
352			x.removeIf(n -> { sum[0] += n; return true; });
353			check.sum(sum[0]);}}},
354	jsr166	1.14	new Job(description + " removeAll") {
355	jsr166	1.1	public void work() throws Throwable {
356			Collection<Integer> x = supplier.get();
357			int[] sum = new int[1];
358			Collection<Integer> universe = universeRecorder(sum);
359			for (int i = 0; i < iterations; i++) {
360			sum[0] = 0;
361			x.addAll(al);
362			x.removeAll(universe);
363			check.sum(sum[0]);}}},
364	jsr166	1.14	new Job(description + " retainAll") {
365	jsr166	1.1	public void work() throws Throwable {
366			Collection<Integer> x = supplier.get();
367			int[] sum = new int[1];
368			Collection<Integer> empty = emptyRecorder(sum);
369			for (int i = 0; i < iterations; i++) {
370			sum[0] = 0;
371			x.addAll(al);
372			x.retainAll(empty);
373			check.sum(sum[0]);}}},
374			new Job(description + " Iterator.remove") {
375			public void work() throws Throwable {
376			Collection<Integer> x = supplier.get();
377			int[] sum = new int[1];
378			for (int i = 0; i < iterations; i++) {
379			sum[0] = 0;
380			x.addAll(al);
381			Iterator<Integer> it = x.iterator();
382			while (it.hasNext()) {
383			sum[0] += it.next();
384			it.remove();
385			}
386			check.sum(sum[0]);}}},
387	jsr166	1.10	new Job(description + " Iterator.remove-rnd-two-pass") {
388			public void work() throws Throwable {
389			ThreadLocalRandom rnd = ThreadLocalRandom.current();
390			Collection<Integer> x = supplier.get();
391			int[] sum = new int[1];
392			for (int i = 0; i < iterations; i++) {
393			sum[0] = 0;
394			x.addAll(al);
395	jsr166	1.12	for (Iterator<Integer> it = x.iterator();
396			it.hasNext(); ) {
397			Integer e = it.next();
398	jsr166	1.10	if (rnd.nextBoolean()) {
399	jsr166	1.12	sum[0] += e;
400	jsr166	1.10	it.remove();
401			}
402			}
403	jsr166	1.12	for (Iterator<Integer> it = x.iterator();
404			it.hasNext(); ) {
405	jsr166	1.10	sum[0] += it.next();
406			it.remove();
407			}
408			check.sum(sum[0]);}}},
409	jsr166	1.1	new Job(description + " clear") {
410			public void work() throws Throwable {
411			Collection<Integer> x = supplier.get();
412			int[] sum = new int[1];
413			for (int i = 0; i < iterations; i++) {
414			sum[0] = 0;
415			x.addAll(al);
416			x.forEach(e -> sum[0] += e);
417			x.clear();
418			check.sum(sum[0]);}}});
419			}
420
421	jsr166	1.8	List<Job> queueJobs(
422			String description,
423			Supplier<Queue<Integer>> supplier,
424			ArrayList<Integer> al) {
425			return List.of(
426			new Job(description + " poll()") {
427			public void work() throws Throwable {
428			Queue<Integer> x = supplier.get();
429			int[] sum = new int[1];
430			for (int i = 0; i < iterations; i++) {
431			sum[0] = 0;
432			x.addAll(al);
433			for (Integer e; (e = x.poll()) != null; )
434			sum[0] += e;
435			check.sum(sum[0]);}}});
436			}
437
438	jsr166	1.1	List<Job> dequeJobs(
439			String description,
440			Supplier<Deque<Integer>> supplier,
441			ArrayList<Integer> al) {
442			return List.of(
443			new Job(description + " descendingIterator().remove") {
444			public void work() throws Throwable {
445			Deque<Integer> x = supplier.get();
446			int[] sum = new int[1];
447			for (int i = 0; i < iterations; i++) {
448			sum[0] = 0;
449			x.addAll(al);
450			Iterator<Integer> it = x.descendingIterator();
451			while (it.hasNext()) {
452			sum[0] += it.next();
453			it.remove();
454			}
455	jsr166	1.6	check.sum(sum[0]);}}},
456			new Job(description + " pollFirst()") {
457			public void work() throws Throwable {
458			Deque<Integer> x = supplier.get();
459			int[] sum = new int[1];
460			for (int i = 0; i < iterations; i++) {
461			sum[0] = 0;
462			x.addAll(al);
463			for (Integer e; (e = x.pollFirst()) != null; )
464			sum[0] += e;
465			check.sum(sum[0]);}}},
466			new Job(description + " pollLast()") {
467			public void work() throws Throwable {
468			Deque<Integer> x = supplier.get();
469			int[] sum = new int[1];
470			for (int i = 0; i < iterations; i++) {
471			sum[0] = 0;
472			x.addAll(al);
473			for (Integer e; (e = x.pollLast()) != null; )
474			sum[0] += e;
475	jsr166	1.1	check.sum(sum[0]);}}});
476			}
477	jsr166	1.3
478			List<Job> blockingQueueJobs(
479			String description,
480			Supplier<BlockingQueue<Integer>> supplier,
481			ArrayList<Integer> al) {
482			return List.of(
483			new Job(description + " drainTo(sink)") {
484			public void work() throws Throwable {
485			BlockingQueue<Integer> x = supplier.get();
486			ArrayList<Integer> sink = new ArrayList<>();
487			int[] sum = new int[1];
488			for (int i = 0; i < iterations; i++) {
489			sum[0] = 0;
490			sink.clear();
491			x.addAll(al);
492			x.drainTo(sink);
493			sink.forEach(e -> sum[0] += e);
494			check.sum(sum[0]);}}},
495			new Job(description + " drainTo(sink, n)") {
496			public void work() throws Throwable {
497			BlockingQueue<Integer> x = supplier.get();
498			ArrayList<Integer> sink = new ArrayList<>();
499			int[] sum = new int[1];
500			for (int i = 0; i < iterations; i++) {
501			sum[0] = 0;
502			sink.clear();
503			x.addAll(al);
504			x.drainTo(sink, al.size());
505			sink.forEach(e -> sum[0] += e);
506			check.sum(sum[0]);}}});
507			}
508	jsr166	1.7
509			List<Job> blockingDequeJobs(
510			String description,
511			Supplier<BlockingDeque<Integer>> supplier,
512			ArrayList<Integer> al) {
513			return List.of(
514			new Job(description + " timed pollFirst()") {
515			public void work() throws Throwable {
516			BlockingDeque<Integer> x = supplier.get();
517			int[] sum = new int[1];
518			for (int i = 0; i < iterations; i++) {
519			sum[0] = 0;
520			x.addAll(al);
521			for (Integer e; (e = x.pollFirst(0L, TimeUnit.DAYS)) != null; )
522			sum[0] += e;
523			check.sum(sum[0]);}}},
524			new Job(description + " timed pollLast()") {
525			public void work() throws Throwable {
526			BlockingDeque<Integer> x = supplier.get();
527			int[] sum = new int[1];
528			for (int i = 0; i < iterations; i++) {
529			sum[0] = 0;
530			x.addAll(al);
531			for (Integer e; (e = x.pollLast(0L, TimeUnit.DAYS)) != null; )
532			sum[0] += e;
533			check.sum(sum[0]);}}});
534			}
535	jsr166	1.1	}