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.Arrays;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Deque;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
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.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.CountDownLatch;
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;
    }

    int iterations;
    int size;
    double warmupSeconds;
    Pattern filter;

    // --------------- 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 long warmupNanos = (long) (warmupSeconds * 1000L * 1000L * 1000L);
        final int size = jobs.size();
        long[] nanoss = new long[size];
        for (int i = 0; i < size; i++) {
            if (warmupNanos > 0) forceFullGc();
            long t0 = System.nanoTime();
            long t;
            int j = 0;
            do { jobs.get(i).work(); j++; }
            while ((t = System.nanoTime() - t0) < warmupNanos);
            nanoss[i] = t/j;
        }
        return nanoss;
    }

    void time(List<Job> jobs) throws Throwable {
        if (warmupSeconds > 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 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
    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().run(args);
    }

    void run(String[] args) throws Throwable {
        iterations    = intArg(args, "iterations", 10_000);
        size          = intArg(args, "size", 1000);
        warmupSeconds = doubleArg(args, "warmup", 5);
        filter        = patternArg(args, "filter");
//         System.out.printf(
//             "iterations=%d size=%d, warmup=%1g, filter=\"%s\"%n",
//             iterations, size, warmupSeconds, filter);

        final ArrayList<Integer> al = new ArrayList<Integer>(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 ArrayBlockingQueue<>(al.size()),
            new ConcurrentLinkedQueue<>(),
            new ConcurrentLinkedDeque<>(),
            new LinkedBlockingQueue<>(),
            new LinkedBlockingDeque<>(),
            new LinkedTransferQueue<>())
            .stream().forEach(
                x -> {
                    String klazz = x.getClass().getSimpleName();
                    jobs.addAll(collectionJobs(klazz, () -> x, al));
                    if (x instanceof Deque) {
                        Deque<Integer> deque = (Deque<Integer>) x;
                        jobs.addAll(dequeJobs(klazz, () -> deque, al));
                    }
                    if (x instanceof List) {
                        List<Integer> list = (List<Integer>) x;
                        jobs.addAll(
                            collectionJobs(
                                klazz + " subList",
                                () -> list.subList(0, x.size()),
                                al));
                    }
                });

        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 + " .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 + " 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> 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]);}}});
    }
}
Revision:	1.1
Committed:	Sun Nov 13 18:57:46 2016 UTC (7 years, 6 months ago) by jsr166
Branch:	MAIN
Log Message:	add RemoveMicroBenchmark
#	Content
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.Arrays;
33	import java.util.ArrayList;
34	import java.util.Collection;
35	import java.util.Deque;
36	import java.util.Enumeration;
37	import java.util.Iterator;
38	import java.util.LinkedList;
39	import java.util.List;
40	import java.util.ListIterator;
41	import java.util.Map;
42	import java.util.Spliterator;
43	import java.util.Vector;
44	import java.util.concurrent.ArrayBlockingQueue;
45	import java.util.concurrent.ConcurrentLinkedDeque;
46	import java.util.concurrent.ConcurrentLinkedQueue;
47	import java.util.concurrent.LinkedBlockingDeque;
48	import java.util.concurrent.LinkedBlockingQueue;
49	import java.util.concurrent.LinkedTransferQueue;
50	import java.util.concurrent.ConcurrentSkipListMap;
51	import java.util.concurrent.CountDownLatch;
52	import java.util.concurrent.ThreadLocalRandom;
53	import java.util.concurrent.TimeUnit;
54	import java.util.regex.Pattern;
55	import java.util.function.Supplier;
56
57	/**
58	* Usage: [iterations=N] [size=N] [filter=REGEXP] [warmup=SECONDS]
59	*
60	* To run this in micro-benchmark mode, simply run as a normal java program.
61	* Be patient; this program runs for a very long time.
62	* For faster runs, restrict execution using command line args.
63	*
64	* @author Martin Buchholz
65	*/
66	public class RemoveMicroBenchmark {
67	abstract static class Job {
68	private final String name;
69	public Job(String name) { this.name = name; }
70	public String name() { return name; }
71	public abstract void work() throws Throwable;
72	}
73
74	int iterations;
75	int size;
76	double warmupSeconds;
77	Pattern filter;
78
79	// --------------- GC finalization infrastructure ---------------
80
81	/** No guarantees, but effective in practice. */
82	static void forceFullGc() {
83	CountDownLatch finalizeDone = new CountDownLatch(1);
84	WeakReference<?> ref = new WeakReference<Object>(new Object() {
85	protected void finalize() { finalizeDone.countDown(); }});
86	try {
87	for (int i = 0; i < 10; i++) {
88	System.gc();
89	if (finalizeDone.await(1L, TimeUnit.SECONDS) && ref.get() == null) {
90	System.runFinalization(); // try to pick up stragglers
91	return;
92	}
93	}
94	} catch (InterruptedException unexpected) {
95	throw new AssertionError("unexpected InterruptedException");
96	}
97	throw new AssertionError("failed to do a \"full\" gc");
98	}
99
100	/**
101	* Runs each job for long enough that all the runtime compilers
102	* have had plenty of time to warm up, i.e. get around to
103	* compiling everything worth compiling.
104	* Returns array of average times per job per run.
105	*/
106	long[] time0(List<Job> jobs) throws Throwable {
107	final long warmupNanos = (long) (warmupSeconds * 1000L * 1000L * 1000L);
108	final int size = jobs.size();
109	long[] nanoss = new long[size];
110	for (int i = 0; i < size; i++) {
111	if (warmupNanos > 0) forceFullGc();
112	long t0 = System.nanoTime();
113	long t;
114	int j = 0;
115	do { jobs.get(i).work(); j++; }
116	while ((t = System.nanoTime() - t0) < warmupNanos);
117	nanoss[i] = t/j;
118	}
119	return nanoss;
120	}
121
122	void time(List<Job> jobs) throws Throwable {
123	if (warmupSeconds > 0) time0(jobs); // Warm up run
124	final int size = jobs.size();
125	final long[] nanoss = time0(jobs); // Real timing run
126	final long[] milliss = new long[size];
127	final double[] ratios = new double[size];
128
129	final String nameHeader = "Method";
130	final String millisHeader = "Millis";
131	final String ratioHeader = "Ratio";
132
133	int nameWidth = nameHeader.length();
134	int millisWidth = millisHeader.length();
135	int ratioWidth = ratioHeader.length();
136
137	for (int i = 0; i < size; i++) {
138	nameWidth = Math.max(nameWidth, jobs.get(i).name().length());
139
140	milliss[i] = nanoss[i]/(1000L * 1000L);
141	millisWidth = Math.max(millisWidth,
142	String.format("%d", milliss[i]).length());
143
144	ratios[i] = (double) nanoss[i] / (double) nanoss[0];
145	ratioWidth = Math.max(ratioWidth,
146	String.format("%.3f", ratios[i]).length());
147	}
148
149	String format = String.format("%%-%ds %%%dd %%%d.3f%%n",
150	nameWidth, millisWidth, ratioWidth);
151	String headerFormat = String.format("%%-%ds %%%ds %%%ds%%n",
152	nameWidth, millisWidth, ratioWidth);
153	System.out.printf(headerFormat, "Method", "Millis", "Ratio");
154
155	// Print out absolute and relative times, calibrated against first job
156	for (int i = 0; i < size; i++)
157	System.out.printf(format, jobs.get(i).name(), milliss[i], ratios[i]);
158	}
159
160	private static String keywordValue(String[] args, String keyword) {
161	for (String arg : args)
162	if (arg.startsWith(keyword))
163	return arg.substring(keyword.length() + 1);
164	return null;
165	}
166
167	private static int intArg(String[] args, String keyword, int defaultValue) {
168	String val = keywordValue(args, keyword);
169	return (val == null) ? defaultValue : Integer.parseInt(val);
170	}
171
172	private static double doubleArg(String[] args, String keyword, double defaultValue) {
173	String val = keywordValue(args, keyword);
174	return (val == null) ? defaultValue : Double.parseDouble(val);
175	}
176
177	private static Pattern patternArg(String[] args, String keyword) {
178	String val = keywordValue(args, keyword);
179	return (val == null) ? null : Pattern.compile(val);
180	}
181
182	private static List<Job> filter(Pattern filter, List<Job> jobs) {
183	if (filter == null) return jobs;
184	ArrayList<Job> newJobs = new ArrayList<>();
185	for (Job job : jobs)
186	if (filter.matcher(job.name()).find())
187	newJobs.add(job);
188	return newJobs;
189	}
190
191	private static void deoptimize(int sum) {
192	if (sum == 42)
193	System.out.println("the answer");
194	}
195
196	private static <T> List<T> asSubList(List<T> list) {
197	return list.subList(0, list.size());
198	}
199
200	private static <T> Iterable<T> backwards(final List<T> list) {
201	return new Iterable<T>() {
202	public Iterator<T> iterator() {
203	return new Iterator<T>() {
204	final ListIterator<T> it = list.listIterator(list.size());
205	public boolean hasNext() { return it.hasPrevious(); }
206	public T next() { return it.previous(); }
207	public void remove() { it.remove(); }};}};
208	}
209
210	// Checks for correctness and prevents loop optimizations
211	class Check {
212	private int sum;
213	public void sum(int sum) {
214	if (this.sum == 0)
215	this.sum = sum;
216	if (this.sum != sum)
217	throw new AssertionError("Sum mismatch");
218	}
219	}
220	volatile Check check = new Check();
221
222	public static void main(String[] args) throws Throwable {
223	new RemoveMicroBenchmark().run(args);
224	}
225
226	void run(String[] args) throws Throwable {
227	iterations = intArg(args, "iterations", 10_000);
228	size = intArg(args, "size", 1000);
229	warmupSeconds = doubleArg(args, "warmup", 5);
230	filter = patternArg(args, "filter");
231	// System.out.printf(
232	// "iterations=%d size=%d, warmup=%1g, filter=\"%s\"%n",
233	// iterations, size, warmupSeconds, filter);
234
235	final ArrayList<Integer> al = new ArrayList<Integer>(size);
236
237	// Populate collections with random data
238	final ThreadLocalRandom rnd = ThreadLocalRandom.current();
239	for (int i = 0; i < size; i++)
240	al.add(rnd.nextInt(size));
241
242	ArrayList<Job> jobs = new ArrayList<>();
243
244	List.<Collection<Integer>>of(
245	new ArrayList<>(),
246	new LinkedList<>(),
247	new Vector<>(),
248	new ArrayDeque<>(),
249	new ArrayBlockingQueue<>(al.size()),
250	new ConcurrentLinkedQueue<>(),
251	new ConcurrentLinkedDeque<>(),
252	new LinkedBlockingQueue<>(),
253	new LinkedBlockingDeque<>(),
254	new LinkedTransferQueue<>())
255	.stream().forEach(
256	x -> {
257	String klazz = x.getClass().getSimpleName();
258	jobs.addAll(collectionJobs(klazz, () -> x, al));
259	if (x instanceof Deque) {
260	Deque<Integer> deque = (Deque<Integer>) x;
261	jobs.addAll(dequeJobs(klazz, () -> deque, al));
262	}
263	if (x instanceof List) {
264	List<Integer> list = (List<Integer>) x;
265	jobs.addAll(
266	collectionJobs(
267	klazz + " subList",
268	() -> list.subList(0, x.size()),
269	al));
270	}
271	});
272
273	time(filter(filter, jobs));
274	}
275
276	Collection<Integer> universeRecorder(int[] sum) {
277	return new ArrayList<>() {
278	public boolean contains(Object x) {
279	sum[0] += (Integer) x;
280	return true;
281	}};
282	}
283
284	Collection<Integer> emptyRecorder(int[] sum) {
285	return new ArrayList<>() {
286	public boolean contains(Object x) {
287	sum[0] += (Integer) x;
288	return false;
289	}};
290	}
291
292	List<Job> collectionJobs(
293	String description,
294	Supplier<Collection<Integer>> supplier,
295	ArrayList<Integer> al) {
296	return List.of(
297	new Job(description + " .removeIf") {
298	public void work() throws Throwable {
299	Collection<Integer> x = supplier.get();
300	int[] sum = new int[1];
301	for (int i = 0; i < iterations; i++) {
302	sum[0] = 0;
303	x.addAll(al);
304	x.removeIf(n -> { sum[0] += n; return true; });
305	check.sum(sum[0]);}}},
306	new Job(description + " .removeAll") {
307	public void work() throws Throwable {
308	Collection<Integer> x = supplier.get();
309	int[] sum = new int[1];
310	Collection<Integer> universe = universeRecorder(sum);
311	for (int i = 0; i < iterations; i++) {
312	sum[0] = 0;
313	x.addAll(al);
314	x.removeAll(universe);
315	check.sum(sum[0]);}}},
316	new Job(description + " .retainAll") {
317	public void work() throws Throwable {
318	Collection<Integer> x = supplier.get();
319	int[] sum = new int[1];
320	Collection<Integer> empty = emptyRecorder(sum);
321	for (int i = 0; i < iterations; i++) {
322	sum[0] = 0;
323	x.addAll(al);
324	x.retainAll(empty);
325	check.sum(sum[0]);}}},
326	new Job(description + " Iterator.remove") {
327	public void work() throws Throwable {
328	Collection<Integer> x = supplier.get();
329	int[] sum = new int[1];
330	for (int i = 0; i < iterations; i++) {
331	sum[0] = 0;
332	x.addAll(al);
333	Iterator<Integer> it = x.iterator();
334	while (it.hasNext()) {
335	sum[0] += it.next();
336	it.remove();
337	}
338	check.sum(sum[0]);}}},
339	new Job(description + " clear") {
340	public void work() throws Throwable {
341	Collection<Integer> x = supplier.get();
342	int[] sum = new int[1];
343	for (int i = 0; i < iterations; i++) {
344	sum[0] = 0;
345	x.addAll(al);
346	x.forEach(e -> sum[0] += e);
347	x.clear();
348	check.sum(sum[0]);}}});
349	}
350
351	List<Job> dequeJobs(
352	String description,
353	Supplier<Deque<Integer>> supplier,
354	ArrayList<Integer> al) {
355	return List.of(
356	new Job(description + " descendingIterator().remove") {
357	public void work() throws Throwable {
358	Deque<Integer> x = supplier.get();
359	int[] sum = new int[1];
360	for (int i = 0; i < iterations; i++) {
361	sum[0] = 0;
362	x.addAll(al);
363	Iterator<Integer> it = x.descendingIterator();
364	while (it.hasNext()) {
365	sum[0] += it.next();
366	it.remove();
367	}
368	check.sum(sum[0]);}}});
369	}
370	}