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