--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/Collection/IteratorMicroBenchmark.java Mon Nov 28 23:36:11 2016 -0800
@@ -0,0 +1,404 @@
+/*
+ * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @summary micro-benchmark correctness mode
+ * @run main IteratorMicroBenchmark iterations=1 size=8 warmup=0
+ */
+
+import static java.util.stream.Collectors.summingInt;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+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.PriorityQueue;
+import java.util.Spliterator;
+import java.util.Vector;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.ConcurrentLinkedDeque;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.LinkedTransferQueue;
+import java.util.concurrent.PriorityBlockingQueue;
+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;
+
+/**
+ * Usage: [iterations=N] [size=N] [filter=REGEXP] [warmup=SECONDS]
+ *
+ * To run this in micro-benchmark mode, simply run as a normal java program.
+ * Be patient; this program runs for a very long time.
+ * For faster runs, restrict execution using command line args.
+ *
+ * This is an interface based version of ArrayList/IteratorMicroBenchmark
+ *
+ * @author Martin Buchholz
+ */
+public class IteratorMicroBenchmark {
+ abstract static class Job {
+ private final String name;
+ public Job(String name) { this.name = name; }
+ public String name() { return name; }
+ public abstract void work() throws Throwable;
+ }
+
+ 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
+
+ IteratorMicroBenchmark(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
+ class Check {
+ private int sum;
+ public void sum(int sum) {
+ if (this.sum == 0)
+ this.sum = sum;
+ if (this.sum != sum)
+ throw new AssertionError("Sum mismatch");
+ }
+ }
+ volatile Check check = new Check();
+
+ public static void main(String[] args) throws Throwable {
+ new IteratorMicroBenchmark(args).run();
+ }
+
+ 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<Integer>(size);
+
+ // Populate collections with random data
+ final ThreadLocalRandom rnd = ThreadLocalRandom.current();
+ for (int i = 0; i < size; i++)
+ al.add(rnd.nextInt(size));
+
+ final ArrayDeque<Integer> ad = new ArrayDeque<>(al);
+ final ArrayBlockingQueue<Integer> abq = new ArrayBlockingQueue<>(al.size());
+ abq.addAll(al);
+
+ // shuffle circular array elements so they wrap
+ for (int i = 0, n = rnd.nextInt(size); i < n; i++) {
+ ad.addLast(ad.removeFirst());
+ abq.add(abq.remove());
+ }
+
+ ArrayList<Job> jobs = new ArrayList<>(Arrays.asList());
+
+ List.of(al, ad, abq,
+ new LinkedList<>(al),
+ new PriorityQueue<>(al),
+ new Vector<>(al),
+ new ConcurrentLinkedQueue<>(al),
+ new ConcurrentLinkedDeque<>(al),
+ new LinkedBlockingQueue<>(al),
+ new LinkedBlockingDeque<>(al),
+ new LinkedTransferQueue<>(al),
+ new PriorityBlockingQueue<>(al))
+ .stream()
+ .forEach(x -> {
+ jobs.addAll(collectionJobs(x));
+ if (x instanceof Deque)
+ jobs.addAll(dequeJobs((Deque<Integer>)x));
+ });
+
+ if (reverse) Collections.reverse(jobs);
+ if (shuffle) Collections.shuffle(jobs);
+
+ time(filter(filter, jobs));
+ }
+
+ List<Job> collectionJobs(Collection<Integer> x) {
+ String klazz = x.getClass().getSimpleName();
+ return List.of(
+ new Job(klazz + " iterate for loop") {
+ public void work() throws Throwable {
+ for (int i = 0; i < iterations; i++) {
+ int sum = 0;
+ for (Integer n : x)
+ sum += n;
+ check.sum(sum);}}},
+ new Job(klazz + " .iterator().forEachRemaining()") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ x.iterator().forEachRemaining(n -> sum[0] += n);
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .spliterator().tryAdvance()") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ Spliterator<Integer> spliterator = x.spliterator();
+ do {} while (spliterator.tryAdvance(n -> sum[0] += n));
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .spliterator().forEachRemaining()") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ x.spliterator().forEachRemaining(n -> sum[0] += n);
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .removeIf") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ x.removeIf(n -> { sum[0] += n; return false; });
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .forEach") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ x.forEach(n -> sum[0] += n);
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .toArray()") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ for (Object o : x.toArray())
+ sum[0] += (Integer) o;
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .toArray(a)") {
+ public void work() throws Throwable {
+ Integer[] a = new Integer[x.size()];
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ x.toArray(a);
+ for (Object o : a)
+ sum[0] += (Integer) o;
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .toArray(empty)") {
+ public void work() throws Throwable {
+ Integer[] empty = new Integer[0];
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ for (Integer o : x.toArray(empty))
+ sum[0] += o;
+ check.sum(sum[0]);}}},
+ new Job(klazz + " .stream().collect") {
+ public void work() throws Throwable {
+ for (int i = 0; i < iterations; i++) {
+ check.sum(x.stream()
+ .collect(summingInt(e -> e)));}}},
+ new Job(klazz + " .parallelStream().collect") {
+ public void work() throws Throwable {
+ for (int i = 0; i < iterations; i++) {
+ check.sum(x.parallelStream()
+ .collect(summingInt(e -> e)));}}});
+ }
+
+ List<Job> dequeJobs(Deque<Integer> x) {
+ String klazz = x.getClass().getSimpleName();
+ return List.of(
+ new Job(klazz + " .descendingIterator() loop") {
+ public void work() throws Throwable {
+ for (int i = 0; i < iterations; i++) {
+ int sum = 0;
+ Iterator<Integer> it = x.descendingIterator();
+ while (it.hasNext())
+ sum += it.next();
+ check.sum(sum);}}},
+ new Job(klazz + " .descendingIterator().forEachRemaining()") {
+ public void work() throws Throwable {
+ int[] sum = new int[1];
+ for (int i = 0; i < iterations; i++) {
+ sum[0] = 0;
+ x.descendingIterator().forEachRemaining(n -> sum[0] += n);
+ check.sum(sum[0]);}}});
+ }
+}