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/*
* Copyright (c) 2012, 2013, 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.
*/
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Supplier;
import java.util.stream.Stream;
import static java.util.stream.Collectors.toList;
import static java.util.stream.Collectors.toSet;
import static org.testng.Assert.*;
/**
* @test
* @run testng RandomStreamTest
* @summary test stream methods on Random
* @author Brian Goetz
* @key randomness
*/
public class RandomStreamTest {
private static final int SIZE = 1000;
@DataProvider(name = "suppliers")
public Object[][] randomSuppliers() {
return new Object[][] {
{new Random(), SIZE},
{new SecureRandom(), SIZE}
};
}
@Test(dataProvider = "suppliers")
public void testRandomIntStream(final Random random, final int count) {
final List<Integer> destination = new ArrayList<>(count);
random.ints().limit(count).forEach(destination::add);
assertEquals(destination.size(), count);
}
@Test(dataProvider = "suppliers")
public void testRandomLongStream(final Random random, final int count) {
final List<Long> destination = new ArrayList<>(count);
random.longs().limit(count).forEach(destination::add);
assertEquals(destination.size(), count);
}
@Test(dataProvider = "suppliers")
public void testRandomDoubleStream(final Random random, final int count) {
final List<Double> destination = new ArrayList<>(count);
random.doubles().limit(count).forEach(destination::add);
random.doubles().limit(count).forEach(d -> assertTrue(d >= 0.0 && d < 1.0));
assertEquals(destination.size(), count);
}
@Test
public void testIntStream() {
final long seed = System.currentTimeMillis();
final Random r1 = new Random(seed);
final int[] a = new int[SIZE];
for (int i=0; i < SIZE; i++) {
a[i] = r1.nextInt();
}
final Random r2 = new Random(seed); // same seed
final int[] b = r2.ints().limit(SIZE).toArray();
assertEquals(a, b);
}
@Test
public void testLongStream() {
final long seed = System.currentTimeMillis();
final Random r1 = new Random(seed);
final long[] a = new long[SIZE];
for (int i=0; i < SIZE; i++) {
a[i] = r1.nextLong();
}
final Random r2 = new Random(seed); // same seed
final long[] b = r2.longs().limit(SIZE).toArray();
assertEquals(a, b);
}
@Test
public void testDoubleStream() {
final long seed = System.currentTimeMillis();
final Random r1 = new Random(seed);
final double[] a = new double[SIZE];
for (int i=0; i < SIZE; i++) {
a[i] = r1.nextDouble();
}
final Random r2 = new Random(seed); // same seed
final double[] b = r2.doubles().limit(SIZE).toArray();
assertEquals(a, b);
}
@Test
public void testThreadLocalIntStream() throws InterruptedException, ExecutionException, TimeoutException {
ThreadLocalRandom tlr = ThreadLocalRandom.current();
testRandomResultSupplierConcurrently(() -> tlr.ints().limit(SIZE).boxed().collect(toList()));
}
@Test
public void testThreadLocalLongStream() throws InterruptedException, ExecutionException, TimeoutException {
ThreadLocalRandom tlr = ThreadLocalRandom.current();
testRandomResultSupplierConcurrently(() -> tlr.longs().limit(SIZE).boxed().collect(toList()));
}
@Test
public void testThreadLocalDoubleStream() throws InterruptedException, ExecutionException, TimeoutException {
ThreadLocalRandom tlr = ThreadLocalRandom.current();
testRandomResultSupplierConcurrently(() -> tlr.doubles().limit(SIZE).boxed().collect(toList()));
}
<T> void testRandomResultSupplierConcurrently(Supplier<T> s) throws InterruptedException, ExecutionException, TimeoutException {
// Produce 10 completable future tasks
final int tasks = 10;
List<CompletableFuture<T>> cfs = Stream.generate(() -> CompletableFuture.supplyAsync(s)).
limit(tasks).collect(toList());
// Wait for all tasks to complete
// Timeout is beyond reasonable doubt that completion should
// have occurred unless there is an issue
CompletableFuture<Void> all = CompletableFuture.allOf(cfs.stream().toArray(CompletableFuture[]::new));
all.get(1, TimeUnit.MINUTES);
// Count the distinct results, which should equal the number of tasks
long rc = cfs.stream().map(CompletableFuture::join).distinct().count();
assertEquals(rc, tasks);
}
}
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