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/*
* Copyright (c) 2022, 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 Verify nextDouble stays within range
* @bug 8280550 8280950 8281183 8202449
*
* @key randomness
* @library /test/lib
* @build jdk.test.lib.RandomFactory
* @run main RandomNextDoubleBoundary
*/
import java.util.SplittableRandom;
import java.util.random.RandomGenerator;
import jdk.test.lib.RandomFactory;
public class RandomNextDoubleBoundary {
public static void main(String... args) {
negativeBounds();
positiveBounds();
nextDoubleHugeRange();
}
private static void negativeBounds() {
// Both bounds are negative
double lowerBound = -1.0000000000000002;
double upperBound = -1.0;
var sr = new SplittableRandom(42L);
var r = sr.nextDouble(lowerBound, upperBound);
if (r >= upperBound) {
System.err.println("r = " + r + "\t" + Double.toHexString(r));
System.err.println("ub = " + upperBound + "\t" + Double.toHexString(upperBound));
throw new RuntimeException("Greater than upper bound");
}
if (r < lowerBound) {
System.err.println("r = " + r + "\t" + Double.toHexString(r));
System.err.println("lb = " + lowerBound + "\t" + Double.toHexString(lowerBound));
throw new RuntimeException("Less than lower bound");
}
}
private static void positiveBounds() {
double[][] originAndBounds = {{10, 100},
{12345, 123456},
{5432167.234, 54321678.1238}};
for (double[] originAndBound : originAndBounds) {
nextDoublesWithRange(originAndBound[0], originAndBound[1]);
}
}
public static void nextDoublesWithRange(double origin, double bound) {
RandomGenerator rg = new RandomGenerator() {
@Override
public double nextDouble() {
return Double.MAX_VALUE;
}
@Override
public long nextLong() {
return 0;
}
};
double value = rg.nextDouble(origin, bound);
if (bound > 0) {
value = rg.nextDouble(bound); // Equivalent to nextDouble(0.0, bound)
assertTrue(value >= 0.0);
assertTrue(value < bound);
}
}
public static void nextDoubleHugeRange() {
var random = RandomFactory.getRandom();
var n = 100_000;
var origin = -(3.0 / 4.0) * Double.MAX_VALUE;
var bound = (3.0 / 4.0) * Double.MAX_VALUE;
assertTrue(bound - origin == Double.POSITIVE_INFINITY);
/* all are within [origin, bound) */
assertTrue(random.doubles(n, origin, bound)
.allMatch(d -> origin <= d && d < bound));
/* some are near the origin */
assertTrue(random.doubles(n, origin, bound)
.anyMatch(d -> d < (15.0 / 16.0) * origin));
/* some are near the bound */
assertTrue(random.doubles(n, origin, bound)
.anyMatch(d -> d > (15.0 / 16.0) * bound));
}
public static void assertTrue(boolean condition) {
if (!condition) {
throw new AssertionError();
}
}
}
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