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8280950: RandomGenerator:NextDouble() default behavior non conformant after JDK-8280550 fix

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Backport-of: 0e70d4504c267174738485c7da82a2ac0ef09770
This commit is contained in:
Joe Darcy 2022-02-09 18:40:13 +00:00
parent 9d4b5edf2c
commit e1dfd9fa3c
2 changed files with 42 additions and 3 deletions
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4
src/java.base/share/classes/jdk/internal/util/random/RandomSupport.java
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@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2020, 2021, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2020, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* *
* This code is free software; you can redistribute it and/or modify it * This code is free software; you can redistribute it and/or modify it
@ -645,7 +645,7 @@ public class RandomSupport {
if (origin < bound) { if (origin < bound) {
r = r * (bound - origin) + origin; r = r * (bound - origin) + origin;
if (r >= bound) // may need to correct a rounding problem if (r >= bound) // may need to correct a rounding problem
r = Math.nextAfter(r, origin); r = Math.nextAfter(bound, origin);
} }
return r; return r;
} }

41
test/jdk/java/util/Random/RandomNextDoubleBoundary.java
View File

@ -24,13 +24,19 @@
/* /*
* @test * @test
* @summary Verify nextDouble stays within range * @summary Verify nextDouble stays within range
* @bug 8280550 * @bug 8280550 8280950
*/ */
import java.util.SplittableRandom; import java.util.SplittableRandom;
import java.util.random.RandomGenerator;
public class RandomNextDoubleBoundary { public class RandomNextDoubleBoundary {
public static void main(String... args) { public static void main(String... args) {
negativeBounds();
positiveBounds();
}
private static void negativeBounds() {
// Both bounds are negative // Both bounds are negative
double lowerBound = -1.0000000000000002; double lowerBound = -1.0000000000000002;
double upperBound = -1.0; double upperBound = -1.0;
@ -49,4 +55,37 @@ public class RandomNextDoubleBoundary {
throw new RuntimeException("Less than lower bound"); 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);
assertTrue(value >= origin);
assertTrue(value < bound);
}
public static void assertTrue(boolean condition) {
if (!condition) {
throw new AssertionError();
}
}
} }