8280950: RandomGenerator:NextDouble() default behavior non conformant…

… after JDK-8280550 fix Reviewed-by: phh Backport-of: 0e70d4504c267174738485c7da82a2ac0ef09770
openjdk · Nov 3, 2022 · 182173a · 182173a · openjdk-notifier · Nov 3, 2022
1 parent 91f1538
commit 182173a
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Showing 4 changed files with 32 additions and 4 deletions.
diff --git a/src/java.base/share/classes/java/util/Random.java b/src/java.base/share/classes/java/util/Random.java
@@ -303,7 +303,7 @@ final double internalNextDouble(double origin, double bound) {
         if (origin < bound) {
             r = r * (bound - origin) + origin;
             if (r >= bound) // correct for rounding
-                r = Math.nextAfter(r, origin);
+                r = Math.nextAfter(bound, origin);
         }
         return r;
     }

diff --git a/src/java.base/share/classes/java/util/SplittableRandom.java b/src/java.base/share/classes/java/util/SplittableRandom.java
@@ -350,7 +350,7 @@ final double internalNextDouble(double origin, double bound) {
         if (origin < bound) {
             r = r * (bound - origin) + origin;
             if (r >= bound) // correct for rounding
-                r = Math.nextAfter(r, origin);
+                r = Math.nextAfter(bound, origin);
         }
         return r;
     }

diff --git a/src/java.base/share/classes/java/util/concurrent/ThreadLocalRandom.java b/src/java.base/share/classes/java/util/concurrent/ThreadLocalRandom.java
@@ -282,7 +282,7 @@ final double internalNextDouble(double origin, double bound) {
         if (origin < bound) {
             r = r * (bound - origin) + origin;
             if (r >= bound) // correct for rounding
-                Math.nextAfter(r, origin);
+                Math.nextAfter(bound, origin);
         }
         return r;
     }

diff --git a/test/jdk/java/util/Random/RandomNextDoubleBoundary.java b/test/jdk/java/util/Random/RandomNextDoubleBoundary.java
@@ -24,13 +24,18 @@
 /*
  * @test
  * @summary Verify nextDouble stays within range
- * @bug 8280550
+ * @bug 8280550 8280950
  */
 
 import java.util.SplittableRandom;
 
 public class RandomNextDoubleBoundary {
     public static void main(String... args) {
+        negativeBounds();
+        positiveBounds();
+    }
+
+    private static void negativeBounds() {
         // Both bounds are negative
         double lowerBound = -1.0000000000000002;
         double upperBound = -1.0;
@@ -49,4 +54,27 @@ public static void main(String... args) {
             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) {
+        SplittableRandom rg = new SplittableRandom(42L);
+        double value = rg.nextDouble(origin, bound);
+
+        assertTrue(value >= origin);
+        assertTrue(value < bound);
+    }
+
+    public static void assertTrue(boolean condition) {
+        if (!condition) {
+            throw new AssertionError();
+        }
+    }
 }