diff -r 9a4184201823 -r b0c958c0e6c6 src/java.base/share/classes/java/util/random/JumpableRNG.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/util/random/JumpableRNG.java	Thu Jun 27 18:02:51 2019 -0300
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2013, 2019, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package java.util;
+
+import java.math.BigInteger;
+import java.util.stream.Stream;
+
+/**
+ * This interface is designed to provide a common protocol for objects
+ * that generate pseudorandom sequences of numbers (or Boolean values)
+ * and furthermore can easily <i>jump</i> forward (by a fixed amount)
+ * to a distant point in the state cycle.
+ *
+ * <p>Ideally, all {@code JumpableRng} objects produced by iterative
+ * jumping from a single original {@code JumpableRng} object are
+ * statistically independent of one another and individually uniform.
+ * In practice, one must settle for some approximation to independence
+ * and uniformity.  In particular, a specific implementation may
+ * assume that each generator in a stream produced by the {@code jumps}
+ * method is used to produce a number of values no larger than either
+ * 2<sup>64</sup> or the square root of its period.  Implementors are
+ * advised to use algorithms whose period is at least 2<sup>127</sup>.
+ *
+ * <p>Methods are provided to perform a single jump operation and also
+ * to produce a stream of generators produced from the original by
+ * iterative copying and jumping of internal state.  A typical
+ * strategy for a multithreaded application is to create a single
+ * {@code JumpableRng} object, calls its {@code jumps} method exactly
+ * once, and then parcel out generators from the resulting stream, one
+ * to each thread.  It is generally not a good idea to call {@code jump}
+ * on a generator that was itself produced by the {@code jumps} method,
+ * because the result may be a generator identical to another
+ * generator already produce by that call to the {@code jumps} method.
+ * For this reason, the return type of the {@code jumps} method is
+ * {@code Stream<Rng>} rather than {@code Stream<JumpableRng>}, even
+ * though the actual generator objects in that stream likely do also
+ * implement the {@code JumpableRng} interface.
+ *
+ * <p>An implementation of the {@code JumpableRng} interface must provide
+ * concrete definitions for the methods {@code nextInt()}, {@code nextLong},
+ * {@code period()}, {@code copy()}, {@code jump()}, and {@code defaultJumpDistance()}.
+ * Default implementations are provided for all other methods.
+ *
+ * <p>Objects that implement {@code java.util.JumpableRng} are
+ * typically not cryptographically secure.  Consider instead using
+ * {@link java.security.SecureRandom} to get a cryptographically
+ * secure pseudo-random number generator for use by
+ * security-sensitive applications.
+ *
+ * @author  Guy Steele
+ * @since   1.9
+ */
+public interface JumpableRng extends StreamableRng {
+    /**
+     * Returns a new generator whose internal state is an exact copy
+     * of this generator (therefore their future behavior should be
+     * identical if subjected to the same series of operations).
+     *
+     * @return a new object that is a copy of this generator
+     */
+    JumpableRng copy();
+
+    /**
+     * Alter the state of this pseudorandom number generator so as to
+     * jump forward a large, fixed distance (typically 2<sup>64</sup>
+     * or more) within its state cycle.
+     */
+    void jump();
+ 
+    /**
+     * Returns the distance by which the {@code jump()} method will jump
+     * forward within the state cycle of this generator object.
+     *
+     * @return the default jump distance (as a {@code double} value)
+     */
+    double defaultJumpDistance();
+
+    /**
+     * Returns an effectively unlimited stream of new pseudorandom
+     * number generators, each of which implements the {@code Rng}
+     * interface.
+     *
+     * @implNote It is permitted to implement this method in a manner
+     * equivalent to {@code jumps(Long.MAX_VALUE)}.
+     *
+     * @implNote The default implementation produces a sequential stream
+     * that  repeatedly calls {@code copy()} and {@code jump()} on this generator,
+     * and the copies become the generators produced by the stream.
+     *
+     * @return a stream of objects that implement the {@code Rng} interface
+     */
+    default Stream<Rng> jumps() {
+	return Stream.generate(this::copyAndJump).sequential();
+    }
+
+    /**
+     * Returns a stream producing the given {@code streamSize} number of
+     * new pseudorandom number generators, each of which implements the
+     * {@code Rng} interface.
+     *
+     * @implNote The default implementation produces a sequential stream
+     * that  repeatedly calls {@code copy()} and {@code jump()} on this generator,
+     * and the copies become the generators produced by the stream.
+     *
+     * @param streamSize the number of generators to generate
+     * @return a stream of objects that implement the {@code Rng} interface
+     * @throws IllegalArgumentException if {@code streamSize} is
+     *         less than zero
+     */
+    default Stream<Rng> jumps(long streamSize) {
+        return jumps().limit(streamSize);
+    }
+    
+    /**
+     * Returns an effectively unlimited stream of new pseudorandom
+     * number generators, each of which implements the {@code Rng}
+     * interface.  Ideally the generators in the stream will appear
+     * to be statistically independent.
+     *
+     * @implNote The default implementation calls {@code jumps()}.
+     *
+     * @return a stream of objects that implement the {@code Rng} interface
+     */
+    default Stream<Rng> rngs() {
+	return this.jumps();
+    }
+
+    /**
+     * Returns a stream producing the given {@code streamSize} number of
+     * new pseudorandom number generators, each of which implements the
+     * {@code Rng} interface.  Ideally the generators in the stream will
+     * appear to be statistically independent.
+     *
+     * @implNote The default implementation calls {@code jumps(streamSize)}.
+     *
+     * @param streamSize the number of generators to generate
+     * @return a stream of objects that implement the {@code Rng} interface
+     * @throws IllegalArgumentException if {@code streamSize} is
+     *         less than zero
+     */
+    default Stream<Rng> rngs(long streamSize) {
+	return this.jumps(streamSize);
+    }
+
+    /**
+     * Copy this generator, jump this generator forward, then return the copy.
+     *
+     * @return a copy of this generator object before the jump occurred
+     */
+    default Rng copyAndJump() {
+	Rng result = copy();
+	jump();
+	return result;
+    }
+
+}