RFR 8032513: The Spliterator characteristics CONCURRENT and IMMUTABLE are mutually exclusive

[Paul Sandoz]

Hi

http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8032513-Spliterator-immutable-concurrent/webrev/

This is really just a clarification making what was implicitly obvious explicitly so.

I will file a CCC.

Paul.

diff -r ff20291021b3 src/java.base/share/classes/java/util/Spliterator.java
--- a/src/java.base/share/classes/java/util/Spliterator.java    Tue Jan 20 16:19:16 2015 +0000
+++ b/src/java.base/share/classes/java/util/Spliterator.java    Tue Jan 20 16:23:23 2015 +0000
@@ -553,6 +553,12 @@
      * sub-split size is known and additions or removals to the source are not
      * reflected when traversing.
      *
+     * <p>A top-level Spliterator should not report both {@code CONCURRENT} and
+     * {@code IMMUTABLE}, since they are mutually exclusive. Such a Spliterator
+     * is inconsistent and no guarantees can be made about any computation using
+     * that Spliterator. Sub-spliterators may report {@code IMMUTABLE} if
+     * additions or removals to the source are not reflected when traversing.
+     *
      * @apiNote Most concurrent collections maintain a consistency policy
      * guaranteeing accuracy with respect to elements present at the point of
      * Spliterator construction, but possibly not reflecting subsequent