RFR (S): CR 8005926: (thread) Merge ThreadLocalRandom state into java.lang.Thread

[Martin Buchholz]

On Wed, Jan 16, 2013 at 7:01 AM, Chris Hegarty <chris.hegarty at oracle.com>wrote:

> Thanks to all for the reviews and suggestions here. As you probably seen,
> I pushed these changes to jdk8/tl earlier today (sorry, I missed Alan as an
> official reviewer on the changeset.). Consider it an initial version,
> pending any outcome from this, or other, discussions.
>
> Also, 8006409: "ThreadLocalRandom should dropping padding fields from its
> serialized form", has been filed to follow up on the changes required to
> update the serial form.
>
> For those watching, I was preferable to push on with these changes ( and I
> apologize if it appeared pushy ), as the Double/Long Adder/Accumulator
> implementation, Striped64, now has a dependency on this change. It has
> become unbearable to keep in sync with different version of across
> different repositories.


Taking a look at this, I don't see any reason why we can't simply do
(while maintaining serialization compatibility):

 diff --git a/src/share/classes/java/util/concurrent/ThreadLocalRandom.java
b/src/share/classes/java/util/concurrent/ThreadLocalRandom.java
--- a/src/share/classes/java/util/concurrent/ThreadLocalRandom.java
+++ b/src/share/classes/java/util/concurrent/ThreadLocalRandom.java
@@ -368,50 +368,6 @@
     private static final long serialVersionUID = -5851777807851030925L;

     /**
-     * @serialField rnd long
-     * @serialField initialized boolean
-     * @serialField pad0 long
-     * @serialField pad1 long
-     * @serialField pad2 long
-     * @serialField pad3 long
-     * @serialField pad4 long
-     * @serialField pad5 long
-     * @serialField pad6 long
-     * @serialField pad7 long
-     */
-    private static final ObjectStreamField[] serialPersistentFields = {
-            new ObjectStreamField("rnd", long.class),
-            new ObjectStreamField("initialized", boolean.class),
-            new ObjectStreamField("pad0", long.class),
-            new ObjectStreamField("pad1", long.class),
-            new ObjectStreamField("pad2", long.class),
-            new ObjectStreamField("pad3", long.class),
-            new ObjectStreamField("pad4", long.class),
-            new ObjectStreamField("pad5", long.class),
-            new ObjectStreamField("pad6", long.class),
-            new ObjectStreamField("pad7", long.class) };
-
-    /**
-     * Saves the {@code ThreadLocalRandom} to a stream (that is,
serializes it).
-     */
-    private void writeObject(java.io.ObjectOutputStream out)
-        throws java.io.IOException {
-
-        java.io.ObjectOutputStream.PutField fields = out.putFields();
-        fields.put("rnd", 0L);
-        fields.put("initialized", true);
-        fields.put("pad0", 0L);
-        fields.put("pad1", 0L);
-        fields.put("pad2", 0L);
-        fields.put("pad3", 0L);
-        fields.put("pad4", 0L);
-        fields.put("pad5", 0L);
-        fields.put("pad6", 0L);
-        fields.put("pad7", 0L);
-        out.writeFields();
-    }
-
-    /**
      * Returns the {@link #current() current} thread's {@code
ThreadLocalRandom}.
      */
     private Object readResolve() {