hg: jdk8/tl/jdk: 8014890: (ref) Reference queues may return more entries than expected

[mandy.chung at oracle.com]

Changeset: 858c75eb83b5
Author:    mchung
Date:      2013-07-08 14:05 +0200
URL:       http://hg.openjdk.java.net/jdk8/tl/jdk/rev/858c75eb83b5

8014890: (ref) Reference queues may return more entries than expected
Summary: When enqueuing references check whether the j.l.r.Reference has already been enqeued or removed in the lock. Do not enqueue them again. This occurs because multiple threads may try to enqueue the same j.l.r.Reference at the same time.
Reviewed-by: mchung, dholmes, plevart, shade
Contributed-by: thomas.schatzl at oracle.com

! src/share/classes/java/lang/ref/Reference.java
! src/share/classes/java/lang/ref/ReferenceQueue.java
+ test/java/lang/ref/EnqueuePollRace.java