--- old/jdk/src/share/classes/java/lang/Thread.java 2013-06-17 12:34:09.868124661 +0400 +++ new/jdk/src/share/classes/java/lang/Thread.java 2013-06-17 12:34:09.656124656 +0400 @@ -1993,12 +1993,21 @@ // The following three initially uninitialized fields are exclusively - // managed by class java.util.concurrent.ThreadLocalRandom. + // managed by class java.util.concurrent.ThreadLocalRandom. These + // fields are used to build the high-performance PRNGs in the + // concurrent code, and we can not risk accidental false sharing. + // Hence, the fields are isolated with @Contended. + /** The current seed for a ThreadLocalRandom */ + @sun.misc.Contended("tlr") long threadLocalRandomSeed; + /** Probe hash value; nonzero if threadLocalRandomSeed initialized */ + @sun.misc.Contended("tlr") int threadLocalRandomProbe; + /** Secondary seed isolated from public ThreadLocalRandom sequence */ + @sun.misc.Contended("tlr") int threadLocalRandomSecondarySeed; /* Some private helper methods */