Unfortunately, this change doesn't fix 8006593. We do have a fix planned for 8006593 in Java 8 but there's a difficulty in the current implementation that means we can't detect if the SecurityManager is initialized. The VM.isBooted() check is insufficient.
Mike On Mar 5 2013, at 06:53 , Salter, Thomas A wrote: > Will this change do anything to fix: > http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8002283? > > -------------------- > Date: Mon, 4 Mar 2013 12:21:08 -0800 > From: Mike Duigou <mike.dui...@oracle.com> > Subject: RFR: 8006593: Performance and compatibility improvements to > hash based Map implementations > To: "core-libs-dev@openjdk.java.net Libs" > <core-libs-dev@openjdk.java.net> > Message-ID: <79a5a703-12da-4c66-94f7-34534761d...@oracle.com> > Content-Type: text/plain; charset=us-ascii > > Hello all; > > The alternative hashing implementation introduced in 7u6 added an unfortunate > bottleneck to the initialization of HashMap and Hashtable instances. This > patch avoids the performance bottleneck of using a shared Random instance by > using a ThreadLocalRandom instead. > > Along with this change are some additional performance improvements to > further reduce the overhead of the alternative hashing feature and generally > improve the performance of Hashtable or HashMap. > > http://cr.openjdk.java.net/~mduigou/JDK-8006593/3/webrev/ > > Once review is completed here this patch will be proposed to JDK7u-dev for > integration into the next 7u performance/feature release. > > Mike >
