I believe that the past performance concern was about the change from using ObjectOutputStream.defaultWriteObject to using OOS.putFields/writeFields, which adds some overhead-- although if you need to use them, you need to use them. (This wouldn't apply to the Hashtable fix, which looks fine to me.)
Cheers, -- Peter On Jan 13, 2011, at 5:31 PM, Mike Duigou wrote: > I know that on the Oracle side we did internally discuss the potential > performance impact. The main performance concern seems to be the extra GC > work from creating the array of values (or the entry stack in the case of > Hashtable). We decided though that for most collections the small size and > short lifetime of the extra objects would mean that they would never escape > the eden generation and would be quickly and efficiently GCed. We don't > expect that this change will result in only insignificant (it's not "free") > performance degradation whether considered from a microbenchmark perspective > or from an overall system performance perspective. > > Alternative opinions, analysis and insights are, of course, welcome. > > Mike > > On Jan 12 2011, at 22:31 , Peter Jones wrote: > >> Hello, >> >> Sorry for chiming in late here, but I was wondering-- has the performance >> impact of this change been measured? Many years ago, the performance impact >> vs. the apparent severity of the bug at the time held back this fix (using >> PutField). Of course, both sides of that consideration may have changed >> since then. >> >> FWIW, the code change looks correct to me. A style nit: I would drop the "= >> null" initializer on line 1060-- it is a value that should never be read, so >> let the compiler enforce that (and then you could declare "data" final as >> well). >> >> Cheers, >> -- Peter >> >> P.S. There is a serialization micro-benchmark framework under >> test/java/rmi/reliability/benchmark >> >> >> On Jan 12, 2011, at 5:42 AM, Neil Richards wrote: >> >>> On 10 January 2011 21:11, Alan Bateman <alan.bate...@oracle.com> wrote: >>>> The update to the javadoc looks fine to me. On the headers then we use the >>>> GPL header on tests (no Classpath Exception). >>> >>> Sorry once again - please find attached with the corrected header for >>> GPL (without Classpath exception). >>> >>> I hope I'm pretty much there now - let me know if you spot anything else. >>> Cheers, >>> Neil >>> >>> -- >>> Unless stated above: >>> IBM email: neil_richards at uk.ibm.com >>> IBM United Kingdom Limited - Registered in England and Wales with number >>> 741598. >>> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU >>> <webrev.6934356.4.zip> >> >
