[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: String interning
Tyler Barker wrote, > You will get similiar results on every platform you test it on > unless the JVM authors figure out a way to make testing for > object identity more expensive than dynamic method > invocation. Doing that would take some real talent (-: I agree that == will always be faster than String.equals(). I don't agree that it will be _significantly_ so. David reported a performance margin of 36:1 in favour of == for his benchmark on a Linux JDK 1.2. That's _way_ too large ... Linux JVMs clearly have a way to go before they're ready for prime-time. On WinNT with Sun's 1.3 beta and Hotspot server VM 2.0RC running David's benchmark I get a margin of 1.3:1 in favour of == (String.equals is presumably getting inlined so we're just adding the cost of a couple of extra instructions and a memory access or two to the inner loop). Even with the JIT disabled I only get a margin of 8:1 in favour of ==. As soon as I get a chance I'll test this on Solaris Sparc ... I'd expect similar results. Bearing in mind that the cost of the code under the conditionals is likely to completely drown out the small cost (with good JIT) of String.equals relative to ==, I find it very difficult to see why the cost of String.intern'ing should be imposed on _all_ SAX implementers. Cheers, Miles -- Miles Sabin Cromwell Media Internet Systems Architect 5/6 Glenthorne Mews +44 (0)20 8817 4030 London, W6 0LJ, England msabin@c... http://www.cromwellmedia.com/ xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ or CD-ROM/ISBN 981-02-3594-1 Please note: New list subscriptions now closed in preparation for transfer to OASIS.
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