Re: Serious concurrency problems on fast systems
On Tue, 8 Jun 2010, Robert Klemme wrote:
On 08.06.2010 05:39, Kevin McMurtrie wrote:
In article<874m08Fib7U1@mid.individual.net>,
Robert Klemme<shortcutter@googlemail.com> wrote:
On 07.06.2010 08:25, Kevin McMurtrie wrote:
Properties is a biggie. A brute-force replacement of Properties caused
the system throughput to collapse to almost nothing in Spring's
ResourceBundleMessageSource. There's definitely a JVM/OS problem. The
next test is to disable hyperthreading.
As someone else (Lew?) pointed out it's a bad idea to always go to
System.properties. You should rather be evaluating them on startup and
initialize some other data structure - if only to not always repeat
checking of input values over and over again.
The properties aren't immutable. The best feature of properties rather
than hard-coded values is being able to update them in an emergency
without server restarts. Anyways, that was fixed by overriding every
method in Properties with a high-concurrency implementation. Too bad
Properties isn't an interface.
Well, then use an immutable Hash map as Lew suggested and store it via
AtomicReference.
Or even a volatile variable. If you're not doing CAS, there's no advantage
to using an AtomicReference over a volatile. Mind you, there shouldn't be
any disadvantage either.
tom
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