Re: Atomic integer array class question

From:
Patricia Shanahan <pats@acm.org>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 10 Jan 2012 07:43:17 -0800
Message-ID:
<PoWdnfMmUu0LwZHSnZ2dnUVZ_o-dnZ2d@earthlink.com>
On 1/10/2012 6:22 AM, raphfrk@gmail.com wrote:

On Jan 9, 6:56 pm, Patricia Shanahan<p...@acm.org> wrote:

Spin waiting, especially spin waiting that has no delay and includes
access to a volatile variable, can be very expensive in terms of load on
the processor-memory interconnect.


So, add a Thread.sleep(1); or something ?


I'm not at all sure you basic approach makes sense.

I'm still unclear what is intent, and what is infrastructure to do with
how you are trying to implement the intent. Could you provide a
description of what you want to have happen?


It's basically a store that has 3 parts per element

id (short)
data (short)
auxData (Object)

However, for most places (say 95%+), it is (0, 0, null), so it really
only needs only a short.

I am planning to have a short array for the main store. That will be
based on AtomicInteger and storing two shorts per index (it uses
compareAndSet to allow one short out of the int to be updated
atomically).

....

My premature optimization detector is clicking rapidly. You are still
talking about a particular implementation, not what you want the
implementation to achieve.

Patricia

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