Re: An Executor-like structure providing more than threads

From:
Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 21 Jan 2010 15:42:08 -0800
Message-ID:
<jD56n.2682$3n2.580@newsfe01.iad>
Tom Anderson wrote:

On Sat, 16 Jan 2010, Daniel Pitts wrote:

Tom Anderson wrote:

What if the resource needed to perform a task, the thing you wanted
to maintain a limited pool of, reuse, and provide shared access to,
was more than a Thread?


The pattern you are asking about is called a Resource Pool. I
wouldn't combine the concept of Thread Pool with HttpClient Pool.
They are orthogonal concepts, so they should be accessible orthogonally.


Except there's a 1:1 relationship between threads and HttpClients. Yes,
you could write a task which looked like:

public void run() {
    HttpClient client = httpClientPool.acquire();
    // do stuff
    httpClientPool.release(client);
}

But that seems like unnecessary boilerplate. Still, it is actually less
code than my smartarse solution, so maybe it's the right answer.

It would deal gracefully with the case where a task needs no HttpClient,
or more than one, which mine doesn't. I wouldn't anticipate those being
common, though.

tom


Are HttpClient objects really that expensive to create? I noticed your
solution is re-using the same connection manager... Perhaps you're
anticipating problems where there are non, and you should just use "new
HttpClient(connectionManager)" where it is needed, and forget about
HttpClient pooling.

*then*, consider profiling your code. If it turns out that there is a
lot of time spent allocating and releasing HttpClient objects, then you
should consider pooling.

--
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