Mailing-List: contact java-user-help@lucene.apache.org; run by ezmlm
Precedence: bulk
Reply-To: java-user@lucene.apache.org
Received-SPF: pass (nike.apache.org: domain of trejkaz@trypticon.org
 designates 209.85.214.176 as permitted sender)
Received-SPF: pass (google.com: domain of trejkaz@trypticon.org designates
 10.60.29.195 as permitted sender) client-ip=10.60.29.195;
Received-SPF: pass (google.com: domain of trejkaz@trypticon.org designates
 10.180.82.39 as permitted sender) client-ip=10.180.82.39;
MIME-Version: 1.0
In-Reply-To: <000b01ccef6c$1371bff0$3a553fd0$@thetaphi.de>
References: 
 <CALhtWkc7Hxo3qQYOWhpXR8=fiS5aLd9Vn2OgO7WeOJjGh1mziw@mail.gmail.com>
	<CAOdYfZV_zwerK2cv_jCgMt+oTO9-h_CaQB6XHPMkNFnDs+-Z8g@mail.gmail.com>
	<CALhtWkei0jqx1gQ_1KUWxF8J5zbDy4Y7uTLc=mTVa_k+3jrz=A@mail.gmail.com>
	<000b01ccef6c$1371bff0$3a553fd0$@thetaphi.de>
Date: Mon, 20 Feb 2012 14:39:28 +1100
Message-ID: 
 <CADuAvzcgQH53LJw3OmzyL0s0FbWiUtO3UoHAftP7ApzeEv9WmA@mail.gmail.com>
Subject: Re: Hanging with fixed thread pool in the IndexSearcher multithread
 code
From: Trejkaz <trejkaz@trypticon.org>
To: java-user@lucene.apache.org
Content-Type: text/plain; charset=UTF-8

On Mon, Feb 20, 2012 at 12:07 PM, Uwe Schindler <uwe@thetaphi.de> wrote:
> See my response. The problem is not in Lucene; its in general a problem of fixed
> thread pools that execute other callables from within a callable running at the
> moment in the same thread pool. Callables are simply waiting for each other.

What we do to get around this issue is to have a utility class which
you call to submit jobs to the executor, but instead of waiting after
submitting them, it starts calling get() starting from the end of the
list. So if there is no other thread available on the executor, the
main thread ends up doing all the work and then returns like normal.

The problem with this solution is that it requires all code in the
system to go through this utility to avoid the issue, and obviously
Lucene is one of those things which isn't written to defend against
this.

Java 7's solution seems to be ForkJoinPool but I gather there is no
simple way to use that with Lucene...

TX

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org