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From Adrian Tarau <adrian.ta...@gmail.com>
Subject Re: Fwd: ThreadLocal in SegmentReader
Date Mon, 07 Jul 2008 21:23:32 GMT
Usually ThreadLocal.remove() should be called at the end(in a finally 
block), before the current call leaves your code.

Ex : if during searching ThreadLocal is used, every search(..) method 
should cleanup any ThreadLocal variables, or even deeper in the 
implementation. When the call leaves Lucene any used ThreadLocal should 
be cleaned up.

Michael McCandless wrote:
>
> ThreadLocal, which we use in several places in Lucene, causes a leak 
> in app servers because the classloader never fully deallocates 
> Lucene's classes because the ThreadLocal is holding strong references.
>
> Yet, ThreadLocal is very convenient for avoiding synchronization.
>
> Does anyone have any ideas on how to solve this w/o falling back to 
> "normal" synchronization?
>
> Mike
>
> Begin forwarded message:
>
>> From: "Yonik Seeley" <yonik@apache.org>
>> Date: July 7, 2008 3:30:28 PM EDT
>> To: java-user@lucene.apache.org
>> Subject: Re: ThreadLocal in SegmentReader
>> Reply-To: java-user@lucene.apache.org
>>
>> On Mon, Jul 7, 2008 at 2:43 PM, Michael McCandless
>> <lucene@mikemccandless.com> wrote:
>>> So now I'm confused: the SegmentReader itself should no longer be 
>>> reachable,
>>> assuming you are not holding any references to your IndexReader.
>>>
>>> Which means the ThreadLocal instance should no longer be reachable.
>>
>> It will still be referenced from the Thread(s) ThreadLocalMap
>> The key (the ThreadLocal) will be weakly referenced, but the values
>> (now stale) are strongly referenced and won't be actually removed
>> until the table is resized (under the Java6 impl at least).
>> Nice huh?
>>
>> -Yonik
>>
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>
>
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