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Re: memory allocation for

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  To: comp.lang.java.gui
Brandon McCombs wrote:

> hello,
> 
> My application makes multiple JNDI search calls to a directory server. 
> The search method returns a NamingEnumeration of SearchResults and I run 
> through a while loop that converts the enumeration to a Vector of 
> SearchResults. At another time I process the Vector to add the 
> SearchResults to a ListModel for viewing their properties.
> 
> My application takes up a lot of memory after running that search 
> operation a handful of times. It seems that the majority of the memory 
> allocation comes from the hasMoreElements() method of the enumeration 
> that I call within the while() mentioned above.  I don't see any way of 
> not calling that method since I need it to grab the search results. The 
> question I have is why would the JVM use so much space for that method 
> and is there anything I can do to reclaim the memory?  JProfiler says 
> that after a handful of search() executions there are over a million 
> allocations of hasMoreElements() that take up 50 megs. Jprofiler shows 
> garbage collections are occurring but since a method and not an Object 
> is taking up the memory I don't know how to fix this problem.
> 
> As a side note, if it was possible to properly cancel JNDI search 
> methods (from the InitialLdapContext class) then I wouldn't have such a 
> problem but once those searches start they can't be canceled from what I 
> can gather, despite utilizing threads.
> 
> thanks
> Brandon

My only guess, and this is a guess, is that because you are hanging on to the
SearchResult returned by the NamingEnumerator, that whatever implemented that
NamingEnumerator isn't getting freed for garbage collection.

Can you change your code so that the objects which are stored in the ListModel
are not the SearchResults, so that no object reference from within the
SearchResult is held onto?

-- 
Nigel Wade, System Administrator, Space Plasma Physics Group,
            University of Leicester, Leicester, LE1 7RH, UK 
E-mail :    nmw@ion.le.ac.uk 
Phone :     +44 (0)116 2523548, Fax : +44 (0)116 2523555

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memory allocation for a m "Brandon McCombs" <brandon.mccombs@THRWHITE.remove-dii-this> - 2011-04-27 15:28 +0000
  Re: memory allocation for "Daniel Pitts" <daniel.pitts@THRWHITE.remove-dii-this> - 2011-04-27 15:28 +0000
    Re: memory allocation for "Brandon McCombs" <brandon.mccombs@THRWHITE.remove-dii-this> - 2011-04-27 15:28 +0000
      Re: memory allocation for "Brandon McCombs" <brandon.mccombs@THRWHITE.remove-dii-this> - 2011-04-27 15:28 +0000
  Re: memory allocation for "Nigel Wade" <nigel.wade@THRWHITE.remove-dii-this> - 2011-04-27 15:28 +0000
    Re: memory allocation for "Brandon McCombs" <brandon.mccombs@THRWHITE.remove-dii-this> - 2011-04-27 15:28 +0000

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