Re: Unloading JVM

[Rik]

On 02/02/2013 09:09 AM, address@hidden wrote:
> Message: 6 Date: Sat, 2 Feb 2013 08:57:56 -0800 (PST) From:
> PhilipNienhuis <address@hidden> To: address@hidden
> Subject: Re: Segfault with Java and "make check" Message-ID:
> <address@hidden> Content-Type: text/plain;
> charset=us-ascii Michael Goffioul wrote
>> > On Fri, Feb 1, 2013 at 12:11 PM, John W. Eaton &lt;
>> > jwe@
>> > &gt; wrote:
>> > 
>>> >> Oops, I forgot to CC the list.
>>> >>
>>> >> jwe
>>> >>
>>> >>
>>> >> -------- Original Message --------
>>> >> Subject: Re: Segfault with Java and "make check"
>>> >> Date: Fri, 01 Feb 2013 11:07:12 -0600
>>> >> From: John W. Eaton &lt;
>> > jwe@
>> > &gt;
>>> >> To: Rik &lt;
>> > rik@
>> > &gt;
>>> >> CC: 
>> > jwe@
>>> >>
>>> >> On 02/01/2013 10:40 AM, Rik wrote:
>>> >>
>>> >>  This seems like  a reasonable supposition.  The quadcc algorithm uses
>>>> >>> adaptive rules which involve recursively subdividing the integration
>>>> >>> region.  When the function is smooth the process doesn't go very far.
>>>> >>> Around singularities or discontinuities the algorithm has to shrink the
>>>> >>> integration step size to small values to ensure it maintains the 
>>>> >>> overall
>>>> >>> accuracy desired.  This would mean lots of recursion.
>>>> >>>
>>> >>
>>> >> The JVM is not supposed to be loaded unless it is actually needed.  Is
>>> >> there some test that runs prior to the one that fails that causes the
>>> >> JVM to be loaded?
>> > 
>> > 
>> > Yes, I guess there is. There are java-related tests in
>> > libinterp/octave-value/ov-java.cc, and these are run before reaching the
>> > tests in m-files.
> (Indeed. I've put those tests in, on Rik's request, and I have a few more in
> various states of development pending)
>
> Isn't there a way to unload the JVM and free its resources if it isn't
> needed anymore, either manually, or automatically after a period of non-use? 
Alas, no.  There is code written but if you attempt to use it you get
segfaults.  There is an outstanding bug report about that
(https://savannah.gnu.org/bugs/?37877).  You can call javamem() which will
at least force the garbage collector to run.

--Rik