Re: Segfault with Java and "make check"

[PhilipNienhuis]

Daniel Sebald wrote
> On 02/02/2013 10:08 AM, Mike Miller wrote:
>> On Sat, Feb 2, 2013 at 1:42 AM, Daniel J Sebald wrote:
>>>> I took a look at quadcc.cc and it is not recursion that is the problem.
>>>> It
>>>> simply implements some huge local variables on the stack that should
>>>> probably be allocated from the heap instead.  There is a #define in the
>>>> code that controls how many singularities can be passed to the
>>>> function.
>>>>
>>>> /* Define the size of the interval heap. */
>>>> #define cquad_heapsize                  200
>>>>
>>>> The current value is 200 which leads to ~322 kB worth of local
>>>> variables
>>>> on
>>>> the stack.  I think that specifying 50 singularities along an integral
>>>> path
>>>> would probably be plenty.  As a quick fix, does changing line 40 of
>>>> corefcn/quadcc.cc to 50 solve the problem?
>>>
>>>
>>> Not very efficient coding there.  Is the stack size always fixed for
>>> Octave?
>>> Or is that a system level thing?  If it is system level, some other
>>> operating system could have similar problems with the number 50 as
>>> opposed
>>> to 200.  That's not the type of thing that should be on a stack, but the
>>> heap.  (We had a discussion about this sort of thing at OctConf2012.)
>>
>> Yes, this was just a quick check to verify the problem, Rik did
>> suggest moving it to the heap as a real solution.
>>
>> The stack size is a configurable per-process resource on Unix-like
>> systems, see ulimit, setrlimit, RLIMIT_STACK.
>>
>> If I reduce my stack size to 64 kB (ulimit -s 64 in bash) and run
>> "make check" it segfaults again on dblquad even with this patch
>> applied.
> 
> OK, nice check.  Seems to verify just what is happening.

The intruiging thing is that it does not segfault in the GUI. 
Doing:

cd <OctaveSRC>/test
fntests

makes the CLI segfault but not the GUI.
What is different in the GUI that it behaves more robust than the CLI (...in
this respect)?

Philip




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