wxruby users - Mar 2009 - MethodMissing calc_min

This is kind of hard to explain, but I''ll do my best.

I have a window that has a complex ListCtrl using LC_VIRTUAL, and my
own implementation of ListView. I use this tons of places and it works
fine, except for here. In Ruby 1.8 there''s no warning, just a segfault
out of nowhere. In Ruby 1.9, when trying to do set_size() on the
Wx::Frame or show(), it crashes every time by raising a NoMethodError
on "calc_min" for various objects. The object changes every time, but
has been String, Array, Hash, and various of my own objects. I don''t
do anything with calc_min() in my ListView, and this doesn''t happen
ANYWHERE else. Sometimes it works fine on 1.8, and sometimes it
segfaults. I can make the code available on a limited basis (it is
private, for the US government), preferably only to Alex, if you think
you can help.

I know that''s not a ton of information, but I''m not sure what
else I
can include. I''ve tried very hard to make sure it''s not
something I''m
doing, and I can''t reproduce it with anything but the exact code I use
now. In order for you to reproduce it you''d probably need the whole
program (which is huge, and complicated), but I can provide you with
traces or anything you need.

Thanks for any help you can provide.

-- Eric Will

/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`calc_min'': undefined method `calc_min'' for
#<DateTime:0x00000003046de0> (NoMethodError)
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`calc_min''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`calc_min''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`calc_min''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`calc_min''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`layout''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`process_event''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`process_event''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`show''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera/ui/equipmentfinder.rb:34:in
`initialize''
	from /home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera.rb:173:in
`new''
	from /home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Palaeoptera.rb:173:in
`block in on_init''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Hymenoptera/ui/main.rb:106:in
`call''
	from
/home/rakaur/Dropbox/Sources/work/Palaeoptera/lib/Hymenoptera/ui/main.rb:106:in
`block (2 levels) in initialize_events''
	from bin/Palaeoptera.rb:20:in `call''
	from bin/Palaeoptera.rb:20:in `process_event''
	from bin/Palaeoptera.rb:20:in `process_event''
	from bin/Palaeoptera.rb:20:in `process_event''
	from bin/Palaeoptera.rb:20:in `on_run''
	from bin/Palaeoptera.rb:20:in `main_loop''
	from bin/Palaeoptera.rb:20:in `<main>''
rakaur@callandor ~/Dropbox/Sources/work/Palaeoptera $

Line 34 is a show() call for a Wx::Frame.

Eric Will wrote:
> This is kind of hard to explain, but I''ll do my best.
>
> I have a window that has a complex ListCtrl using LC_VIRTUAL, and my
> own implementation of ListView. I use this tons of places and it works
> fine, except for here. In Ruby 1.8 there''s no warning, just a
segfault
> out of nowhere. In Ruby 1.9, when trying to do set_size() on the
> Wx::Frame or show(), it crashes every time by raising a NoMethodError
> on "calc_min" for various objects. The object changes every time,
but
> has been String, Array, Hash, and various of my own objects. I
don''t
> do anything with calc_min() in my ListView, and this doesn''t
happen
> ANYWHERE else. Sometimes it works fine on 1.8, and sometimes it
> segfaults. I can make the code available on a limited basis (it is
> private, for the US government), preferably only to Alex, if you think
> you can help.
>   
 From the sound of it it''s some kind of memory / object-tracking bug. I
haven''t come across one for a while but they are quite hard to diagnose
and reproduce.

calc_min is an overridable method of Wx::Sizer; like other similar 
methods, it''s sometimes called by the C++ core. Probably wxRuby is 
trying to call this on an Ruby object it thinks is a Wx::Sizer, but is 
something else.

If you want to contact me off-list I can take a look at your code on a 
confidential basis. I''m a bit short of time but can try to reproduce
it,
although the bugs are often dependent on each platform''s memory 
allocation order. It might be useful to know also:

- if the Frame concerned is explicitly sized, rather than using Sizers 
(as perhaps the other non-problematic ones)
- if the bug only occurs after some Frame has been opened and destroyed

a

On Mar 30, 2009, at 3:05 PM, Alex Fenton <alex at pressure.to>
wrote:
>>
> From the sound of it it''s some kind of memory / object-tracking
bug.
> I haven''t come across one for a while but they are quite hard to  
> diagnose and reproduce.
>
> calc_min is an overridable method of Wx::Sizer; like other similar  
> methods, it''s sometimes called by the C++ core. Probably wxRuby is
> trying to call this on an Ruby object it thinks is a Wx::Sizer, but  
> is something else.
>
> If you want to contact me off-list I can take a look at your code on  
> a confidential basis. I''m a bit short of time but can try to  
> reproduce it, although the bugs are often dependent on each  
> platform''s memory allocation order. It might be useful to know
also:
>
> - if the Frame concerned is explicitly sized, rather than using  
> Sizers (as perhaps the other non-problematic ones)
> - if the bug only occurs after some Frame has been opened and  
> destroyed
It happens in OS X, WinXP, and Linux. It crashes while trying to  
show() the Frame the ListView is in. It often tries calc_min() on  
members of my ListView. All my windows use Sizers.

I''ll get back to you tomorrow. Off work for now. I''m going to
do some
poking in my ListView which I have no problem making available before  
I burden anyone.

--
Eric Will