[fxruby-users] crash analysis

[Andreas Schmidt]

Hi together,

I get the following error when I close my fxruby application:

watobo_gui.rb: [BUG] Segmentation fault
ruby 1.9.3p448 (2013-06-27) [i386-mingw32]

-- Control frame information -----------------------------------------------
c:0001 p:0000 s:0002 b:0002 l:00182c d:00182c TOP


-- C level backtrace information -------------------------------------------
C:\Windows\SysWOW64\ntdll.dll(ZwWaitForSingleObject+0x15) [0x77e4f8d1]
C:\Windows\syswow64\kernel32.dll(WaitForSingleObjectEx+0x43) [0x762b1194]
C:\Windows\syswow64\kernel32.dll(WaitForSingleObject+0x12) [0x762b1148]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_vm_bugreport+0xf9) [0x62e5bec5]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_name_err_mesg_new+0x17a) [0x62d3a87a]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_bug+0x2f) [0x62d3b557]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_check_safe_str+0x194) [0x62dee898]
[0x004011e6]
C:\Program Files\ThinkPad\Bluetooth
Software\SysWOW64\BtMmHook.dll(SetAndWaitBtM
mHook+0xfac9) [0x10013989]
C:\Windows\SysWOW64\ntdll.dll(RtlKnownExceptionFilter+0xb7) [0x77ea74ff]


Is this a thread problem? Because I use threads, but not for updating
the gui. I use Queues and Mutexes inside fxruby Timeouts (addTimeout).
Are there any limitations?

Is there an easy way to narrow it down to the responsible code? Because
I don't get any debug messages when the program is running in debug-mode
(-d). I only get the crash when I close the program.



regards,

Andy
_______________________________________________
fxruby-users mailing list
fxruby...@rubyforge.org
http://rubyforge.org/mailman/listinfo/fxruby-users

[Damián M. González]

I recommend you that write an issue here: https://github.com/larskanis/fxruby/issues?state=open if you want a relative quickly answer.

> Date: Thu, 26 Sep 2013 08:57:58 +0200
> From: wat...@siberas.de
> To: fxruby...@rubyforge.org
> Subject: [fxruby-users] crash analysis

[Damián M. González]

 Just to say something. Are you using recursive timeouts? I mean:

 timeout = app.addTimeout(delay, :repeat => true) do |sender, sel, data|

    ... handle the timeout ...
    ... re-add the timeout with the same delay ...
end

 If you are doing that try to finish them at exit. There's hooks in fxruby and in Ruby to do that. Also if your timeouts are not recursive, ask FXRuby if there are still running or just finish them with app.handleTimeouts . Try that.

> Date: Thu, 26 Sep 2013 08:57:58 +0200
> From: wat...@siberas.de
> To: fxruby...@rubyforge.org
> Subject: [fxruby-users] crash analysis
>

[Andreas Schmidt]

Thanks Damian,

I tried it, but it didn't work.
I updated the issue here: https://github.com/larskanis/fxruby/issues/8

thanks again,

andy

[Andreas Schmidt]

Hi,

after running in circles I finally found the real issue of my crashes.
It's based on FXTreeList.


## Crash
~~~
F:\Projects\TMP\fxruby_bugs>treelist_dialog.rb
Dialog Canceled
F:/Projects/TMP/fxruby_bugs/treelist_dialog.rb: [BUG] Segmentation fault

ruby 1.9.3p448 (2013-06-27) [i386-mingw32]

-- Control frame information -----------------------------------------------

c:0001 p:0000 s:0002 b:0002 l:00051c d:00051c TOP

-- C level backtrace information -------------------------------------------

C:\Windows\SysWOW64\ntdll.dll(ZwWaitForSingleObject+0x15) [0x77d6f8d1]
C:\Windows\syswow64\kernel32.dll(WaitForSingleObjectEx+0x43) [0x76561194]
C:\Windows\syswow64\kernel32.dll(WaitForSingleObject+0x12) [0x76561148]

C:\Ruby193\bin\msvcrt-ruby191.dll(rb_vm_bugreport+0xf9) [0x62e5bec5]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_name_err_mesg_new+0x17a) [0x62d3a87a]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_bug+0x2f) [0x62d3b557]
C:\Ruby193\bin\msvcrt-ruby191.dll(rb_check_safe_str+0x194) [0x62dee898]
[0x004011e6]
C:\Program Files\ThinkPad\Bluetooth
Software\SysWOW64\BtMmHook.dll(SetAndWaitBtM
mHook+0xfac9) [0x10013989]

C:\Windows\SysWOW64\ntdll.dll(RtlKnownExceptionFilter+0xb7) [0x77dc74ff]
~~~

## Analysis
The crash happens only when
* `myelements=` is called
* `appendItem` is called with a FXTreeItem object -> [2]
* a minimum of '4' num_root_nodes are used -> [3]

## Script
~~~
require 'fox16'
include Fox

class CheckBoxTreeList < FXTreeList
def myelements=(x)
clearItems
begin
x.each do |e|
node = nil
levels = e[:name].split('|')

levels.each_with_index do |l,i|
item = findItem(l, node, SEARCH_FORWARD|SEARCH_IGNORECASE)
if item.nil? then
new_item = FXTreeItem.new( l )
# [1]
# crash occurs when appendItem is called with a FXTreeItem
object
item = appendItem(node, new_item)
# [2]
# no crash when simple appendItem is used
#item = appendItem(node, i.to_s)
end
node = item
end
end

rescue => bang
puts bang
puts bang.backtrace
end
end

def initialize(parent)

@parent = parent
super(parent, :opts =>
LAYOUT_FILL_X|LAYOUT_FILL_Y|TREELIST_SHOWS_LINES|TREELIST_SHOWS_BOXES|TREELIST_ROOT_BOXES)#|TREELIST_MULTIPLESELECT)

end
end

class TestGui < FXMainWindow
class TreeDlg < FXDialogBox
include Responder

def initialize(parent, project=nil, prefs={} )

super(parent, "CheckBox Dialog", DECOR_ALL, :width => 300, :height
=> 400)

frame = FXVerticalFrame.new(self, :opts =>
LAYOUT_FILL_X|LAYOUT_FILL_Y|FRAME_GROOVE)
elements = []
# [3]
num_root_nodes = 10
max_child_nodes = 2
num_root_nodes.times do |ri|
max_child_nodes.times do |si|
name = "root#{ri}|sub#{si}"
data = name + "-data"
e = { :name => name, :enabled => false, :data => data }
elements << e
end
end

@cbtree = CheckBoxTreeList.new(frame)
# [4]
@cbtree.myelements = elements

@cancel_btn = FXButton.new(frame, "Cancel" , :target => self,
:selector => FXDialogBox::ID_CANCEL, :opts => BUTTON_NORMAL|LAYOUT_RIGHT)
FXMAPFUNC(SEL_COMMAND, ID_ACCEPT, :onAccept)
@accept_btn = FXButton.new(frame, "Accept" ,
:target => self, :selector => FXDialogBox::ID_ACCEPT,
:opts => BUTTON_NORMAL|LAYOUT_RIGHT)

end

def onAccept(sender, sel, event)
getApp().stopModal(self, 1)
self.hide()
1
end

end

def initialize(app)
super(app, "Test Application", :width => 800, :height => 600)
frame = FXVerticalFrame.new(self,
LAYOUT_FILL_X|LAYOUT_FILL_Y|FRAME_GROOVE)

FXButton.new(frame, "Open TreeDialog",:opts =>
FRAME_THICK|FRAME_RAISED|LAYOUT_FILL_X|LAYOUT_TOP|LAYOUT_LEFT).connect(SEL_COMMAND){
dlg = TreeDlg.new(self)
if dlg.execute != 0 then
puts "* Dialog Finished"
else
puts "Dialog Canceled"
end
}

FXButton.new(frame, "Exit",:opts =>
FRAME_THICK|FRAME_RAISED|LAYOUT_FILL_X|LAYOUT_TOP|LAYOUT_LEFT).connect(SEL_COMMAND){
leave }
end

def create
super # Create the windows
show(PLACEMENT_SCREEN) # Make the main window appear
end

def leave
getApp().exit(0)
end
end

application = FXApp.new('LayoutTester', 'FoxTest')
TestGui.new(application)
application.create
application.run
~~~


I appreciate any help,

Andy