Cocoa mail archive
Re: Breaking into debugger after program hangs....
FROM : John Draper
DATE : Thu Apr 28 22:12:36 2005
Ondra Cada wrote:
> John,
>
> On 28.4.2005, at 10:48, John Draper wrote:
>
>> Is there a way to break into the debugger when the program hangs? Is
>> it a
>> special key combination?
>
>
> There's the "pause" ("||") nice small bu
> t in --- I'm sorry this line is so munged, but this stupid
thunderbird is a really bad FUCKUP...
> in t
In the GUI of what? The Debugger? X-Code? What GUI are you talking
about. I see no pause button in MY GUI so you must not be talking about
the Debugger or X-Code.
<>
>Also, ctrl-c in the gdb console used to work pretty well, but thate I
haven't trid
fora long time.
WTF is it with this CRAPPY "Thunderbird" editor...
> And once in the debugger, how do I get the current stack trace using
> gdb or source level debugger. To find out where it crashed....
>Gdb is the source level debugger.
It is? I thought "gdb" was a console type debugger with command prompts.
>Anyway, in GUI there is a pane with the stack trace; in the console
enter "bt".
Isn't "bt" just to seat a breakpoint. What is the difference between
the "gdb" "bt"
and "b" which also sets breakpoints.
> Is there a way to cause the application to break at a breakpoint
> when I try and send a message to a de-allocated object?
>
> I set NSZombieEnabled = YES, and I got...
>
> Program received signal: "EXC_BAD_ACCESS".
>Does not feel right, the problem would be elsewhere. If zombies
enabled, the program does not crash this way. It would >report what happened
Well - that's what I'm getting, and I sure would like to find out what
it means, so if anyone ELSE
reading this can shed me some light, please don't hesitate to tell
me... APPLE PEOPLE - WHERE
are you? - I thought I remember reading that Apple people sometimes
read this mailing list.... Can
someone please convence me this is true?
> Then, the tech note says... You can use GDB to set a breakpoint on
> -[_NSZombie methodSignatureForSelector:] to further debug this sort of
> problem.
>Before, of course. What's the point of setting a breakpoint *after*
the code crashed?
That's the point of my asking that question.... obviously there isn't -
but why did the tech note
even mention it, and why didn't it go off and tell the reader how to
use that breakpoint, and
when to set it, and give examples of what the output is with an
explanation.
>Nevertheless, I fear it won't break anyway, for, as said above, the
problem seems to be caused by something other.
If that's the case, then can someone please shed some light on how I
can find out what's going on?
I'm almost sure some handle got de-allocated, and I'm also sure there
MUST be a way to identify
which one it is.... I hear people talking about it, but nobody seems
to ever bother with explaining it
to us Newbees..... nor can we find adequate Docs, expecially on all
this unsupported debugger
info in some of these tech notes.
John
DATE : Thu Apr 28 22:12:36 2005
Ondra Cada wrote:
> John,
>
> On 28.4.2005, at 10:48, John Draper wrote:
>
>> Is there a way to break into the debugger when the program hangs? Is
>> it a
>> special key combination?
>
>
> There's the "pause" ("||") nice small bu
> t in --- I'm sorry this line is so munged, but this stupid
thunderbird is a really bad FUCKUP...
> in t
In the GUI of what? The Debugger? X-Code? What GUI are you talking
about. I see no pause button in MY GUI so you must not be talking about
the Debugger or X-Code.
<>
>Also, ctrl-c in the gdb console used to work pretty well, but thate I
haven't trid
fora long time.
WTF is it with this CRAPPY "Thunderbird" editor...
> And once in the debugger, how do I get the current stack trace using
> gdb or source level debugger. To find out where it crashed....
>Gdb is the source level debugger.
It is? I thought "gdb" was a console type debugger with command prompts.
>Anyway, in GUI there is a pane with the stack trace; in the console
enter "bt".
Isn't "bt" just to seat a breakpoint. What is the difference between
the "gdb" "bt"
and "b" which also sets breakpoints.
> Is there a way to cause the application to break at a breakpoint
> when I try and send a message to a de-allocated object?
>
> I set NSZombieEnabled = YES, and I got...
>
> Program received signal: "EXC_BAD_ACCESS".
>Does not feel right, the problem would be elsewhere. If zombies
enabled, the program does not crash this way. It would >report what happened
Well - that's what I'm getting, and I sure would like to find out what
it means, so if anyone ELSE
reading this can shed me some light, please don't hesitate to tell
me... APPLE PEOPLE - WHERE
are you? - I thought I remember reading that Apple people sometimes
read this mailing list.... Can
someone please convence me this is true?
> Then, the tech note says... You can use GDB to set a breakpoint on
> -[_NSZombie methodSignatureForSelector:] to further debug this sort of
> problem.
>Before, of course. What's the point of setting a breakpoint *after*
the code crashed?
That's the point of my asking that question.... obviously there isn't -
but why did the tech note
even mention it, and why didn't it go off and tell the reader how to
use that breakpoint, and
when to set it, and give examples of what the output is with an
explanation.
>Nevertheless, I fear it won't break anyway, for, as said above, the
problem seems to be caused by something other.
If that's the case, then can someone please shed some light on how I
can find out what's going on?
I'm almost sure some handle got de-allocated, and I'm also sure there
MUST be a way to identify
which one it is.... I hear people talking about it, but nobody seems
to ever bother with explaining it
to us Newbees..... nor can we find adequate Docs, expecially on all
this unsupported debugger
info in some of these tech notes.
John
