Multithreaded debugging with gdb

[Milian Wolff]

On Sunday 30 November 2014 16:50:52 Gregor Mi wrote:
> On 30/11/14 14:59, Milian Wolff wrote:
> > On Saturday 29 November 2014 23:53:15 Gregor Mi wrote:
> >> Hello,
> >> 
> >> I am debugging a QT app that used QtConcurrent::run with kdevelop/gdb.
> >> The
> >> application hangs until the run method is completed.
> >> 
> >> Is this a gdb issue (like here [1]) or am I maybe missing some QT
> >> specific
> >> setting?
> > 
> > Have you tried the example in the bug report? What version of GDB are you
> > using?
> 
> No, I did not try the example. I was debugging ksnapshot for this RR:
> https://git.reviewboard.kde.org/r/120920/ and I was wondering why the
> application window is blocked. It leads to the case that I cannot debug
> code that is executed while the menu is still constructed.

Well then, try the example. It's simple to compile, really and just takes a 
few seconds to verify it's GDB's fault.

> So I understand that this is not a general issue with QT/KDE and there are
> not special settings.
> 
> GNU gdb (GDB; openSUSE 13.2) 7.8

Is that 7.8.0? Afaik that was indeed the faulty release.

Anyhow, if you'd read the bugreport you'd also see there is a workaround, 
which you can also test: Sent any signal, e.g. SIGCONT, to GDB to let it 
continue.

while true; do killall -s SIGCONT gdb || break; done

Bye
-- 
Milian Wolff
mail at milianw.de
http://milianw.de