[Qt-creator] regular couple of second hangs

[Oswald Buddenhagen]

hi,

please don't top-post to mailing lists -
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On Tue, Dec 22, 2009 at 11:24:06AM +0100, ext Damien Fagnou wrote:
> >>> On Fri, Dec 11, 2009 at 05:26:33PM +0100, ext Damien Fagnou wrote:
> >>>> building a local version of QtCreator
> >>>>
> >>>> and breaking when the IDE hang , the debugger say I am  in :
> >>>>
> >>>> ---->>>        int nselect = select(qt_qprocess_deadChild_pipe[0] + 1, 
> >>>>
> >>> this is useless without a complete backtrace. [...]
> >>
> >> thanks for your reply . I am trying to track down what is this process 
> >> could be .
> >> is there any way you recommend I approach the problem ?
> >>
> >> when breaking in those "hangs" I consistently fall in a select call :
> >> see below the stack trace from qt-creator .
> >>
> >> 0    select    /lib64/libc.so.6    0    0x00000038abccc4c2   
> >> 1    QProcessManager::run    qprocess_unix.cpp    245    
> >> 0x00002b6eb12f93c4   
> >> 2    QThreadPrivate::start    qthread_unix.cpp    244    
> >> 0x00002b6eb121f035   
> >> 3    start_thread    /lib64/libpthread.so.0    0    0x00000038ac806367   
> >> 4    clone    /lib64/libc.so.6    0    0x00000038abcd2f7d   
> >>
> >> I am not sure how to tell what process is running that is hanging the 
> >> system ?
> >>
> >> any hint ?
> >>
> > also some other useful info
> > this is using the Makefile base project , with .includes and .files
> >
> > before starting to use qtCreator I spend some time developing couple of 
> > plugin on for Creator
> > and while I was doing that I dont remember experiencing any of those 'hangs'
> >
> > maybe that help ?
> >
> I have done some more testing .
> though it might be some hangs on the file system because of the include 
> paths on the network .
> but I cleared it and work a little and the same problem was there .
> 
> the hangs mostly appear when the application get the focus back. 
> breaking when it hand invariably set me into this
> select call I describe below , so I have not sure where to look to 
> figure out what can be wrong .
> 
> I am happy to investigate the problem on my own but at the moment I 
> really don't know where to start .
> 
> anyone would have an idea on a way to track down this problem ?
> 
the backtrace you gave is somewhat useless, as it seems to be from
qprocess' worker thread only, i.e. we don't know what the application
was actually doing. getting a backtrace for all threads would be done
in gdb with "thread apply all bt".