GDB 7.7 Eating An Entire CPU Core On QT App Launch For A Solid 20
Seconds
lazarus / 12-Debugger

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Rails · 2014-07-28 19:08

What the subject line says. This prevents the application from
actually appearing on the desktop, although a system monitor shows the
app's process running. The 20 second period is 100% repeatable. It
makes no difference if the app is compiled with debugging support or
without.

Launching the application from the command line has no delay and it
functions normally.  Other than the delay waiting for GDB to subside,
it also functions normally running under the IDE. Actual GDB debugging
also appears normal.

The issue only occurs with the application compiled for QT. It does
not occur if the application is compiled for GTK2. It makes no
difference if the IDE itself is compiled for GTK2 or QT.

Laz 1.2.4 from sourceforge yesterday. Same for FPC 2.6.4. Recent i386
Linux Mint Debian Edition w/XFCE4, fully updated this morning. When
that didn't help, pulled in Debian Unstable and further updated. GDB
now at 7.7.1-2 (Debian). No change.

I am assuming this is just another GDB problem, but if anyone has an
idea or two, I'm all ears.

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jwdietrich · 2014-07-28 21:59

Yes, as you say, this is just another GDB problem. I see a similar
delay on Mac OS X with the carbon widgetset.

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Martin_fr · 2014-07-28 22:48

Try this
http://wiki.lazarus.freepascal.org/GDB_Debugger_Tips#gdb.exe_has_stopp
ed_working

no-solib

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jwdietrich · 2014-07-28 22:52

Quote from: Martin_fr on July 29, 2014, 12:48:07 amTry this
http://wiki.lazarus.freepascal.org/GDB_Debugger_Tips#gdb.exe_has_stopp
ed_working

no-solib

The wiki page refers to loading of DLLs under Windows. Do similar
considerations apply to unixoid operating systems?

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Rails · 2014-07-29 00:16

Thanks Martin and JW.

Setting DisableLoadSymbolsForLibraries to True took care of the
problem for me. It's an imperfect solution, but I can always change
back if need be.

BTW, before I did this, I tried a couple of older versions of gdb on
the same machine without success. I have another 32 bit machine with
Laz 1.2.4 (older download) and FPC 2.6.4 from the Debian repository.
It doesn't have this problem for some reason.  'Tis a bit of a mystery
it seems.

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jwdietrich · 2014-07-29 17:31

GDB sucks. I wish ThinkPascal's LightsBug to be back, but this is a
kind of illusion.