On Wed, Sep 14, 2005 at 05:22:08PM -0500, John Gotts wrote: > Hi, I'm working on solving an intermittent bug with our gtk+ 1.x/Glade 1.x > application, although my problem should be general enough that people more > accustomed to 2.x should be able to help. > > We're embedding the GtkSheet widget as a custom widget. Occasionally, for no > rhyme or reason, Gtk+ gets into a CPU-consuming loop where the user is locked > out of X. Only changing to a virtual terminal and delivering a signal to the > running process will allow the user to interact with X again. This bug has > occurred using various versions of the X server, Fedora Core 2 and 3, RHL 9, > and on desktops and laptops. When I deliver a signal to the running process I > get something like this: > > #0 0x008bc380 in XDrawRectangle () from /usr/X11R6/lib/libX11.so.6 > (gdb) bt > #0 0x008bc380 in XDrawRectangle () from /usr/X11R6/lib/libX11.so.6 > #1 0x00a1dc68 in gdk_draw_rectangle () from /usr/lib/libgdk-1.2.so.0 > #2 0x00214abf in gtk_sheet_get_active_cell () > from /usr/lib/libgtkextra-0.99.so.17 > #3 0x00226e24 in gtk_sheet_delete_rows () from /usr/lib/libgtkextra-0.99.so.17 > #4 0x00be0e79 in gtk_marshal_BOOL__POINTER () from /usr/lib/libgtk-1.2.so.0 > #5 0x00baf333 in gtk_signal_emit_stop_by_name () from /usr/lib/libgtk-1.2.so.0 > #6 0x00bafee7 in gtk_signal_emit () from /usr/lib/libgtk-1.2.so.0 > #7 0x00b751b9 in gtk_widget_event () from /usr/lib/libgtk-1.2.so.0 > #8 0x00be2c0c in gtk_propagate_event () from /usr/lib/libgtk-1.2.so.0 > #9 0x00be2fa7 in gtk_main_do_event () from /usr/lib/libgtk-1.2.so.0 > #10 0x00a1d620 in gdk_event_get () from /usr/lib/libgdk-1.2.so.0 > #11 0x009e7287 in g_get_current_time () from /usr/lib/libglib-1.2.so.0 > #12 0x009e7f13 in g_main_add_poll () from /usr/lib/libglib-1.2.so.0 > #13 0x009e80e5 in g_main_run () from /usr/lib/libglib-1.2.so.0 > #14 0x00be2232 in gtk_main () from /usr/lib/libgtk-1.2.so.0 > #15 0x080d3357 in main (argc=1, argv=0xbfe33584) at main.c:113 > > gtk_sheet_delete_rows() is never called by my program. gtk_sheet_get_active_ > cell() is never called by gtk_sheet_delete_rows(). gdk_draw_rectangle() is > never called by gtk_sheet_get_active_cell(). Every backtrace of the running > process is identical up to #2, although there are some variations above it. > When I put a debugging printf() in gtk_sheet_delete_rows() nothing is printed, > which tells me that the stack got corrupted somehow. Admittedly, I'm no > debugger expert. Perhaps someone could fill me in on how obviously not > called functions can appear in a backtrace? > > Any clues on how to diagnose this problem? Is it just a random double free() > somewhere in my application which happens to stomp all over memory or could it > be a Gtk+ bug of some kind? ah, don't you love problems like that? I love them. ;) first re-compile with optimizations turned off. still have a problem? still get a weird stack? compiler optimazations can make instructions seem to run out of order. I don't recall this ever affecting the stack like this though. second. are you using any sort of non-linear processing like threads or posix signals? or... long-jump stuff? (other?) Don't mess with any gtk widgets during a posix signal handler. it will screw things up. also, when I'm looking at wonky stacks I look for pointers that point into the stack, and double check how they're being used. good luck. - Ben _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
