On 2009-11-12 12:05 PM, Andrew Straw wrote: > Celil Rufat wrote: >> I just installed matplotlib on Snow Leopard 10.6 with the Qt4 backend >> (via macports). However, when I try one of the Qt4 examles: >> >> python >> /opt/local/share/py26-matplotlib/examples/user_interfaces/embedding_in_qt4.py >> >> >> IOError: [Errno 4] Interrupted system call >> >> Any ideas on what could be causing this? > Out of curiosity, does anyone know where the signal interrupting the > system call is originating? Is this a standard communication mechanism > within Qt4? (I have never used Qt4.) I'm interested in knowing about OSS > that use signals as a means of across-thread or across-process > communication.
This problem arises when signal handlers are installed, not necessarily when a signal itself is sent (dtrace doesn't detect any). PyQt4 doesn't do it, but I think something in QApplication does. I really don't know what, though. Here are the files that call signal(3) or sigaction(3): ./src/3rdparty/freetype/src/tools/ftrandom/ftrandom.c ./src/3rdparty/phonon/qt7/quicktimevideoplayer.mm ./src/3rdparty/sqlite/shell.c ./src/3rdparty/webkit/JavaScriptCore/jsc.cpp ./src/corelib/io/qfilesystemwatcher_dnotify.cpp ./src/corelib/io/qprocess_unix.cpp ./src/corelib/kernel/qcrashhandler.cpp ./src/corelib/kernel/qeventdispatcher_unix.cpp ./src/gui/embedded/qwindowsystem_qws.cpp ./src/gui/embedded/qwssignalhandler.cpp ./tools/qvfb/main.cpp It's not obvious to me that any of these are activated on OS X (the qcrashhandler.cpp file is intriguing, but it only seems to be used in the X11 QApplication). dtrace doesn't actually show either signal(3) or sigaction(3) being called at all. Actually, running a program under dtrace while probing those functions makes the problem go away. Sometimes. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
