[PATCH 0/2] Capture and display frame thumbnails in qapitrace. (Pass 2)

Tue Mar 13 10:55:41 PDT 2012

On 03/13/2012 02:15 AM, José Fonseca wrote:
> On Mon, Mar 12, 2012 at 4:32 PM, Dan McCabe<zen3d.linux at gmail.com>  wrote:
>> On 03/11/2012 07:36 AM, José Fonseca wrote:
>>> On Tue, Mar 6, 2012 at 1:20 AM, Dan McCabe<zen3d.linux at gmail.com>    wrote:
>>>> This patch set automatically captures and displays thumbnails for each
>>>> frame in qapitrace.
>>>>
>>>> qapitrace spawns glretrace in a separate process to replay traces and
>>>> capture relevent information about those traces. In the first patch, a
>>>> sequence of snapshots is generated and captured thumbnails. In the second
>>>> patch, those thumbnails are associated with the approproate
>>>> ApiTraceFrame.
>>>> When the ApiTraceEvent is processed for each frame, the thumbnail is
>>>> displayed at the front of the frame's information.
>>>>
>>>> Deltas from the previous iteration of the patch set:
>>>>
>>>> 1) Replaced readAllStandardOutput with QProcess::setReadChannel() and
>>>> QProcess::read() while capturing snapshot stream. This eliminates the
>>>> out-of-memory exceptions I was encountering in my previous patch set.
>>>>
>>>> 2) Testing for going past end of QList in bindThumbnailsToFrames. This
>>>> should eliminate asset failures that Jose encountered (but which I never
>>>> saw).
>>> Dan, I'm now seeing a slightly different assertion failure:
>>>
>>> ASSERT failure in QList<T>::operator[]: "index out of range", file
>>> /usr/include/qt4/QtCore/qlist.h, line 460
>>>
>>> Program received signal SIGABRT, Aborted.
>>> 0x00007ffff3830475 in *__GI_raise (sig=<optimized out>) at
>>> ../nptl/sysdeps/unix/sysv/linux/raise.c:64
>>> 64      ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or
>>> directory.
>>> (gdb) bt
>>> #0  0x00007ffff3830475 in *__GI_raise (sig=<optimized out>) at
>>> ../nptl/sysdeps/unix/sysv/linux/raise.c:64
>>> #1  0x00007ffff38336f0 in *__GI_abort () at abort.c:92
>>> #2  0x00007ffff4392571 in qt_message_output(QtMsgType, char const*) ()
>>> from /usr/lib/libQtCore.so.4
>>> #3  0x00007ffff43928ef in ?? () from /usr/lib/libQtCore.so.4
>>> #4  0x00007ffff4392a94 in qFatal(char const*, ...) () from
>>> /usr/lib/libQtCore.so.4
>>> #5  0x000000000043121f in QList<ApiTraceFrame*>::operator[]
>>> (this=0x85a3b0, i=0) at /usr/include/qt4/QtCore/qlist.h:460
>>> #6  0x000000000042f62d in ApiTrace::callInFrame (this=0x85a390,
>>> callIdx=6) at /home/jfonseca/projects/apitrace/gui/apitrace.cpp:454
>>> #7  0x000000000042f6e7 in ApiTrace::setCallError (this=0x85a390,
>>> error=...) at /home/jfonseca/projects/apitrace/gui/apitrace.cpp:471
>>> #8  0x0000000000462bf6 in MainWindow::slotRetraceErrors
>>> (this=0x7fffffffdd70, errors=...)
>>>      at /home/jfonseca/projects/apitrace/gui/mainwindow.cpp:1047
>>> #9  0x0000000000464784 in MainWindow::qt_metacall
>>> (this=0x7fffffffdd70, _c=QMetaObject::InvokeMetaMethod, _id=35,
>>> _a=0x7fffffffd400)
>>>      at /home/jfonseca/projects/apitrace/gui/mainwindow.moc:179
>>> #10 0x00007ffff4494eba in QMetaObject::activate(QObject*, QMetaObject
>>> const*, int, void**) () from /usr/lib/libQtCore.so.4
>>> #11 0x000000000046fcb9 in Retracer::retraceErrors (this=0x81eb80,
>>> _t1=...) at /home/jfonseca/projects/apitrace/gui/retracer.moc:248
>>> #12 0x000000000046fb3c in Retracer::qt_metacall (this=0x81eb80,
>>> _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0x903270)
>>>      at /home/jfonseca/projects/apitrace/gui/retracer.moc:207
>>> #13 0x00007ffff4498a6a in QObject::event(QEvent*) () from
>>> /usr/lib/libQtCore.so.4
>>> #14 0x00007ffff4cbcc64 in QApplicationPrivate::notify_helper(QObject*,
>>> QEvent*) () from /usr/lib/libQtGui.so.4
>>> #15 0x00007ffff4cc1af1 in QApplication::notify(QObject*, QEvent*) ()
>>> from /usr/lib/libQtGui.so.4
>>> #16 0x00007ffff448228c in QCoreApplication::notifyInternal(QObject*,
>>> QEvent*) () from /usr/lib/libQtCore.so.4
>>> #17 0x00007ffff4485648 in
>>> QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)
>>> () from /usr/lib/libQtCore.so.4
>>> #18 0x00007ffff44ac9d3 in ?? () from /usr/lib/libQtCore.so.4
>>> #19 0x00007ffff1e950cf in g_main_context_dispatch () from
>>> /lib/x86_64-linux-gnu/libglib-2.0.so.0
>>> #20 0x00007ffff1e958c8 in ?? () from
>>> /lib/x86_64-linux-gnu/libglib-2.0.so.0
>>> #21 0x00007ffff1e95a99 in g_main_context_iteration () from
>>> /lib/x86_64-linux-gnu/libglib-2.0.so.0
>>> #22 0x00007ffff44ace2f in
>>> QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
>>> () from /usr/lib/libQtCore.so.4
>>> #23 0x00007ffff4d60eee in ?? () from /usr/lib/libQtGui.so.4
>>> #24 0x00007ffff4481492 in
>>> QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
>>> from /usr/lib/libQtCore.so.4
>>> #25 0x00007ffff448168f in
>>> QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
>>> /usr/lib/libQtCore.so.4
>>> #26 0x00007ffff4485837 in QCoreApplication::exec() () from
>>> /usr/lib/libQtCore.so.4
>>> #27 0x000000000046cd7a in main (argc=2, argv=0x7fffffffe198) at
>>> /home/jfonseca/projects/apitrace/gui/main.cpp:68
>>> (gdb)
>>>
>>> I don't have time to debug this myself right now. But from the looks
>>> of it, I get the feeling that glretrace is being invoked before the
>>> trace is fully scanned.
>>>
>>> Jose
>> Thanks, Jose. I'll look into it further.
>>
>> Do you have an app scenario to help me repro the error you encountered? I
>> haven't seen the problem myself.
> Dan,
>
> This is the trace:
> http://people.freedesktop.org/~jrfonseca/traces/chromium-egl-field.trace
>
> It is an EGL trace, which leads to two issues:
>
> - glretrace can't retrace and emits a warning, and it is this warning
> while generating the thumbnails that causes the assertion. I suspect
> that the problem is that the thumbnail starts before the trace is
> fully scaned, and can proceed faster.
>
> - eglretrace should be used -- but thumbnails are created before the
> user can choose the api. Either qapitrace autodetects the API from the
> trace first call, or the thumbnails is not automatic. I think
> autodetection is the best, and I also hope one day to unify glretrace
> and eglretrace.
>
> With regular GL traces it works ok, and is pretty neat!
>
> Concerning the PNM parsing, I believe a good way to organize the code
> would be to have a PNM parser class with the following interface
>
>       class PNMParser {
>
>       // callback to read one line
>       virtual readLine(...);
>       // callback to read a buffer
>       virtual readBuffer(...);
>
>       // callback to handle comments
>       virtual handleComment(const char *comment);
>
>       // callback
>       virtual handleImage(Image&image);
>
>       // parse concatenated PNM images till EOF
>       parse();
>
>       };
>
> Then there would be a
>
>       class ThumnailParser : public PNMParser {
>
>       ThumnailParser(QProcess&process, ...);
>
>       }
>
>
> This would allow to have the PNM parsing, and thumnail contstruction separated.
>
> Jose
Great details on the repo! Thanks for the info.

Also, thanks for the suggestions on a better way to deal with PNM 
parsing. Stay tuned :).

cheers, danm