[PATCH 0/2] Capture and display frame thumbnails in qapitrace

[José Fonseca]

On Wed, Feb 29, 2012 at 7:56 PM, 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. In the second patch,
> those snapshots are associated with the approproate ApiTraceFrame. When
> the ApiTraceEvent is processed for each frame, the snapshot is reduced
> in size for a thumbnail and that thumbnail is displayed at the front
> of the frame's information.

Thanks for doing this. This is a really nice feature!

I've pushed your patches to a gui-thumbnails branch to facilitate testing.

I'll defer to Zack comments on the gui implementation.

> Open issue: the thumbnail isn't immediately displayed. However, the
> instant the user interacts with the app, all thumbnails are displayed.
> Suggestions on how to force the app to initiate that update without
> user interaction would be appreciated.

We should also have an option for glretrace to run headless (don't
show any window), as they can be distracting sometimes.

> Open issue: the communication of an image stream from glretrace to
> qapitrace is a bit fragile. I have encountered several exceptions when
> Qt runs out of memory in QProcess::readAllStandardOutput() and an
> exception is thrown. Qt isn't particularly graceful about handling
> this exception. There are ways to mitigate this running out of memory
> and I am currently working on that. One way is to reduce the snapshot
> size at the time of capture. I prototyped a snapshot scaling arg in
> glretrace, but I'm open to other suggestions.

readAllStandardOutput should be replaced with something that doesn't
read the whole output. For example QProcess::setReadChannel()  and
read()


I'm also running into assert failures with any trace I try:

ASSERT failure in QList<T>::at: "index out of range", file
/usr/include/qt4/QtCore/qlist.h, line 456

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.
	in ../nptl/sysdeps/unix/sysv/linux/raise.c
(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 qt_message(QtMsgType, char const*,
__va_list_tag*) () from /usr/lib/libQtCore.so.4
#4  0x00007ffff4392a94 in qFatal(char const*, ...) () from
/usr/lib/libQtCore.so.4
#5  0x000000000043197d in QList<QImage>::at (this=0xb1c910, i=21) at
/usr/include/qt4/QtCore/qlist.h:456
#6  0x000000000042f77a in ApiTrace::bindSnapsToFrames (this=0x812500,
snaps=0xb1c910) at
/home/jfonseca/projects/apitrace/gui/apitrace.cpp:505
#7  0x00000000004619cb in MainWindow::replaySnapsFound
(this=0x7fffffffdcc0, snaps=0xb1c910) at
/home/jfonseca/projects/apitrace/gui/mainwindow.cpp:855
#8  0x0000000000464077 in MainWindow::qt_metacall
(this=0x7fffffffdcc0, _c=QMetaObject::InvokeMetaMethod, _id=9,
_a=0x7fffffffd350)
    at /home/jfonseca/projects/apitrace/gui/mainwindow.moc:153
#9  0x00007ffff4494eba in QMetaObject::activate(QObject*, QMetaObject
const*, int, void**) () from /usr/lib/libQtCore.so.4
#10 0x000000000046f0c5 in Retracer::foundSnaps (this=0x7db6a0,
_t1=0xb1c910) at /home/jfonseca/projects/apitrace/gui/retracer.moc:234
#11 0x000000000046ef9f in Retracer::qt_metacall (this=0x7db6a0,
_c=QMetaObject::InvokeMetaMethod, _id=2, _a=0x8909a0) at
/home/jfonseca/projects/apitrace/gui/retracer.moc:205
#12 0x00007ffff4498a6a in QObject::event(QEvent*) () from
/usr/lib/libQtCore.so.4
#13 0x00007ffff4cbcc64 in QApplicationPrivate::notify_helper(QObject*,
QEvent*) () from /usr/lib/libQtGui.so.4
#14 0x00007ffff4cc1af1 in QApplication::notify(QObject*, QEvent*) ()
from /usr/lib/libQtGui.so.4
#15 0x00007ffff448228c in QCoreApplication::notifyInternal(QObject*,
QEvent*) () from /usr/lib/libQtCore.so.4
#16 0x00007ffff4485648 in
QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)
() from /usr/lib/libQtCore.so.4
#17 0x00007ffff44ac9d3 in postEventSourceDispatch(_GSource*, int
(*)(void*), void*) () from /usr/lib/libQtCore.so.4
#18 0x00007ffff1eaf0cf in g_main_dispatch (context=0x7034e0) at
/tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:2442
#19 g_main_context_dispatch (context=0x7034e0) at
/tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:2998
#20 0x00007ffff1eaf8c8 in g_main_context_iterate (context=0x7034e0,
block=<optimized out>, dispatch=1, self=<optimized out>) at
/tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:3076
#21 0x00007ffff1eafa99 in g_main_context_iteration (context=0x7034e0,
may_block=1) at /tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:3139
#22 0x00007ffff44ace2f in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
() from /usr/lib/libQtCore.so.4
#23 0x00007ffff4d60eee in
QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
() 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 0x000000000046c544 in main (argc=2, argv=0x7fffffffe0e8) at
/home/jfonseca/projects/apitrace/gui/main.cpp:65

Jose