Crashes subscribing to some topics

[erichahn]

[~]$ rosrun plotjuggler PlotJuggler
"libDataLoadCSV.so" : is a DataLoader plugin
"libDataLoadROS.so" : is a DataLoader plugin
"libDataLoadULog.so" : is a DataLoader plugin
"libDataStreamROS.so" : is a DataStreamer plugin
"libDataStreamSample.so" : is a DataStreamer plugin
"libDataStreamSample.so" ...but will be ignored unless the argument -t is used.
"libRosoutPublisher.so" : is a StatePublisher plugin
"libRosTopicPublisher.so" : is a StatePublisher plugin
terminate called after throwing an instance of 'RosIntrospection::RangeException'
what(): Floating point truncated
Stack trace (most recent call last):
#31 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa6b0ea4, in QDesktopWidget::qt_metacall(QMetaObject::Call, int, void**)
#30 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa65e631, in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer&, bool)
#29 Object "/usr/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f20f98d98d7, in QCoreApplication::notifyInternal2(QObject*, QEvent*)
#28 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa65f65e, in QApplication::notify(QObject*, QEvent*)
#27 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa65783b, in QApplicationPrivate::notify_helper(QObject*, QEvent*)
#26 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa7da6fa, in QMenu::event(QEvent*)
#25 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa696047, in QWidget::event(QEvent*)
#24 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa7d83d2, in QMenu::mouseReleaseEvent(QMouseEvent*)
#23 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa7d75aa, in QMenu::leaveEvent(QEvent*)
#22 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa7d00fb, in QMenu::setIcon(QIcon const&)
#21 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa65380b, in QAction::activate(QAction::ActionEvent)
#20 Object "/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f20fa651121, in QAction::triggered(bool)
#19 Object "/usr/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f20f990866e, in QMetaObject::activate(QObject*, int, int, void**)
#18 Object "/opt/ros/melodic/lib/plotjuggler/PlotJuggler", at 0x5632fdb4b137, in main
#17 Object "/opt/ros/melodic/lib/plotjuggler/PlotJuggler", at 0x5632fdb4acc1, in main
#16 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e875e9, in DataStreamROS::start(QStringList*)
#15 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e863b2, in DataStreamROS::extractInitialSamples()
#14 Object "/opt/ros/melodic/lib/libroscpp.so", at 0x7f20c14ac61a, in ros::CallbackQueue::callAvailable(ros::WallDuration)
#13 Object "/opt/ros/melodic/lib/libroscpp.so", at 0x7f20c14aa8a8, in ros::CallbackQueue::callOneCB(ros::CallbackQueue::TLS*)
#12 Object "/opt/ros/melodic/lib/libroscpp.so", at 0x7f20c14fffa1, in ros::SubscriptionQueue::call()
#11 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e97681, in ros::SubscriptionCallbackHelperT<boost::shared_ptr<RosIntrospection::ShapeShifter const> const&, void>::call(ros::SubscriptionCallbackHelperCallParams&)
#10 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e8cce1, in boost::detail::function::void_function_obj_invoker1<boost::function<void (boost::shared_ptr<RosIntrospection::ShapeShifter const> const&)>, void, boost::shared_ptr<RosIntrospection::ShapeShifter const> >::invoke(boost::detail::function::function_buffer&, boost::shared_ptr<RosIntrospection::ShapeShifter const>)
#9 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e85871, in DataStreamROS::topicCallback(boost::shared_ptr<RosIntrospection::ShapeShifter const> const&, std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&)
#8 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e9dfdb, in CompositeParser::parseMessage(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, nonstd::span_lite::span<unsigned char, -1l>, double)
#7 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8e9e2c5, in IntrospectionParser::parseMessage(nonstd::span_lite::span<unsigned char, -1l>, double)
#6 Object "/opt/ros/melodic/lib/plotjuggler/libDataStreamROS.so", at 0x7f20a8ea1fb6, in double RosIntrospection::Variant::convert() const
#5 Object "/usr/lib/x86_64-linux-gnu/libstdc++.so.6", at 0x7f20f9358d53, in __cxa_throw
#4 Object "/usr/lib/x86_64-linux-gnu/libstdc++.so.6", at 0x7f20f9358b20, in std::terminate()
#3 Object "/usr/lib/x86_64-linux-gnu/libstdc++.so.6", at 0x7f20f9358ae5, in std::rethrow_exception(std::__exception_ptr::exception_ptr)
#2 Object "/usr/lib/x86_64-linux-gnu/libstdc++.so.6", at 0x7f20f9352956, in
#1 Source "/build/glibc-2ORdQG/glibc-2.27/stdlib/abort.c", line 79, in __GI_abort [0x7f20f895f8b0]
#0 Source "/build/glibc-2ORdQG/glibc-2.27/signal/../sysdeps/unix/sysv/linux/raise.c", line 51, in __GI_raise [0x7f20f895df47]
Aborted (Signal sent by tkill() 10395 1000)
Aborted (core dumped)

using

[facontidavide]

You know I am going to ask you for a rosbag to reproduce this, don't you?

[erichahn]

I do thanks to your wonderful issue templates - it has been sent to you.
When playing the bag and subscribing to it from plotjuggler the issue is present.

When attempting to load the entire bag it complains "Floating point truncated"
Older versions of plot juggler supported this bag. If I knew what version it was I would attach that here.

I am on 18.04 melodic if that makes a difference.

[facontidavide]

Ok, mystery solved. The error is exactly what it says it is.

You are converting a very large long integer to double and there is numerical cancelation in the process.

Therefore, the value you will see in PlotJuggler WILL be slightly misleading. False data is worse than no data at all.

A simple solution would be to convert your number, currently expressed in nanoseconds, to microseconds on your side.

https://en.wikipedia.org/wiki/Double-precision_floating-point_format

This is one of the incriminated numbers:

    1597865833630083120 unsigned long

As long as your big number can be expressed in 52 bits (roughly 4 * 10^15), you are safe from numerical cancelation.

[facontidavide]

Said that, I need a better message in the UI ;)

I am also reopening the issue, because it should NOT crash, but show instead an error in a dialog box.

[erichahn]

Right now the message type is a uint64. Looking at the ros wiki could the reason for part of the issue be the translation over to python?
http://wiki.ros.org/msg - see uint64

`

Primitive Type	Serialization	C++	Python2	Python3
bool (1)	unsigned 8-bit int	uint8_t (2)	bool
int8	signed 8-bit int	int8_t	int
uint8	unsigned 8-bit int	uint8_t	int (3)
int16	signed 16-bit int	int16_t	int
uint16	unsigned 16-bit int	uint16_t	int
int32	signed 32-bit int	int32_t	int
uint32	unsigned 32-bit int	uint32_t	int
int64	signed 64-bit int	int64_t	long	int
uint64	unsigned 64-bit int	uint64_t	long	int
float32	32-bit IEEE float	float	float
float64	64-bit IEEE float	double	float
string	ascii string (4)	std::string	str	bytes
time	secs/nsecs unsigned 32-bit ints	ros::Time	rospy.Time
duration	secs/nsecs signed 32-bit ints	ros::Duration	rospy.Duration

`

[facontidavide]

Not at all. That is my code throwing an exception because I am paranoid about showing you a wrong number. As I said, if your int requires more than 52 bits, there WILL be numerical cancellation. I COULD ignore this and go on with my life, but I don’t want to.