I'm fairly new to dtrace. I'm using it on Oracle Linux 7.
I want the following probe only to fire when the execname equals a defined string. I've tried different ways without success. The way described in most tutorials didn't work
syscall::write*:entry
/execname=="dtrace"/
{
...
This doesn't work.
But the other way around works
syscall::write*:entry
/execname!="dtrace"/
{
...
Now the probe fires for every execname except "dtrace"
What's my mistake?
I don’t know how but a reboot fixed the problem...
Related
Hi all I had seen one webrtc old source code which has this method called CreateVideoSource() for adding streams after an CreateAudioTrack() call.
rtc::scoped_refptr<webrtc::VideoTrackSourceInterface> video_source =
peer_connection_factory_->CreateVideoSource(std::unique_ptr<cricket::VideoCapturer>(
media_source->GetVideoCapturer()),
NULL);
What's happening is whenever I try to build it gives an error for the above CreateVideoSource() that it is undefined. And the reason behind that is the latest webrtc-checkout has deprecated this.
So my question is, I wanted to know the alternative which they have introduced after deprecating this method. So can anyone tell me what the alternate approach is.
Okay, Finally I was able to come up with an alternative(i.e the current implementation of libwebrtc) after looking into bundle examples and tests.
Line 71 is a good point to start
After converting over to Swift 3, my AWS iOS App now crashes when being run.
Has anyone seen anything similar after converting over to Swift 3?
Its crashing because you are doing a few things here:
trying to return a method call (which I don't think is possible - but I've never tried it)
application: didFinishLaunching should only ever return true because it's a boolean function as the name suggests. So the return value should be true. If you'd like to override application: didFinishLaunching you can declare that later in your AppDelegate
So here's what you can do... Try deleting the method and slowly type it back until Xcode auto-completes it for you. That will allow you to see what has been depreciated, or what other methods might be useful, also if you haven't yet hit Command + Shift + K to run a clean on your project. Xcode 8 and Swift 3 might have altered a few more things you aren't aware of.
launchOptions is an optional parameter. Doing a forced unwrap with the ! will crash if the value is nil, which it usually is.
I'm looking for a way to register somthing like an end-build callback in scons. For example, I'm doing something like this right now:
def print_build_summary():
failures = SCons.Script.GetBuildFailures()
notifyExe = 'notify-send '
if len(failures) > 0:
notifyExe = notifyExe + ' --urgency=critical Build Failed'
else:
notifyExe = notifyExe + ' --urgency=normal Build Succeed'
os.system(notifyExe)
atexit.register(print_build_summary)
This only works in non-interactive mode. I'd like to be able to pop up something like this at the end of every build, specifically, when running multiple 'build' commands in an interactive scons session.
The only suggestions I've found, looking around, seem to be to use the dependency system or the AddPostAction call to glom this on. It doesn't seem quite right to me to do it that way, since it's not really a dependency (it's not even really a part of the build, strictly speaking) - it's just a static bit of code that needs to be run at the end of every build.
Thanks!
I don't think there's anything wrong with using the dependency system to resolve this. This is how I normally do it:
def finish( target, source, env ):
raise Exception( 'DO IT' )
finish_command = Command( 'finish', [], finish )
Depends( finish_command, DEFAULT_TARGETS )
Default( finish_command )
This creates a command that depends on the default targets for it's execution (so you know it'll always run last - see DEFAULT_TARGETS in scons manual). Hope this helps.
Ive been looking into this and havent found that SCons offers anything that would help. This seems like quite a usefull feature, maybe the SCons developers are watching these threads and will take the suggestion...
I looked at the source code and figured out how to do it. I'll try to suggest this change to the SCons developers on scons.org.
If you're interested, the file is engine/SCons/Script/Main.py, and the function is _build_targets(). At the end of this funcion, you would simply need to add a call to a user supplied callback. Of course this solution would not be very useful if you build on several different machines in your network, since you would have to port the change everywhere its needed, but if you're only building on one machine, then maybe you could make the change until/if SCons officially provides a solution.
Let me know if you need help implementing the change, and I'll see what I can do.
Another option would be to wrap the call to SCons, and have the wrapper script perform the desired actions, but that wouldnt help in SCons interactive mode.
Hope this helps,
Brady
EDIT:
I create a feature request for this: http://scons.tigris.org/issues/show_bug.cgi?id=2834
I am using the Aria C++ programming libs for mobile robots (http://robots.mobilerobots.com/wiki/ARIA). I am new to this API so I wanted to start with a simple action class derived from ArAction. Now I tried to develop a small test program (an ArAction) in order to
control a simulated p3dx robot via MobileSim. Development takes place under Ubuntu 10.10, using gcc 4.4.5. Making (compiling) my code works fine, without errors. I can also set the desired speed for example in my ArAction's fire() method, and the simulation is also working as desired.
But, unfortunately, I can't use the ArRobot object attached to the ArAction I am overriding. The problem is that none of the member functions of the ArRobot object seems to work. For example, calling getVel() or getCompass() always returns a zero value. And when I call the hasFrontBumpers() method the program even crashes with the error message "Aria: Received signal 'SIGSEGV'. Exiting.". As soon as I remove this method call and recompile the error is also gone again...
Here is the relevant code that leads to the crash:
ArActionDesired * forward::fire(ArActionDesired d)
{
desiredState.reset();
ArRobot *r = getRobot();
if(r == NULL)
{
printf("ArRobot = NULL\n");
deactivate();
return &desiredState;
}
printf("ok, ArRobot is not NULL, check for bumpers...\n");
r->hasFrontBumpers(); // <-- this leads to the SIGSEV-based "crash"
return &desiredState;
}
Any ideas what I am missing here -- is it a problem with my coding, or with the simulation environment? Thanks in advance for your help!
Kind regards, Matthias
ok, found it out now -- for the records: the Aria libs in version 2.7.2 are based on gcc-3 and libstdc++ 5, but Ubuntu 10.10 (which I am using) is shipped with gcc-4 and libstdc++ 6 per default. So I had to manually install the older versions of both packages, now my code is running fine...
cheers!
Calling hasFrontBumpers() for a p3dx from the fire() works fine for me on a similar Linux platform. If something is wrong, it is not in this method but in the initialization of the system. A reason for the non-moving robot could be that robot.enableMotors() hasn't been called.
So I'm trying to make use of a GtkSourceView in C++ using GtkSourceViewmm, whose documentation and level of support give me the impression that it hasn't been very carefully looked at in a long time. But I'm always an optimist :)
I'm trying to add a SourceView using some code similar to the following:
Glib::RefPtr<gtksourceview::SourceLanguageManager> source_language_manager = gtksourceview::SourceLanguageManager::create();
Glib::RefPtr<gtksourceview::SourceLanguage> source_language = Glib::wrap(gtk_source_language_manager_guess_language(source_language_manager->gobj(), file, NULL));
Glib::RefPtr<gtksourceview::SourceBuffer> source_buffer = gtksourceview::SourceBuffer::create(source_language);
gtksourceview::SourceView* = m_source_view = new gtksourceview::SourceView(source_buffer);
m_vbox.pack_start(*m_source_view);
Unfortunately, it spits out the warning
(algoviz:4992): glibmm-WARNING **:
Failed to wrap object of type
'GtkSourceLanguage'. Hint: this error
is commonly caused by failing to call
a library init() function.
and when I look at it in a debugger, indeed the second line above (the one with the Glib::wrap()) is returning NULL. I have no idea why this is, but I tried to heed the warning by adding Glib::init() to the begining of the program, but that didn't seem to help at all either.
I've tried Google'ing around, but have been unsuccessful. Does anyone know what Glib wants me to init in order to be able to make that wrap call? Or, even better, does anyone know of any working sample code that uses GtkSourceViewmm (not just regular GtkSourceView)? I haven't been able to find any actual sample code, not even on Google Code Search.
Thanks!
It turns out, perhaps not surprisingly, that what I needed to init was:
gtksourceview::init();
After this, I ran into another problem with one of the parameter to gtksourceview::SourceLanguageManager, but this was caused by a genuine bug which I subsequently reported and was promptly fixed. So everything's working great now!
I use gtkmm. Typically you have to initialize things with something like :
_GTKMain = new Gtk::Main(0, 0, false);
Of course do not forget :
delete _GTKMain;
Check here for details :
http://library.gnome.org/devel/gtkmm/2.19/classGtk_1_1Main.html
(Sorry but the link option does not work ...)