Crash in the Guitar Tuner example

[bergie]

I ported the guitar tuner example from GNOME developer docs to node-gir and CoffeeScript:

https://github.com/bergie/node-gir/blob/master/examples/guitartuner.coffee

When I try to make GStreamer to play a sound (by clicking a button), there is a segfault. Backtrace is:

(gdb) run guitartuner.js
Starting program: /usr/bin/node guitartuner.js
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff63a8700 (LWP 14064)]
[New Thread 0x7fffee905700 (LWP 14065)]
[New Thread 0x7fffed093700 (LWP 14066)]
369.23

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff5769d60 in g_base_info_equal () from /usr/lib/libgirepository-1.0.so.1
(gdb) bt full
#0  0x00007ffff5769d60 in g_base_info_equal () from /usr/lib/libgirepository-1.0.so.1
No symbol table info available.
#1  0x00007ffff599f21b in gir::GIRObject::New(_GObject*, _GIBaseInfoStub*) () from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#2  0x00007ffff599c358 in gir::Args::FromGType(_GIArgument*, _GIBaseInfoStub*, int) () from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#3  0x00007ffff599d35b in gir::Func::Call(_GObject*, _GIBaseInfoStub*, v8::Arguments const&, bool) ()
   from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#4  0x00007ffff599de75 in gir::GIRObject::CallStaticMethod(v8::Arguments const&) () from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#5  0x0000000000592b62 in ?? ()

[bergie]

After this commit from @piotras it doesn't crash on the first button press, but does crash on the second. Backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x00000000005761f2 in v8::Value::IsFunction() const ()
(gdb) bt full
#0  0x00000000005761f2 in v8::Value::IsFunction() const ()
No symbol table info available.
#1  0x00007ffff599eb24 in gir::GIRObject::Emit(v8::Handle<v8::Value>*, int) () from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#2  0x00007ffff599ec9d in gir::GIRObject::SignalCallback(_GClosure*, _GValue*, unsigned int, _GValue const*, void*, void*) ()
   from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#3  0x00007ffff5521ca2 in g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#4  0x00007ffff5532fdd in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#5  0x00007ffff553b099 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#6  0x00007ffff553b242 in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#7  0x00007ffff3e0f0b8 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#8  0x00007ffff5521ca2 in g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#9  0x00007ffff5533179 in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#10 0x00007ffff553b099 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#11 0x00007ffff553b242 in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#12 0x00007ffff3e0d7f7 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#13 0x00007ffff3ece501 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#14 0x00007ffff5521eca in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#15 0x00007ffff553a741 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#16 0x00007ffff553b242 in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
No symbol table info available.
#17 0x00007ffff3ff97e9 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#18 0x00007ffff3ecc3ab in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
---Type <return> to continue, or q <return> to quit---
No symbol table info available.
#19 0x00007ffff3ece0c1 in gtk_main_do_event () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#20 0x00007ffff3b1dd32 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
No symbol table info available.
#21 0x00007ffff5264d53 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#22 0x00007ffff52650a0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#23 0x00007ffff526549a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#24 0x00007ffff3ecd42d in gtk_main () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
No symbol table info available.
#25 0x00007ffff4ac7a14 in ffi_call_unix64 () from /usr/lib/x86_64-linux-gnu/libffi.so.6
No symbol table info available.
#26 0x00007ffff4ac7435 in ffi_call () from /usr/lib/x86_64-linux-gnu/libffi.so.6
No symbol table info available.
#27 0x00007ffff576aa59 in ?? () from /usr/lib/libgirepository-1.0.so.1
No symbol table info available.
#28 0x00007ffff576be0e in g_function_info_invoke () from /usr/lib/libgirepository-1.0.so.1
No symbol table info available.
#29 0x00007ffff599d294 in gir::Func::Call(_GObject*, _GIBaseInfoStub*, v8::Arguments const&, bool) ()
   from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.
#30 0x00007ffff59a34bb in gir::GIRFunction::Execute(v8::Arguments const&) () from /home/bergie/Projects/node-gir/build/Release/lib.target/girepository.node
No symbol table info available.

Also, no sound is emitted.

[JumpLink]

I think the problem is not the second button, the problem are on all buttons.
You example crash on repeated click on any button, too.
The same on my programm.

If I click on the pdf button, the function generate_pdf dosn't work correctly and my app crash on the second click.

pdf_button.on("clicked", function(){
    generate_pdf('test.pdf');
});

If I change "generate_pdf('test.pdf');" to a simple console.log, my programm works fine.
I think anything is wrong with the button-signal.
Maybe gir think the function is finished and delete anything before he is finished?

[JumpLink]

Its very crazy, I have a gtk-program with 2 buttons. The first create a string and run exec, the second create new gtk.widget's. If I click on any button, my program is crashing, but If I comment out the first on-clicked function, my programm works.. So my program are only working if I have not more than 1 on-button-clicked-signals and I run only 1 function they is a non-gir function or I run only gir-functions (more or less).

I hope this is helpful.

[piotras]

Crash is caused by exception being thrown in callback. This exception is completely silent. In case of guitar example,you can add try catch block:

try {
    return pipeline.set_state(gst.State.PLAYING);
} catch (err) {
    console.log(err);
}

It doesn't solve the problem, but at least crash goes away and we have proper human readable message.
I am investigating it, cause for some reason playing state is introspectable as interface. Which is obviously wrong as it's enum.