[lttng-dev] python bindings for babel trace example fails

[Yan Grange]

Good afternoon,

I have been able to get lttng running on a machine and now would like to do some experiments with babeltrace. I’d like to write out a ctf file using babeltrace. Therefore I wanted to try out the babeltrace python bindings out and since you provide a set of examples, of which one is about writing a ctf, I wanted to try that one out.

When I use the latste release of babeltrace (1.2.4), the library fails on the following line:

print("Clock name is \"{}\"".format(clock.name))

because it seems like the getter for clock.name doesn’t exist. to solve the issues I have with this example, I have checked out the most recent version of babeltrace from the git repo. If I run the ctf_writer using python, I get

yan at paul ~/build_bbt/babeltrace/bindings/python/examples $ python3 ctf_writer.py
Writing trace at /tmp/tmptlhq3i
Clock name is "A_clock"
Clock description is "Simple clock"
Clock frequency is 1000000000
Clock precision is 1
Clock offset_seconds is 0
Clock offset is 0
Clock is absolute: False
Clock time is 0
Clock UUID is 874be90c-6c68-46ee-ac0d-6142cafe23f5

Fields in default packet context:
<class 'babeltrace.CTFWriter.IntegerFieldDeclaration'> timestamp_begin
<class 'babeltrace.CTFWriter.IntegerFieldDeclaration'> timestamp_end
<class 'babeltrace.CTFWriter.IntegerFieldDeclaration'> content_size
<class 'babeltrace.CTFWriter.IntegerFieldDeclaration'> packet_size
<class 'babeltrace.CTFWriter.IntegerFieldDeclaration'> events_discarded
<babeltrace.CTFWriter.Writer object at 0x7f57058360d0>
close: Bad file descriptor
Traceback (most recent call last):
  File "ctf_writer.py", line 130, in <module>
    stream.append_event(event)
  File "/usr/lib64/python3.3/site-packages/babeltrace.py", line 3462, in append_event
    raise ValueError("Could not append event to stream.")
ValueError: Could not append event to stream.


Is this a reproducible issue? I am on a gentoo system (3.17.7), with python3 version Python 3.3.5 (default, Jan 14 2015, 19:01:12) [GCC 4.8.3] on linux

For compilation, I used the following flags of the configure script:

./configure --prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --disable-dependency-tracking --disable-silent-rules --libdir=/usr/lib64 --enable-glibtest --enable-python-bindings

Is there anything I cold do to fix this?

Regards,

Yan Grange