[Avocado-devel] Subprocess termination

[Amador Pahim]

On Fri, Feb 17, 2017 at 9:42 AM, Radek Duda <rduda at redhat.com> wrote:
> Good morning folks,
> Andrei thanks  for this line of code I've forgotten to include it. So the
> code reads:
>
> def run(vt_test, test_params, env):
>   cmd = "nc -l %s" % test_params['some_port']
>   nc_process = process.SubProcess(cmd)
>   nc_process_pid = nc_process.start()
>   return
>
> Amador thanks for your advice, but it doesn't work for me. I need the
> process to run in the background and not block test flow. That's why I used
> start() method. I tried run() method as well, but the process does not go to
> background and blocked test flow. I think the process should be killed
> automatically after test finishes.

Oh, now I see what you need.
Well, I'd recommend to finish the process in tearDown(). Not sure if
we should make the runner to track the sub-processes created by the
test... let me open a card to discuss that.


>
> Radek
>
> On Thu, Feb 16, 2017 at 5:09 PM, Amador Pahim <apahim at redhat.com> wrote:
>>
>> On Thu, Feb 16, 2017 at 5:02 PM, Andrei Stepanov <astepano at redhat.com>
>> wrote:
>> > I think
>> >
>> > nc_process_pid = nc_process.start()
>>
>> In that case, the missing part is the `wait()` (and the possible
>> timeout handling) which are both present in `run()`. You can call it
>> directly (with `process.run(cmd)`) instead of keeping the SubProcess
>> object. Unless you have other reasons to have that object.
>>
>> >
>> > On Thu, Feb 16, 2017 at 4:58 PM, Amador Pahim <apahim at redhat.com> wrote:
>> >>
>> >> On Thu, Feb 16, 2017 at 4:38 PM, Radek Duda <rduda at redhat.com> wrote:
>> >> > Dear avocado users and developers,
>> >> > I have made a testcase in which is executed nc process in run
>> >> > function :
>> >> > (simplified version):
>> >> >
>> >> > from avocado.utils import process
>> >> >
>> >> > def run(vt_test, test_params, env):
>> >> >   cmd = "nc -l %s" % test_params['some_port']
>> >> >   nc_process = process.SubProcess(cmd)
>> >> >   return
>> >> >
>> >> > after testcase is executed, nc does not terminate and is still
>> >> > present.
>> >> > To
>> >> > avoid this I have to kill the process e.g. by
>> >> > process.safe_kill(nc_process_pid, signal.SIGKILL)
>> >>
>> >> Are you running the process with `nc_process.run()`? It's expected to
>> >> wait for the process to finish.
>> >>
>> >>
>> >>
>> >> https://github.com/avocado-framework/avocado/blob/master/avocado/utils/process.py#L596-L643
>> >>
>> >>
>> >> >
>> >> > It is pretty awkward to close the process manually particularly in
>> >> > case
>> >> > of
>> >> > complex testcase code
>> >> > Shouldn't be the subprocess killed automatically after test exits?
>> >> > After all its called SubProcess
>> >> >
>> >> >
>> >> > regards,
>> >> >
>> >> > Radek Duda
>> >>
>> >
>
>