Re: [Qemu-devel] [Qemu-block] [PATCH 2/2] iotests: Warn if python subprocess is killed

[John Snow <jsnow@redhat.com>]

On 08/31/2015 03:05 PM, Max Reitz wrote:
> Currently, if a subprocess of a python test (i.e. qemu-io, qemu-img, or
> qemu) receives a signal and is subsequently aborted, this is not logged.
> 
> This patch makes python tests always check the exit code of these
> subprocesses, and emit a message if they have been killed.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/qemu-iotests/iotests.py | 26 +++++++++++++++++++++-----
>  1 file changed, 21 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
> index 927c74a..d082597 100644
> --- a/tests/qemu-iotests/iotests.py
> +++ b/tests/qemu-iotests/iotests.py
> @@ -49,20 +49,34 @@ socket_scm_helper = os.environ.get('SOCKET_SCM_HELPER', 'socket_scm_helper')
>  def qemu_img(*args):
>      '''Run qemu-img and return the exit code'''
>      devnull = open('/dev/null', 'r+')
> -    return subprocess.call(qemu_img_args + list(args), stdin=devnull, stdout=devnull)
> +    exitcode = subprocess.call(qemu_img_args + list(args), stdin=devnull, stdout=devnull)
> +    if exitcode < 0:
> +        sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
> +    return exitcode
>  

Why tack on the arguments after the retcode for the print? The format
makes it look like it should be a description for the signal received.

>  def qemu_img_verbose(*args):
>      '''Run qemu-img without suppressing its output and return the exit code'''
> -    return subprocess.call(qemu_img_args + list(args))
> +    exitcode = subprocess.call(qemu_img_args + list(args))
> +    if exitcode < 0:
> +        sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
> +    return exitcode
>  
>  def qemu_img_pipe(*args):
>      '''Run qemu-img and return its output'''
> -    return subprocess.Popen(qemu_img_args + list(args), stdout=subprocess.PIPE).communicate()[0]
> +    subp = subprocess.Popen(qemu_img_args + list(args), stdout=subprocess.PIPE)
> +    exitcode = subp.wait()
> +    if exitcode < 0:
> +        sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
> +    return subp.communicate()[0]
>  
>  def qemu_io(*args):
>      '''Run qemu-io and return the stdout data'''
>      args = qemu_io_args + list(args)
> -    return subprocess.Popen(args, stdout=subprocess.PIPE).communicate()[0]
> +    subp = subprocess.Popen(args, stdout=subprocess.PIPE)
> +    exitcode = subp.wait()
> +    if exitcode < 0:
> +        sys.stderr.write('qemu-io received signal %i: %s\n' % (-exitcode, ' '.join(args)))
> +    return subp.communicate()[0]
>  
>  def compare_images(img1, img2):
>      '''Return True if two image files are identical'''
> @@ -197,7 +211,9 @@ class VM(object):
>          '''Terminate the VM and clean up'''
>          if not self._popen is None:
>              self._qmp.cmd('quit')
> -            self._popen.wait()
> +            exitcode = self._popen.wait()
> +            if exitcode < 0:
> +                sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode, ' '.join(self._args)))
>              os.remove(self._monitor_path)
>              os.remove(self._qtest_path)
>              os.remove(self._qemu_log_path)
>