| Message ID | 20170824072202.26818-2-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Aug 24, 2017 at 08:22:00AM +0100, Stefan Hajnoczi wrote: > There are a number of ways to ensure that the QEMU process is shut down > when the test ends, including atexit.register(), try: finally:, or > unittest.teardown() methods. All of these require extra code and the > programmer must remember to add vm.shutdown(). > > A nice solution is context managers: > > with VM(binary) as vm: > ... > # vm is guaranteed to be shut down here > > Cc: Eduardo Habkost <ehabkost@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
diff --git a/scripts/qemu.py b/scripts/qemu.py index 880e3e8219..4d8ee10943 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -21,7 +21,14 @@ import qmp.qmp class QEMUMachine(object): - '''A QEMU VM''' + '''A QEMU VM + + Use this object as a context manager to ensure the QEMU process terminates:: + + with VM(binary) as vm: + ... + # vm is guaranteed to be shut down here + ''' def __init__(self, binary, args=[], wrapper=[], name=None, test_dir="/var/tmp", monitor_address=None, socket_scm_helper=None, debug=False): @@ -40,6 +47,13 @@ class QEMUMachine(object): self._socket_scm_helper = socket_scm_helper self._debug = debug + def __enter__(self): + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + self.shutdown() + return False + # This can be used to add an unused monitor instance. def add_monitor_telnet(self, ip, port): args = 'tcp:%s:%d,server,nowait,telnet' % (ip, port)
There are a number of ways to ensure that the QEMU process is shut down when the test ends, including atexit.register(), try: finally:, or unittest.teardown() methods. All of these require extra code and the programmer must remember to add vm.shutdown(). A nice solution is context managers: with VM(binary) as vm: ... # vm is guaranteed to be shut down here Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- scripts/qemu.py | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)