Re: [Autotest PATCH] KVM test: No need close session when login timeout

[Amos Kong <akong@redhat.com>]

On Sat, Dec 26, 2009 at 10:07:58AM -0500, Michael Goldish wrote:
> 
> ----- "Amos Kong" <akong@redhat.com> wrote:
> 
> > On Fri, Dec 25, 2009 at 08:28:18AM -0500, Michael Goldish wrote:
> > > 
> > > ----- "Amos Kong" <akong@redhat.com> wrote:
> > > 
> > > > If login timeout, wait_for() returned 'None' and assigned to
> > > > 'session'.
> > > > When call session.close(), this prlblem was caused:
> > > > "AttributeError: 'NoneType' object has no attribute 'close'"
> > > > 
> > > > Signed-off-by: Amos Kong <akong@redhat.com>
> > > > ---
> > > >  client/tests/kvm/tests/timedrift_with_migration.py |    3 ++-
> > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > > 
> > > > diff --git a/client/tests/kvm/tests/timedrift_with_migration.py
> > > > b/client/tests/kvm/tests/timedrift_with_migration.py
> > > > index a012db3..0b93183 100644
> > > > --- a/client/tests/kvm/tests/timedrift_with_migration.py
> > > > +++ b/client/tests/kvm/tests/timedrift_with_migration.py
> > > > @@ -76,7 +76,8 @@ def run_timedrift_with_migration(test, params,
> > > > env):
> > > >                                               time_filter_re,
> > > > time_format)
> > > >  
> > > >      finally:
> > > > -        session.close()
> > > > +        if session != None:
> > > > +            session.close()
> > > 
> > > Agreed, but we can make this simply:
> > > 
> > > if session:
> > >     session.close()
> > 
> > Yes,
> > 
> >  
> > > There's no need to explicitly check for None (and if there was,
> > > the preferred syntax would be 'is not None' rather than '!= None').
> > > 
> > > Also, just to be safe, we should make the same modification to
> > > timedrift_with_reboot.py.
> > 
> > 
> > In timedrift_with_reboot.py, 'session' has been assigned before 'try'.
> > If re-login timout, kvm_test_utils.reboot() returns nothing, the value
> > of 'session' isn't changed.
> > So session.close() couldn't cause this problem:
> > "AttributeError: 'NoneType' object has no attribute 'close'"
> 
> The two tests are nearly identical so I thought we might as well make
> the change in both of them, but I agree that it doesn't matter (unless
> we change the behavior of kvm_test_utils.reboot() in the future).
>
> > In other testcases, if session wasn't assigned before 'try',
> > when calling kvm_test_utils.wait_for_login()/kvm_test_utils.reboot()
> > timeout,
> > It returns nothing, if close 'session' in finally part, Another
> > problem will occur:
> > "NameError: name 'session' is not defined"
> > 
> > In this condition,
> > """ 
> > if session:
> >     session.close()
> > """
> > also causes this error.
> 
> In what tests exactly does this happen?
> 
> 'if session' is preferable to 'if session is not None' because it's
> shorter, not because it's safer.

There is no this kind of test in upstream testcases,
---

I touch this problem, when I write new testcase.
For example,

def run_test_close_session(test, params, env):

    vm = kvm_test_utils.get_living_vm(env, params.get("main_vm"))
    try:
       ...
       session = kvm_test_utils.reboot(vm, session)
       ...
    finally:
        session.close()


> > > We can also consider removing the try..finally clauses altogether
> > > because sessions are now closed automatically when they're no
> > longer
> > > needed.
> > > 
> > > >  
> > > >      # Report results
> > > >      host_delta = ht1 - ht0
> > > > -- 
> > > > 1.5.5.6
> > 
> > -- 
> > Amos Kong
> > Quality Engineer
> > Raycom Office(Beijing), Red Hat Inc.

-- 
Amos Kong
Quality Engineer
Raycom Office(Beijing), Red Hat Inc.
Phone: +86-10-62608183