Comment 14 for bug 1083720

I have pushed an alternative fix to lp:~martinal/dolfin/work,
but I'm not yet comfortable pushing it to trunk. It would be nice
if the buildbot got green again sometime soon...

On 28 November 2012 20:58, Joachim Haga <email address hidden> wrote:

> >> Will the circular references "functionspace <->
> >> testfunction" be a problem for garbage collection?
> >
> > Yes.
>
> I am not familiar with the particulars here, but the circular
> references are only a problem if the objects have custom deleters
> (__del__ methods). Swig likes to generate (empty) __del__ methods, but
> they can be disabled by the should-have-been-default flag
> --noproxydel.
>
> -j.
>
> On 28 November 2012 20:03, Johan Hake <email address hidden> wrote:
> > On 11/28/2012 07:15 PM, Martin Sandve Alnæs wrote:
> >> I fixed this permanently by constructing both test and trial function
> >> simultaneously on demand using Argument(V) and storing them to
> >> V._argument_functions. Will the circular references "functionspace <->
> >> testfunction" be a problem for garbage collection?
> >
> > Yes.
> >
> > I wonder how this can be implemented without some error prone
> > heuristics. A robust, but quite intrusive way, would be to always
> > instantiate a TestFunction together with a TrialFunction whenever one
> > need the latter.
> >
> > Or one could introduce a trial and test space specific counter.
> > Something like:
> >
> > class Argument(.):
> > _test_and_trial_counters = [dict(test=False, trial=False)]
> > ...
> >
> > class TestFunction(.):
> > def __init__(.):
> > .
> > counters = Argument._test_and_trial_counters
> > if counters[-1]["test"]:
> > counters.append(dict(test=False, trial=False))
> > counters[-1]["test"] = True
> > Argument(self, ., count=len(counters)*2)
> >
> > class TrialFunction(.):
> > def __init__(.):
> > .
> > counters = Argument._test_and_trial_counters
> > if counters[-1]["trial"]:
> > counters.append(dict(test=False, trial=False))
> > counters[-1]["trial"] = True
> > Argument(self, ., count=len(counters)*2-1)
> >
> > Johan
> >
> > --
> > You received this bug notification because you are a member of DOLFIN
> > Team, which is subscribed to DOLFIN.
> > https://bugs.launchpad.net/bugs/1083720
> >
> > Title:
> > replace() fails if the new function spaces have a different mesh
> >
> > Status in DOLFIN:
> > Fix Committed
> >
> > Bug description:
> > I submit this bug report following Marie's suggestions on the related
> > DOLFIN question
> > (https://answers.launchpad.net/dolfin/+question/215120)
> >
> > DOLFIN crashes in the solve() routine after using replace() to replace
> > the function spaces of a form.
> >
> > While the solve succeeds if replaced function spaces have:
> > - a different polynomial degree or
> > - a different polynomial degree and a different mesh,
> > it does not work if the new function spaces is based on a new mesh
> only.
> >
> > This is the error message I get:
> > ***
> -------------------------------------------------------------------------
> > *** Error: Unable to define linear variational problem a(u, v) = L(v)
> for all v.
> > *** Reason: Expecting the solution variable u to be a member of the
> trial space.
> > *** Where: This error was encountered inside
> LinearVariationalProblem.cpp.
> > ***
> ------------------------------------------------------------------------
> >
> > The attached file demonstrates the problem.
> >
> > To manage notifications about this bug go to:
> > https://bugs.launchpad.net/dolfin/+bug/1083720/+subscriptions
>
> --
> You received this bug notification because you are a member of DOLFIN
> Core Team, which is subscribed to DOLFIN.
> https://bugs.launchpad.net/bugs/1083720
>
> Title:
> replace() fails if the new function spaces have a different mesh
>
> Status in DOLFIN:
> Fix Committed
>
> Bug description:
> I submit this bug report following Marie's suggestions on the related
> DOLFIN question
> (https://answers.launchpad.net/dolfin/+question/215120)
>
> DOLFIN crashes in the solve() routine after using replace() to replace
> the function spaces of a form.
>
> While the solve succeeds if replaced function spaces have:
> - a different polynomial degree or
> - a different polynomial degree and a different mesh,
> it does not work if the new function spaces is based on a new mesh only.
>
> This is the error message I get:
> ***
> -------------------------------------------------------------------------
> *** Error: Unable to define linear variational problem a(u, v) = L(v)
> for all v.
> *** Reason: Expecting the solution variable u to be a member of the
> trial space.
> *** Where: This error was encountered inside
> LinearVariationalProblem.cpp.
> ***
> ------------------------------------------------------------------------
>
> The attached file demonstrates the problem.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/dolfin/+bug/1083720/+subscriptions
>