On Tue, Nov 30, 2010 at 11:12:18PM +0000, Garth N. Wells wrote: > > > On 30/11/10 23:09, Anders Logg wrote: > >On Tue, Nov 30, 2010 at 10:48:09PM +0000, Garth N. Wells wrote: > >> > >> > >>On 30/11/10 22:37, Johan Hake wrote: > >>>On Tuesday November 30 2010 14:30:18 Garth N. Wells wrote: > >>>>On 30/11/10 22:25, Anders Logg wrote: > >>>>>On Tue, Nov 30, 2010 at 10:20:52PM +0000, Garth N. Wells wrote: > >>>>>>We have a thread-safe problem in GenericFunction with the member object > >>>>>> > >>>>>> mutable Data data; > >>>>>> > >>>>>>Any ideas on how to get rid of it? We really should pass data > >>>>>>through the function interfaces, but we're constrained in this case > >>>>>>by the UFC interface. > >>> > >>>This is ironical, as Data was introduced so we in the future (now present) > >>>could be thread safe... > >> > >>Really? I remember Martin always warning against such a design > >>because it's not thread-safe. > >> > >>>But I do not think GenericFunction was a ufc::function > >>>at that time. > >>> > >>>Is it time to introduce the notion of thread in the ufc interface? > >>> > >> > >>Not for this purpose. What would be helpful is a way to pass > >>user-defined data through the UFC interface. Perhaps more > >>importantly, we should avoid using 'mutable'. A 'const' object > >>should in principle be thread-safe, but using mutable clouds this. > > > >Another solution (in addition to making the mutable data thread safe) > >would be to extend the UFC interface with a void* optional argument > >that can be passed to evaluate. > > > >Even if we add that, I suspect there will be a performance penalty if > >we need to recreate the Data object each time in > >restrict_as_ufc_function. In addition to convenience, Data is cached > >between calls so it can be reused. > > > > I'm trying the re-creation now. A good compiler might optimise away > the overhead.
Let's hope. -- Anders _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
