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. -- Anders _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
