Level 1 AMR Periodic Boundary support commited! Roy, I did not commit the example. You already have it in the patch I previously posted except you no longer need to clear the point locator in user code. Please let me know if you would like me to build an Example 24 or if you plan to build something slightly more interesting.
Thanks, Cody On Nov 17, 2010, at 3:44 PM, Cody Permann wrote: > > On Nov 17, 2010, at 3:09 PM, Roy Stogner wrote: > >> >> >> On Wed, 17 Nov 2010, Cody Permann wrote: >> >>> On Nov 17, 2010, at 2:24 PM, Roy Stogner wrote: >>> >>>> And because >>>> PointLocatorTree only operates on active elements, it shouldn't care >>>> whether or not we delete subactive elements after it's constructed. >>> >>> Sounds good, but are you completely sure? Check out the find_element() >>> routine >>> on line 501 inside of tree_node.C which is where the seg fault occurs. >>> That method >>> is using an internal data structure of pointers to elements. That data >>> structure would >>> be out of date after the call to mesh::contract() because contract() calls >>> renumber_nodes_and_elements() which changes pointers around. >> >> I don't think it's supposed to change pointers around (other than by >> deleting the subactive elements and unused nodes), at least in the >> existing Mesh implementations. ParallelMesh uses a mapvector<Elem*> >> as a container; SerialMesh uses a vector<Elem*>. We move Elem* from >> place to place within at least the latter data structure, but the Elem >> itself should never change addresses. > > OK fair enough. Here is my latest observation. I would assume that the calls > to coarsen_elements() and refine_elements() in EquationSystems::reinit() would > both return false having just completed the refine_and_coarsen_elements() > routine > right before hand. However this is not the case. There are additional > elements > coarsened or refined in the reinit() routine - further changing the mesh and > invalidating > the point_locator... > >> >>> I propose we add a call to clear_point_locator() right after the >>> call to contract() inside of EquationSystems.reinit(). I already >>> made this change in my local copy and everything seems to be working >>> correctly without the explicit call to clear the point locator in >>> user code anymore. >> >> Sounds like the best place for an additional clear_point_locator() is >> at the end of UnstructuredMesh::contract(), then. That method is >> supposed to be callable in more contexts, even if we never do so and I >> doubt any of our users do either. >> >> Once that's done, your patch is probably safe to commit - I still want >> to better understand this bug but it appears we've at least fixed it. >> --- >> Roy > ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev _______________________________________________ Libmesh-devel mailing list Libmesh-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-devel
