I agree -- all of the things you mention are do-able. But it's a whole lot more bookkeeping and care/feeding to ensure that nothing goes wrong vs. just calling a hwloc core function and assuming it's there. Such things will require maintenance over time.
In the end -- it's a tradeoff: - do we want the maintenance associated with a struct full of core function pointers? or - do we want to use the solution I mentioned in http://www.open-mpi.org/community/lists/hwloc-devel/2012/09/3253.php? Both have strengths / weaknesses. On Sep 5, 2012, at 11:25 AM, Samuel Thibault wrote: > Jeff Squyres, le Wed 05 Sep 2012 17:13:56 +0200, a écrit : >>> The source code shouldn't need to be modified: >>> >>> #define hwloc_foo_bar(arg1, arg2) hwloc_funcs->foo_bar(arg1, arg2) >> >> You need to make sure that #define is only effected in certain places in the >> code. > > Well, all the places that will constitute a plugin, no? > >> And you need to ensure that hwloc_funcs->[foo] isn't attempted to be used >> before it has been filled in. > > As I said in my earlier mail, hwloc_funcs would be provided by the > loader of the plugin, so it can make sure it's filled in (I forgot to > mention that what I call hwloc_funcs above is an internal variable of > the plugin, not a symbol provided by libhwloc.so). > >> And unless there is a very fixed set of functions that can be called by >> plugins, > > Well, I believe we'll have to have that anyway. That was part of the > whole discussion about plugins a long time ago. > >> you'll probably need to grow hwloc_funcs over time, which may lead to ABI >> issues...? > > Sure. We can for instance make the plugin check for the size of > hwloc_funcs provided by the plugin loader vs the size that it was > compiled against, and thus refuse to get loaded by an older hwloc. > > Samuel > _______________________________________________ > hwloc-devel mailing list > hwloc-de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-devel -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
